Physics PAN Seminar by Dr. Konrad Tywoniuk (University of Bergen, Norway)

Warning Icon This event is in the past.

Date: February 12, 2021
Time: 3:30 p.m. - 4:30 p.m.
Location: zoom
Category: Seminar

Physics PAN Seminar by Dr. Konrad Tywoniuk (University of Bergen, Norway)

Title: Energy loss of QCD jets in heavy-ion collisions

Abstract:

The quark-gluon plasma (QGP) created in high-energy heavy-ion collisions at RHIC and LHC is opaque to energetic and heavy particles that are created in short-distance particle scattering. Jets, aligned collections of energetic hadrons resulting from the fragmentation of fundamental quarks and gluons that are collected within a cone of radius R, are of special interest since they develop on time-scales comparable to the lifetime of the plasma. Jet ``quenching'', or the suppression of the jet yield at large transverse momentum, is therefore a probe not only of the elastic and inelastic interactions with the medium, but also of the medium's capability to resolve correlated QCD color charges. The energy removed from the jet is redistributed in modes that span hard collinear gluon radiation (bremsstrahlung) to softer excitations that ultimately thermalize with the surrounding medium.

The radius dependence of the jet spectrum is particularly sensitive to the rich physics outlined above. In the first part of the talk, I will present a recent calculation of the jet spectrum in heavy-ion collisions where the medium parameters are sampled from a realistic hydrodynamic evolution of the QGP. Up to relatively large radii R~0.6, the suppression is dominated by perturbative physics while non-perturbative effects, related to the details of thermalization, start to dominate at R~1. This provides, for the first time, a solid basis for higher-order precision calculations of the jet spectrum that are paramount to realize the potential of hard probes as precision tools to extract the properties of the QGP.

However, jets are rare events and their spectrum drops rapidly with transverse momentum. This induces a strong bias on any process happening in the medium and makes it hard to dig out rare events where heavy-ion jets were substantially modified. In the second part of my talk, I will report on a recent attempt to extract the jet energy before quenching using machine learning. This allows to reduce the biases and enhance the signal of medium modifications. It also allows to better constrain jets as tomographic tools of the medium.

Recording (Please download it for future use. It will be deleted after 6 months from Feb 12, 2021):
https://wayne-edu.zoom.us/rec/share/troyK7v9UFbKG8F2OFfKp0jLUitCQSdrkjoPWY-FQkhr2oFlbTSYcKMqxvXqCzzi.TNSG9sqSS_8UI8fT

Slides:https://waynestateprod-my.sharepoint.com/:b:/g/personal/gx1689_wayne_edu/EcA_yFlK5GNFlQGXabEDgn8BoO3wu9U_ifhvb-GPeNoJ9A?e=I92ZmO

Join Zoom Meeting

https://wayne-edu.zoom.us/j/5456648463?pwd=bXM5bGhCMndiMmt3UzdqQ0FRNjlRdz09

Meeting ID: 545 664 8463
Passcode: 810058
One tap mobile
+13017158592,,5456648463#,,,,,,0#,,810058# US (Washington D.C)
+13126266799,,5456648463#,,,,,,0#,,810058# US (Chicago)

Dial by your location
        +1 301 715 8592 US (Washington D.C)
        +1 312 626 6799 US (Chicago)
        +1 646 876 9923 US (New York)
        +1 346 248 7799 US (Houston)
        +1 408 638 0968 US (San Jose)
        +1 669 900 6833 US (San Jose)
       
Meeting ID: 545 664 8463
Passcode: 810058
Find your local number: https://wayne-edu.zoom.us/u/abCNul4agt



Contact

Debojit Sarkar
3138029672
debojit03564@gmail.com

Cost

Free
February 2021
SU M TU W TH F SA
31123456
78910111213
14151617181920
21222324252627
28123456