Related papers: Photons, dileptons and hard thermal loops
Both hot QCD matter and extremely strong electromagnetic fields are generated in relativistic heavy-ion collisions. We employ the transport model and the equivalent photon approximation (EPA) to study charmonium hadroproduction and…
The intensive synchrotron radiation resulting from quarks interacting with the collective confining color field in relativistic heavy ion collisions is discussed. The spectrum of photons with large transverse momentum is calculated and…
The experimental and phenomenological status of high energy photoproduction is reviewed. Topics covered include the structure of the photon, production of jets, heavy flavours and prompt photons, rapidity gaps, energy flow and underlying…
The hadroproduction of lepton pairs with mass $Q$ and transverse momentum $Q_T$ can be described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton…
The ratio of transverse momentum distribution of thermal photons to dilepton has been evaluated. It is observed that this ratio reaches a plateau beyond a certain value of transverse momentum. We argue that this ratio can be used to…
We discuss the production of soft photons in high energy hadron-hadron collisions. We present a model where quarks and antiquarks in the hadrons emit ``synchrotron light'' when being deflected by the chromomagnetic fields of the QCD vacuum,…
Interactions between charge carriers in graphene lead to logarithmic renormalization of observables mimicking the behavior known in (3+1)-dimensional quantum electrodynamics (QED). Here we analyze soft electron-hole (e-h) excitations…
Exclusive and semi-exclusive processes, the diffractive dissociation of hadrons into jets, and hard diffractive processes such as vector meson leptoproduction provide new testing grounds for QCD and essential information on the structure of…
One of the outstanding problems in J/\psi physics is a systematic understanding of the differential photo-production cross section dsigma/dz(gamma + p -> J/psi + X), where z= E_psi/E_gamma in the proton rest frame. The theoretical…
We calculate a novel "magnetic contribution" to the dilepton spectrum in heavy-ion collisions arising from interaction of relativistic quarks with intense magnetic field. Synchrotron radiation by quarks, which can be approximated by the…
The thermal model properly describes the production yields of light nuclei in relativistic heavy-ion collisions even so the loosely bound sizable nuclei cannot exist in the dense and hot hadron gas at a chemical freeze-out. Within the…
We investigate different methods to incorporate the effect of photons in hard processes. We compare two different approaches used for calculating cross sections for two-photon $p p \to l^+ l^- X$ process. In one of the approaches photon is…
Elliptic flow of direct photons in high-energy heavy ion collisions has been a topic of great interest as it is experimentally found larger than most hydrodynamic expectations. I discuss the implication of possible late formation of quark…
We calculate the production of dileptons and photons in the presence of a nontrivial Polyakov loop in QCD. This is applicable to the semi-Quark Gluon Plasma (QGP), at temperatures above but near the critical temperature for deconfinement.…
Relativistic heavy ions are sources of strong electromagnetic fields which produce photon-induced interactions. These interactions are usually studied in ultra-peripheral collisions (UPCs) of the relativistic heavy ions. The UPCs can…
Coherent photoproduction of heavy quarkonia on nuclear targets is studied within the QCD color dipole formalism including several main phenomena: i) The correlation between impact parameter of a collision $\vec b$ and dipole orientation…
The generating functional for hard thermal loops in QCD is important in setting up a resummed perturbation theory. I review how this functional is related to the eikonal for a Chern-Simons theory, and using an auxiliary field, to the gauged…
The dilepton production rate in hot QCD medium is studied within a effective description of the medium in the presence of magnetic field. This could be done by obtaining the one-loop self energy of photon due to the effective (quasi-) quark…
In view of possible photoproduction studies in ultraperipheral heavy-ion collisions at the LHC, we briefly review the present theoretical understanding of photons and hard photoproduction processes at HERA, discussing the production of…
We investigate whether the soft mode that becomes massless at the QCD critical point (CP) causes an enhancement of the dilepton production rate (DPR) and the electric conductivity around the CP through the modification of the photon…