Diapositive 1

HADES experiments at GSI.

B. Ramstein, IPN Orsay

ECT, Trento, 20/05/20131Electromagnetic structure of Time-Like baryonic transitions in pion induced reactions

B. Ramstein e+e-NROutlineIntroduction: General context of HADES experiments In-medium modifications of vector mesons Link to Time-Like elctromagnetic structure of baryonic transitions

Results from pp reactions with HADES Sensitivity to Time-Like electromagnetic structure of baryonic transitions

Perspectives of HADES measurements with the GSI pion beam (2014) -p ne+e- below threshold Time-Like electromagnetic transition form factors -p -p, -p -+n, -p -0p and kaon production PWA baryonic resonance parameters

Conclusions

2Trento, 20/05/2013 B. Ramstein 3Exploring the phase diagram of hadronic matter..Motivations of the HADES experiment

E/A=1-2 AGeV /o ~ 1-3, T < 100 MeV N/Apart 10%.. using dilepton emission: rare but undistorted probeTrento, 22/02/2013 B. Ramstein e+e-

CERES

AGSSPSRHICQGPhadronsSIS-100SIS-300SIS-18CBMG7HADESKEK,JLAB,TAPSNa60DLSDLSLHC34In-medium vector meson modifications:see e.g. Leupold ,Metag,Mosel Int. J. of Mod. Phys. E19 (2010) 147 for a recent reviewN-1N*+ ...

Rapp and Wambach EPJA 6 (1999) 415Rapp, Chanfray and Wambach NPA 617, (1997) 472in-medium broadeningIn-medium spectral function depends on NN* couplingTrento, 20/05/2013 B. Ramstein 44The meson in hot and dense hadronic matter from SIS18 to SPS

Depends on RN coupling5Source of mesons

Source of mesons at 1-2 AGeVNN NR NNN R N

Source of mesons

Source of mesons at ultra relativistic energies+-

Coupling of to baryonic resonances can be studied in NN and N collisions at 1-2 GeV 5Relation to electromagnetic structure of baryons electromagnetic elastic or transition form factors

g*e+e-g*e+e-r, w,Coupling constantsRNRN6Dalitz decay of baryonic resonances RNe+e- meson production and decay Trento, 20/05/2013 B. Ramstein Vector Meson Dominance Modelq2 0 : Time like region electromagnetic form factors are unknown !q2=M2inv(e+e-)=M2* >0

Trento, 20/05/2013 B. Ramstein 7Baryonic electromagnetic form factors are measured for q20

Data: Mainz, JlabI.G. Aznauryan, V.D. Burkert Prog. Part. Nucl. Phys. 67, 1 (2012)

Helicity amplitudes for *pN(1520) D13 compared to quark models Magnetic form factor for *p(1232) Baryonic transition electromagnetic form factors in space-Like region No measurement at q2 > 0 use models fitted on space like data D+pe+e-*q2=M2*