相关论文: Ultra-peripheral heavy ion collisions at STAR
At the initial stage of nuclear-nuclear collisions, heavy quarks are generated in hard partonic scatterings. This allows them to participate in the entire evolution of the heavy-ion collisions. During hadronization, different type of…
We argue that the STAR data on $J/\psi$ photoproduction in $d+Au$ ultraperipheral collisions (UPCs) at the momentum transfer $t \neq 0$ primarily probes elastic and possibly nucleon-dissociative $J/\psi$ photoproduction on quasi-free…
The strong electromagnetic fields of short duration associated with relativistic heavy ions make a heavy-ion collider a unique tool to study two-photon and photonuclear collisions. In this talk, we introduce the principles of…
During the 2008 run the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven Nation Laboratiory (BNL), NY, provided high luminosity in both p+p and d+Au collisions at $\sqrt{s_{NN}}=200\mathrm{\,GeV}$. Electromagnetic calorimeter…
The exclusive $\Upsilon$ photoproduction in ultraperipheral proton-nucleus and nucleus-nucleus collisions at LHC energies is being investigated using pQCD framework which constrain the gluon distribution in the proton and nuclei at low $x$.…
The isospin- and momentum-dependent MDI interaction, which has been extensively used in intermediate-energy heavy-ion reactions to study the properties of asymmetric nuclear matter, is extended to include the nucleon-hyperon and…
In this talk, I discuss some recent results obtained in Heavy Ion Collisions and what they tell us -- or what questions they raise -- about the physics of the system of quarks and gluons formed in these collisions.
We review the production of lepton pairs during high energy nuclear collisions. We highlight the information being carried out of the hot and dense strongly interacting medium. We describe the phenomenon of scalar-vector mixing that can…
We propose to measure the linear polarization of the external electromagnetic fields of a relativistic heavy ion through azimuthal asymmetries in dilepton production in ultraperipheral collisions. The asymmetries estimated with the…
We present full (3+1)D dynamical simulations to study collective behavior in ultra-peripheral nucleus-nucleus collisions (UPC) at the Large Hadron Collider (LHC) with the 3DGlauber+MUSIC+UrQMD framework. By extrapolating from asymmetric…
Results are presented of an ongoing analysis of direct photon production in s_(NN)=200GeV deuteron-gold collisions with the STAR experiment at RHIC. A significant excess of direct photons is observed near mid-rapidity 0<y<1 and found to be…
We use a Glauber-like approach to describe very energetic nucleus-nucleus collisions as a sequence of binary nucleon-nucleon collisions. No free parameters are needed: all the information comes from simple parametrizations of…
We show that introducing subnucleon scale fluctuations constrained by HERA diffractive $J/\Psi$ production data significantly affects the incoherent diffractive $J/\Psi$ production cross section in ultraperipheral heavy ion collisions. We…
We investigate proton-antiproton ($p\bar{p}$) pair production via photon-photon fusion in the ultra-peripheral collisions at RHIC, employing a joint impact parameter and transverse momentum dependent formalism. We consider proton exchange,…
Simple geometrical considerations show that the collision zone in high energy nuclear collisions may be divided into a central part (``core''), with high energy densities, and a peripheral part (``corona''), with smaller energy densities,…
A detailed understanding of complete fusion cross sections in heavy-ion collisions requires a consideration of the effects of the deformation of the projectile and target. Our aim here is to show that deformation and orientation of the…
Two-photon processes in relativistic heavy-ion collisions have emerged as a critical probe of quantum electrodynamics in ultra-intense electromagnetic fields, with recent focus extending beyond dileptons to hadronic final states. At…
We consider trasfer-ionization in collisions of fast (3.6 -- 11 MeV/u) protons, alpha-particles and lithium nuclei with helium atoms. There are just a few basic mechanisms contributing to this process which can be grouped into correlated…
In ultra-peripheral collisions (UPCs) of relativistic heavy ions, photoproduction occurs when a photon emitted from one nucleus interacts with the other nucleus from the opposing beam, producing particles in the final state. Measurements of…
The STAR collaboration has observed an excess production of $e^+e^-$ pairs in relativistic heavy ion collisions, over the expectations from hadronic production models. The excess pairs have transverse momenta $p_T < 150\ {\rm MeV}/c$ and…