This talk presents precise measurements of the mass and natural width of the Higgs boson, obtained using the full dataset collected in pp collisions at 13 TeV during Run 2 of the LHC. The measurements are performed in various Higgs boson production and decay modes, as well as their combinations. The talk will describe the adopted analysis strategies, and it will stress the impact of the...
The characterisation of the Higgs boson relies on the determination of all the properties of this particle, including its mass, which is a free parameter in the SM, and its width. This presentation will discuss the latest developments in measurements of the Higgs boson mass and width with the four-lepton and di-photon final state, with data collected by the CMS experiment at a centre of mass...
The Yukawa couplings of the Higgs boson to quarks and leptons are an important window into the mechanism of electroweak symmetry breaking and the origin of fermion masses. This talk presents several measurements of Higgs boson decays to bottom quarks, tau leptons and muons, as well as constraints on the rate of Higgs boson decays to charm quarks and on the magnitude of the charm-Yukawa...
After the discovery of the Higgs boson with LHC Run-1 data, its production cross sections have been measured at the increasing centre-of-mass energies that were reached in LHC proton-proton collisions. Comparisons with theoretical calculations so far confirm the predictions of the Standard Model. The diphoton decay channel offers a clean final state and relatively high event rate, allowing...
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 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...
Measurements of total, fiducial, and differential cross-sections offer a key window into the properties of Higgs boson production and decay at the LHC. This talk presents results obtained using the full dataset collected in pp collisions at 13 TeV during Run 2 of the LHC in various production and decay processes, providing fine-grained description of their kinematics and associated production....
Effective Field Theories provide an interesting way to parameterize indirect BSM physics, when its characteristic scale is larger than the one directly accessible at the LHC, for a large class of models. Even if the Higgs boson is SM-like, BSM effects can manifest itself through higher-dimension effective interactions between SM fields, providing indirect sensitivity through distortions of...
The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable to solely explain some observations. Many extensions of the Standard Model addressing such shortcomings introduce additional Higgs-like bosons which can be either...
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.
While the Standard Model predicts that the Higgs boson is a CP-even scalar, CP-odd contributions
to the Higgs boson interactions with fermions and vector bosons are presently not strongly constrained. A variety of Higgs boson production processes and decays can be used to study the CP nature of the Higgs boson interactions. This talk presents the most recent CP measurements by the ATLAS...
With the full Run2 data set of the LHC at sqrt(s)=13 TeV it is possible to search for subdominant production modes of the Higgs boson at a pp collider, like associate production of the Higgs with two b-quarks, with a c-quark, or vector boson scattering production with two associated Ws, profiting of high BR decay modes. Vice versa, by using all the possible production mechanism, searches for...
The production of Higgs boson pairs (HH) at the LHC is the main handle for the measurement of the Higgs boson interaction with itself and is thus a fundamental test of the Standard Model theory as well as for determining the Higgs potential. The most recent results from the CMS collaboration on measurements of non-resonant HH production using different final states and their combination using...
In the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. The Standard Model makes a definite prediction for the Higgs boson self-coupling and...
One of the LHC experiment's main goals is to precisely measure the Higgs boson production mechanisms to clarify its coupling structure. In the Standard Model of particle physics, the coupling of the Higgs boson to fermions is introduced via the Yukawa interaction. Due to the low cross-section and overwhelming background processes, the Yukawa coupling to b-quarks ($y_{b}$) was measured only in...
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.
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....
Vector boson scattering is a key production process to probe the electroweak symmetry breaking of the standard model, since it involves both self-couplings of vector bosons and coupling with the Higgs boson. If the Higgs mechanism is not the sole source of electroweak symmetry breaking, the scattering amplitude deviates from the standard model prediction at high scattering energy. Moreover,...
Measurements of diboson production in association with two additional jets at the LHC probe interactions between electroweak vector bosons predicted by the Standard Model and test contributions from anomalous quartic gauge couplings. The ATLAS experiment has recently performed such measurements in a variety of final states, amongst them the scattering into a massive electroweak gauge boson and...
Measurements of multiboson production at the LHC are important probes of the electroweak gauge structure of the Standard Model and can constrain anomalous gauge boson couplings. In this talk, recent measurements of diboson production by the ATLAS experiment at 13 TeV and 13.6 TeV are presented. Studies of gauge-boson polarisation and their correlation in WZ and ZZ events are also presented. In...
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 high center-of-mass energy of proton-proton collisions and the large available datasets at the CERN Large Hadron Collider allow to study rare processes of the Standard Model with unprecedented precision. Measurements of rare SM processes provide new tests of the SM predictions with the potential to unveil discrepancies with the SM predictions or provide important input for the improvement...
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...
High-precision measurements of top quark cross-sections are crucial to advance our understanding of perturbative and soft QCD and provide a deeper understanding of the partons inside the proton. In this talk, recent highlights of top quark cross-section measurements at CMS ranging from 5 TeV up to 13.6 TeV will be presented. Moreover, new results of differential cross-section measurements in...
The LHC is a top factory and run 2 has delivered billions of top quarks to the experiments. In this contribution, the results are presented of searches by the ATLAS experiment for Charge Lepton Flavour Violation (cLFV), lepton flavour universality, Heavy-neutrinos, and rare flavour-changing neutral current interactions of the top quark (FCNC). FCNC analyses combine search regions targeted at...
Millions of top quarks already produced at LHC TeV are ideal for searching for rare top-quark decays. Besides flavor-changing neutral currents that are highly suppressed in the Standard Model, baryon and lepton number conservation can be probed in top quark events. In this talk, recent searches for rare and beyond the Standard Model top-quark production and decay with significantly increased...
The presence of a non-baryonic Dark Matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If Dark Matter interacts weakly with the Standard Model (SM) it could be produced at the LHC. The ATLAS experiment has developed a broad search program for DM candidates, including resonance searches for the mediator which would couple DM to the SM,...
The Standard Model of Particle Physics explains many natural phenomena yet remains incomplete. Leptoquarks (LQs) are hypothetical particles predicted to mediate interactions between quarks and leptons, bridging the gap between the two fundamental classes of particles. Vectorlike quarks (VLQs) lie at the heart of many extensions seeking to address the Hierarchy Problem, as they can naturally...
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.
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.
Many new physics models predict the existence of resonances decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for Vy, VV, and VH resonances have been performed in various final states. In some of these searches, jet substructure techniques are used to disentangle the hadronic decay products in highly boosted...
In the SM, the electroweak bosons couple to the three lepton families with the same strength, the only difference in their behavior being due to the difference in mass. In recent years, some deviations have been found in measurements of the ratios of branching fractions for b-hadrons decaying into final states with different lepton flavours. This talk presents recent results of lepton flavour...
The NA62 experiment at CERN collected the world's largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio of the ultra-rare $K^+ \rightarrow \pi^+ \nu \bar\nu$ decay, based on 20 candidates.
In this talk NA62 reports new results from the analyses of rare kaon and pion decays, using data samples collected in 2017-2018. A sample of $K^+...
The NA62 experiment at CERN took data in 2016–2018 with the main goal of measuring the $K^+ \rightarrow \pi^+ \nu \bar\nu$ decay. In this talk we report on the search for visible decays of exotic mediators from data taken in "beam-dump" mode with the NA62 experiment. NA62 can be run as a "beam-dump" experiment by removing the kaon production target and moving the upstream collimators into a...
Rare kaon decays are among the most sensitive probes of both heavy and light new physics beyond the Standard Model description thanks to high precision of the Standard Model predictions, availability of very large datasets, and the relatively simple decay topologies. The NA62 experiment at CERN is a multi-purpose high-intensity kaon decay experiment, and carries out a broad rare-decay and...
The bound state of two tau leptons, ditauonium $\mathcal{T}$, is the heaviest and also most compact QED atom, and remains unobserved to date. There are several motivations for its study such as precisely extracting properties of the tau lepton, carrying out novel tests of SM and its basic CPT symmetries, and searching for BSM effects impacting the tau lepton. We will first discuss the...
Many theories beyond the Standard Model (SM) have been proposed to address several of the SM shortcomings. Some of these beyond-the-SM extensions predict new particles or interactions directly accessible at the LHC, but which would leave unconventional signatures in the ATLAS detector. These unconventional signatures require special techniques and reconstruction algorithms to be developed,...
The LHC is not only the energy-frontier collider for parton-parton collisions, but it has proven to work as a powerful photon collider providing photon-photon collisions at center-of-mass energies never reached before. I will present results of the gamma-UPC Monte Carlo event generator [1] that can calculate any arbitrary exclusive final states produced via photon fusion in ultraperipheral...
Muon reconstruction performance plays a crucial role in the precision and sensitivity of the Large Hadron Collider (LHC) data analysis of the ATLAS experiment. Accurately measuring the muon performance of the ATLAS detector is of paramount importance to provide fundamental input to physics analyses involving muons. Furthermore, the ATLAS Muon Spectrometer was significantly upgraded for LHC...
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....
