Today's Progress 6. March. 2007

General discussion of YN correlation analysis.

Until now, we have exhibitted the YN correlation analysis from pp/pn/nn back-to-back on PB/NT L/R + &pi on TC events, and the acceptance was limited to strongly back-to-back events. We can generalize the analysis method, and it is possible to study YN correlation at 90 degree, indeed. This is extremely important not only for dibaryon seacrch, but also for tribaryon search, by possible YN/YNN decay modes.

Possible event topology for YN analysis

Classification of possible YN analysis. for the "selection" on the 2nd row, see the description below. The color of the 1st row YN pair represents the analysis status.

Black:no condensed data exists,

Blue:1st order condensed data file, in which NT-detected particles are all identified, and TC-detected particles are partly identified, exists,

Sky-blue:2nd order condensed data file, in which PID on all 4 arms is finalized, all neutron momenta are calculated, and the energy-loss correction for &pi/p are prepared for all existing arms,

Purple:p/&pi energy-corrected data file, in which all particle momentum have been calculated, exists, hence YN correlation analysis is immediately executable,

Red:The result is already presented.

YN pair(dibaryon/tribaryon channel) case ID(Selection) Angler acceptance PA/PB/NT particle TC particle Trigger mode Possible &Lambda VertexEffective VCA
&Lambda p (X+/S0) 1(A-b-1-x) 180 +- 30p + p &pi Kst*Charged 2 &Lambda path
&Lambda p (X+/S0) 1(A-b-x-1') 90 +- 45p &pi + p Kst*Charged 2 &Lambda path
&Lambda n (X0/S+) 1(A-b-3-x) 180 +- 30p + n &pi Kst*Charged 1 &Lambda path
&Lambda n (X0/S+) 1(A-b-x-3') 90 +- 45p &pi + n Kst*Charged 1 &Lambda path
&Lambda p (X+/S0) 2(B-a-1-x) 90 +- 45&pi + pp Kst*Charged 2 &Lambda path
&Lambda p (X+/S0) 2(B-a-x-1') 180 +- 30&pi p + p Kst*Charged 2 &Lambda path
&Lambda n (X0/S+) 2(B-a-3-x) 90 +- 45&pi + np Kst*Charged 1 &Lambda path
&Lambda n (X0/S+) 2(B-a-x-3') 180 +- 30&pi p + n Kst*Charged 1 &Lambda path
&Sigma-p (X0/S0) 1(C-b-1-x/A-b-3-x) 180 +- 30n + p &pi Kst*Charged 1 BLC-VDC
&Sigma-p (X0/S0) 1(C-b-x-1') 90 +- 45n &pi + p Kst*VTC*NT 1 BLC-VDC
&Sigma+-n (X+/S+) 1(C-b-3-x) 180 +- 30n + n &pi Kst*VTC*NT 0 BLC-VDC
&Sigma+-n (X+/S+) 1(C-b-x-3') 90 +- 45n &pi + n Kst*VTC*NT 0 BLC-VDC
&Sigma- p (X0/S0) 2(B-c-1-x) 90 +- 45&pi + pn Kst*Charged 1 BLC-PDC
&Sigma- p (X0/S0) 2(B-c-x-1'/B-a-x-3') 180 +- 30&pi n + p Kst*Charged 1 BLC-PDC
&Sigma+- n (X+/S+) 2(B-c-3-x) 90 +- 45&pi + nn Kst*Charged 0 BLC-PDC
&Sigma+- n (X+/S+) 2(B-c-x-3') 180 +- 30&pi n + n Kst*Charged 0 BLC-PDC
&Sigma- p (X0/S0) 3(B-a-3-x) 90 +- 45&pi + np Kst*Charged 1 -
&Sigma+- n (X+/S+) 3(B-c-3-x) 90 +- 45&pi + nn Kst*Charged 0 -
&Sigma- p (X0/S0) 4(B-x-1-x) 180 +- 30(&pi + n) + p - Kst*Charged 1 -
&Sigma+- n (X+/S+) 4(B-x-3-x) 180 +- 30(&pi + n) + n- Kst*Charged 0 -

Data condensation procedure for generalized YN analysis

1st stage selections...

Selection A. (at least 1)proton on NT (from Kst*Charged Trigger)

Selection B. (at least 1)&pi on NT (from Kst*Charged Trigger)

Selection C. (at least 1)neutron on NT (from Kst*VTC*NT Trigger)

2nd stage selections...

Selection a. (at least 1)proton on TC

Selection b. (at least 1)&pi on TC

Selection c. (at least 1)neutron on TC

3rd stage selections...

Selection 1. 1 addtional proton on NT

Selection 2. 1 addtional &pi on NT

Selection 3. 1 additional neutron on NT

4th stage selections....

Selection 1'. 1 additional proton on TC

Selection 2'. 1 additional &pi on TC

Selection 3'. 1 additional neutron on TC