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Related papers: The $\pi N \to e^+e^- N$ reaction close to the vec…

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We discuss two processes, the $\pi N \to e^+e^- N$ and the $\gamma N \to e^+e^- N$ reactions, below and close to the vector meson production threshold ($1.40<\sqrt s <1.75$ GeV). The aim is to gain understanding of the coupling of vector…

Nuclear Theory · Physics 2010-12-16 Madeleine Soyeur , Matthias F. M. Lutz

The study of the $\pi N\to \rho^0 N$ and $\pi N \to \omega N$ amplitudes below and close to the vector meson production threshold ($1.4<\sqrt s <1.8$ GeV)reveals a rich structure arising from the presence of baryon resonances in this energy…

Nuclear Theory · Physics 2010-12-16 M. F. M. Lutz , B. Friman , M. Soyeur

We present consistent theoretical descriptions of the $\pi N \to e^+e^- N$ and $\gamma N \to e^+e^- N$ reactions on proton and neutron targets for total center of mass energies $\sqrt s$ ranging between 1.50 GeV and 1.75 GeV. These…

Nuclear Theory · Physics 2007-05-23 Madeleine Soyeur , Matthias F. M. Lutz

The exclusive photoproduction of $e^+e^-$ pairs from nucleons close to the vector meson production threshold ($1.4<\sqrt s <1.8$ GeV) results from two main processes: the emission of Bethe-Heitler pairs and the photoproduction of $\rho^0$-…

Nuclear Theory · Physics 2010-12-16 Matthias F. M. Lutz , Madeleine Soyeur

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 present a dynamical study of $e^+e^-$ production in $\pi^-$A reactions at 1.3 and 1.7 GeV on the basis of the Coupled-Channel-BUU approach. The contributions from vector mesons ($\rho,\omega$) are calculated taking into account the…

Nuclear Theory · Physics 2009-10-30 Th. Weidmann , E. L. Bratkovskaya , W. Cassing , U. Mosel

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…

Nuclear Theory · Physics 2007-05-23 B. Kampfer , L. P. Kaptari , A. I. Titov

The $\rho^0-\omega$ interference has been studied in the dilepton invariant mass distribution spectra in the photonuclear reaction, but that is not done for the gamma-nucleon reaction. Recent past, the $e^+e^-$ invariant mass distribution…

Nuclear Theory · Physics 2019-10-29 Swapan Das

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 $,…

Nuclear Theory · Physics 2008-11-26 Amand Faessler , C. Fuchs , M. I. Krivoruchenko , B. V. Martemyanov

Recent data from the PIONS$@$MAX-lab Collaboration, measuring the total cross section of the pion incoherent photoproduction $\gamma d\to\pi^-pp$ near threshold, have been used to extract the E$_{0+}$ multipole and total cross section of…

Nuclear Theory · Physics 2020-04-07 W. J. Briscoe , A. E. Kudryavtsev , I. I. Strakovsky , V. E. Tarasov , R. L. Workman

The process $e^+e^- \to \pi^0\gamma$ has been studied in the experiment with the SND detector at the VEPP-2M $e^+e^-$ collider. The $e^+e^- \to \pi^0\gamma$ cross section has been measured in the center-of-mass energy range from 0.60 to…

We consider the reaction g+d -> pi+d in a wide energy range around and above the eta-meson photoproduction threshold at backward CM angles of the outgoing pion. Our theoretical analysis is essentially motivated by the recent measurements of…

Nuclear Theory · Physics 2008-11-26 A. E. Kudryavtsev , V. E. Tarasov , I. I. Strakovsky , W. J. Briscoe , Y. Ilieva

The production and decay of vector mesons ($\rho, \omega$) in $pA$ reactions at COSY energies is studied with particular emphasis on their in-medium spectral functions. It is explored within transport calculations, if hadronic in-medium…

Nuclear Theory · Physics 2007-05-23 W. Cassing

A study of hadron production at the nucleon-antinucleon threshold has been performed with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. A very fast rise with about 1 MeV width has been observed in the $e^+e^- \to p\bar p$ cross…

High Energy Physics - Experiment · Physics 2019-05-29 3 Collaboration

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…

Phi meson production in pion-baryon and baryon-baryon interactions near the production threshold is studied in a boson-exchange model. Parameters in this model are either taken from the Bonn model for the nucleon-nucleon potential or…

Nuclear Theory · Physics 2009-10-30 W. S. Chung , G. Q. Li , C. M. Ko

The production near threshold of isoscalar pion pairs in the pd -> 3He(pi pi)^0 reaction is estimated in a two-step model which successfully describes the production of eta, omega and eta' mesons. A virtual pion beam, generated through an…

Nuclear Theory · Physics 2009-11-06 G. Faldt , A. Gardestig , C. Wilkin

The isoscalar-isovector ($\rho-\omega$) interferences in the exclusive reactions $\pi^- p \to n e^+ e^-$ and $\pi^+ n \to p e^+ e^-$ near the $\omega$ threshold leads to a distinct difference of the dielectron invariant mass distributions…

Nuclear Theory · Physics 2008-11-26 A. I. Titov , B. Kampfer

The cross section is estimated for the $\pi^+\pi^-\pi^0$ invariant mass distribution in the $\gamma p$ reaction in the GeV region. This reaction is assumed to proceed through the formation of the $\omega$ meson in the intermediate state,…

Nuclear Theory · Physics 2011-04-07 Swapan Das
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