Next-to-Leading Order Differential Cross Sections forJ/ψ,ψ(2S), andΥProduction in Proton-Proton Collisions at a Fixed-Target Experiment Using the LHC Beams

Yu Feng,Jian-Xiong Wang

doi:10.1155/2015/726393

Abstract

Using nonrelativistic QCD (NRQCD) factorization, we calculate the yields forJ/ψ,ψ(2S), andΥ(1S)hadroproduction ats=72 GeV and 115 GeV including the next-to-leading order QCD corrections. Both these center-of-mass energies correspond to those obtained with 7 TeV and 2.76 TeV nucleon beam impinging a fixed target. We study the cross section integrated inptas a function of the (center-of-mass) rapidity as well as theptdifferential cross section in the central rapidity region. Using different NLO fit results of the NRQCD long-distance matrix elements, we evaluate a theoretical uncertainty which is certainly much larger than the projected experimental uncertainties with the expected 20 fb−1to be collected per year with AFTER@LHC forppcollision at the center of mass energys≃115 GeV.

Highlights

Non-relativistic quantum chromodynamics (NRQCD) [1] is the most systematic factorization scheme to describe the decay and production of heavy quarkonia
In the past few years, significant progress has been made in next-to-leading order (NLO) QCD calculations based on NRQCD
Calculations and fits of NRQCD long-distance matrix elements (LDMEs) for both the J/ψ yield and polarization in hadroproduction have been carried out [2,3,4,5,6] as well as for Υ hadroproduction [7, 8]. Using these LMDEs, one can in principle predict the transverse momentum pt differential cross section at any energies

Summary

INTRODUCTION

Non-relativistic quantum chromodynamics (NRQCD) [1] is the most systematic factorization scheme to describe the decay and production of heavy quarkonia. Calculations and fits of NRQCD long-distance matrix elements (LDMEs) for both the J/ψ yield and polarization in hadroproduction have been carried out [2,3,4,5,6] as well as for Υ hadroproduction [7, 8]. Using these LMDEs, one can in principle predict the transverse momentum pt differential cross section at any energies. We confirm that charmonium yields can reach 109 per year and 106 for bottomonia

NEXT-TO-LEADING ORDER CALCULATION

CONSTRAINS ON THE LDMES

NUMERICAL RESULTS

SUMMARY