Please contact rishi(at)theory(dot)tifr(dot)res(dot)in for the zoom meeting id and the password for this seminar.
The two incoming partons from proton-proton and heavy-ion collisions occasionally interact by hard-scattering and go back-to-back in azimuth angles, these partons further fragment into sprays of hadron—known as jets. In heavy-ion collisions, the outgoing parton loses a fraction of its energy by emitting gluons while traversing through the hot-dense QCD medium. This phenomenon is known as jet quenching—one of the key signatures of Quark-Gluon Plasma—created in heavy-ion collisions. The jet energy loss, intra-jet broadening, modification of jet shape, and jet-acoplanarity are consequences of jet-quenching in heavy-ion collisions.
In this seminar, I will discuss the recent observation of intra-jet broadening in p+p relative to heavy-ion collisions that provides a way to disentangle the vacuum shower and medium-induced gluon radiations in QCD. On the other hand, the measurement of jet acoplanarity in the QGP promises to provide unique and incisive insight into the physics of jet-medium interaction and the quasi-particle nature of the QGP. I will discuss the first observations of intra-jet broadening and medium-induced acoplanarity using semi-inclusive direct photon+jet and hadron+jet measurements in Au+Au and p+p collisions at a center of mass energy of 200 GeV. I will also shed light on STAR's data-taking plan for the high statistics measurements with extended kinematic coverage.