PID Band Structure Check and p p pi- final state

PID Band Structure Checkandp p pi- final state Y.C.Han@ K0 meeting Nov22, 2007

PID Band Structure Yellow: Deutron Red: Proton Purple: Kaon Green: Pi+ Blue: Pi-

Time Relation IH CTime OH MeanCTime Flight Time (OH – IH)

Target Region -2.5cm<X<1.5cm

Particle Type Pion Plus Pion Minus Unknown Proton

Vertex Type Proton Proton Pi- Proton Pi+ Pi- Pi+ Pi- Pi- Pi+ Pi+ Pi- Unknown

IH OH and Tag segment No obvious dependence on single segment.

Conclusion PID band structure related to the 2nsec like band structure of time of flight; The band structure tends to more obvious in the non-target region, unknown particles, unknown vertex; while shows no dependence on the IH, OH, or Tag segment hit.

Tagger photon and pppi final state Final Momentum= | mom_p1+mom_p2+mom_pi- |

Cut region 50 40 30 20 10 1

Cut Result Jan2007 Total pppi- Events: 22138 50 2470 events 40 1953 events 20 999 events 30 1454 events 10 508 events 1 58 events

IH deposit energy correction Mean Momentum Proton 520 531 Pi- 363.5 365.9

After correction

After correction 50 40 30 20 10 1 /c

After correction Cut region MeV/c Cut region MeV/c 1935 events 2431 events 50 40 1455 events 947 events 30 20 457 events 51 events 1 10

Tagger photon vs final mom with final IM cut Cut Region 50 40 30 20 10 1 /(c*c)

Tagger photon vs final mom with final IM cut 2014 events 2482 events 1465 events 947 events 469 events 45 events

PID Band Structure Check and p p pi- final state