Related papers: Measuring initial temperature through photon to di…
The squared momentum transfer spectra of $\eta$ and $\eta ^0$, produced in high-energy photon-proton ($\gamma p$) $\rightarrow \eta(\eta^0)+p$ processes in electron-proton ($ep$) collisions performed at CEBAF, NINA, CEA, SLAC, DESY, and WLS…
We have studied transverse momentum ($p_{\rm{T}}$) spectra of charged hadrons in various pseudo-rapidity ranges for p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV. The medium effects such as collective flow and energy loss resulting…
We employ a hybrid approach to describe the light nuclei production mechanism where the nucleons are assumed to be thermally produced, and are allowed to form light nuclei using a coalescence prescription. In this approach, we first fit…
In this note, we discuss the derivation of a formula that has been used in the literature in order to compute the number of photons emitted by a hot or dense system during a finite time. Our derivation is based on a variation of the…
We study the production of photons and dileptons during the pre-equilibrium Glasma stage in heavy ion collisions and discuss the implications in light of the PHENIX data. We find that the measured distributions of such electromagnetic…
We discuss the transverse momentum distribution of thermal and prompt photons in ultrarelativistic heavy ion collisions. The prompt photons are mostly produced by fragmentation of quark jets (bremsstrahlung). If these quark jets suffer a…
The photon-photon interaction in ultra-relativistic heavy-ion collision is a source of the $(e^+,e^-)$ pairs. The photon-photon fusion leads the lepton creation in the broad configuration space around "collision" point. Those created close…
It is believed that a novel state of matter - Quark Gluon Plasma (QGP) will be transiently produced if normal hadronic matter is subjected to sufficiently high temperature and/or density. We have investigated the possibility of QGP…
Electromagnetic probes are excellent messengers from the hot and dense medium created in high-energy heavy-ion collisions. Since leptons do not interact strongly, their spectra reflect the entire space-time evolution of the collision. The…
The transverse momentum (pt) dependence, the centrality dependence and the rapidity dependence of the elliptic flow of thermal photons in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV are predicted, based on a three-dimensional ideal…
Transverse-momentum spectra in hard processes are typically described either in terms of intrinsic transverse momentum of partons, or in terms of perturbative radiation. The relation between these descriptions is discussed for the example…
Thermal radiation of photons and dileptons from hadronic matter plays an essential role in understanding electromagnetic emission spectra in high-energy heavy-ion collisions. In particular, baryons and anti-baryons have been found to be…
The current status of evaluating thermal production of lepton pairs in high-energy collisions of heavy nuclei is discussed. After a brief survey of emission rates from hot and dense matter, we address applications to (and interpretations…
By photo-transmutation of leptons we mean photon-lepton reactions of the following type: $\gamma l_\alpha \longrightarrow \gamma l_\beta$ with $l_\alpha \neq l_\beta$, occurring as a consequence of the lepton mass matrix changing its…
This contribution summarizes the main experimental results presented at the 2009 Quark Matter conference concerning single and dilepton production in proton and heavy ion collisions at high energy. The dilepton invariant mass spectrum has…
A brief overview of direct-photon measurements in ultra-relativistic nucleus-nucleus collisions is given. The results for Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV and for Au+Au collisions at sqrt{s_NN} = 200 GeV are compared to estimates…
Aspects of the dilepton spectrum in heavy-ion collisions are discussed, with special emphasis on using lattice computations to guide the phenomenology of finite temperature hadronic matter. The background rates for continuum dileptons…
We introduce a general expression which enables the parton distribution, unintegrated over the parton transverse momentum, to be obtained from the conventional parton densities. We use the formalism to study the effects of the transverse…
We compare the predictions of different models for transverse momentum spectra in relativistic heavy ion collisions. Particular emphasis is given to hydrodynamic flow with different assumptions for the radial expansion, and to models based…
The production rate of soft real photons or soft lepton pairs by a hot QCD plasma is dominated by strong collinear divergences. As a consequence, it appears that the effective theory based on the resummation of hard thermal loops fails to…