Nuclear modification of high-p_T hadron spectra in p+A collisions at LHC

Abstract

Multiple parton scatterings in high-energy p+A collisions involve multi-parton correlation inside the projectile and color coherence of multiple jets which will lead to nuclear modification of final hadron spectra relative to that in p+p collisions. Such modification of final hadron spectra in p+A collisions is studied within HIJING 2.1 model which includes initial parton shadowing, transverse momentum broadening, parton flavor and momentum correlation inside the projectile through flavor and momentum conservation and fragmentation of multiple jets. They are shown to modify the partonic flavor content of final jets and momentum spectra of final hadrons in p+A collisions at the Large Hadron Collider.

Figures (6)

• Figure 1: (color online) Charged hadron rapidity distribution from HIJING 2.1 with (solid) and without (dot-dashed) parton shadowing in $p(d)+A$ and $p+p$ (dashed) collisions at $\sqrt{s}_{NN}=200$ GeV (upper) and 5.0 TeV (lower) as compared to data from the STAR Abelev:2007nt and PHOBOS Alver:2010ck experiment.
• Figure 2: (color online) Nuclear modification factor for parton $p_{T}$ spectra in $p(d)+A$ collisions at $\sqrt{s}_{NN}=200$ GeV (upper) and 5.0 TeV (lower) from HIJING 2.1 with (solid), without (dashed) parton shadowing and with de-coherent hard scatterings (DHC) (dot-dashed and doted).
• Figure 3: (color online) Quark to gluon ratio as a function of $p_{T}$ in $p+p$ (dotted) $p(d)+A$ collisions at the RHIC (upper) and LHC (lower) energies from HIJING 2.1 without (solid) and with (dashed) de-coherent hard scatterings (DHC).
• Figure 4: (color online) Proton to pion ratio at RHIC and LHC from HIJING 2.1 with different options: default (solid), without shadowing (ashed), DHC (dot-dashed), DHC without parton shadowing (dotted) in $d+Au$ collisions at RHIC and $p+Pb$ at LHC. The ratio in $p+p$ collisions is also shown (long dashed). The RHIC experimental data are from STAR Adams:2006nd.
• Figure 5: (color online) Nuclear modification factor for charged hadrons in $p+A$ collisions from HIJING 2.1 with different options: default (solid), DHC (dashed), DHC without parton shadowing (dot-dashed) and DHC without parton shadowing and independent fragmentation (dotted), as compared to data from the PHENIX and STAR experiment Adler:2003iiAdams:2003im. The arrowed lines indicate the most possible behavior of the nuclear modification factors at LHC between low and high $p_{T}$ regions.