Nuclear modification of high transverse momentum particle production in p + A collisions at RHIC and LHC

Zhong-Bo Kang,Ivan Vitev,Hongxi Xing

doi:10.1016/j.physletb.2012.10.046

Zhong-Bo Kang, Ivan Vitev + Show 1 more

Open Access

https://doi.org/10.1016/j.physletb.2012.10.046

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Abstract

We present results and predictions for the nuclear modification of the differential cross sections for inclusive light hadron and prompt photon production in minimum bias d+Au collisions at s=200 GeV and minimum bias p+Pb collisions at s=5 TeV at RHIC and LHC, respectively. Our calculations combine the leading order perturbative QCD formalism with cold nuclear matter effects that arise from the elastic, inelastic and coherent multiple scattering of partons in large nuclei. We find that a theoretical approach that includes the isospin effect, Cronin effect, cold nuclear matter energy loss and dynamical shadowing can describe the RHIC d+Au data rather well. The LHC p+Pb predictions will soon be confronted by new experimental results to help clarify the magnitude and origin of cold nuclear matter effects and facilitate precision dense QCD matter tomography.

Highlights

Medium-induced modification of high transverse momentum particle production in nucleus collisions (p+A, A+A) relative to the naive binary collision-scaled proton-proton (p+p) baseline expectation is a powerful probe of the properties of dense QCD matter
The nuclear modification in d+Au collisions at the RHIC and the forthcoming p+Pb results at the LHC can provide valuable information on the elastic, inelastic and coherent multiple parton scattering processes inside a large nucleus and are vital testing grounds for novel nontrivial QCD dynamics [1]. The manifestation of such nontrivial QCD dynamics in p+A reactions is usually referred to as cold nuclear matter (CNM) effects, as opposed to the effects of parton and particle formation and propagation in the ambiance of the quark-gluon plasma created in high energy A+A collisions [2]
With the future RHIC upgrade program in mind, we show predictions for the nuclear modification factor RdAu for photon and π0 production in different kinematic regions: the dashed curves are for y = 1.5 and the dotted curves are for y = 3

Summary

INTRODUCTION

Medium-induced modification of high transverse momentum (pT ) particle production in nucleus collisions (p+A, A+A) relative to the naive binary collision-scaled proton-proton (p+p) baseline expectation is a powerful probe of the properties of dense QCD matter. The nuclear modification in d+Au collisions at the RHIC and the forthcoming p+Pb results at the LHC can provide valuable information on the elastic, inelastic and coherent multiple parton scattering processes inside a large nucleus and are vital testing grounds for novel nontrivial QCD dynamics [1]. There are calculations and predictions for the nuclear modification factor in Monte Carlo models such as HIJING [15] In this manuscript we follow an approach different from the above mentioned. It is based on perturbative QCD factorization and CNM effects are implemented separately within the formalism.

SINGLE INCLUSIVE PARTICLE PRODUCTION

Basic pQCD formalism

Cold nuclear matter effects

SUMMARY