Hard scattering production measurements in p+Au collisions at √s_NN = 200 GeV in STAR

With the observation of flow-like correlations in small system collisions at both RHIC and the LHC, the existence of the quark-gluon plasma (QGP) in such collisions has become a question under active pursuit over recent years.

Multiple probes have been used to tackle this problem, such as studies of hard scattering products and their system size dependent modifications. Hard scatterings can be probed by either collimated particle clusters called jets, or high momentum particles as a proxy.

Jet quenching has been a successful probe of the QGP in heavy-ion collisions and widely used in small systems.

While most results in minimum-bias events agree with the expectation based on absence of QGP in such systems, hints of suppression and enhancement are observed respectively in high and low event activity (EA) events.

In this talk, we present investigations of p+Au collisions at √s_NN =200 GeV at STAR for possible evidence of medium modification of hard scattering by differentially measuring high momentum particle yield and inclusive jet yield.

Progress toward obtaining the nuclear modification factors R_pAu will be presented. Further details on EA definition and comparison between yields in high vs. low EA events will be discussed.