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Measurement of B (D + + ). Sadia Khalil & Sheldon Stone Syracuse University 05/30/2007. Method. Look for D - D + +
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Measurement of B(D+ + ) Sadia Khalil & Sheldon Stone Syracuse University 05/30/2007
Method Look for D-D+ + K+- - K+- - 0 Ks - Ks- - + Ks- 0 K+ K -- We also looked at, K+- - Ks - K+ K --0 Signal Tags
How to count the Tags? • For signal require E to be within 2.5 . • Fit the Mbc distributions using Crystal Ball • function for the signal and Argus function for the • background • Fix the background shape parameters by fitting the E sidebands, defined as 5 < |E| <7 using the Argus function. • Count the events within 3 of the Mbc distribution.
D+ + Selection Criteria • Search for events with a single additional charged track on the • ‘otherside’ • Calculate the Missing Mass squared, • MM2 = (Ebeam - E + )2 – (-pD- - p +)2 • Veto events with additional charged tracks arising from the event vertex or having a maximum neutral energy cluster of more than 250 MeV to reduce D+ +0 events • Muon candidate is required to be within barrel region, • |cos|<0.81 and deposit less than 300 MeV of energy in the • calorimeter, characteristic of a minimum ionizing particle
An effort to look for some other modes@281pb-1 E plot for K+ K -- 0 E plot for Ks- # of Events/20MeV
Mbc for K+-- Signal MC Data @281 pb-1 # of Events/0.6MeV
Next! • Estimate the backgrounds on the signal side. • Keep on looking for more new modes, e.g; D- K+---+ • and D- Ks-0 0