Dilepton radiation at the CERN super-proton synchrotron
152 citations recorded by the source corpus.
Abstract A quantitative evaluation of dilepton sources in heavy-ion reactions is performed taking into account both thermal and non-thermal production mechanisms. The hadronic thermal emission rate is based on an electromagnetic current-correlation function with a low-mass region (LMR, M ≲ 1 GeV ) dominated by vector mesons ( ρ , ω , ϕ ) and an intermediate-mass region (IMR, 1 GeV ⩽ M ⩽ 3 GeV ) characterized by (the onset of) a multi-meson continuum. A convolution of the emission rates over a thermal fireball expansion results in good agreement with experiment in the low-mass spectra, confirming the predicted broadening of the ρ meson in hadronic matter in connection with the prevalence of baryon-induced medium effects. The absolute magnitude of the LMR excess is mostly controlled by the fireball lifetime, which in turn leads to a consistent explanation of the dilepton excess in the IMR in terms of thermal radiation. The analysis of experimental transverse-momentum ( q T ) spectra reveals discrepancies with thermal emission for q T ≳ 1 GeV in non-central In–In collisions, which we address by extending our calculations by: (i) a refined treatment of ρ decays at thermal freeze-out, (ii) primordially produced ρ 's subject to energy-loss, (iii) Drell–Yan annihilation, and (iv) thermal radiation from t -channel meson exchange processes. We investigate the sensitivity of dilepton spectra to the critical temperature and hadro-chemical freeze-out of the fireball. The ρ broadening in the LMR turns out to be robust, while in the IMR Quark–Gluon Plasma radiation is moderate unless the critical temperature is rather low.
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/b8695edfaa49fafa58166c3c62915ac97ef11f71
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Nuclear and High Energy Physics
Citations in the corpus
- Properties of hot and dense matter from relativistic heavy ion collisions (2015, background): “It is worth pointing out that the model of Rapp, Wambach and van Hees, is able to reproduce the observed excess for all beam energies even at the low energies where the fireball consists mostly of baryon resonances [345].”
- Mapping the phases of quantum chromodynamics with beam energy scan (2019, background): “The analysis of these data [52, 53] indicate that the spectral function flattens, i.”