Related papers: Thermal Radiation from Nucleons and Mesons
The production of the light vector mesons $V = \rho, \omega, \phi$ in the reactions $\pi N \to V N$ and $N N \to V N N$ near threshold is studied. The subsequent electromagnetic decay $V \to \gamma^* \to e^+ e^-$ is particularly suited for…
Various mechanisms of thermal photon production are reviewed and their implications for heavy ion collisions are briefly sketched.
Today's accelerator facilities used for studies of relativistic heavy-ion collisions cover an energy range spanning over three orders of magnitude, from a few GeV up to a few TeV in center-of-mass energy per nucleon pair ($\sqrt{s_{NN}}$).…
We provide a method to test if hadrons produced in high energy heavy ion collisions were emitted at freeze-out from an equilibrium hadron gas. Our considerations are based on an ideal gas at fixed temperature $T_f$, baryon number density…
An extension of the QED 'return to resonance' mechanism to light meson emission ($\pi$, $\rho$) in (anti)proton collisions with a hadronic target (nucleon or nucleus) is proposed. The cross section and the multiplicity distributions are…
The recently discovered sharp peak in the K+/pi+ ratio in relativistic heavy-ion collisions is discussed in the framework of the thermal model. In this model a rapid change is expected as the hadronic gas undergoes a transition from a…
The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158 AGeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse…
The production of $\eta$ and $\eta^\prime$ mesons in photon- and hadron-induced reactions are studied in a combined analysis based on an effective Lagrangian approach in order to learn about the relevant production mechanisms and the…
Ultrarelativistic collisions of large nuclei produce a short-lived plasma of deconfined quarks and gluons. Of all the GeV-energy photons detected in these nuclear collisions, only a small number are emitted directly by the quark-gluon…
We calculate the axion emission rate from reactions involving thermal pions in matter encountered in supernovae and neutron star mergers, identify unique spectral features, and explore their implications for astrophysics and particle…
The indirect ground-based observations of cosmic rays through extensive air showers in modern experiments typically involve the use of Monte Carlo simulations to determine the characteristics of the primary particles. These simulations…
The vacuum polarisation effects from the nucleon sector lead to large medium modifications of the vector meson masses in the Walecka model. With a quantum hadrodynamic framework including the quantum effects, and using a quasiparticle…
Temperature dependence of hadronic decay widths and masses are studied within the framework of an effective Lagrangian approach. At finite temperature the hadronic masses do not seem to follow a universal scaling law. Considering an…
Radiative emission of neutrino pair (RENP) from atomic states is a new tool to experimentally investigate undetermined neutrino parameters such as the smallest neutrino mass, the nature of neutrino masses (Majorana vs Dirac), and their CP…
The $e^+e^-$ invariant mass distribution spectra are calculated to estimate the hadron parameters of the $\rho$ meson produced coherently in the photonuclear reaction. The elementary reaction occurring in the nucleus is considered to…
The cosmic background neutrino of temperature 1.9 K affects rates of radiative emission of neutrino pair (RENP) from metastable excited atoms, since its presence blocks the pair emission by the Pauli exclusion principle. We quantitatively…
The emission of direct (hard and thermal) photons from nucleon-nucleon Bremsstrahlung in heavy-ion collisions at Fermi energies is analyzed. We utilize a photon emission rate based on a quantum-field-theoretical model together with nucleon…
We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schrodinger…
We use quasiparticle description of deconfined matter in nuclear collisions at finite temperature and chemical potential. We assume that evolution of expanding system is isentropic. Using theoretical formulas and experimental meaning for…
The effect of the heating of neutrinos by scattering with electrons and positrons and by e-e+ annihilation on nucleosynthesis is calculated for a spherically symmetric baryon inhomogeneous model of the universe. The model has a high baryon…