Pi0 Mass recon in the NCC R. Seto Oct 17, 2005

What I did Ran pisa – took hits file which gives dedx in each Si layer Partitioned the dedx into cells to look like NCC 1.5 cm^2 three layers in z found “normalization” Clustered “photons” Found energy and position of each photon

Sample I studied Threw sample of single pi0’s –1 to 5 GeV momentum –10-30 degrees both gammas had to hit NCC required gamma to be separated by 6 cm required E1 and E2 > 0.5 GeV |E1-E2|/(E1+E2)<0.5

Clustering algorithm Find hottest tower in compartments 1 or 2 and use as seed Connect to vertex. Find “central” hot core by extrapolating to other compartments From central towers look for neighboring blocks. (all blocks must be a next-door neighbor to central tower) remove blocks from search Go again. Allow myself to find up to 3 showers pi0/gamma not used yet

display top left all 3 views bottom right 3 views colors are photons found “mass” is real mass “mass recon” – is reconstruct ed mass

GeV cm

expectations GeV input mass mass after smearing energy

Mass reconstruction GeV

Plans understand limitations of Ncc –Effect of position resolution –how close can the photons be? –how high energy can it do? Add backgounds –several pi0’s –Full event begin to use pi0/gamma Go after direct photons Go after W background

More general plans CDR planning –go back to looking at outline –have a CDR fest? –Work on physics section management section WBS Goal : Thanksgiving PS Eduard and I go to Korea Nov Purchases –equipment ordered (some in) –Ordering si wafers? RPC HV?