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Muon trigger upgrade. Kazuya Aoki (Kyoto Univ.). Outline. [MuID LL1] performance( Ken’s estimate) and required rejection factor Cerenkov Upgrade idea An estimate of [MuID LL1 with Cerenkov] performance. [MuID LL1] trigger rate. Required rejection factor
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Muon trigger upgrade Kazuya Aoki (Kyoto Univ.)
Outline • [MuID LL1] performance( Ken’s estimate) and required rejection factor • Cerenkov Upgrade idea • An estimate of [MuID LL1 with Cerenkov] performance
[MuID LL1] trigger rate • Required rejection factor • Ken Read estimated rejection factor using PYTHIA 5.72 , JETSET 7.4 , PISA and V.Cianciolo’s LL1 algorithm. @Sqrt(s)=200GeV • R = 900~1000 (depend on algorithm versions) • We can’t directly say from this but we maybe need additional rejction factor ~ 6 or more (needs further investigation)
Cerenkov idea -- outline • Detector configuration idea • The definition of the new trigger [MuIDLL1 with Cerenkov] • Rejection factor estimate from RUN2 • Neglecting electron effect. • RUN3 analysis • The Cerenkov detector • Private DAQ analysis results • PHENIX DAQ analysis results
Cerenkov idea • By Using CO2 , The Cerenkov threshold will be • 3.5 GeV/c for muons @Cerenkov ( higher than MuID trigger) • 17 MeV/c for electrons @Cerenkov ( problem!) MuID Tunnel Cerenkov Cerenkov behind MuID Threshold = 5.5 GeV@IP MuTr particles IP We don’t have enough space to cover all of the acceptance behind MuID. But threshold is higher than that of Cerenkov between MuTr and MuID. IR Cerenkov Cerenkov between MuTr and MuID Threshold = 4 GeV@IP
Cerenkov idea -- backgrounds • Knock on electrons • Knock on electrons associated with muons whose momentum is lower than the Cereknov threshold • To investigate these electrons we installed a small cerenkov detector. materials muons electrons
# of [MuID LL1] triggered events # of [MuID LL1 with Cerenkov] triggered events Rc= The definition of[MuID LL1 with Cerenkov] • [MuID LL1 with Cerenkov] • When all roads are in the Cerenkov acceptance • If Cerenkov was fired , the event is accepted • If Cerenkov was not fired , the event is rejected • When at least one road is out of Cerenkov acceptance • All of the events is accepted. • Additional rejection factor
Rc= electrons Roads,tracks and Cerenkov MuID roads : the events which has at least one road MuTr tracks : the events which has at least one track Cerenkov : the events which fired the Cerenkov ntracks>0 : the events which has reconstructed tracks. MuID roads ~ MuID LL1 MuTr tracks • Outside of the MuTr • Outside of 1.2<eta<2.2 • MuTr frames • MuTr electronics and HV problems • Ghost roads Current framework Doesn’t reconstruct tracks without roads (ntracks>0) High momentum muons MuTr inefficiency Cerenkov
Rc • Rc = (A+B+C+D) / (B+C) • If we neglect electrons , We can obtain these values from RUN2 • Rc’ = (A+B+C+D)/(B+C) (with MuTr efficiency correction) • Rc’’= (A+B+C+D)/(B) (without MuTr efficiency correction) • Rc < Rc’<Rc’’ • MuTr efficiency (Hiroki) • 0.7 due to MuTr frames • 0.7 due to MuTr electronics and HV problems • Rc’ = Rc’’ x 0.7 x 0.7 MuTr tracks MuID roads ~ MuID LL1 A D B C MuTr inefficiency Cerenkov
Rc’ -- RUN2 pp analysis • RUN#40146 ~ RUN#40639 • uDSTs of these runs are available at /phenix/data30/phnxreco/run2pp_v01_burn1/ • I reject some runs which is not on the good run list used for J/psi analysis (Hiroki’s good run list) • Trigger :MUIDS_1D&&(BBC||NTCw)p0 • I rejected some runs which used the trigger [MUIDS_1D&&(BBC||NTCw)p4](prescale=4) • Because it’s Easy to count numbers. • I also rejected some strange runs. • Which has enough number of roads to have tracks but have NO track at all. • Integrated L = 22.5 (nb)-1
Run2 pp analysis -- result • (nroads>0) • Events which have at least one road • ~[MuID LL1] triggered events • (ntracks>0) • Events which has at least one track • Current framework doesn’t reconstruct tracks without roads. • Tunnel GCT cut • With cerenkov in the tunnel side • Full GCT cut • With cerenkov in the tunnel and the IR -- • BBC/(nroads>0)~430 • 50(mb)/21.8(mb) x 430 ~ 990 • (nroads>0)/(ntracks>0) ~ 4.7 • (ntracks>0)/tunnel cut ~ 2.5 • (ntracks>0)/full cut ~ 6.8 • Rc’’(tunnel) = (nroads>0)/tunnel GCT cut ~ 12 • Rc’’(tunnel+IR) = (nroads>0)/full cut ~ 32 RUN
Run2 pp analysis -- result • Rc’ (tunnel) ~ 6 • Rc’ (tunnel+IR) ~ 16 • Rc = (A+B+C+D)/(B+C) • Rc’ = (A+B+C+D)/(B+C) (with MuTr efficiency correction) • Rc’’= (A+B+C+D)/(B) (without MuTr efficiency correction) MuTr tracks MuID roads ~ MuID LL1 A D B C MuTr inefficiency Cerenkov
E Run2 pp analysis neglects electrons • We need information about ‘E’ • Electrons will reduce the rejection factor. • We can get [E&&B] from RUN3 data analysis MuTr tracks MuID roads ~ MuID LL1 A D B C Cerenkov
RUN3 test experiment • Cerenkov + 4 scintillators + 2” Al plates • Trigger • SC1xSC2xMUID_S1D (for PHENIX DAQ) • SC1xSC2 (for private DAQ) Note that Cerenkov was not included for trigger. Al Al Cerenkov IP SC4 SC3 SC2 SC1
The Cerenkov Counter and The Range Counter Three scintillators Cerenkov Cerenkov particles particles 2” Al plates Range counter SC1
Cerenkov in the South Tunnel 15deg MuID wall Beam pipe 20deg
RUN3 private analysisThe Number of Photo-electron CO2 gas Efficiency = 58% N2 gas Efficiency = 63%
Al Al Cerenkov IP SC4 SC1 RUN3 private resultsElectron energy spectrum • Electron spectrum O : hit X : no hit • The energy deposit • Scintilator ~ 2.9 MeV • Al ~ 22.4 MeV • Cerenkov window ~ 0.1 MeV • Cerenkov mirror ~ 0.45 MeV
Run3 private analysisElectron energy spectrum • Tunnel 15 deg • Black : no selection • Blue : SC1xSC2xMuIDS1D • Red : SC1xSC2xBeam Clock NOTE Upper edge unknown
Run3 private analysisElectrons • This plot shows the number of S1xS2xC events divided by the integrated luminosity calculated from BBC live trig. • Estimated muons ( p>5.5 ) in the cerenkov reagion • (@theta = 15 deg +- 0.5 deg) (from RUN2 data) • 0.1 nb nb • Please note that MuIDS1D was not included. • Statistical error only
Run3 private analysisExpected # of Photo-electron • The # of Photo-electron • L ~ 50cm • Collection eff ~ 90% (with careful design -- by Part.Data) • Quantum eff ~ >20%(240nm-460nm) • n=1.000450 (CO2) n=1.000297 (N2) • Expected : • CO2 -> 7.3 • N2 -> 4.8 (240nm-460nm) Radiator length Light collection efficiency Quantum efficiency
Run3 PRDFF analysis • RUN3 GCT&MUIDS_1D filtered data • Trigger : S1xS2xMUIDS-1D • (please NOTE that Cerenkov hit was not required) • The data available at CCJ(Japan) are used • Run selection criteria • MUIDS HV on , MUIDS granule OK , south magnet on • 5188 events ( 67.9 nb-1) • # of events which have roads (nroads>0) • 683 events • # of events which have tracks (ntracks>0) • 1 event ( The track is out of the trigger scintillators) • Expected # of events firing trigger scintillator from RUN2 : 26.5 events • TOTAL ( if we filter the whole runs and apply the run selection above ) • 7835 events (112 nb-1)
Cerenkov idea Summary • Estimated maximum rejection factor with tunnel cerenkov ~ 6 • Electrons will reduce this rejection factor to some extent. • We need to finalize the analysis • We have GCT&MUIDS1D data but we need to compare with Atsushi’s estimation • I’ll try MUIDS1D data analysis , too to confirm above results.
MuTr LL1 • We can’t directly add MuTr information to the trigger. • It takes about 800 nsec for the current electronics to measure the amount of the charge deposited on a strip. • ADC conversion : 40 usec • We need course but faster decision of momentum! • If we use discriminator instead of ADC • Position resolution will be ~1 cm ( 2 strips )
Cathode strip readout • If we use discriminator instead of ADC • Position resolution will be ~1 cm ( 2 strips )
MuTr muon rejection simulation • From hits at MuTr ST#1 plane#1 and ST#2 plane #1, we can calculate hit at MuTr ST#3 plane #1 assuming straight track. • The distance between calculated hit at ST#3 and actual hit at ST#3 is used to judge the particle momentum • The definition of the distance • Abs(dx)+abs(dy) • the calculation is faster than that of sqrt(dx+dy) • To emulate 1cm resolution • I calculated (x,y) from ( theta,phi,z ) and rounded (x,y) • (x,y) = (1.245 , 4.654 ) (1 , 4)
Momentum VS survival rate • Theta = 150 deg 5cm 4cm Survival rate 3cm 2cm Momentum (GeV/c)
Momentum vs survival rate • Theta = 155 deg 5cm Survival rate 4cm 3cm 2cm Momentum (GeV/c)
MuTr LL1 summary • A lots of works • Background • Needs minbias