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Update on Pb-Pb spectra

HMPID weekly meeting

CERN, 04/09/2013

G. Volpe

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Spctra in Pb-Pb collisions: fit exapmples

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Spectra in Pb-Pb collisions: pions raw yields

Centrality bins:0 – 5 %5 – 10 %10 – 20 %20 – 30 %30 – 40 %40 – 50 %

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Spectra in Pb-Pb: kaons raw yields

Centrality bins:0 – 5 %5 – 10 %10 – 20 %20 – 30 %30 – 40 %40 – 50 %

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Spectra in Pb-Pb collsions: protons raw yields

Centrality bins:0 – 5 %5 – 10 %10 – 20 %20 – 30 %30 – 40 %40 – 50 %

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Spectra in Pb-Pb collisions: tracking efficiency

Tracking efficiency convoluted with the detector acceptance in the required rapidity range(MC prod. : LHC12a17a_fix)

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Spectra in Pb-Pb collisions: PID efficiency (0-5 % centr.)

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Spectra in Pb-Pb collisions: PID efficiency (5-10 % centr.)

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Spectra in Pb-Pb collisions: PID efficiency

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Spectra in Pb-Pb collisions: distance cut correction

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Spectra in Pb-Pb collisions: pions (0-10 % centr.)

Corrected spectra

PRELIMINARY

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Spectra in Pb-Pb collisions: kaons (0-10 % centr.)

Corrected spectra

PRELIMINARY

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Spectra in Pb-Pb collisions: protons (0-10 % centr.)

Corrected spectra

PRELIMINARY

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Conclusions

• Pb-Pb corrected spectra have beeb evaluated in two most central centrality bins (0-5%, 5-10%). The same procedure will be applied for the semi central collisions asap.

• Main corrections have been applied (tracking eff., PID eff., distance cut), feed down still missing.

• PID efficiency has been extracted from Monte Carlo. It is a very critical parameter, real data have to be also used (V0’s decays).

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Backup

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Primary tracks multiplicity

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Pb-Pb analysis status: protons PID eff. from V0s

ProtonsAnti-protons From

Francesco

PID efficiency for protons and anti-protons, extracted by means of V0s selection. Difference between the two charge is present.