Probing the gluon structure of the nucleon through baryon stopping in photonuclear collisions

by Nicole Lewis (University of Michigan`)

Tuesday 30 Nov 2021, 11:00 → 13:00 US/Eastern

Photonuclear collisions are one of the simplest possible processes that can happen in a heavy-ion collision. They occur when one nucleus emits a quasi-real photon which interacts with the other colliding nucleus, similar to an electron-ion collision except that the photon tends to have a much smaller virtuality. Photonuclear collisions can be used to study bulk properties in the medium such as small-system collectivity due to initial state-effects and hadron chemistry. Baryon stopping describes the loss of rapidity of projectile baryons in hadronic collisions. In this talk we will discuss recent measurements of photonuclear collisions at STAR in $\rm{Au} + \rm{Au}$ data with $\sqrt{s_{NN}} = 54~\rm{GeV}$, in which significant baryon stopping was observed at low $p_{T}$. This result could indicate the existence of a baryon junction within the nucleon, a nonperturbative Y-shaped configuration of gluons which carries the baryon number and is attached to all three valence quarks.

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The recording of the seminar is available here:


https://bnl.zoomgov.com/rec/share/GHBkSZxKpzKfzu8BlsFdKhsSnW4k8xK4LL9UsvVISbP1YzZZ_8OWOJ811wVDQ9kr.Sqy3KD7nZohzj51b

Passcode: 42ichC%L

 

Slides:

Lewis_Nuclear_Physics_Seminar_21.pdf