1. Status of Multiplicity Studies at Primary Vertex Umut Kose

2. DATA # of events for neutrino 969 events analyzed # of events for anti-neutrino We have 975 events  756 events vertex in emulsion  522 events grey not counted 234 events grey counted and slope measured

3. 234 events scanned but not documented. Information on event sheets. For 522 events additional measurement is necessary (Grey tracks slope should be measured) By summer, we have coherent sample (~1K neutrino, 756 antineutrino events)

4. Manual scanning procedure when the vertex point found, first the tracks classified according to ionization. The black tracks, heavy ionizing particles, appear as continues lines. They have short lengths; often stop in the plate. The grey tracks, medium ionizing particles, are usually emitted at wide angles and they look like thicker than minimum ionizing ones. The others, the minimum ionizing tracks, MIP, are also called shower tracks; and mostly they are emitted in the forward direction. then the tracks labeled as black, grey and shower; black ones are just counted event by event; for the others, the emission angle is measured. Finally by using the pseudorapidity the remaining tracks can be classified as grey/shower tracks.