Muon trigger upgrade

Muon trigger upgrade

Kazuya Aoki

(Kyoto Univ.)

Kazuya Aoki (Kyoto Univ.) 2

Outline

[MuID LL1] performance( Ken’s estimate) and required rejection factor

Cerenkov Upgrade idea An estimate of [MuID LL1 with Cerenkov] perform

ance


[MuID LL1] trigger rate

Sqrt(s) L

(/cm2s)

Cross section

(mb)Rate

(Hz)

Rejection factor required

200 8x1031 50 4x106 2000

500 2x1032 60 12x106 6000 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)

kHz

LR

2

Cerenkov Upgrade idea


Cerenkov idea -- outline

Detector configuration idea The definition of the new trigger [MuIDLL1 w

ith 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!)

MuTrMuIDTunnel Cerenkov

Cerenkov behind MuID

Threshold = 5.5 GeV@IP

IR Cerenkov

Cerenkov between MuTr and MuID

Threshold = 4 GeV@IP

IPparticles

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.


Cerenkov idea -- backgrounds

Knock on electrons Knock on electrons associated with muons wh

ose momentum is lower than the Cereknov threshold

To investigate these electrons we installed a small cerenkov detector.

electrons

muons

materials


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# of [MuID LL1] triggered events

# of [MuID LL1 with Cerenkov] triggered eventsRc=


Rc=

Roads,tracks and Cerenkov

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)

Cerenkov

High momentum muons

MuTr inefficiency

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.

electrons


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’’

MuID roads ~ MuID LL1 MuTr tracks

Cerenkov

A

BC

D

MuTr inefficiency

•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


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 t

rack 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 r

oads. Tunnel GCT cut

With cerenkov in the tunnel side Full GCT cut

With cerenkov in the tunnel and the IR --

RUN

• 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


Run2 pp analysis -- result

Rc’ (tunnel) ~ 6

Rc’ (tunnel+IR) ~ 16


Cerenkov

A

BC

D

MuTr inefficiency

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)


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


Cerenkov

A

B

C

D

E


RUN3 test experiment

Cerenkov + 4 scintillators + 2” Al plates Trigger

SC1xSC2xMUID_S1D (for PHENIX DAQ) SC1xSC2 (for private DAQ)

Cerenkov

SC4

Al Al

IP

SC3 SC2 SC1

Note that Cerenkov was not included for trigger.


The Cerenkov Counter and The Range Counter

Range counterSC1

particles

particles

Cerenkov

Cerenkov

2” Al plates

Three scintillators


Cerenkov in the South Tunnel

Beam pipeMuID wall

15deg

20deg


RUN3 private analysisThe Number of Photo-electron

Efficiency = 63%

CO2 gas

N2 gas

Efficiency = 58%


RUN3 private resultsElectron energy spectrum

Electron spectrum

Cerenkov

SC4

Al

IP

SC1

Al

MeV S1 S2 S3 S4 Cerenkov

4-20 O O X X X

20-28.5 O O X X O

28.5-54 O O O X O

>54 O O O O O

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.

nb

Please note that MuIDS1D was not included. Statistical error only

Estimated muons ( p>5.5 ) in the cerenkov reagion (@theta = 15 deg +- 0.5 deg) (from RUN2 data) 0.1 nb


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)

dEEEEcmr

ZLN ccoll

ee

)(sin)()( 2det2

22

Radiator length Light collectionefficiency

Quantum efficiency nc

1cos

)/(3702

2

eVcmcmr ee


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)


Run3 PRDFF analysisWe missed the right beam clock??


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 idea


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 mome

ntum! 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

2cm

3cm

4cm

5cm

Momentum (GeV/c)

Survival

rate


Momentum vs survival rate

Theta = 155 deg

Momentum (GeV/c)

Survival

rate

2cm

3cm4cm

5cm


MuTr LL1 summary

A lots of works Background

Needs minbias

The end of this file

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Muon trigger upgrade