Speaker: Dr. Gustavo Conesa Balbastre, LPSC/CNRS, France

Location: Room409

Time: 10:00AM May 28.2025

Abstract: 

The four experiments at the LHC test QCD predictions with their measurements in ultra-relativistic  proton—proton (pp),  proton—nucleus and nucleus—nucleus collisions, and in particular, they are interested in the measurement of the properties of the quark-gluon plasma (QGP) created in heavy-ion collisions. Among the different probes that the experiment explores, high-energy hadrons and isolated prompt photons are useful to study the jet-quenching effect in the QGP: the loss of energy of high-energy partons (quarks and gluons) produced at the initial stages of the collision, while traversing the strongly interacting plasma. Isolated prompt photons do not interact with the QGP therefore, their production in AA collisions spectrum should not be modified with respect pp collisions, unlike hadrons, which are strongly suppressed. Isolated prompt photons are emitted back-to-back with a parton that will interact with the QGP, therefore, such photons help to tag the initial energy of the parton at its production time.
In this presentation, I will present the different results obtained with the LHC Run 1 and 2 data, concentrating on the isolated photons pt-differential production spectrum in pp, p—Pb and Pb—Pb collisions and the correlation of isolated photons with hadrons in Pb—Pb collisions.

Speaker Profile:
Dr Gustavo Conesa Balbastre is a Spanish researcher with expertise in calorimeter related physics. He obtained his PhD degree with joint Doctorate program between the Universities of Valencia (Spain) and Nantes (France) in 2005, with a main focus on prompt photon identification combining calorimeter shower shape analysis and isolation techniques, and prompt photon correlation with jet measurements. After PhD, he joined the laboratory LNF from the INFN in Frascati, Italy as a postdoc, where he worked as ALICE-EMCal detector software developer and coordinator (2006–2020) and continued the study of the calorimeters' performance and photon-related measurements including neutral mesons and prompt photons.  Starting 2012, he became a permanent researcher at the laboratory LPSC from the CNRS in France and continues working on ALICE in photon-related measurements until today. He was the convener of ALICE Working Grooup "Photon and Neutral Mesons" between 2015 and 2017, and the coordinator of Data Preparation Group for recontruction, simulation and analysis software development from 2006 until 2023, he was also served as Conference Committee Member in ALICE collaboration between 2018 and 2022, for which he was in charge of reviewing and approving all conference related abstracts, presentations and posters with the subjects on "Jets and Photons" during that period.