Speaker
Description
Soft particle production accompanying a hard scattering in proton-proton (p+p) collisions arises from a variety of sources, including multiple parton interactions, initial- and final-state radiation, and the color neutralization of the beam remnant. Quantifying the underlying event associated with a high energy jet provides sensitivity to these contributions and their interplay with the hard process. In this talk, we present a new measurement of the transverse energy in the region transverse in azimuth to the leading jet using the large p+p data set collected in 2024 with the sPHENIX detector at RHIC. The underlying event activity is reported as a function of leading jet kinematics, including the highest jet p$_T$ regions where the partitioning of the collision energy between the hard scattering and the underlying event is of particular interest. Comparisons to event generators such as PYTHIA and HERWIG are shown to assess model sensitivity to multiple parton interactions and QCD radiation at RHIC energies. We also discuss comparisons with underlying event measurements at other center-of-mass energies, from RHIC to LHC scales, to evaluate the evolution of these contributions with collision energy and hard scattering process.
| Is this an experimental talk? | Yes |
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| Is this on behalf of a collaboration? | Yes |
| Which collaboration? | sPHENIX Collaboration |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |