Test beam preliminary results D. Di Filippo, P. Massarotti, T. Spadaro

2010 Test beam CERN T9 area

Focus at beam wire chambers + 2m

Scintillator for trigger “Palback” for muon selection Two cherenkov counters: 2 different thresholds for electron/muon discrimination: Both counters above threshold  electron Only counter 1 above threshold  muon 2010 Test beam setup: trigger logics

2010 Test beam: front palettes and quality cut Beam tagging condition: A circle centered in (48,68) pQ with 15 pQ of radius at least one TDC hit for both palettes

test beam: most hit crystals map

2010 test beam: electron identification All events & Palette tagging cut & Both Cherenkov counters above the threshold muons electrons Run GeV

2010 test beam: muon identification All events & Palette tagging cut & “palback” ON & Cherenkov 1 ON Cherenkov 2 Off All events & Palette tagging cut & “palback” ON & at least 3 aligned block ON & Cherenkov1 ON Cherenkov 2 Off Run GeV Run GeV

Test beam 2010: Charge vs. ToT Run 627, Threshold=4 mV MUON Runs Q (QDC) [pC] ToT (TDC) [ns] Ch 10 Ch 26 Ch 10 Ch 26 Run 638, Threshold=8 mV

Test beam 2010: Charge vs. ToT * ch 26 muon run o ch 10 muon run o ch 10 electron run * ch 10 muon run Different response for each block and for electon and muon

Test beam 2010: Charge vs. ToT Polynomial parametrization: p9 Q (pC ) ToT (ns) Parametrizations block by block summing over different energy runs. Different parametrizations for muon and electron. Muon parametrization not reliable to reproduce electron energy Electron selection QDC TDC (ele) TDC (muon)

Test beam 2010: Charge vs. ToT Polinomilal parametrizzation: p9 Q (pC ) ToT (ns) Global parametrization summing energies and blocks: good agreement TDC (muon) TDC (ele) QDC

Test beam 2010: LAV linearity from Q(T) 4 mV threshold Electron identification with Cherenkov counters: both ON Energy between 0.3 and 2 GeV Charge obtained by QDC and by ToT

Test beam 2010: LAV linearity from Q(T) 4 mV threshold

Test beam 2010: LAV energy resolution 4 mV threshold Energy resolution fitted with A/√E[GeV] + B/E[GeV] + C

Test beam 2010: LAV time resolution 4 mV threshold Ch 10 Ch 26  t = 220 ps/√E[GeV] ps Trigger time given by the time weighted mean of “front” palettes and cherenkov counters. Slewing correction, signal shape assumption: V(t) ~ t a e -bt The constant term is due to trigger jitter

Test beam 2010: LAV time resolution Ch mV threshold  t = 250 ps/√E[GeV] ps Trigger time given by the time weighted mean of “front” palettes and cherenkov counters. Slewing correction, signal shape assumption: V(t) ~ t a e -bt

Test beam 2010: LAV time resolution 4 mV threshold Slewing correction from V(t) ~ t a e -tb No constant term 210 ps /√[E 10 E 26 /(E 10 +E 26 )] (GeV)

Test beam 2010: MC studies MC study for efficiency evaluation: Simulation with test beam geometry Move a pencil 300-MeV beam in a 2cm-2cm wide grid and evaluate: Total Energy released (%) X block (cm) Y block (cm)

Test beam 2010: MC studies MC study for efficiency evaluation: Simulation with test beam geometry Move a pencil 300-MeV beam in a 2cm-2cm wide grid and evaluate: Energy RMS (MeV) X block (cm) Y block (cm)

Test beam 2010: MC studies MC study for efficiency evaluation: Simulation with test beam geometry Move a pencil 300-MeV beam in a 2cm-2cm wide grid and evaluate: % of energy smaller than Energy mean - 3 RMS Non gaussian distribution! X block (cm) Y block (cm)

Test beam 2010: MC studies Total charge collected after conversion from number of optical photons produced: 1.Take into account photocathode efficiency 2.Threshold imposed by FE for TDC measurement Q (pC) MC Data MC RMS smaller than data by a factor of more than 2

Test beam 2010: MC studies Total charge collected after conversion from number of optical photons produced: 1.Take into account photocathode efficiency 2.Threshold imposed by FE for TDC measurement Q (pC) MC Data MC RMS smaller than data by a factor of more than 2

Test beam 2010: MC studies Fraction of charge collected in each layer Data MC Q (pC) First Layer

Test beam 2010: MC studies Fraction of charge collected in each layer Data MC Q (pC) First Layer

Test beam 2010: MC studies Fraction of charge collected in each layer Data MC Q (pC) Second Layer Third Layer

Conclusions – Data analysis Good linearity of energy response using single average parametrization Good energy resolution measured Excellent time resolution measured after slewing corrections.  t =300 ps /√E (GeV)  E /E = 0.092/√E[GeV] /E[GeV]

To do list: Data-MC agreement We have to simulate the PMT signal including gain fluctuations in order to reproduce the collected charge Other studies needed for the evaluation of the contamination in the electron beam at low energy. Tune MC beam parameters to improve Data-MC agreement. Use TOF for electron muon/pion discrimination.

2010 Test beam: palettes and Cherenkov counters quality cut Front Palettes Cherenkov Counters