Related papers: Low-mass dileptons at the SPS
We analyze dilepton emission from hot and dense matter using a hybrid approach based on the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport model with an intermediate hydrodynamic stage for the description of heavy-ion…
A detailed analysis of transverse momentum spectra of several identified hadrons in high energy collisions within the canonical framework of the statistical model of hadronisation is performed. The study of particle momentum spectra…
The dilepton production in elementary ${pp\to e^{+}e^{-}X}$ reactions at BEVALAC energies $T_{lab}=1\div 5$ GeV is investigated. The calculations include direct ${e^{+}e^{-}}$ decays of the vector mesons $\rho ^{0}$, $\omega $, and $\phi $,…
The dilepton emission in heavy-ion reactions at low beam energies is examined within a hadronic transport approach. In this article the production of electron-positron pairs from a new approach named SMASH (Simulating Many Accelerated…
A measurement is presented of the exclusive and semi-exclusive production of charged pion pairs in proton-proton collisions, pp to p(p*) + $\pi^+\pi^-$ + p(p*) here the $\pi^+\pi^-$ pair is emitted at central rapidities, and the scattered…
The production of D*+-(2010) mesons in ep scattering in the range of exchanged photon virtuality 0.05 < Q^2 < 0.7 GeV^2 has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The decay channels D*+ -> D0…
Quarkonium production in proton-proton collision is interesting in profiling the partons inside the nucleon. Recently, the impact of double parton scatterings (DPSs) was suggested by experimental data of associated quarkonium production…
The dilepton transverse momentum spectra and invariant mass spectra for low $p_T <0.15$~GeV/c in Au+Au collisions of different centralities at $\sqrt{s_{NN}}$ = 200 GeV are studied within the parton-hadron-string dynamics (PHSD) transport…
We consider the reaction (gamma p) to (pi+ pi- p) at high energies. Our description includes dipion production via the resonances rho, omega, rho-prime and f2, and via non-resonant mechanisms. The calculation is based on a model of high…
We point out that formation time of pions produced in heavy ion collisions modifies the mass spectrum of dileptons produced via pipi -> ee annihilation. Increasing formation time enhances the production of dileptons with lower masses. The…
We discuss the exclusive photoproduction of $\pi^{+}\pi^{-}$ pairs in photon-proton and in proton-proton collisions at high energies. The $\rho^{0}$, $\omega$, $f_{2}(1270)$, and non-resonant (Drell-S\"oding) contributions are considered.…
Electro-magnetic probes such as dileptons and photons are strong probes to investigate the thermodynamical state of the early stages of collisions since they leave the system unscathed. The PHENIX experiment has measured both photons and…
Recently, significant enhancements of $e^{+} e^{-}$ pair production at very low transverse momentum ($p_{T} < 0.15$ GeV/c) were observed by the STAR collaboration in peripheral hadronic A+A collisions. This excesses can not be described by…
We present the status of the description of hadron production in central nucleus-nucleus collisions within the statistical model . Extending previous studies by inclusion of very high-mass resonances (m>2 GeV), and the up-to-now neglected…
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured single electrons at midrapidity and single muons at forward and backward rapidities (1.2<|y|< 2.2) for p+p and d+Au collisions at sqrt(sNN)=200 GeV. The inclusive…
Precise knowledge of hadron production rates in the generation of neutrino beams is necessary for accelerator-based neutrino experiments to achieve their physics goals. NA61/SHINE, a large-acceptance hadron spectrometer, has recorded…
We report on the first measurements of J/$\psi$ production at very low transverse momentum ($p_{T} <$ 0.2 GeV/c) in hadronic Au+Au collisions at $\sqrt{s_{\rm{NN}}} =$ 200 GeV and U+U collisions at $\sqrt{s_{\rm{NN}}} =$ 193 GeV.…
The $\pi^-p \to e^+e^- n$ and $\pi^+n \to e^+e^- p$ reaction cross sections are calculated below and in the vicinity of the vector meson ($\rho^0$, $\omega$) production threshold. These processes are largely responsible for the emission of…
The inclusive production of charged hadrons in the collisions of quasi-real photons e+e- -> e+e- +X has been measured using the OPAL detector at LEP. The data were taken at e+e- centre-of-mass energies from 183 to 209 GeV. The differential…
Rho meson propagation in hot hadronic matter is studied in a model with coupling to $\pi\pi$ states. Medium modifications are induced by a change of the pion dispersion relation through collisions with nucleons and $\Delta's$ in the…