1. Kaon and Phi production in p-C and p-W reactions A
Kaon and Phi production in p-C and p-W reactions A. Scordo, LNF (INFN), Jia-Chii Berger-Chen (TUM) XXX Hades Collaboration Meeting Lisbon, 08/10/2015

2. Latest shown results
No data for
p > 450 MeV/c

3. General cuts for PID Vertex cuts : Vz cut + r cut OR Vz = -1000
Phase Space binning:
Pcorr : 12 bins → 150 – 990 MeV/c
q : 6 bins → 15° - 90°
Vertex cuts : Vz cut + r cut OR Vz = -1000
0 < MDC dE/dX < 50
0 < b < 1
Bad strips: 2,5,9,11,23,29,35
kIsUsed==1
REMOVED: 0 < pT < 400 MeV/c
Pcorr = Puncorr * getDeltaMom(npid, mom, theta, mat) (Exp Data)
Pcorr = Puncorr + getDeltaMom(npid, mom, theta, mat) ( MC )
A. Scordo, XXX Hades Collaboration Meeting, 2015

4. PID for p-C & p-W TOF K RPC Carbon Carbon K p p p p K TOF Wolfram K
A. Scordo, XXX Hades Collaboration Meeting, 2015

5. Fit procedure PREFITS : Signal: Gaussian Pre-fit in K+ region
Background:
• Prefit with “expo” on left tail (pions)
• Prefit with “expo” on right tail (protons)
TOTAL FITS:
• Fit of the mass spectra using prefits
parameters as input to the final function:
Total = Gauss + expop + expop
Background = expop + expop
A. Scordo, XXX Hades Collaboration Meeting, 2015

6. K+ reconstruction in p-C (RPC)
Fit looks good
Better understanding is needed
Out of final results
No reliable K-
(for the moment…)
A. Scordo, XXX Hades Collaboration Meeting, 2015

7. K+ reconstruction in p-C (TOF)
A. Scordo, XXX Hades Collaboration Meeting, 2015

8. K+ reconstruction in p-W (RPC)
A. Scordo, XXX Hades Collaboration Meeting, 2015

9. K+ reconstruction in p-W (TOF)
A. Scordo, XXX Hades Collaboration Meeting, 2015

10. K- reconstruction in p-C (RPC)
Due to low statistics for K-, some q bins
(for fixed p bin) have been merged
Average value is then taken for each point
A. Scordo, XXX Hades Collaboration Meeting, 2015

11. K- reconstruction in p-C (TOF)
Few points due to
low statistics for K-
A. Scordo, XXX Hades Collaboration Meeting, 2015

12. K- reconstruction in p-W (RPC)
2 or 3 q bins berged and averaged
A. Scordo, XXX Hades Collaboration Meeting, 2015

13. K- reconstruction in p-W (TOF)
Few points due to
low statistics for K-
A. Scordo, XXX Hades Collaboration Meeting, 2015

14. q integrated K- / K+ Ratios
Under study…
NEW
OLD
A. Scordo, XXX Hades Collaboration Meeting, 2015

15. MC dEdX for p-C & p-W TOF K RPC Carbon Carbon K p p p p K TOF Wolfram
A. Scordo, XXX Hades Collaboration Meeting, 2015

16. Acceptance+efficiency correction
TRUE MC input :
4p GiBUU simulations
K signal boosted to increase statistics
MC reconstruction:
hydra (l.v.) + local analysis
same general cuts, NO magnetic field corr
NO dEdX vs P selection → PID geant
Gaus fit + polynomial background (low P)
Same binning for all matrices : 12x6 (q,q)
For each pq bin, efficiency is calculated:
e = MCrec / TRUE
Including error propagation
For each pq bin, correction is applied:
Kcorr = Kuncorr / e
Example: K+
RPC (Carb)
A. Scordo, XXX Hades Collaboration Meeting, 2015

17. q integrated K- / K+ ratios Correction effects
With Cor
NO cor
A. Scordo, XXX Hades Collaboration Meeting, 2015

18. Conclusions (of part 1) Biasing 0 < pT < 400 MeV/c cut removed
Data for p > 450 MeV/c included
First acceptance & efficiency correction
NEXT STEPS:
Better MC PID -> s constraining
Different tail fit function
Extrapolation to unfitted bins
Merging of RPC & TOF
PT-Y analysis for consistency check