All Low Energy Events with MuDst Rosi Reed UC Davis March Events Events with at least 1 primary track Vx = Primary Vertex x position (cm) Vy = Primary Vertex y position (cm) Beam-Beam defined as (Vx^2+Vy^2) < 2 cm –6773 Events Beam-Pipe defined as (Vx^2 + Vy^2) > 2 cm –4150 Events

All Low Energy Events Good = Events with refMult > 158, -100<Vz<100, Vr<2

All Low Energy Events Bold Events cogged at PHENIX Run 90 started out cogged in PHENIX (6 out of 15 min)

Z Vertex Position of all Events with at least 1 Primary Track

Z Vertex Position of all Events with at least 1 Primary Track and (Vx^2 + Vy^2) < 2 cm

Z Vertex Position of all Events with at least 1 Primary Track and (Vx^2 + Vy^2) > 2 cm

XY Vertex Position of all Events with at least 1 Primary Track

Pi+ Pi- yields out of 474 events Pion Mass Assumption

p+ p- yields out of 474 events Proton Mass Assumption – p- counts found by picking a window from p+ results (mu +/- sigma) and counting # of particles within the window Only done in “clean” mT-m0 bins

K+ K- yields out of 474 events Kaon Mass Assumption – 1 st 2 points for each done by counting particles in a window