Related papers: Azimuthal Correlations in Photon-Photon Collisions
We calculate the probability for dilepton production in central relativistic heavy ion collisions due to the gamma-gamma mechanism. This is a potential background to more interesting mechanisms. We find that this mechanism is negligible in…
Relationships are obtained connecting the two-nucleon overlap function of the eigenstates in the (A-2) particle system with the asymptotic behavior of the two-body density matrix for the ground state of the A-particle system.This makes it…
We compute cross sections for events where two pairs of partons scatter off each other in the same $\gamma\gamma$ reaction, giving rise to at least 3 high--{\mbox{$p_T^{}$}} jets. Unlike in {\mbox{$p \bar p$}}\ collisions we find the signal…
We propose a scenario where the pattern of the recently observed charge-dependent azimuthal correlations can be understood qualitatively. This is based on the cluster picture and the assumption that the charged hadrons that flow outward…
The double-polarization observable $E$ and helicity-dependent cross sections $\sigma_{1/2}$, $\sigma_{3/2}$ have been measured for the photoproduction of $\pi^0$ pairs off quasi-free protons and neutrons at the Mainz MAMI accelerator with…
Light-by-light scattering sumrules based on general field theory principles relate cross-sections with different helicities. In this paper the simplest sumrule is tested for the $I=0$ and $2$ channels for "real" photon-photon collisions.…
Methodology is presented for analysis of two-particle azimuthal angle correlation functions obtained in collisions at ultra-relativistic energies. We show that harmonic and di-jet contributions to these correlation functions can be reliably…
The azimuthal correlations of direct photons ($\gamma_{_{dir}}$) with high transverse momentum ($p_{_{T}}$), produced at mid-rapidity ($|\eta^{\gamma_{_{dir}}}|<1$) in Au+Au collisions at center-of-mass energy $\sqrt{s_{_{NN}}}=200$~GeV,…
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an electron-electron or…
Using a generating-function formalism, we compute the contribution of momentum conservation to multiparticle correlations between the emitted particles in high-energy collisions. In particular, we derive a compact expression of the genuine…
Recent results at STAR for direct $\gamma$-charged hadron azimuthal correlations in heavy-ion collisions are presented. These correlations are used to study the color charge density of the medium through the medium-induced modification of…
We demonstrate that the striking systematics of two-particle azimuthal Fourier harmonics $v_2$ and $v_3$ in ultrarelativistic collisions of protons, deuterons and helium-3 ions off gold nuclei measured by the PHENIX Collaboration…
The measurement of azimuthal distributions in nucleus-nucleus collisions relies upon the assumption that azimuthal correlations between particles result solely from their correlation with the reaction plane (i.e. flow). We show that at SPS…
Two-pion correlation functions, measured as a function of azimuthal emission angle with respect to the reaction plane, provide novel information on the anisotropic shape and orientation of the pion-emitting zone formed in heavy ion…
We review recent theoretical progress in describing collective effects in photon+nucleus collisions. The approaches considered range from the color glass condensate where correlations are encoded in the initial state, to hydrodynamic…
We develop a Hamiltonian formalism to study energy and position/momentum correlations between a single Stokes photon and a single material excitation that are created as a pair in the spontaneous Raman scattering process. Our approach…
We discuss the reaction $e p \to e \tilde{p} X$ in the one-photon exchange approximation, where it is in essence the reaction $\gamma^{*} p \to \tilde{p} X$. A large rapidity gap is required between the particle or particles of the proton…
We calculate total and differential cross sections for $J/\psi$ photoproduction in ultrarelativistic lead-lead collisions at the LHC energy $\sqrt{s_{NN}}=2.76$ TeV. We use a simple model based on vector dominance picture and multiple…
Spatially entangled twin photons allow the study of high-dimensional entanglement, and the Laguerre-Gauss modes are the most commonly used basis to discretize the single photon mode spaces. In this basis, to date only the azimuthal degree…
A method is suggested to deduce the anisotropy in neutral pions by measuring the azimuthal anisotropy of photons in ultra-relativistic nuclear collisions. The ratio of the estimated anisotropy in photons to the anisotropy in neutral pions…