fKK analysis in Run3 d+Au collisions: Update Dipali Pal & Debsankar M. L/H PWG meeting March 16, 2006

Analysis after QM2005 Fiducial cuts (presented on Feb 2, 2006 L/H meeting): - QM2005 preliminary data on d+Au phiKK includes only momentum independent zed vs phi fiducial cuts.(backup slides) - After QM2005 1/p vs phi fiducial regions have been studied for both data and MC. (backup slides) - Present data contain both momentum dependent and momentum independent fiducial cuts. Track matching cuts: - phi  KK analysis uses 3 sigma matching cuts at TOF and EMCAL. - Preliminary d+Au data uses matching parameters at TOF and EMCAL simply from CNT files. - Checks on matching parameters have been done. - Tuned the matching parameters and applied to data and MC (showed in this presentation) PID cuts: - phiKK analysis uses 2 sigma kaon PID cuts at TOF and PbSc. - The PID nsigma parameters have been studied and tuned. - Applied tuned PID parameters to data and MC. A fresh set of mT spectra have been derived.

Tuning of the track matching parameters for K+/- Expectation: Distribution of z and phi matching parameters should have mean = 0 and sigma = 1 Measured distributions are not consistent with expectations for both data and MC. Constructed z and phi residual distributions, fitted each of those with gaussian signal + 2nd order polynomial background to determine mean and sigmas. Define {subsystem}sdz(phi) = (Measured – mean)/sigma Apply to data and MC.

Examples of before and after tuning effects on track matching : TOF K+ for data Z “After tuning” (blue) data points are fitted with constant parameter. Improvements in matching parameters after tuning. Mean Mean Z matching Sigma Sigma

Examples of before and after tuning effects on track matching : TOF K+ for monte-carlo Z “After tuning” (blue) data points are fitted with constant parameter. Improvements in matching parameters after tuning. There is an offset in sigma after tuning. Mean Sigma

How to apply 2nd order tuning to the matching parameters? We apply the following cut: tofsdR = sqrt(tofsdz2 + tofdsphi2) < 3 If we consider 1 sigma matching at z and f, then that is equivalent to √2 sigma in R. After tuning, {subsystem}sdz and {subsystem}sdphi distributions show some constant offsets with reference to 1. For tofsdz, this offset is ~1.07, and for tofsdphi this is ~0.97, so that for tofsdR, this is sqrt(1.072 + 0.972) = 1.44. We expect tofsdR to be sqrt(2) = 1.41.  Multiply, 1.41/1.44 = 0.98 with tofsdR and put a 3 sigma cut on that.

Tuning of PID parameters (isK) Expectation: Distribution of isK matching parameters should show mean = 0 and sigma = 1 Measured distributions are not consistent with expectations for both data. For MC, EMCAL isK distributions do exhibit mean ~ 0 and sigma ~ 1; but TOF doesn’t. Constructed mass-squared distributions, fitted each of those with double gaussian function to determine mean and sigmas. Define isK = (Measured – mean)/sigma Apply to data and MC.

Examples of before and after tuning effects on isK parameters: TOF Improvements after tuning. “After tuning” data points have been fitted with constant parameter. Sigma shows some contant offset with reference to 1. Same exercises have been done for EMCAL. Mean Mean Data MC s s Data MC

f KK mT spectra after applying modified fiducial cuts, matching and PID tuning dN/dy T TOF – TOF 0.041 +/- 0.008 397 +/- 31 TOF – East 0.037 +/- 0.005 404 +/- 47 East – East 0.038 +/- 0.007 352 +/- 57 West – West 0.036 +/- 0.004 393 +/- 50 Comparison with QM’05 results are shown in slide 11.

Subsystem consistency plots Yields from all subsystems are consistent with each other.

Comparison: New and QM05 results Ratios are consistent with 1 within error. dN/dy (new) (QM’05) TOF-TOF 0.041+/- 0.008 0.038+/-0.007 TOF-East 0.037+/-0.005 0.043+/-0.005 East-East 0.034+/-0.006 West-West 0.035+/-0.004 0.036+/-0.004 T (MeV) (new) T(MeV) (QM’05) TOF-TOF 397+/-31 423+/-30 TOF-East 404+/-47 396+/-40 East-East 352+/-57 381+/-67 West-West 393+/-50 340+/-38

Summary Fine tuning of matching and PID parameters have been done. Application of matching and PID tuning, does not change yields and inverse slopes.

Backup slides

fKK and fee

EMC East

f KK mT spectra after applying modified fiducial cuts, matching and PID tuning but no second order tuning Min bias yields and temperatures are consistent for all subsystems.

Momentum independent fiducial studies (Next 3 slides) Shown in L/H PWG on 12/02/2004

Zed vs phi distributions: DC + PC1 + TOF Before fiducoial cut After fiducial cut Data MC Data MC Rejected region -2 < zed [cm[ < 1 186.0 < phi[deg] < 191.0 167.8 < phi[deg] < 172.0 Shown in L/H PWG on 12/02/2004

Zed vs phi distributions: DC + PC1 + PbSc(E) Before fiducial cut After fiducial cut Data MC Data MC Rejected region -2 < zed [cm[ < 1 173.6 < phi[deg] < 174.0 169.0 < phi[deg] < 173.0 138.0 < phi[deg] < 146.0 Shown in L/H PWG on 12/02/2004

Zed vs phi distributions: DC + PC1 + PbSc(W) After fiducial cut Before fiducial cut Data MC Data MC Rejected region -2 < zed [cm[ < 2 -10.0 < phi[deg] < -2.8 7.6 < phi[deg] < 12.0 21.2 < phi[deg] < 24.6 Shown in L/H PWG on 12/02/2004

Momentum dependent fiducial studies (Next 3 slides) Shown on February 2, 2006 L/H meeting

TOF North South Charge/momentum phiDC

PbSc-E Before After North South Charge/momentum phiDC

PbSc-W Before Charge/momentum After North South phiDC