Nuclear Physics Seminar

"Longitudinal double spin asymmetry for incluisve jet and dijet production in proton-proton collisions at $\sqrt{s} = $ 510 GeV"

Presented by Zilong Chang, BNL

Tuesday, September 10, 2019, 11:00 am — Small Seminar Room, Bldg. 510

Jets productions from $pp$ collisions at RHIC kinematics are dominated by quark-gluon and gluon-gluon scattering processes. Both of these longitudinal double spin dependent processes have sizable asymmetries in the pseudorapidity range, $-1 < \eta < 1$. Therefore the longitudinal double-spin asymmetry $A_{LL}$ for jets is an effective channel to explore the gluon polarization in the proton. Early STAR inclusive jet $A_{LL}$ results at $\sqrt{s} = $ 200 GeV provided the first evidence of the non-zero gluon polarization at $x > $ 0.05. In this talk, we will report the first measurement of the midrapidity inclusive jet and dijet $A_{LL}$ at $\sqrt{s} =$ 510 GeV. The inclusive jet $A_{LL}$ measurement provides sensitivity to the gluon helicity distribution down to a Bjorken-$x$ of 0.015, while the dijet measurements, binned in four jet-pair topologies, will allow for tighter constraints on the $x$ dependence. Both results are consistent with previous measurements made at $\sqrt{s} =$ 200 GeV and show excellent agreement with predictions from recent next-to-leading order global analyses. In addition the new techniques designed for this analysis, for example, the underlying event correction to the jet transverse energy and its effect on the jet $A_{LL}$ will be discussed.

Hosted by: Rongrong Ma

15213  |  INT/EXT  |  Events Calendar


Not all computers/devices will add this event to your calendar automatically.

A calendar event file named "calendar.ics" will be placed in your downloads location. Depending on how your device/computer is configured, you may have to locate this file and double click on it to add the event to your calendar.

Event dates, times, and locations are subject to change. Event details will not be updated automatically once you add this event to your own calendar. Check the Lab's Events Calendar to ensure that you have the latest event information.