Related papers: A new gamma*-p / pbar-p factorization test in diff…
In this Letter, we consider strong and electromagnetic (ultraperipheral) mechanisms in proton-nucleus coherent diffraction at the CERN Large Hadron Collider. We explicitly demonstrate the dominance of the latter and explain the CMS data on…
It is argued that the breakdown of factorization observed recently in the diffractive dijet production in deep inelastic lepton induced and hadron induced processes is naturally explained in the Good-Walker picture of diffraction…
Recent experimental results on the Lambda_c/D^0 ratio in proton-proton collisions have revealed a significant enhancement compared to expectations based on universal fragmentation fractions/functions across different colliding systems, from…
A new effort to explore the diffractive regime in polarized $p+p$ collisions in a broad high energy range ($\sqrt{s}$ = 200 - 500 GeV) has been initiated with the STAR detector at RHIC. Staged implementation of multiple Roman Pot stations…
There is a significant discrepancy between the values of the proton electric form factor, $G_E^p$, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can…
In this paper we develop a QCD motivated model for both hard and soft interactions at high energies. In this model the long distance behavior of the scattering amplitude is determined by the approximate solution to the non-linear evolution…
The factorization of short-distance partonic cross-sections from universal long-distance kinematic distributions is fundamental to phenomenology at hadron colliders. It has been predicted however that observables sensitive to momenta…
New predictions regarding the role of color flow in high energy Quantum Chromodynamics (QCD) processes have emerged in the last decade. In particular, the role of color flow is now being explored through many different observables; one such…
The meson-photon transition form factors $\gamma\gamma^*\to P$ ($P$ stands for $\pi$, $\eta$ and $\eta'$) provide strong constraints on the distribution amplitudes of the pseudoscalar mesons. In this paper, these transition form factors are…
We present a new measurement of the Z/gamma* transverse momentum distribution in the range 0 - 330GeV, in proton-antiproton collisions at sqrt{s}=1.96 TeV. The measurement uses 0.97 fb-1 of integrated luminosity recorded by the D0…
Factorization underlies all predictions at the Large Hadron Collider, but has only been rigorously proven in a few cases. One of these cases is the Drell-Yan process, $pp \to Z/\gamma + X$, in the limit of small boson transverse momentum.…
The search for remnants of the QCD chiral critical point is a central objective of current and future high-energy ion collision experiments. Previous studies suggest that a scaling law relating higher-order factorial moments of hadron…
Factorization violating effects in hadron scattering are due mainly to spectator-spectator interactions. While it is known that these interactions cancel in inclusive cross sections, like for the Drell-Yan process, not much is known about…
We propose a new formula for extracting the polarized gluon distribution $\Delta g$ in the proton from the large--$p_T$ light hadron pair production in deep inelastic semi-inclusive reactions. Though the process dominantly occurs via…
Background: Heavy-flavor production in p+p collisions tests perturbative-quantum-chromodynamics (pQCD) calculations. Modification of heavy-flavor production in heavy-ion collisions relative to binary-collision scaling from p+p results,…
We study coherent and incoherent diffractive hadron production in high energy quarkonium--heavy nucleus collisions as a probe of the gluon saturation regime of QCD. Taking this process as a model for pA collisions, we argue that the…
The contribution of the box and crossed two-pion-exchange diagrams to proton-proton scattering at 90$^{\circ}_{c.m.}$ is calculated in the laboratory momentum range up to 12 GeV/c. Relativistic form factors related to the nucleon and pion…
Hadron pair production gamma* gamma -> h hbar in the region where the c.m. energy is much smaller than the photon virtuality can be described in a factorized form, as the convolution of a partonic handbag diagram and generalized…
The PHENIX experiment presents results from the RHIC 2005 run with polarized proton collisions at sqrt(s)=200 GeV, for inclusive \pi^0 production at mid-rapidity. Unpolarized cross section results are given for transverse momenta p_T=0.5 to…
We report a measurement of the fraction of events with a large pseudorapidity gap $\Delta\eta$ within the pseudorapidity region available to the proton dissociation products $X$ in $\bar p+p\to \bar p+X$. For a final state $\bar p$ of…