English
Related papers

Related papers: $e^+e^-$ pairs from $\pi^-$A reactions

200 papers

The in-medium spectral functions of $\rho$ and $\omega$ mesons and the broadening of the nucleon resonances at finite baryon density are calculated self-consistently by combining a resonance dominance model for the vector meson production…

Nuclear Theory · Physics 2008-11-26 E. Santini , M. D. Cozma , Amand Faessler , C. Fuchs , M. I. Krivoruchenko , B. Martemyanov

We present a dynamical study of $e^+e^-$ production in C + C and Ca + Ca collisions at BEVALAC/SIS energies on the basis of the covariant transport approach HSD employing momentum-dependent $\rho$-meson spectral functions that include the…

Nuclear Theory · Physics 2009-10-30 E. L. Bratkovskaya , W. Cassing , R. Rapp , J. Wambach

Neutral gauge bosons beyond the Standard Model are becoming interesting as possible mediators to explain several experimental anomalies. They have small masses, below one GeV, and are referred to as dark photons, $U$, $A'$ or $Z'$ bosons.…

High Energy Physics - Phenomenology · Physics 2018-06-07 I. Alikhanov , E. A. Paschos

We study the process $e^- + e^+ \to e^+ + e^+ + e^- + e^-$ for ILC and CLIC energy regimes, in the minimal 3-3-1 model framework. The main contributions, for the production of two bileptons each one decaying into two same-sign leptons, come…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Ramirez Barreto , Y. A. Coutinho , J. Sá Borges

We investigate the production of $e^+e^-$ pairs from $p + Be$ and nucleus-nucleus collisions from 2 GeV/A to 200 GeV/A within a covariant transport approach and focus on the dilepton angular anisotropies as a function of the dilepton…

Nuclear Theory · Physics 2007-05-23 E. L. Bratkovskaya , W. Cassing , U. Mosel

The invariant-mass spectrum of $e^+ e^-$ pairs produced in $^{12}$C+$^{12}$C collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over five orders of…

Nuclear Experiment · Physics 2012-03-22 Piotr Salabura

The pi omega rho coupling constant is calculated in a relativistic hadronic framework incorporating nucleons and Delta(1232) isobars. Medium modifications are included. The vertex is analyzed in context of the omega to pi e+e- and rho to pi…

Nuclear Theory · Physics 2009-11-10 Agnieszka Bieniek

The study of the pi^- p -> rho^0 n and pi^- p -> omega n amplitudes close and below the vector meson production threshold (1.2< sqrt(s) <1.8 GeV) reveals a rich dynamics arising from the presence of specific baryon resonances in this energy…

Nuclear Theory · Physics 2007-05-23 Madeleine Soyeur , Matthias Lutz , Bengt Friman

We consider lepton pair production via two-hadron annihilation through various isoscalar vector mesons within hot, baryon-free matter. This is tantamount to constructing effective form factors which we model using a vector-meson-dominance…

Nuclear Theory · Physics 2009-10-28 Kevin Haglin , Charles Gale

The cross section of the $e^+e^-\to\omega\pi^0\to\pi^0\pi^0\gamma$ reaction was measured by the SND detector at VEPP-2M $e^+e^-$ collider in the energy range from threshold up to 1.4 GeV. Results of the cross section fitting by the sum of…

We use the microscopic GiBUU transport model to calculate dilepton ($e^+e^-$) production in heavy-ion collisions at SIS18 energies focusing on the effect of collisional broadening of the $\rho$-meson. The collisional width of the…

Nuclear Theory · Physics 2021-03-05 A. B. Larionov , U. Mosel , L. von Smekal

Motivated by the ongoing analysis by the BESIII Collaboration on the single-tagged $e^+e^-\to e^+e^- \eta \pi^+\pi^-$ reaction, we present a phenomenological study of the diphoton fusion to $\eta \pi^+ \pi^-$, focusing on the production…

High Energy Physics - Phenomenology · Physics 2024-11-22 Xiu-Lei Ren , Igor Danilkin , Marc Vanderhaeghen

The emission of e+e- pairs from C+C collisions at an incident energy of 1 GeV per nucleon has been investigated. The measured production probabilities, spanning from the pi0-Dalitz to the rho/omega! invariant-mass region, display a strong…

Nuclear Experiment · Physics 2008-11-26 HADES Collaboration , G. Agakishiev , C. Agodi , H. Alvarez Pol , A. Balanda , R. Bassini , G. Bellia , D. Belver , A. Belyaev , A. Blanco , M. Boehmer , A. Bortolotti , J. L. Boyard , P. Braun-Munzinger , P. Cabanelas , E. Castro , T. Christ , M. Destefanis , J. Diaz , F. Dohrmann , A. Dybczak , T. Eberl , L. Fabbietti , P. Finocchiaro , P. Fonte , J. Friese , I. Froehlich , T. Galatyuk , J. A. Garzon , R. Gernhaeuser , A. Gil , C. Gilardi , M. Golubeva , D. Gonzalez Diaz , E. Grosse , F. Guber , M. Heilmann , T. Hennino , R. Holzmann , A. Ierusalimov , I. Iori , A. Ivashkin , M. Jurkovic , B. Kaempfer , K. Kanaki , T. Karavicheva , D. Kirschner , I. Koenig , W. Koenig , B. W. Kolb , R. Kotte , A. Kozuch , A. Krasa , F. Krizek , R. Kruecken , W. Kuehn , A. Kugler , A. Kurepin , J. Lamas Valverde , S. Lang , J. S. Lange , K. Lapidus , L. Lopes , L. Maier , A. Mangiarotti , J. Marin , J. Markert , V. Metag , B. Michalska , D. Mishra , E. Moriniere , J. Mousa , M. Muench , C. Muentz , L. Naumann , R. Novotny , J. Otwinowski , Y. C. Pachmayer , M. Palka , Y. Parpottas , V. Pechenov , O. Pechenova , T. Perez , J. Pietraszko , R. Pleskac , W. Przygoda , B. Ramstein , A. Reshetin , M. Roy Stephan , A. Rustamov , A. Sadovsky , B. Sailer , P. Salabura , A. Schmah , R. Simon , Y. Sobolev , S. Spataro , B. Spruck , H. Stroebele , J. Stroth , C. Sturm , M. Sudol , A. Tarantola , K. Teilab , P. Tlusty , A. Toia , M. Traxler , R. Trebacz , H. Tsertos , I. Veretenkin , V. Wagner , M. Weber , H. Wen , M. Wisniowski , T. Wojcik , J. Wuestenfeld , S. Yurevich , Y. Zanevsky , P. Zhou , P. Zumbruch

We have performed a detailed study of dilepton production from pp collisions including the subthreshold $\rho$ production via baryonic resonances (N(1520), N(1700)) in addition to the conventional dilepton sources as $\pi^0, \eta, \omega$…

Nuclear Theory · Physics 2009-10-31 E. L. Bratkovskaya , W. Cassing , M. Effenberger , U. Mosel

This study measured the invariant mass spectra of $\rho$ and $\omega$ mesons in the $e^+e^-$ decay channel for 12 GeV (12.9 GeV/$c$) $p+\mathrm{C}$ and $p+\mathrm{Cu}$ reactions ($\sqrt{s}_{NN}=5.1$ GeV) at the KEK 12-GeV Proton…

We present a dynamical study of $e^+e^-$ and $\mu^+ \mu^-$ production in proton-nucleus and nucleus-nucleus collisions at CERN-SPS energies on the basis of the covariant transport approach HSD employing a momentum-dependent $\rho$-meson…

Nuclear Theory · Physics 2008-11-26 W. Cassing , E. L. Bratkovskaya , R. Rapp , J. Wambach

The DLS collaboration has recently completed a high statistics study of dilepton production at the Bevalac. In particular, we have measured dielectrons (e+e-) from p-p and p-d collisions to understand the basic dilepton production…

Dielectron production in the $\pi N$ interaction at not large energies is studied. The dominant contribution of the $\Delta$-isobar creation in the intermediate state at incident pion momenta of about 0.3-0.4 GeV$/$c is shown. The…

High Energy Physics - Phenomenology · Physics 2017-05-23 A. P. Ierusalimov , G. I. Lykasov

We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The…

Nuclear Theory · Physics 2016-09-08 K. Shekhter , C. Fuchs , Amand Faessler , M. Krivoruchenko , B. Martemyanov