Related papers: Nuclear Dependence in Direct Photon Production
The production of hard photons in hadronic collisions is studied using Soft-Collinear Effective Theory (SCET). This is the first application of SCET to a physical, observable cross section involving energetic partons in more than two…
Light nuclei can be produced in the central reaction zone via coalescence in relativistic heavy ion collisions. E864 at BNL has measured the production of ten light nuclei with nuclear number of A=1 to A=7 at rapidity $y\simeq1.9$ and…
We present a systematic investigation of lepton pair production through photon-photon fusion processes in heavy-ion collisions. It is demonstrated that the dilepton production at a given impact parameter ($b_\perp$) with a fixed transverse…
We predict a strong enhancement of multijet production in proton-nucleus collisions at collider energies, as compared to a naive expectation of a cross section $\propto A$. The study of the process would allow to measure, for the first…
We update briefly our understanding of hadron production in relativistic nucleus-nucleus collisions in terms of statistical models with emphasis on the relation of the data to the QCD phase boundary and on a puzzle in the beam energy…
We report measurements of differential cross sections and decay asymmetries of incoherent $\phi$-meson photoproduction from the deuteron at forward angles using linearly polarized photons at \Eg=1.5-2.4 GeV. The nuclear transparency ratio…
A formalism for the electromagnetic production of hypernuclei is developed where the cross section is written as a contraction between a leptonic tensor and a hadronic tensor. The hadronic tensor is written in a model-independent way by…
Direct photons are an important tool for the detection of the quark-gluon plasma in ultra-relativistic nucleus-nucleus collisions. Direct-photon measurements were made in Pb+Pb collisions at sqrt{s_NN}=17.2 GeV and in Au+Au collisions at…
The invariant cross sections for direct photon production in hadron-hadron collisions are calculated for several initial energies (SPS, ISR, S$p \bar p$S, RHIC, Tevatron, LHC) including initial parton transverse momenta within the formalism…
We study the photoproduction of vector mesons off proton and off nuclear targets. We work within the colour dipole model in an approach that includes subnucleon degrees of freedom, so-called hot spots, whose positions in the…
Elastic virtual photoproduction of charmonia on nucleons is calculated in a parameter free way with the light-cone dipole formalism and the same input: factorization in impact parameters, light-cone wave functions for the photons and the…
We report on recent work concerning the phenomenology of initial-state parton-kt effects in direct-photon production and related processes in hadron collisions. After a brief summary of a kt-smearing model, we present a study of recent…
In a previous work, we studied the momentum fraction and hard--scale dependence of double parton scattering (DPS) in proton--proton collisions and the resulting dependence of the effective cross section on the final--state observables. In…
We re\,examine the theory of hadronic photon-nucleon interactions at the quark-gluon level. The possibility of multiple parton collisions in a single photon-nucleon collision requires an eikonal treatment of the high-energy scattering…
Define the nuclear dependence coefficient $\alpha(A,q_T)$ in terms of ratio of transverse momentum spectrum in hadron-nucleus and in hadron-nucleon collisions: $\frac{d\sigma^{hA}}{dq_T^2}/ \frac{d\sigma^{hN}}{dq_T^2}\equiv…
We discuss the nuclear dependence of $\psi$ and $\psi'$ production in hadron-nucleus interactions as a function of longitudinal momentum fraction $x_F$. Nuclear effects such as final-state absorption, interactions with comovers, shadowing…
Changes of hadronic properties in dense nuclear matter as predicted by theory have usually been investigated by means of relativistic heavy-ion reactions. In this talk I show that observable consequences of such changes can also be seen in…
Changes of hadronic properties in dense nuclear matter as predicted by theory have usually been investigated by means of relativistic heavy-ion reactions. In this talk I show that observable consequences of such changes can also be seen in…
We study in detail the influence of the nuclear form factor both on the Born cross section and on the Coulomb corrections to the photo-production of muon pairs off heavy nuclei (gamma Z -> mu+ mu- Z$) and in heavy-ion collisions (ZZ -> ZZ…
We present a study of inclusive direct-photon and pion production in hadronic interactions, focusing on a comparison of the ratio of gamma/pi0 yields with expectations from next-to-leading order perturbative QCD (NLO pQCD). We also examine…