Jet sub-structure as a probing tool of the Quark Gluon Plasma
IDPASC Portugal - PHD Programme 2019
2019 / 2020
Theoretical Particle Physics
José Guilherme Milhano
Instituto Superior Técnico
Laboratório de Instrumentação e Física Experimental de Partículas
Ultra-relativistic collisions of heavy atomic nuclei recreate temperature and density conditions prevalent in the early stages of the history of the Universe. The Quark Gluon Plasma (QGP) created in these collisions is the most perfect liquid ever observed. Its formation and evolution constitutes one of the most relevant and fundamental problems currently under study. The experimental and theoretical heavy-ion research programme has evolved from its initial QGP-discovery phase (CERN-SPS and BNL-RHIC) to a full-fledged QCD-probing effort at the LHC. Extraction of QGP properties from data requires the availability of adequate probes — that are both under excellent theoretical control and that are generated within the QGP as its very short lifetime (a few yoctoseconds) precludes any external probing approach. At the LHC at CERN, Lead nuclei are collided at the highest ever centre-of-mass energy (~5 TeV per nucleon pair, a factor 25 increase from RHIC). The large collision energy leads to the abundant production of QCD jets that have proved to have a huge potential as detailed probes of the QGP. In particular the sub-structure properties of jets offer unique opportunities to fully characterize the QGP. The aim of this thesis is to develop the theory of jet sub-structure for jets that are created within and travel through the QGP, to simultaneously carry out event-generator based phenomenological studies aimed at establishing the sensitivity of specific sub-structure observables to specific QGP properties. Our group is at the forefront of efforts in this domain. The selected candidate will develop both strong and highly transferable computational skills and solid competence in Quantum Chromodynamics. The thesis work, co-supervised by Guilherme Milhano and Liliana Apolinário, will take place within the Phenomenology group at LIP-Lisbon in close collaboration with colleagues at CERN, Santiago de Compostela, and MIT.