PHENIICS Fest 2018

Study of baryonic resonances in the reaction pp→ppπ+π− at 3.5 GeV with HADES

29 mai 2018, 12:00

20m

200/0-Auditorium - Auditorium P. Lehmann (IJCLab)

Talk Hadronic and Particle Physics - 2

Orateur

Mme Amel Belounnas (PHEN)

Description

Pion production in NN collisions is one of the sources of information on the NN interaction and on the contribution of nucleon resonances. In particular, two-pion production in the few energy range, carries information both on single and double baryon excitation and on $\pi \pi$ dynamics, which are also useful for the interpretation of dielectron production. Baryonic resonances indeed contribute to the dielectron spectra via their Dalitz decay ($R\to N{e}^{+}{e}^{-}$) and indirectly as intermediate states for neutral meson Dalitz decays. In addition, the ${\pi }^{+}{\pi }^{-}$ production channel gives access to the $\rho$ contribution, which, due to its coupling to the baryonic resonances, is a crucial ingredient of calculations of the $e^{+}{e}^{-}$ emissivity in hadronic matter. The possibility to measure simultaneously with HADES pion and $e^{+}{e}^{-}$ production is therefore a great advantage.
Recently, differential and integrated cross sections for the reactions $pp\to pp{\pi }^0$, $pp\to pn{\pi }^{+}$ $[1]$, $[2]$, $pp\to pp{\pi }^{+}{\pi }^{-}$, $pn\to pn{\pi }^{+}{\pi }^{-}$ $[3]$, $pn\to d{\pi }^{+}{\pi }^{-}$ $[4]$ have been investigated with HADES at kinetic energies 1.25, 2.2 and 3.5 GeV. We focus here on the analysis of the $pp\to pp{\pi }^{+}{\pi }^{-}$ channel at 3,5 GeV, using results from $pp\to pp{\pi }^0$, $pp\to pn{\pi }^{+}$ and $pp\to pK\mathrm{\Lambda }$ $[3]$ measured at the same energy by HADES.
$[1]$ G. Agakishiev et al., Eur. Phys. J. A41, 243-277 (2009).
$[2]$ G. Agakishiev et al. Eur.Phys.J. A48 (2012) 74.
$[3]$ G. Agakishiev et al. Eur.Phys.J. A50 (2014) 82.
$[4]$ G. Agakishiev et al. , Eur.Phys.J. A51 (2015), 137.
$[5]$ G. Agakishiev et al., Phys.Lett. B750 (2015) 184.
$[6]$ G. Agakishiev et al. Phys.Lett. B742 (2015) 242-248.

Documents de présentation

Pheniics fest ABelounnas.pdf