Related papers: Breakdown of QCD factorization at large Feynman x
We consider the diffractive Drell-Yan process in proton-(anti)proton collisions at high energies in the color dipole approach. The calculations are performed at forward rapidities of the leptonic pair. Effect of eikonalization of the…
We present quantitative predictions for the nuclear modification factor in both small and peripheral systems from a pQCD-based energy loss model that is constrained by light- and heavy-flavor suppression data from central heavy-ion…
We suggest the variation of charmonium suppression with Feynman x_F in heavy ion collisions as a novel and sensitive probe for the properties of the matter created in such reactions. In contrast to the proton-nucleus case where nuclear…
We consider the J/Psi production in proton (deuteron) -- nucleus collisions at high energies. We argue that the production mechanism in this case is different from that in pp collisions due to gluon saturation in the nucleus and formation…
Discussing the general case of a hard partonic production process, we show that the notion of parton energy loss is not always sufficient to fully address medium-induced gluon radiation. The broader notion of gluon radiation associated to a…
Measurements of J/$\psi$ production by the PHENIX experiment in p+p, d+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV are reviewed. The results show a suppression beyond what can be explained by cold nuclear matter effects in the…
We evaluate the nuclear suppression factor, $R_{AA}(p_T)$ for light hadrons by taking into account the collisional energy loss. We show that in the measured $p_T$ domain of RHIC the elastic process is the dominant mechanism for the partonic…
I review a number of topics where conventional wisdom in hadron physics has been challenged. For example, hadrons can be produced at large transverse momentum directly within a hard higher-twist QCD subprocess, rather than from jet…
We investigate the low transverse momentum heavy quarkonium ($J/\psi$, $\Upsilon$) productions in the forward rapidity region of $pp$ and $pA$ collisions at the LHC as an important probe to the transverse momentum tomography of the gluons…
Au+Au, $s^{1/2} = 200$ A GeV measurements at RHIC, obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors, have all indicated a suppression of neutral pion production, relative to an appropriately normalized NN level. For central…
We calculate nuclear suppression $R_{AA}$ of heavy quarks produced from the initial fusion of partons in nucleus-nucleus collisions at RHIC and LHC energies. We take the shadowing as well as the energy loss suffered by them while passing…
Hadron production and their suppression in Pb+Pb collisions at LHC at a center-of-mass energy of s_NN = 2.76 TeV are studied within a multiphase transport (AMPT) model whose initial conditions are obtained from the recently updated HIJING…
We calculate the nucleon and nuclear photoproduction cross sections for heavy quarks within the $k_{\perp}$-factorization formalism, considering the current high energy approaches which include nuclear and saturation effects. Our results…
We derive a quantum mechanical upper bound on the amount of radiative energy loss suffered by high energy quarks and gluons in nuclear matter. The bound shows that the nuclear suppression observed in quarkonium production at high $x_F$…
We calculate nuclear suppression factor ($R_{AA}$) for light hadrons by taking only the elastic processes and argue that in the measured $p_T$ domain of RHIC, collisional rather than the radiative processes is the dominant mechanism for…
We study the suppression of high-pT hadron spectra in nuclear collisions, supplementing the perturbative QCD factorized formalism with radiative parton energy loss. We find that the nuclear modification factor which quantifies the degree of…
I give a pedagogical survey of the nuclear collective effects associated with gluon saturation and their impact on particle production in high-energy proton (or deuteron)-nucleus collisions at RHIC. At central rapidity, the theory predicts…
Data on high-$p_T$ hadron production in heavy ion collisions at Feynman $x_F=0$ indicate at universality of the observed nuclear suppression. Our analysis of the production mechanisms demonstrates important role of the color transparency…
Parton propagation in dense nuclear matter results in elastic, inelastic and coherent multiple soft scattering with the in-medium color charges. Such scattering leads to calculable modifications of the hadron production cross section that…
Heavy quarkonia production is expected to be sensitive to the formation of a quark gluon plasma (QGP). It was (and still is with ongoing data analyses) extensively studied at the CERN SPS, at collision energy $\sqrt{s_{NN}}$ of the order of…