Related papers: Ultra-peripheral Au+Au collisions at PHENIX
We present recent STAR results on photoproduction in ultra-peripheral relativistic heavy ion collisions. In these collisions the impact parameter of the beam particles is larger than the sum of their nuclear radii, so that they interact via…
Measurements of exclusive $J/\psi$, $\psi(2s)$, and electron-positron ($e^{+}e^{-}$) pair photoproduction in Au$+$Au ultra-peripheral collisions are reported by the STAR experiment at $\sqrt{s_{_\mathrm{NN}}}=200~\rm{GeV}$. We report…
Large-distance ultraperipheral collisions of two relativistic ions are considered. The clouds of photons surrounding the ions are responsible for their distant electromagnetic interaction. The perturbative approach and the method of…
We report on our recent investigations in photonuclear production of heavy quarks and vector meson in ultraperipheral heavy ion collisions. In particular, our theoretical predictions are compared with the recent experimental measurements on…
The Lorentz-contracted electromagnetic fields of the ions in ultra-relativistic heavy-ion collisions generate intense quasi-real photon fluxes. These lead to photon-induced interactions that are observed in ultra-peripheral collisions…
Ultraperipheral collisions at heavy ion colliders use the strong Coulomb fields surrounding the ions to study photon-photon and photon-hadron processes at high energy. A number of processes of interest are discussed here.
Ultra-peripheral collisions (UPCs) of relativistic ions are an important tool for studying photoproduction at high energies. Vector meson photoproduction is an important tool for nuclear structure measurements and other applications. A…
PHENIX has measured $\Upsilon$ production in p+p, d+Au and Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV. A baseline cross-section measurement has been made in p+p collisions. Preliminary studies of d+Au collisions found no suppression in the…
As predicted by theory and confirmed by measurements, one, two or three neutrons are emitted frequently in ultraperipheral collisions (UPCs) of heavy relativistic nuclei, in particular, $^{208}$Pb. The exchange of low-energy…
We present a theoretical investigation of photonuclear tomography as a novel technique for probing the internal structure of nuclei. In this approach, ultraperipheral heavy-ion collisions (UPCs) serve as a source of intense fluxes of…
A comprehensive analysis of the photoproduction of $J/\Psi$ and $\Upsilon$ mesons in peripheral $PbPb$ collisions at the center - of - mass energies of the Large Hadron Collider (LHC) is performed, considering distinct assumptions for the…
We have investigated light nuclei pair photoproduction in relativistic heavy ion ultraperipheral collisions. As a first attempt, we employ our previously developed quantum electrodynamics model, which incorporates a wave-packet description…
High energy photons originating from the electromagnetic field of ultrarelativistic lead nuclei can interact with the other lead ion. These reactions are studied in the ultra-peripheral heavy ion collisions to probe the physics of strong…
Results from the PHENIX experiment at RHIC on direct photon production in p+p, d+Au, and Au+Au collisions at sqrt(s_NN) = 200 GeV are presented. In p+p collisions, direct photon production at high p_T behaves as expected from perturbative…
The ultraperipheral collisions are the source of various interesting phenomena based on photon-induced reactions. We calculate cross sections for single and any number of n, p, $\alpha$, $\gamma$-rays in ultraperipheral heavy-ion collision…
We report a measurement of exclusive $J/\psi$ photoproduction in Au$+$Au ultra-peripheral collisions at $\sqrt{s_{_\mathrm{NN}}}=200$ GeV using the STAR detector. For the first time, i) the rapidity correlation between $J/\psi$…
The production of mesons in ultra-peripheral collisions of relativistic heavy ions is re-analyzed using a projection technique to calculate the amplitudes for the appropriate Feynman diagrams. The virtuality of the exchanged photons is…
Vector mesons are copiously produced in ultra-peripheral nucleus-nucleus collisions. In these collisions, the nuclei are separated by impact parameters larger than the sum of the nuclear radii, and the interaction is mediated by the…
Ultra-peripheral collisions (UPCs) have been a significant source of study at RHIC and the LHC. In these collisions, the two colliding nuclei interact electromagnetically, via two-photon or photonuclear interactions, but not hadronically;…
The ultrarelativistic collisions of heavy ions provide rich spectrum of possibilities to discuss the response of the nucleus to photons. Newly published neutron and proton multiplicities measured in the ALICE experiment in ultraperipheral…