Related papers: K+K- photoproduction in ultra$-$peripheral Pb$--$P…
The production of charged kaon pairs in ultraperipheral heavy-ion collisions can proceed via photoproduction (gamma-Pomeron interaction) or via photon-photon fusion. An important contribution to this process arises from the decays of…
K$^{+}$K$^{-}$ pairs may be produced in photonuclear collisions, either from the decays of photoproduced $\phi (1020)$ mesons, or directly as non-resonant K$^{+}$K$^{-}$ pairs. Measurements of K$^{+}$K$^{-}$ photoproduction probe the…
Ultra-peripheral collisions (UPC) of heavy-ions involve long range electromagnetic interactions at impact parameters twice larger than the nuclear radius, where no nucleon-nucleon collisions occur. The first measurement of photoproduction…
Ultra-peripheral Pb-Pb collisions, in which the two nuclei pass close to each other, but at an impact parameter greater than the sum of their radii, provide information about the initial state of nuclei. In particular, heavy vector meson…
Ultra-peripheral collisions (UPC) occur when the interacting nuclei or protons have an impact parameter larger than the sum of their radii. They are mediated by virtual photon exchange. The photoproduction of heavy vector mesons is…
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 $x$.…
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…
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…
Photoproduction in ultra-peripheral relativistic heavy-ion collisions displays many unique features, often involving quantum mechanical coherence and two-source interference between photon emission from the two ions. We review the recent…
Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study $\gamma$-nucleus and $\gamma$-proton interactions at the LHC in the so called ultra-peripheral collisions (UPC). Here we report ALICE…
In relativistic heavy ion collisions, top quarks can be produced by photon-gluon fusion when a photon from the Weizs\"acker-Williams virtual photon field of one nucleus interacts with a gluon in the other nucleus. Photoproduction with heavy…
The strong electromagnetic fields present in ultra-peripheral collisions of heavy-ions offer a possibility to study two-photon and photonuclear collisions complementary to similar studies with lepton beams but over an increased photon…
The LHC is not only the highest energy collider for protons and heavy ions, but also for photon photon and photon hadron ($\gamma$p and $\gamma$Pb) interactions. This is because the protons and ions accelerated in the LHC carry an…
The intense photon fluxes of relativistic nuclei provide a possibility to study photonuclear and two-photon interactions in ultra-peripheral collisions (UPC) where the nuclei do not overlap and no strong nuclear interactions occur. 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…
Heavy quarks are copiously produced in ultra-peripheral heavy ion collisions. In the strong electromagnetic fields, c c-bar and b b-bar are produced by photonuclear and two-photon interactions; hadroproduction can occur in grazing…
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…
We present a summary of recent photoproduction results in ultra peripheral relativistic heavy ions collisions with STAR. These collisions have impact parameters larger then twice the nuclear radius; the nuclei do not physically collide, but…
High energy ultra-peripheral collisions (UPC) of heavy-ions generate strong electromagnetic fields which open the possibility to study gamma-gamma and gamma-nucleus processes in a kinematic regime so far unexplored. We report on preliminary…
Photoproduction of heavy quarks in ultraperipheral collisions can help elucidate important features of the physics of heavy quarks in Quantum Chromodynamics (QCD). Due to the dependence on parton distributions it can also potentially offer…