Study of elementary reactions with the hades dielectron spectrometer

Results obtained with the HADES dielectron spectrometer at GSI are discussed, with emphasis on dilepton production in elementary reactions. Díaz Medina, José, Jose.Diaz@uv.es ; Gil Ortiz, Alejandro, Alejandro.Gil@ific.uv.es

Deep sub-threshold $K^\ast (892)^{\circ}$ production in collisions of Ar + KCl at 1.76 A GeV

Commissioning of the CALIFA Barrel Calorimeter of the R3B Experiment at FAIR

5 pags., 4 figs. -- FAIRNESS2019: FAIR NExt generation ScientistS 20-24 May 2019, Arenzano, Genova, Italy

pp and ππ intensity interferometry in collisions of Ar+KCl at 1.76A GeV

Results on pp, π+π+, and π-π- intensity interferometry are reported for collisions of Ar+KCl at 1.76$A$~GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time extent of the corresponding emission sources. The π π source radii are found significantly larger than the pp emission radius. The present radii do well complement the source-size excitation functions of the collision system of size $A+A \simeq 40+40$. The pp source radius at fixed beam energy is found to increase linearly with the cube r…

HADES experiment: di-lepton spectroscopy in p + p (2.2 GeV) and C+C (1 and 2 A GeV) collisions

The HADES (High Acceptance Di-Electron Spectrometer) is a tool designed for lepton pair (e+e−) spectroscopy in pion, proton and heavy ion induced reactions in the 1–2AGeV energy range. One of the goals of the HADES experiment is to study in-medium modifications of hadron properties like effective masses, decay widths, electromagnetic form factors etc. Such effects can be probed with vector mesons ( ρ,ω,ɸ ) decaying into e+e− channel. The identification of vector mesons by means of a HADES spectrometer is based on invariant mass reconstruction of e+e− pairs. The combined information from all spectrometer sub-detectors is used to reconstruct the di-lepton signal. The recent results from 2.2Ge…