I report on the progress in the precision studies of hadronic parton distributions by the CTEQ-TEA (Tung Et Al.) group.
COMPASS is the longest-running experiment at CERN, with a record-breaking 20 years of data collection from 2002 to 2022. The experiment has a unique and diverse physics programme focused on nucleon structure and spectroscopy measurements.
The experimental results obtained by COMPASS during Phase I (2002-2011) and Phase II (2012-2022) for a wide range of nucleon spin structure-related DIS...
In this talk we will summarise the latest updates to PDF fits using the MSHT
approach. This will include details of high-x PDF sensitivity to jet/dijet
data, Z boson transverse distributions and high x data providing information
on quark flavours. We will also discuss the most recent determinations of
the strong coupling constant at both NNLO and N^3LO in perturbation theory.
We will...
n order to fulfill the requirements of the high luminosity and hard radiation in HL-LHC, CMS is upgrading most of the sub detectors. In this talk, an overview of the phase-2 upgrade of CMS detector will be presented.
I present recent progress in the framework of the NNPDF global PDF analyses. These include a determination of proton structure at aN3LO accuracy and the assessment of its implications for N3LO cross-sections at the LHC; NNPDF4.0 variants with QED effects and missing higher order uncertainties accounted for; the intrinsic valence charm content of the proton; selected methodological studies; and...
In this talk, I will present the results of the first
calculation of open bottom production at hadron colliders at NNLO+NNLL,
i.e. a next-to-next-to-leading-order calculation that resums collinear
logarithms at next-to-next-to-leading-logarithmic accuracy. This new
computation achieves significantly reduced theory errors compared to
previous calculations, with errors of just a few percent...
Hard exclusive meson production is one of the common approaches to constrain Generalised Parton Distributions. Such exclusive measurement and notably exclusive $\pi^{0}$ production were conducted at COMPASS in 2016 and 2017 at the M2 beamline from the CERN SPS using the 160 GeV/$c$ muon beam scattering off a 2.5~m long liquid hydrogen target inserted into a~barrel-shaped time-of-flight...
We investigate the impact of recent LHC measurements of differential top-quark pair production cross sections on the proton parton distribution functions (PDFs) using the ABMP16 methodology. The theoretical predictions are computed at NNLO QCD using the state-of-the-art MATRIX framework. The top-quark mass and strong coupling constants are free parameters of the fit, and we pay particular...
Recent results from ATLAS on heavy flavours are presented. They include measurement of $B^0$ lifetime, effective lifetime in $B^0_s\to\mu^+\mu^-$ decay, measurement of prompt and non-prompt charmonium production and studies of exotic contributions in low-mass four-muon final state.
We will present preliminary results on Spin Density Matrix Elements (SDMEs) measured in hard exclusive $\phi$ meson muoproduction on protons at COMPASS using 160 GeV/$c$ polarised $\mu ^{+}$ and $\mu ^{-}$ beams scattering off a liquid hydrogen target. The measurements cover the range 6 GeV/$c^2$ < W < 17 GeV/$c^2$, 1.0 (GeV/$c$)$^2 <$ Q$^2 <$ 10.0 (GeV/$c$)$^2$ and 0.01 (GeV/$c$)$^2$ <...
Recent analyses on high-energy inclusive Higgs-boson rates in proton collisions, matched with the state of-the-art fixed-order N$^3$LO accuracy, have shown that the impact of high-energy resummation corrections reaches 10% at the FCC nominal energies. This supports the statement that electroweak physics at 100 TeV is expected to receive relevant contributions from small-$x$ physics. In this...
We give an overview of recent developments in the computation of the anomalous dimension matrix of composite operators in non-forward kinematics. The elements of this matrix determine the scale dependence of non-perturbative parton distributions, such as GPDs, and hence constitute important input for phenomenological studies of exclusive processes like deeply-virtual Compton scattering....
We will present the latest differential measurements of Higgs boson cross sections with the CMS detector. Both fiducial differential cross section measurements and measurements in the simplified template cross section framework will be discussed, analyzing several decay modes of the Higgs boson. The data collected during Run 2 of the LHC by the CMS experiment are used. We also present...
In recent years, precision in PDF determinations has significantly improved due to a combination of experimental (better statistics, control over uncertainties) and theoretical improvements (NNLO predictions, N3LO splitting functions). Thanks to this enhanced precision,
differences in the methodologies, data treatment and theory choices can now be resolved between different fitting...
Heavy quarks are predominantly produced in the initial hard partonic scatterings, and thus their production cross-section can be calculated by pQCD.
Quarkonia and heavy-flavor hadrons can also be employed as tools for investigating heavy-quark dynamics in Quark-Gluon Plasma created in heavy-ion collisions. The changes in the production rate of quarkonia in the QGP are indicative of the...
The measurement of the Higgs self-coupling will be one of the benchmarks at a future hadron collider at 100 TeV, like the FCC-hh. Here we present an analysis based on the envisioned integrated luminosity of 30 ab$^{-1}$, using fast simulation samples with different systematics scenarios. The studies combine the decay channels in bb$\gamma \gamma$ and bbll+MET, to achieve a precision on...
We formulate a light-front spectator model for the proton incorporating the gluonic degree of freedom. We investigate the helicity distribution which is consistent with existing experimental data and satisfies the perturbative QCD constraints at small and large longitudinal momentum of gluon in this model. We present the transverse momentum dependent distributions (TMDs) for gluon in this...
Recent measurements of jet cross sections in proton-proton collisions with the CMS experiment are presented. The measured jet cross sections are corrected for detector effects and compared with the predictions from perturbative QCD, and exploited to derive constraints on parton distribution functions and to mesure alpha_S.
The proposed STCF is a symmetric electron-positron beam collider designed to provide e+e− interactions at a centerof-mass energy from 2.0 to 7.0 GeV. The peaking luminosity is expected to be 0.5×10^35 cm−2s−1. STCF is expected to deliver more than 1 ab−1 of integrated luminosity per year. The huge samples could be used to make precision measurements of the properties of XYZ particles; search...
Nucleon structure functions, as measured in lepton-nucleon scattering, have historically provided a critical observable in the study of partonic dynamics within the nucleon. However, at very large parton momenta it is experimentally and theoretically challenging to extract parton distributions due to the onset of non-perturbative contributions. New results will be presented from experiment...
Many next-to-leading order QCD predictions are available through Monte Carlo (MC) simulations. Usually multiple CPU-hours are needed to calculate the physical predictions at a feasible precision and are therefore impractical for global PDF analyses. This problem is solved by a process known as "gridding": The values of the hard-scattering cross-section are calculated only once with the MC...
Many LHC measurements with multi-lepton final states and missing energy, in particular top differential distributions, show strong tensions with the SM predictions. I discuss how they can be explained by new physics within the Delta2HDMS and show the correlations to the hints for narrow resonances at the electroweak scale.
The available world deep-inelastic scattering data on the proton and deuteron structure functions F2p and F2d, and the ratio F2p/F2d, were leveraged to extract the free neutron structure function, F2n, and associated uncertainties using the latest nuclear effects calculations with the deuteron data. Special attention was devoted to the normalization of the proton and deuteron experimental...
Generalized Parton Distributions (GPD) are multidimensonal structure functions that encode the information about the internal structure of hadrons. Using privileged channels such as Deeply Virtual Compton Scattering (DVCS) or Timelike Compton Scattering (TCS), it is possible to make direct measurements at points where the momentum fraction of the parton equals the respective scaling...
The FoCal is a high-granularity forward calorimeter to be installed as an ALICE upgrade subsystem during the LHC Long Shutdown 3 and take data during the LHC Run 4. It will cover a pseudorapidity interval of $3.4 < \eta < 5.8$, allowing to explore QCD at unprecedented low Bjorken-$x$ of down to $\approx 10^{-6}$ -- a regime where non-linear QCD dynamics are expected to be sizable. It consists...
Proton-proton collisions at the LHC generate a high-intensity collimated beam of neutrinos in the forward (beam) direction, characterised by energies of up to several TeV. The recent observation of LHC neutrinos by FASERν and SND@LHC signals that this hitherto ignored particle beam is now available for scientific inquiry. Here we quantify the impact that neutrino deep-inelastic scattering...
The High-Luminosity Large Hadron Collider (HL-LHC) is expected to deliver an integrated luminosity of up to 3000 fb-1. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (“pileup”) superimposed on each event of interest, providing extremely challenging experimental conditions. Prospects for Standard Model (SM) measurements and searches...
We present a next-to-leading order perturbative QCD calculation of dimuon production in neutrino-nucleus collisions. This process is vital in the determination of the strange and anti-strange quark distributions in global PDF analyses. It is usually calculated by assuming factorization to the inclusive DIS charm production cross section, with a multiplicative acceptance correction to account...
Vacuum-like e+e- collisions provide outstanding opportunities to characterize the properties of Quantum chromodynamics across different energy scales. At high pT, they can be used to study the parton-shower evolution in the cleanest experimental conditions, including modern jet-substructure techniques. At low pT, measurements of two-particle long-range correlations can constrain the possible...
In the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton-proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost...
Abstract 210:
Flavour-tagging is a critical component of the ATLAS experiment physics programme. Existing flavour tagging algorithms rely on several low-level taggers, which are a combination of physically informed algorithms and machine learning models. A novel approach presented here instead uses a single machine learning model based on reconstructed tracks, avoiding the need for low-level...
The spin physics program of the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has a number of recent and ongoing analyses exploring the spin structure of the proton. Leveraging the unique capability of RHIC to collide polarized proton beams, transverse single spin asymmetry ($A_N$) measurements at PHENIX are performed on a variety of final states. These analyses are typically...
The increased instantaneous luminosity levels expected to be delivered by the High-Luminosity LHC (HL-LHC) will present new challenges to High-Energy Physics experiments, both in terms of detector technologies and software capabilities. The current ATLAS inner detector will be unable to cope with an average number of 200 simultaneous proton-proton interactions resulting from HL-LHC collisions....
About 50 years ago, it was discovered that $\Lambda$ hyperons are produced polarized in collisions of unpolarized protons on beryllium. Since then, the $\Lambda$ polarization has been observed in various collision systems, including $e^+$+$e^-$ collisions. Majority of current results indicate the importance of final state effects, such as hadronization or fragmentation, in polarization of the...
We report progress on the determination and study of quarkonium formation within the fragmentation approximation. Our analyses address the moderate and large transverse-momentum regime, where the production mechanism based on the collinear fragmentation from a single parton is expected to prevail over the short-distance emission, directly from the hard-scattering subprocess, of the constituent...
We perform the first complete one-loop study of exclusive photoproduction of vector quarkonia off a proton, including full generalised parton distribution (GPD) evolution. We confirm the perturbative instability of the cross section at high photon-proton-collision energies at Next-to-Leading Order (NLO) using a Collinear-Factorisation (CF) framework. This issue can be tackled by a scale-fixing...
Recent results on the EW sector from the CMS Collaboration will be presented. This includes measurements of the properties of the vector bosons and of fundamental parameters of the theory connected to the sector.
Distribution amplitudes are functions of non-perturbative matrix elements describing the hadronization of an initial set of quarks and gluons. They are the crossed-channel analogs of the more commonly known parton distribution functions, which describe the longitudinal momentum distribution inside a hadron. Thanks to factorization theorems, they can be used to compute the scattering amplitude...
I review the recent efforts in the NNPDF collaboration towards a new extraction of polarized parton distributions functions (pPDF) which will be highly relevant for the upcoming Electron-Ion-Collider (EIC) experiments. This includes a recent study on heavy quark effects in polarized DIS, where we apply the FONLL prescription for the first time in a polarized setup and demonstrate the...
The formalism of short-distance factorization, conveyed through the pseudo-distribution approach, allows for the extraction of lightcone correlators from field theories formulated on Euclidean geometries. Thus, within this formalism, the extraction of parton distributions from Lattice-QCD becomes feasible. In this work we take advantage of the pseudo-distribution idea to compute, for the first...
The impact of Next-to-Leading Order (NLO) QCD corrections to the differential distributions of $J/\psi$ and $\Upsilon$ mesons produced inclusively in $\gamma\gamma$ collisions is revisited for the kinematical conditions of LEPII DELPHI, the Circular Electron-Positron Collider (CEPC) and the Future Circular (Lepton) Collider (FCC-ee). We take into account all sizeable LO in $v^2$ contributions...
The study of single W and Z boson production at the LHC provides stringent tests of the electroweak theory and perturbative QCD. The ATLAS experiment has measured the W boson production cross section in the LHC data from 2022 at 13.6 TeV. By forming ratios with Z and ttbar production cross sections, this measurement becomes a sensitive probe of the quark and gluon content of the proton....
We present a new determination of the helicity-dependent parton distribution functions (PDFs) of the proton from a set of longitudinally polarised inclusive deep-inelastic scattering and semi-inclusive deep-inelastic scattering data. The determination includes, for the first time, next-to-next-to-leading order QCD corrections to both processes, and is carried out in a framework that combines a...
The four-loop DGLAP splitting functions, which govern the scale evolution of the Parton Distribution Functions (PDFs), are of the missing ingredients to push the frontier of QCD calculations to N3LO accuracy, as required to match the experimental precision at the LHC and at the forthcoming EIC. In this talk, I will report on the recent progress in the determination of the splitting functions...
Calculations at NNLO in QCD require an analytic understanding of the infrared singular structure involving up to two unresolved partons, which was achieved up to now only for unpolarized matrix elements. We derive the full set of splitting amplitudes arising in longitudinally polarised tree-level QCD matrix elements at NNLO in the Larin $\gamma_5$ scheme. They are extracted from DIS-like...
To cope with the increase of the LHC instantaneous luminosity, new trigger readout electronics were installed on the ATLAS Liquid Argon Calorimeters.
On the detector, 124 new electronic boards digitise at high speed 10 times more signals than the legacy system. Downstream, large FPGAs are processing up to 20 Tbps of data to compute the deposited energies. Moreover, a new control and...
The general mass variable flavor number (GMVFN) scheme S-ACOT-MPS will
be discussed for proton-proton collisions. The impact of heavy-flavor
contributions within this factorization scheme will be shown for the production of a $Z$ boson in association with a charm/bottom quark in pQCD. An amended version of the QCD factorization formula for proton-proton collisions will be discussed as well...
We investigate the different decompositions of the angular momentum in QCD for a relativistic spin $1/2$ composite state, namely a quark dressed with a gluon. We use light-front Hamiltonian perturbation theory, and in the light-front gauge, use the two-component framework by eliminating the constrained degrees of freedom. We also investigate the different decompositions of the angular momentum...
The Phase-II Upgrade of the LHC will increase its instantaneous
luminosity by a factor of 7 leading to the HL-LHC era.
At the HL-LHC, the number of proton-proton collisions in one bunch
crossing, pileup, increases significantly, putting stringent
requirements on the LHC detectors electronics and real-time data
processing capabilities.
The ATLAS LAr calorimeter measures the...
Inclusive top quark pair production at the LHC proceeds primarily via gluon fusion. Decays of the polarized top pairs through various particle and jet channels have strong angular dependences reflecting the top and anti-top polarizations that produce a variety of correlations among the decay products - particles and jets. Those correlations are determined by the spin dependent gluon...
A new measurement of inclusive-jet cross sections in the Breit frame in neutral current deep inelastic scattering using the ZEUS detector at the HERA collider is presented. The data were taken in the years 2004–2007 at a centre-of-mass energy of 318 GeV and correspond to an integrated luminosity of 347 pb$^{-1}$. The jets were reconstructed using the $k_T$-algorithm in the Breit reference...
The origin of the large single transverse-spin asymmetries(SSAs) has been a long-standing problem since they were first observed in the pion production and the transversely polarized hyperon production about a half century ago. We currently know two successful pQCD based frameworks in the description of the SSA. One of them is transverse-momentum-dependent(TMD) factorization which is valid...
The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $\tau_{1}^{b}$ in neutral-current deep-inelastic electron-proton scattering. The analysis is based on data recorded in 2003-2007 by the H1 detector at the HERA collider for ep collisions at $\sqrt{s}=319$ GeV, with integrated luminosity of 351.1 pb$^{-1}$. The observable $\tau_{1}^{b}$ is equivalent to...
This talk reviews recent measurements of multiboson production using CMS data. Inclusive and differential cross sections are measured using several kinematic observables. Constraints on new physics using the effective field theory framework are reported.
The energy-energy correlator(EEC) is an event shape observable that probes the angular correlations of energy depositions in detectors at high-energy collider facilities. It has been investigated extensively in the context of precision QCD. In this talk, I will present our recent works on the energy-energy correlator in DIS. In the back-to-back limit, the observable we propose is sensitive to...
The longitudinal spin transfer of the fragmentation function, $G_{1L}$, represents the probability density of producing longitudinally polarized hadrons from longitudinally polarized quarks or circularly polarized gluons. It thus was usually measured in polarized reactions or high-energy collisions where weak interaction dominates. In our work, we propose the dihadron polarization correlation...
We study the longitudinal spin transfer of $\Lambda$-hyperon production in semi-inclusive deep inelastic scattering with both current and target fragmentation mechanisms. For existing fixed-target experiments, such as JLab, COMPASS and HERMES, the events from the current region and those from the target fragmentation region are not clearly separated. However the study of target fragmentation...
We perform a simultaneous global analysis of hadron fragmentation functions (FFs) to various charged hadrons at next-to-leading order in QCD. The world data set includes results from electron-positron single-inclusive annihilation, semi-inclusive deep inelastic scattering, as well as proton-proton collisions including jet fragmentation measurements which lead to strong constraints on the gluon...
In this talk I will re-examine the definition of PDF errors within the MSHT framework. This is a key issue in light of LHC high precision requirements that must be addressed if we are to provide accurate as well as precise PDF determinations. I will in particular examine the role of the tolerance and the question of parameterisation flexibility and bias, and comment on the implications of this...
The possibility to reanalyse data taken by the HERA experiments offers the chance to study modern QCD jet and event-shape observables in deep-inelastic scattering. In this talk I will present resummed and matched predictions for the event shapes 1-jettinesss [1] and invariant mass including the effect of grooming the hadronic final state using the soft-drop technique. Non-perturbative...
The 2023 Long Range Plan for Nuclear Science, titled "A New Era of Discovery," outlines the significant opportunities and key challenges for our community over the next decade. It is the culmination of the July 2022 charge from the Department of Energy Office of Science and the National Science Foundation to the Nuclear Science Advisory Committee to "conduct a new study of the opportunities...
An overview of the JLab program on nucleon spin and 3-d structure will be given. Highlights from recent experimental results will be presented with measurements focusing in the high-x (valence quark) region and/or in the low to intermediate Q2 region. Future perspective will be discussed.
This study presents a novel methodology for estimating uncertainty intervals in fits of Parton Distribution Functions (PDFs). By combining toy examples and fitting real-world PDFs, we critically evaluate the robustness of the Monte-Carlo (MC) replica method and the Hessian method in estimating credible intervals for PDFs. Our findings reveal that the methodologies typically used in PDF fits...
The H1 Collaboration at HERA reports the first measurement of groomed event shapes in deep inelastic e−p and e+p scattering (DIS) at $\sqrt{s} = 319$ GeV, using data recorded between 2003 and 2007 with an integrated luminosity of $351.1\pm 9.5$ pb$^{−1}$. Event shapes in DIS collisions provide incisive probes of perturbative and non-perturbative QCD, and recently developed grooming techniques...
The top-quark mass is one of the key fundamental parameters of the Standard Model that must be determined experimentally. Its value has an important effect on many precision measurements and tests of the Standard Model. The Tevatron and LHC experiments have developed an extensive program to determine the top quark mass using a variety of methods. In this contribution, the top quark mass...
The Solenoidal Large Intensity Device (SoLID) is a large acceptance detector capable of operating at the luminosity frontier. It was proposed to fully exploit the potential of the continuous electron beam accelerator facility (CEBAF) 12 GeV energy upgrade at Jefferson Lab. The pillars of its scientific program consist of a series of Semi-Inclusive Deep Inelastic Scattering (SIDIS) experiments...
Measurements of semi-inclusive deep inelastic scattering (SIDIS) are an important constraint on the description of the parton structure functions. Both the intrinsic $k_\perp$ of the quarks as well as the $p_\perp$ dependence of the hadronization process affect the dependence of the SIDIS cross section on transverse momentum ($P_T$). Experimental determination of the transverse momentum...
The Lund jet plane is a jet substructure tool introduced to understand the radiation pattern of jets by organizing hadrons into a hierarchical tree of emissions using the Cambridge/Aachen clustering algorithm. The primary LJP, the first triangular leaf of Lund diagrams, is well understood analytically, and measurements at the LHC show how it can be used to constrain parton showers and...
The CEBAF Large Acceptance Spectrometer, CLAS12, in Hall B at Jefferson Lab runs experiments with a multitude of unpolarized and polarized targets using electron beams of 2 GeV to 11 GeV energies at close to the design luminosity of $L=10^{35}$ cm${-2}$ sec$^{-1}$. Since its commissioning in early 2018, CLAS12 has successfully executed a physics program that covers a broad range of topics in...
We explore the azimuthal angle decorrelation of lepton-jet pairs in e-p and e-A collisions as a means for precision measurements of the three-dimensional structure of bound and free nucleons. Utilizing soft-collinear effective theory, we perform the first-ever resummation of this process in e-p collisions at NNLL accuracy using a recoil-free jet axis. Our results are validated against Pythia...
As a future high energy nuclear physics project, an Electron-Ion Collider in China (EicC) has been proposed, to be constructed based on the High Intensity heavy-ion Accelerator Facility (HIAF) in Huizhou, China. The EicC will provide highly polarized electrons with a polarization of ~80% and protons with a polarization of ~70% with variable center of mass energies from 15 to 20 GeV and the...
The current scientific standard in PDF uncertainty estimation relies either on repeated fits over artificially generated data to arrive at Monte Carlo samples of best fits or on the Hessian method, which uses a quadratic expansion of the figure of merit, the $\chi^2$-function. Markov chain Monte Carlo methods allows one to access the uncertainties of PDFs without making use of quadratic...
Deeply Virtual Compton Scattering is the most direct channel to access
Generalized Partons Distributions (GPDs) and understand more about the 3D
structure of the nucleon, the origin of its spin and the forces at play
within it. The complete extraction of GPDs requires the use of polarized
electron beams and polarized nucleon targets in DVCS measurements.
The first polarized target...
The Electron-Proton/Ion Collider Experiment (ePIC) Collaboration was formed to design, build, and operate the Electron-Ion Collider (EIC) project detector, which will be the first experiment at the collider. Positioned at the IP6 interaction region of the EIC accelerator, ePIC is poised to play a pivotal role in unraveling fundamental mysteries within the structure of visible matter by...
We discuss the preliminary results of our new global nuclear PDF analysis that combines a number of our previous improvements into one consistent framework with updates to the underlying theoretical treatment as well as the addition of new available data. In particular, the new global analysis will be the first to include neutrino DIS scattering data together with JLab high-$x$ DIS data and...
Generalized parton distributions (GPDs) encode important non-perturbative information of hadron structures including the tomographic parton images. We introduce a type of exclusive processes for a better study of GPDs, which we refer to as single diffractive hard exclusive processes (SDHEPs), and give a general argument for their factorization into GPDs. We advocate a two-stage framework for...
The ePIC detector is being designed as a general-purpose detector to deliver the full physics program of the Electron-Ion Collider (EIC) in BNL USA. Particle Identification (PID) plays a crucial role in the EIC physics scope. The PID system, globally covering the pseudorapidity range (from -3.3 to 3.5), supports the electromagnetic calorimeters in electron identification thanks to its...
In this talk, we present our results for the azimuthal decorrelation of a vector boson and jet in proton-proton collisions. We show that using a recoil-free jet definition reduces the sensitivity to contamination from soft radiation on the measurement and simplifies our theoretical calculation by eliminating complications associated with non-global logarithms. Specifically, we consider the...
Generalized parton distributions (GPDs) are off-forward matrix elements of quark and gluon operators that work as a window to the total angular momentum of partons and their transverse imaging (nucleon tomography). To access GPDs one needs to look into exclusive processes, out of which double deeply virtual Compton scattering (DDVCS) is a promising mechanism to measure GPDs outside the lines...
Nuclear Parton Distribution Functions (nPDFs) are crucial for understanding nuclear structure and for providing predictions for heavy-ion collisions. nPDFs have been determined via ‘global QCD analyses’, which is a statistical approach based on performing a fit of nPDF-dependent theoretical predictions to the relevant experimental data. One of the crucial aspects of nPDF determination is the...
Achieving outstanding tracking and vertexing accuracy over a wide kinematic range is essential for the physics program of the future Electron-Ion Collider (EIC). To address this need, the ePIC experiment at the EIC will exploit Monolithic Active Pixel Sensors in 65 nm CMOS imaging technology to realize a high-resolution, low material budget, and low power consumption Silicon Vertex Tracker. ...
We present theoretical calculations of higher-order QCD and electroweak corrections for the associated production of a top-antitop quark pair and a $W$ boson ($t{\bar t}W$ production) at LHC energies. We show predictions for cross sections at approximate N$^3$LO (aN$^3$LO) which include second-order and third-order soft-gluon corrections added to the exact NLO QCD+electroweak result. We...
In this talk, I will discuss our work in 2311.09146, regarding the breakdown of collinear factorisation in the exclusive photoproduction of a $\pi^0 \gamma$ pair. Such a process is sensitive to both quark and gluon GPD channels. In the latter case, the amplitude fails to factorise, due to the presence of a Glauber pinch, which has the same power counting as the collinear pinch. The Glauber...
The forthcoming Electron-Ion Collider (EIC), expected to commence operations in the early 2030s, has already reached several significant milestones on its path toward completion. The core of the EIC physics program is the 3D imaging of partonic structures in protons and nuclei. The experimental detector setup required to enable this primary objective utilizes "Far-Forward" (FF) and...
Determination of the nature of dark matter is one of the most fundamental problems of particle physics and cosmology. This talk presents recent searches for dark matter particles rom the CMS experiment at the Large Hadron Collider. The results are based on proton-proton collisions recorded at sqrt(s) = 13 TeV with the CMS detector.
The EIC will deliver collisions of electrons with protons and nuclei at a wide variety of energies and at luminosities up to 1000 times higher than HERA. Precisely measuring both the scattered electron and the hadronic final state is crucial for the physics of the EIC, necessitating unique designs for the electromagnetic and hadronic calorimeters in the backward, central, and forward regions....
We present a further step toward a global extraction of generalized parton distributions (GPDs) in the Generalized parton distributions through universal moment parameterization (GUMP) framework. We include HERA measurements of Deeply Virtual Meson Production (DVMP) in order to study gluon GPDs at non-zero skewness using the same moment parameterization ansatz as the previous global fit which...
Recent highlights of supersymmetry searches from the CMS experiment are presented. These searches use proton-proton collision data with luminosity up to 138 fb-1 recorded by the CMS detector at center of mass energy 13 TeV during the LHC Run 2.
We study the systematic uncertainty and possible biases introduced by theoretical assumptions needed to include DIS data at large x in a global QCD analysis. In particular, working in the CTEQ-JLab framework, we focus on different implementations of higher-twist corrections to the nucleon structure functions, and of off-shell deformations of PDF in deuteron targets, and how their interplay...
We evaluate the top-bottom interference contribution to the fully-inclusive Higgs production cross section at next-to-next-to-leading order in QCD. Although bottom-quark-mass effects are power-suppressed, the accuracy of state-of-the-art theory predictions makes an exact determination of this effect indispensable. With this result, we address one of the leading theory uncertainties of the...
The Electron-Ion Collider (EIC) is the next-generation US-based project for QCD and nuclear science. It will collide polarized electrons with polarized protons and light ions, as well as heavier ions across the full mass range, at a high luminosity, over a wide range of c.m. energies. The first detector (ePIC) will support a broad science program, but having two detectors would significantly...
In this talk I will describe a Lattice QCD calculation of parton structure from off-forward matrix elements. Similar to DVCS cross sections, these matrix elements are convolutions of Generalized Parton Distributions (GPDs), or equivalently Double Distributions (DDs). In our methodology, the computational cost of many different momenta combinations can be ameliorated allowing for a plethera of...
After two decades of RHIC running as a polarized proton collider, we summarize recent achievements of the PHENIX spin program and their impact on our understanding of the nucleon’s spin structure on partonic level (e.g. quark and gluon spin contribution to the spin of the proton), and transverse spin phenomena giving access to parton dynamics within the nucleon. Of particular interest are...
Results published in 1983 by the European Muon Collaboration (EMC) at CERN suggested that a nucleon's partonic structure is modified when multiple nucleons are bound together in the nuclear environment. This phenomenon, now known as the EMC Effect, came as a surprise due to the relatively small energies involved in nucleon-nucleon interactions when compared to the energies present in DIS...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton collisions with instantaneous luminosities of $10^{34}$ cm$^{−2}$s$^{−1}$. In this talk we will review the opportunities for measuring standard and anomalous top quark couplings, both to lighter quarks and to gauge...
With the growing precision of experimental measurements, combining fixed-order perturbative calculations with parton-shower effects becomes essential for an accurate description of LHC phenomenology. In this talk, we focus on the computation of Higgs production via bottom-quark annihilation ($b \bar{b}H$) at next-to-next-to-leading order (NNLO) in QCD perturbation theory, consistently matched...
New preliminary results from COMPASS on pion and kaon multiplicities in Semi-Inclusive Deep Inelastic Scattering on a proton target are presented. These proton findings serve as a complementary dataset to the deuteron results published in 2017. In this updated analysis, we have implemented an enhanced treatment of Radiative Corrections using DJANGOH MC. A comparison with the previously...
Abstract: Studies of the transverse-spin dependent azimuthal asymmetries in the Drell-Yan process permit to access the spin-dependent structure of the nucleon and especially to test the limited universality of its transverse-momentum dependent parton distributions. In 2015 and 2018 the COMPASS Collaboration at CERN performed measurements of the $\pi^-$p $\rightarrow \mu^+\mu^-$X reaction at...
Transverse Momentum Dependent (TMD) factorization leads to well established theorems for a restricted class of processes. In such cases, some of the effects produced by the soft radiation cancel out and the physics associated to them cannot be accessed. Extension of the factorization to non-standard processes inevitably leads to deal with the non trivial structure of the soft sector, revealing...
In light of recent progress on both the experimental and lattice-QCD sides, our understanding of the pion’s structure has evolved. Phenomenological, or global, QCD analyses — the focus of this talk— play a crucial role in establishing a bridge between experimental data, theoretical predictions, and lattice-QCD studies. I will present recent efforts in the determination of the distribution of...
Jet vetoes are important tools that are frequently used to cut away backgrounds or separate different hard scattering processes. The most commonly used variable to veto jets is the simple transverse momentum of a jet. However it can be useful to use a jet veto that is tight in transverse momentum at central rapidities, and gradually becomes looser as one goes forward in rapidity - for example,...
The future collider LHeC is set to operate at a center-of-mass energy of 1.2 TeV and is anticipated to provide an integrated electron-proton luminosity of 1 ab$^{-1}$. This talk aims to present a comprehensive survey of studies of high-energy photon-photon processes at the LHeC, for
the $\gamma \gamma$ center-of-mass energy of up to 1~TeV.
The scientific potential of studying such...
We present an analysis to extract kaon parton distribution functions (PDFs) using meson-induced Drell-Yan and quarkonium production data. Starting from the statistical model, first developed for describing the partonic structure of nucleons and later applied to the pion, we have extended this approach to perform a global fit to existing kaon-induced Drell-Yan and charmonium production data....
We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to TMD phenomenology applied to Drell-Yan like processes, including lepton pair production at moderate $Q^2$ and $Z^0$ boson production.
We compare and contrast general features of our methodology with other common practices and emphasize the improvements derived from our approach that...
High-energy collisions of hadrons (protons and nuclei) at the CERN Large Hadron Collider (LHC) are characterized by multiple interactions of their underlying partonic constituents. The simultaneous production of several particles with large transverse momentum and/or mass ($p_\mathrm{T}, m \gg 3$~GeV) in different independent hard partonic interactions has attracted an increasing interest in...
The MOLLER experiment has been designed to significantly expand the reach for new dynamics beyond the Standard Model of electroweak interactions. Using the high intensity, high precision electron beam at Jefferson Lab, MOLLER will measure the parity-violating asymmetry $A_{PV}$ in the scattering of longitudinally polarized electrons off unpolarized electrons to an overall fractional accuracy...
The transversity distribution function, $h_1^q(x)$, describes the transverse quark polarization within a transversely-polarized nucleon, where $x$ is the longitudinal momentum fraction carried by quark $q$. Being chiral-odd, $h_1^q(x)$ can be accessed only when coupled with another chiral-odd function, such as the spin-dependent interference fragmentation function (IFF) via the di-hadron...
We present a systematic quantum algorithm, which integrates both the hadronic state preparation and the evaluation of real-time light-front correlators, to study parton distribution function (PDF) and light cone distribution amplitude (LCDA). As a proof of concept, we demonstrate the first direct simulation of the PDF and LCDA in the 1+1 dimensional Nambu-Jona-Lasinio model. We show the...
The aim of the upcoming MOLLER experiment at Jefferson Laboratory, a national accelerator facility, is to probe electroweak interactions with unprecedented sensitivity reach at both low and high energy scales to discover new beyond the Standard Model dynamics. MOLLER is an extremely precise measurement of parity violation in electron scattering searching for new neutral currents in...
Inclusive photoproduction of dijets in ultra-peripheral nucleus-nucleus collisions (UPCs) has been suggested as a new probe for studying the nuclear parton distributions (nPDFs). In this talk, we present new NLO pQCD predictions for the photoproduction of dijets in PbPb UPCs at 5.02 TeV with up-to-date nPDFs and realistic impact-parameter dependent photon flux obtained through the nuclear form...
We introduce our novel Bayesian parton density determination code, \partondensity. The motivation for this new code, the framework and its validation are described. As we show, \partondensity provides both a flexible environment for the determination of parton densities and a wealth of information concerning the knowledge update provided by the analyzed data set.
In recent decades, there have been numerous efforts to unravel the origin of the unexpectedly significant transverse single spin asymmetry ($A_{N}$) observed in inclusive hadron productions at forward rapidities in $p^{\uparrow}$+$p$ collisions at various center-of-mass energies ($\sqrt{s}$). Several theories have been proposed to explain this phenomenon, including the twist-3 contributions...
Future e$^+$e$^-$ colliders, with their clean environment and triggerless operation, offer a unique opportunity to search for long-lived particles (LLPs). Considered in this contribution are prospects for LLP searches with the International Large Detector (ILD) providing almost continuous tracking in Time Projection Chamber (TPC) as the core of its tracking systems. The ILD has been developed...
The energy dependence for the singlet sector of Parton Distributions Functions (PDFs) is described by an entangled pair of ordinary linear differential equations. Although there are no closed analytic solutions, it is possible to provide approximated results depending on the assumptions and the methodology adopted. These results differ in their sub-leading, neglected terms and ultimately they...
The study of proton-lead events that have gaps in the rapidity distribution of final-state particles provides a unique opportunity to study colorless interactions such as pomeron-lead and photon-lead. The relative contribution of these processes depends on the size of the rapidity gap. The CMS Collaboration has previously studied the cross section of such processes as a function of the...
Two of the questions posed by the 2023 Nuclear Science Long Range Plan are how hadrons produced in deep inelastic scattering of electrons are correlated with one another, and how the nuclear medium modifies the hadronization process. The results we present in this talk on azimuthal correlations in $\pi^+\pi^-$ and $\pi^+p$ pairs measured by the CLAS collaboration at Jefferson Lab seek to...
The transverse single spin asymmetries (TSSAs) in semi-inclusive deep inelastic scattering (SIDIS) have been intensively investigated over the last two decades. The TSSAs of $\rho^{0}$ are recently measured by COMPASS. Among these, the Sivers asymmetry can be expressed within the transverse momentum dependent (TMD) factorization framework, as the convolution of the Sivers function of the...
We propose to study hard processes and bulk nuclear matter on the same footing in heavy-ion collisions using Glauber modelling of heavy nuclei. To exemplify this approach, we calculate the leading-order corrections to azimuthal decorrelation in Drell-Yan and boson-jet processes due to cold nuclear effects. At leading order in both the hard momentum scale and the nuclear size, the...
COMPASS is a fixed target high energy physics experiment that has been collecting data for 20 years (2002 to 2022) at the M2 beamline (SPS, North Area) at CERN. One of the goals of the experiment's broad physics program was to perform semi-inclusive measurements of target-spin dependent asymmetries in (di-)hadron production in DIS with high-energy muons colliding with polarised targets. The...
Pion-induced Drell-Yan muon-pair production is one of the key processes providing information on the structure of the $\pi$ meson. In this channel, the world data set is limitted to the cross-section measurements performed by the NA10 and E615 experiments more than 30 years ago. In 2015 and 2018, the COMPASS experiment at CERN collected data sensitive to the Drell-Yan process using a 190 GeV...
The DsTau (NA65) experiment at CERN was proposed to measure an inclusive differential cross-section of $D_s$ production, and its decay branching ratios in $p$-$A$ interactions. The DsTau detector is based on the nuclear emulsion technique providing an excellent spatial resolution for detecting short-lived particles like charmed hadrons. The first results of the analysis of the pilot-run...
In this talk we present the latest results by the MAP Collaboration about the extraction of unpolarized quark Transverse-Momentum-Dependent Distributions (TMD PDFs) and Fragmentation Functions (TMD FFs) from global fits of Drell-Yan and Semi-Inclusive Deep-Inelastic Scattering (SIDIS) data sets.
The understanding of the gluon Sivers effect is one of the main objectives of current and future experiments as a possible solution to the large single transverse-spin asymmetry(SSA) which has been a mystery in high energy QCD over 40 years. The collinear twist-3 framework has been a successful perturbative QCD framework for the description of the SSA in the high transverse momentum region of...
A series of completed, ongoing, and proposed Semi Inclusive Deep Inelastic Scattering (SIDIS) experiments using the CLAS12 spectrometer in Hall B at Jefferson Lab are reviewed. These studies consist of scattering data from a highly polarized 11 GeV electron beam incident on a fixed proton/deuteron target which, in the case of the recently completed Run Group C experiment, were longitudinally...
In this talk, I will present our extensions of MadGraph5_aMC@NLO for two asymmetric systems, photoproduction and proton-nucleus collisions as well as progress towards automation of computations for inclusive-quarkonium production, currently being worked out at leading order.
Indeed, to consolidate the figures of merit of a variety of measurements at the Electron-Ion Collider and...
The increasingly precise experimental data from LHC have led to global extractions of parton distribution functions with significantly improved accuracy. While there are ways to approximate some theoretical uncertainties like those arising from the choices of the factorization scale, alternative approaches to tame the remaining theoretical uncertainties may eventually be needed for precision...
The initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV will be presented. The proposed physics program encompasses a large and diverse range of transforamtive investigations centered around the non-perturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon...
The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $ep$ scattering at HERA has been studied using HERA II data collected with the ZEUS detector. The data set features $e^{\pm}p$ collisions at a centre-of-mass energy of $\sqrt{s} = 318$ GeV, corresponding to an integrated luminosity of 326 pb$^{-1}$. A measurement of jet cross...
Splitting functions, often referred to as the DGLAP evolution kernel, control the scale evolution of parton distribution functions. A highly effective approach for computing these splitting functions involves the use of off-shell operator matrix elements. Nonetheless, complications arise in the singlet sector, where physical operators become entangled with non-physical ones, giving rise to...
Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) has been delivering high polarization and high current electron beams for fixed target nuclear physics experiment for more than two decades. Plans are now being developed to use the CEBAF accelerator for providing highly polarized positrons to the experimental halls. This work builds on the successful Polarized Electrons for...
In the era of the upcoming Electron-Ion Collider (EIC), the importance of accurate modeling of deep inelastic scattering (DIS) events is ever increasing. We aim to improve the modeling of DIS by implementing multi-jet merging capabilities in Pythia, the most widely-used Monte Carlo (MC) event generator among the LHC experiments. Multi-jet merging allows the combination of parton shower...
We discuss the current staus of PDFs at NLO in perturbation theory, making comparisons with NNLO and between groups, and also summariusing the current status of the remaining uncertainty at NLO.In particular we show the result of a recent benchmarking study of PDF evolution between groups.
We present the first lattice QCD calculation of the rapidity anomalous dimension of transverse-momentum-dependent distributions (TMDs), i.e. the Collins-Soper (CS) kernel, employing the recently proposed Coulomb-gauge-fixed quasi-TMD formalism as well as a chiral-symmetry-preserving lattice discretization.
This unitary lattice calculation is conducted using the domain wall fermion...
Jefferson Lab is proposing to add positron beams to the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF). A team of accelerator, physics and engineering staff have been developing the concept for the generation, production and delivery of Continuous (CW) polarized positron beams to the experimental halls, up to the full 12 GeV. A layout of the proposed concept will be shown. We...
With a large momentum transfer, high energy lepton-hadron scattering induces both QED and QCD radiations. Contribution of induced QCD radiation to scattering cross sections has been consistently evaluated in terms of QCD factorization approach, while contribution from induced QED radiation has been historically corrected by imposing a “radiative correction factor” to the lowest order (LO)...
The Breit frame provides a natural reference frame to analyze lepton-proton (ep) scattering events when the process of interest is plainly considered as a photon-hadron interaction. In the Breit frame, the photon runs on the z axis into the positive direction, and in the leading order picture the struck quark leaves the interaction on the z axis, too. Higher-order QCD corrections change that...
The Large Hadron Collider beauty (LHCb) experiment provides an opportunity to study hadronization processes, how particular hadrons are formed from scattered quarks and gluons (partons), in the forward region, 2 < η < 5. Going beyond traditional collinear non-perturbative fragmentation functions (FFs), transverse-momentum-dependent (TMD) FFs provide multidimensional information on the...
I will illustrate the agenda of the preparation of the NuPECC LRP. Then, I will highlight some (temporary) outcomes that regard physics and facilities where Deep-Inelastic Scattering in involved.
We present a new event generator for the simulation of both neutral- and charged-current DIS at NLO QCD matched to parton showers using the POWHEG method. Our implementation builds on the existing POWHEG BOX framework originally designed for hadron-hadron collisions, supplemented by considerable extensions to account for the genuinely different kinematics inherent to lepton-hadron collisions....
The Parton Branching (PB) method outlines the evolution of transverse momentum-dependent (TMD) parton distributions across various kinematic regions, ranging from small to large transverse momenta $k_T$. In the small $k_T$ region, the PB method is highly sensitive to both the intrinsic motion of partons (intrinsic $k_T$) and the resummation of soft gluons, as described by the PB TMD evolution...
The Belle II experiment has collected a 424 fb$^{-1}$ data set of $e^+e^-$ collisions produced by the asymmetric-energy SuperKEKB collider. Three-quarters of the data have a centre-of-mass energy equal to the mass of the $\Upsilon(4S)$ resonance, which decays to $B$-meson pairs, allowing measurements of rare $B$ decays, $C\!P$ violation, and searches for lepton universality violation....
Leveraging the novel concept of Energy Recovery Linacs (ERL), we present the LHeC and FCC-eh colliders that allow the exploration of electron-hadron interactions above the TeV scale. The presented design of the electron accelerator is based on two superconducting linear accelerators in a racetrack configuration that can produce lepton beam energies in excess of 50 GeV. In energy recovery mode,...
We describe a novel procedure to determine moments of parton distribution functions of any order with lattice QCD computations. The procedure is based on the gradient flow for fermion and gauge fields. The flowed matrix elements of twist-2 operators renormalize multiplicatively, and the matching with physical matrix elements is obtained making use of continuum symmetries. We calculate the...
We introduce a transverse-momentum dependent (TMD) factorization scheme designed to unify both large and small Bjorken-x regimes. We compute the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the gluon TMD operator for an unpolarized hadron within this proposed scheme. This leads to the emergence of a new TMD evolution, incorporating those in transverse momentum,...
The proposed Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode will make possible the study of DIS in the TeV regime. These facilities will provide electron-proton (nucleus) collisions with per nucleon instantaneous luminosities around $10^{34}$($10^{33}$) cm$^{−2}$s$^{−1}$ by colliding a 50-60 GeV electron beam from a highly innovative energy-recovery...
Ultra-peripheral heavy-ion collisions (UPCs) occur when the impact parameter of the collision is greater than the sum of the radii of the colliding nuclei. These collisions allow one to study photon-induced reactions, such as the photoproduction of a vector meson, which is a well-established tool to probe the gluon structure of the colliding nuclei.
This talk will focus on the observation...
Ultra-relativistic heavy-ion collisions provide strong electromagnetic fields that induce photo-nuclear interactions. These processes are well studied in ultra-peripheral collisions, where nuclear overlap is absent. When the emitted photon couples with the entire target nucleus, a vector meson (VM) like the J/$\psi$ can be coherently photoproduced. The coherence condition is characterized by...
We compute the back-to-back dijet cross-section in deep inelastic scattering (DIS) at small $x$ to next-to-leading order (NLO) in the Color Glass Condensate effective field theory. Our result can be factorized into a convolution of the Weizsäcker-Williams gluon transverse momentum dependent distribution function (WW gluon TMD) with a universal soft factor and an NLO coefficient function. The...
We present the results obtained by confronting the next-to-leading order (NLO) CGC/saturation approach, as outlined in Ref. [Eur. Phys. J. C 80, 1029 (2020)], with the experimental combined HERA data. The model includes two features that are in accordance with our theoretical knowledge of deep inelastic scattering: the use of analytical solution for the non-linear Balitsky-Kovchegov (BK)...
We will present the exclusive production of charged hadrons in CMS using intact protons tagged in the TOTEM roman pot detectors.
We compute the transverse and longitudinal diffractive structure functions to full next-to-leading order accuracy in the dipole picture of deep inelastic scattering [1]. Our calculation uses the standard light-cone perturbation theory method for the partonic content of the virtual photon, together with the Color Glass Condensate description of the target color field. Our result includes as a...
ALICE has measured the diffractive photo-nuclear cross section for coherent J$/\psi$ production off lead (Pb) nuclei. This process is highly sensitive to the gluon distribution in Pb. This measurement reaches centre-of-mass energies of the photon-nucleus system up to 813 GeV which is more than 340 GeV larger than ever before. It also covers three orders of magnitude of the relevant variable,...
The intense photon fluxes of relativistic nuclei provide an opportunity to study photonuclear interactions in ultra-peripheral collisions. Exclusive final states of vector mesons can be studied in the process $\gamma$ + A $\rightarrow$ meson + A. The measurement of photoproduced $\pi^+\pi^-\pi^+\pi^-$ final states in ultra-peripheral Pb–Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV at...
The center-of-mass energies available at modern accelerators, such as the Large Hadron Collider (LHC), and at future generation accelerators, such as the Electron-Ion Collider (EIC) and Future Circular Collider (FCC), offer us a unique opportunity to investigate hadronic matter under the most extreme conditions ever reached. One of the most intriguing phenomena of strong interaction is the...
In this talk we analyze the possibility to determine the partonic structure of colorless exchanges, Pomeron and Reggeon, from diffractive measurements in the four diffractive kinematic variables in ep collisions at the EIC. We present the model we use to generate the pseudodata and explain our fitting strategy. We show the results on the uncertainties in the extraction of quark and gluon...
Incoherent $\rm{J/\psi}$ photoproduction is sensitive to fluctuations of the gluonic structure of the target. Thus, the measurement of $\rm{J/\psi}$ photoproduction off the colliding hadron sheds light on the initial state of QCD and provides important constraints on the initial conditions used in hydrodynamical models of heavy ion collisions. In this talk, we present the first measurement of...
We analyze the world polarized deep-inelastic scattering (DIS) and semi-inclusive DIS (SIDIS) data at $x < 0.1$, using small-$x$ evolution equations at the more realistic large-$N_c\& N_f$ limit for the flavor singlet and nonsinglet helicity parton distribution functions (hPDFs), which resum all powers of both $\alpha_s\ln^2(1/x)$ and $\alpha_s\ln(1/x)\ln(Q^2/Q^2_0)$ with $\alpha_s$ the strong...
Parton saturation is one of the most intriguing phenomena in the high energy nuclear physics research frontier, especially in the upcoming era of the Electron-Ion Collider (EIC). The lepton-jet correlation in deep inelastic scattering provides us with a new gateway to the parton saturation at the EIC. In particular, we demonstrate that azimuthal angle anisotropies of the lepton-jet correlation...
Based on the recently obtained result [1] for the virtual corrections for the impact factor $g+R \to c\bar{c}$ ($R$-Reggeized gluon) with the $c\bar{c}$ pair being in the $^1S_0^{[1]}$ state, which is relevant for the forward-rapidity production of the $\eta_c$ meson, we compute the real-emission correction to this impact factor: $g+R \to c\bar{c}+g$ analyze the structure and cancellation of...
In this talk we present our analysis of the inclusive photoproduction of heavy charmonia-bottomonia pairs in the Color Glass Condensate framework and demonstrate that the cross-section of the process is sensitive to dipole and quadrupole forward scattering amplitudes (2- and 4-point correlators of Wilson lines). Using the phenomenological parametrizations of these amplitudes, we estimate...
We explore the possibility to use Ultra-Peripheral proton-lead Collisions (UPC) at the LHC to study inclusive vector-quarkonium photoproduction. Due to the extremely large energies of the colliding hadrons circulating in the LHC, the range of accessible photon-nucleon centre-of-mass energies largely exceeds what has been and will be studied at lepton-hadron colliders, HERA and the EIC.
We...
The study of incoherent production of a vector meson in diffractive processes provides information about the inner composition of the target hadron at the partonic level. The incoherent cross section is sensitivite to fluctuations in the configuration of the color field of the target. The energy-dependent hotspot model, based on the color dipole approach, incorporates subnucleon degrees of...
In this work, we constrain the initial condition for the leading order Balitsky-Kovchegov (BK) evolution equation with an uncertainty estimate by applying Bayesian inference.
The BK equation describes the high-energy evolution of the scattering of a quark - antiquark dipole and a proton or a CGC field. The determined initial condition is then sensitive to the non-perturbative structure of the...
An investigation on η’ photoproduction on quasi-free neutron (Deuterium target) is presented, by showing a preliminary estimation of Beam Asimmetry Σ as function of polar angle in the center-of-mass system near the threshold by analyzing the experimental data of GRAAL experiment. The η’ photoproduction channel is useful because it acts as an isospin filter, allowing to select only resonant...
In ultra-peripheral collisions (UPCs), the photon fluctuates to a quark-antiquark dipole which then elastically scatters off the nucleus, emerging as vector meson or an oppositely charged pseudoscalar meson pair.
The powerful particle identification capability of ALICE allows the study of photoproduced $\pi^{+}\pi^{-}$ pairs and $K^{+}K^{-}$ pairs at midrapidity in Pb--Pb collisions at...
We study the small-$x_B$ asymptotics of the leading-twist quark Transverse Momentum Dependent parton distribution functions (TMDs). We apply the recently developed Light Cone Operator Treatment (LCOT) to rewrite the TMD operator definitions at small-$x_B$ in terms of polarized dipole amplitudes, then construct and solve small-$x_B$ evolution equations for the dipole amplitudes in the...
The investigation of particle-particle correlations in proton-proton and heavy-ion collisions is an important tool in the effort to understand the fundamental dynamics of the strong force. Here we present a study of final state correlations in proton-proton collisions based on the BFKL dynamics in an attempt to see how relevant the high-energy limit of QCD is
in understanding the enigmatic...
This talk introduces a model for classical gauge field correlators in a large hadronic medium beyond the eikonal approximation. We incorporate plus and transverse components, which are absent in the eikonal approach, while disregarding the $x^-$-dependence of the field. Our model facilitates the analytical computation of the cross section for quark-antiquark (dijet) production in nuclear Deep...
In this contribution I would like to report on our recent computations [1] of exclusive $\chi_c$ productions in high-energy electron-proton collisions. $\chi_c$ quarkonia are $C$-even and serve as a probe of the odderon amplitude in the proton which is an off-forward generalized transverse momentum distribution formed by at least three gluons in a $C$-odd state. We are motivated by the odderon...
Kovchegov and Sievert showed that the phase required for Transverse Single Spin Asymmetries (TSSA) in $q^\uparrow p$ and $q^\uparrow A$ collisions can be generated by QCD odderon [1]. Their results for TSSA possess interesting nuclear dependence that was recently measured at RHIC [2,3]. We consider $p^\uparrow p$ and $p^\uparrow A$ collisions and show that the contribution in [1] comes from...
A key focus of the physics program at the LHC is the study of head-on proton-proton collisions. However, an important class of physics can be studied for cases where the protons narrowly miss one another and remain intact. In such cases, the electromagnetic fields surrounding the protons can interact producing high-energy photon-photon collisions. Alternatively, interactions mediated by the...
We consider the powers of leading order eigenvalue of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation at zero conformal spin. Using reflection identities of harmonic sums we demonstrate how involved generalized polygamma functions are introduced by pole separation of a rather simple digamma function. This generates higher weight generalized polygamma functions at any given order of...
For the DIS dijet cross section at low x, Next-to-Eikonal power corrections with respect to the Shockwave/CGC result have been calculated (at LO in alpha_s). In this talk, we will present the expansion of that result in the back-to-back dijet limit, keeping terms of twist 2 or 3. This allows us to check the consistency between the Shockwave/CGC formalism and the TMD factorization formalism...
We calculate the next to leader order (NLO) corrections to single and double inclusive hadron production in DIS at small $x$ using the Color Glass Condensate formalism. We show that all divergences either cancel or can be absorbed into evolution of the leading order cross sections. We then investigate the high $Q^2$ limit of our results and make a connection to Sudakov single and double logs....
A solution of the target-rapidity Balitsky-Kovchegov (BK) equation is presented considering, for the first time, the complete impact-parameter dependence, i.e. including the orientation of the dipole with respect to the impact-parameter vector. To address the non-local behaviour introduced in the target-rapidity formulation of the BK equation, three different prescriptions are considered to...
Ultra peripheral heavy ion collisions measured at RHIC and at the LHC provide a unique opportunity to study photon-nucleus scattering in the very high center-of-mass energy domain. Exclusive vector meson photoproduction is an especially interesting process in UPCs as it is experimentally clean, and additionally such diffractive processes are especially sensitive to non-linear QCD...
One of the most intriguing results in ultra-peripheral collisions (UPCs) of heavy ions is that the cross section of J/ψ photoproduction in heavy nuclei has been found to be significantly suppressed relative to that of a free proton. The suppression was found across a wide range of photon-nucleon center-of-mass energy, going from below 20 GeV to nearly 1 TeV. Many theoretical models can...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton (nucleus) collisions with per nucleon instantaneous luminosities around $10^{34}$ ($10^{33}$) cm$^{−2}$s$^{−1}$. Following the renewal of the CERN mandate, in this talk we present the status of the studies on proton and...
I describe the challenges in implementing the kinematical constraint in the JIMWLK evolution equation and the status of current numerical results. In particular, I concentrate on the conditions necessary for the reduction of the dynamics of dipole amplitude to the kinematically constrained BK equation. I provide numerical checks of these conditions and discuss their implications.
The JIMWLK Hamiltonian governs evolution of high energy collision processes. At next-to-leading order, the Hamiltonian features large logarithms, which have to be resummed. We discuss partial resummation of these logarithms into running coupling and DGLAP-like resummation.
We show that elastic pp cross-section has a unique universal property that the ratio of bump-to-dip position is constant from the energies of the ISR to the LHC. We explore this property to compare geometrical scaling present at the ISR with the recently proposed scaling law at the LHC. We argue that at the LHC, within present experimental uncertainties, there is fact a family of scaling laws....
After a brief introduction on the peculiarities of QCD in the high-energy regime and the bFKL approach for its description, we proceed to the theoretical
analysis of virtual photon scattering.
Here, the crucial theoretical objects are the photon impact factors and the BFKL gluon Green’s func-
tion, which up to now are known in leading and
next-to-leading logarithmic approximation.
We...
One of the main approximations adopted in the Color Glass Condensate (CGC) is the so-called eikonal approximation, which amounts to neglecting power-suppressed corrections in the high-energy limit. This approximation is well justified for asymptotically high energies. However, corrections to it might be sizable in the upcoming Electron Ion Collider. Furthermore, Deep inelastic scattering (DIS)...
We argue that diffractive jet production in photon-nucleus interactions at high energy represents a golden channel to study gluon saturation at the future Electron-Ion Collider. The most interesting process in that sense is the diffractive production of a pair of hard jets with transverse momenta much larger than the saturation momentum $Q_s$ of the nuclear target. We show that the dominant...
Transverse energy-energy correlators (TEECs) are event-shape observables that can be used to study QCD by examining angular correlations between produced particles. As they are weighted by the energy of the particle, they are an infrared-safe observable that can be calculated to high accuracy. This makes TEECs a potentially useful tool in extracting the target structure in DIS and studying...
Ultra peripheral collisions provide a chance to study exclusive processes in heavy ion collisions. These includes light vector mesons from coherent effects and other probes requiring soft particle tracking. The LHCb experiment has unique capabilities to study multiple UPC observables, thanks to its low transverse momentum tracking and particle identification. The forward rapidity coverage of...
