Experimental Results of Photon and Pion Production in p+C Collisions at 5.13 GeV

RQMD: p+C γ X at T=5.13 GeV 2-arms FLINT at 300 cm S.Kiselev, ITEP ITEP meeting S.Kiselev

Input info • RQMD4.12 generator • 106 min. bias (b<RC =2.5 fm) p+C events as at T=5.13 GeV • Two arms FLINT: 80x80 cm2 at 300 cmfrom the target, arm centers: (X,Y)=(45,0) and (=-45,0)  θ = 10 - 160 • Only γ from π0 will be analyzed • Low momentum cut: 400 MeV/c. • Energy resolution: 6%/√E • Space resolution: cell size 10x10 cm2 momentum is matched to the center of a cell • Trigger: pγ> 0.4 GeV/c, i.e. without a trigger ITEP meeting S.Kiselev

γ multiplicity 1 arm 2 arms 2 arms  ~ 2 times larger events with photons ITEP meeting S.Kiselev

π0 spectra 1 arm 2 arms 2 arms  ~3 times larger π0 larger p and smaller θ ITEP meeting S.Kiselev

ΔRγγ from π0 vs P 1 arm 2 arms 2 arms  a bit larger ΔR ITEP meeting S.Kiselev

pt dependence 1 arms No pt dependence of the Mγγ width ↓ ~ 2 times ↓~ 4 times 2 arms pairs of photons from different arms have mainly low pt larger background ITEP meeting S.Kiselev

2 arms • pairs of photons • from different arms ITEP meeting S.Kiselev

Summary • 106 RQMD p+C events at T=5.14 GeV • two arm FLINT at 300 cm • 2 arms  ~2 times larger events with γ • 2 arms  ~3 times larger number of π0 • No pt dependence of the Mγγ width • 2 arms  pairs of photons from different arms have mainly low pt • 2 arms  larger background, but still small S/(S+B) ~ 84% ITEP meeting S.Kiselev

Experimental Results of Photon and Pion Production in p+C Collisions at 5.13 GeV