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Séminaires et colloques
Séminaires des Doctorants 2016: B. Bolliet, H. Yokoyama
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Europe/Paris
Grand Amphithéâtre
Grand Amphithéâtre
Description
10h00: Présentation de Boris Bolliet
The expanding universe: primordial and present acceleration
There are two times in the standard cosmological scenario when the universe enters a phase of accelerated expansion: primordial inflation and dark energy domination. Understanding the acceleration of the universe is one of the major challenges for modern cosmology.
I will present my recent results within two lines of research: (i) the equation of state approach for cosmological perturbations in the dark sector as a way of characterizing dark energy and (ii) loop quantum cosmology for explaining the naturalness of inflation and extend its predictive power towards quantum gravity.
talk: anglais, slides: anglais
10h30: Présentation de Hiroki Yokoyama
Measurements of Jet Quenching in Pb-Pb collisions at sqrt(s_NN) = 5.02 TeV in the ALICE experiment at the LHC
Nuclear matter at extremely high densities and/or temperatures, the so-called Quark-Gluon Plasma, formed by quarks and gluons with mostly liberated degrees of freedom as predicted by QCD, is believed to have filled the early universe during its QCD epoch with relics still observable today. In laboratory, high-energy heavy ion collisions offer the only possibility to recreate such QGP droplets experimentally. To characterize the dense QCD matter produced in central collisions of relativistic heavy nuclei, jets have proven to be excellent tools. Jet production has indeed been observed to be attenuated in the presence of a QGP. Our theoretical picture of this jet quenching mechanism as pQCD energy loss of hard partons strongly interacting with the medium has considerably progressed since the advent of the LHC era.
In this seminar, I will present my contribution towards quantifying jet quenching at the LHC, firstly by the development and commissionning of the new ALICE electromagnetic calorimeter L1 jet trigger algorithm for the LHC Run 2 started in 2015, and secondly by the jet reconstruction in the very demanding heavy ion environment to measure the inclusive jet production and nuclear modification factors.
talk: anglais, slides: anglais
