RPCs in the PHENIX Muon Trigger

Forward Upgrade Meeting, BNL, August 18-19th

RPCs in the PHENIX Muon Trigger

Matthias Grosse Perdekamp, RBRC and UIUC

Required rejection and what can be obtained fromdedicated level 1 trigger trackers

What are RPCs ?

Pattern recognition

RLT

The CMS RPCs

Plans for 2004

Beam related backgrounds


The chamber structure: • Gap: 2 mm;• HV electrodes : 100 m graphite • Gas pressure : ~ 1 Atm• Gas mixture: ~ 95% F134a, ~ 4.5% Iso-Butane, 0.5%SF6;•bakelite resistivity 10 10- 10 12 cm

Basics of Resistive Plate ChamberBasics of Resistive Plate Chamber

The signal is induced on the read-out electrodes.

From Yong Ban


Avalanche:The electric field is such that the electron energy is larger than the ionising potential

Basics of Resistive Plate Chamber: working modeBasics of Resistive Plate Chamber: working mode

The separation avalanche-streamer decreases with increasing HV .

CMS-RPC will work at avalanche mode, to ensure the proper operation at very high rate.

RPC has been used in L3, ARGO-YBJ,Belle, BaBar experiments. all 4 LHC experiments will use RPC for muon system.

From Yong Ban


Interest in the Muon Trigger

Brookhaven National Laboratory: Brookhaven National Laboratory: Edward Kistenev, Peter Kroon, Mike Tannenbaum, Craig Woody

University of ColoradoUniversity of ColoradoFrank Ellinghaus, Ed Kinney, Jamie Nagle, Joseph Seele, Matt Wysocki

University of California at RiversideUniversity of California at RiversideKen Barish, Stefan Bathe, Vasily Dzhordzhadze, Tim Hester, Xinhua Li, Astrid Morreale, Richard Seto, Alexander Solin

University of Illinois at Urbana ChampaignUniversity of Illinois at Urbana ChampaignMickey Chiu, Matthias Grosse Perdekamp, Hiro Hiejima, Cody McCain,

Jen-Chieh Peng, Ralf SeidelIowa State UniversityIowa State University

John Lajoie, John Hill, Gary SleegeKyoto UniversityKyoto University

Kazuya Aoki, Ken-ichi Imai, Naohito Saito, Kohei ShojiMoscow State UniversityMoscow State University

Mikhail Merkin, Alexander VoroninNevis LaboratoryNevis Laboratory

Cheng Yi ChiPeking UniversityPeking University

Yong Ban, Yajun Mao, Ye’ Yanlin University of New MexicoUniversity of New Mexico

Doug FieldsRIKENRIKEN

Atsushi TaketaniRBRCRBRC

Gerry Bunce, Wei XieUniversity of TenneseeUniversity of Tennesee

Ken Read, Soren SoerensenINFN Trieste

Andrea Vacchi, Mirko Boboesio, Gianluigi Sampa

Group with re-newed interestin PHENIX with the possibleaddition some members of theCMS muon trigger group atPeking University.


Muon Trigger Rates in Run 2003 at 200 GeV

At √s=500GeV, L=2x1032cm-2s-1:

Collision related: o decay-muon and hadron punch thru background rate > 30kHz Reject with momentum cut

o “remanent induced showers” shielding, pointing, radial cuts

Beam related backgrounds: o hadron punch thru o neutrons o decay muons with incoming beam or outgoing beam

Wei Xie

rejected with timing cut

in time but have to punch through all of PHENIX


•Upgraded muon triggerUpgraded muon trigger– Add dedicated muon trigger detectors up- and downstream of the muon

tracker magnet.– Need robustness against beam and

collision related backgrounds.– Support muon tracking

What has been simulated? I

New trackers

similar in the south arm!

•Nose cone calorimeter (NCC)Nose cone calorimeter (NCC)– Can the NCC be used to improve the W-identifcation off-line?- Is this necessary??

Wei Xie


What has been simulated? II

» Current muon trigger:Current muon trigger:– 2.3GeV “deep” muon– Factor of 20-50 rejection and robustness to

background required for p+p at highest luminosities

RPC R&D at UIUC and RPC R&D at UIUC and prototype for run 5.prototype for run 5.

Build on CMS experience?Build on CMS experience?

W

Z

bottom

charm

» Two new tracking chambers add Two new tracking chambers add momentum information to trigger.momentum information to trigger.– RPC’s are the solution for downstream tracker

– Even modest timing information help remove beam related background.

– Upstream: RPC or upgrade muTR front end with output to LL1

» Detailed simulations with lookup-Detailed simulations with lookup-table algorithms give table algorithms give specifications:specifications:– Upstream tracker granularity 10x10cm2 into

look-up table – Downstream tracker granularity 30x30cm2

into look-up table– resolution = 1o


Muon trigger rejections

LUT for tile size: 10cm upstream, 30cm, downstream

Trigger:

(UT*DT*muID.LL1)match*angle-cut


Results on Rejection Factors (see Wei’s talk for details)

degree

<1 <2 <3 <4 <5 <6 <7 <8 <9 <inf

eff 58% 63% 63% 64% 64% 64 % 64 % 64 % 64 % 64 %

rej 24286 17000 11333 8500 6800 6296 5152 4857 3778 1735

(2). MuTr#1. PC2 Res(R)=20cm, Res(phi)=1o. Mutr#1 tile size 25cm/PC2 tile size 60cm

degree

<1 <2 <3 <4 <5 <6 <7 <8 <9 <10

eff 67% 72% 73% 73% 73% 73% 73% 73% 74% 74%

rej 24286 15455 10000 7391 6071 5484 4250 3864 3091 1518

(1). MuTr#1. PC2 Res(R)=10cm, Res(phi)=1o. Mutr#1 tile size 25cm/PC2 tile size 60cm

• PISA hits is smeared in R/. Need to re-do using real detector configuration.

• efficiency for MuTr/PC2/symset LUT is only 76%. Need to understand.

• efficiency for angle cut <1 degree is less since the PC2 angular resolution is 1 degree.

• Efficiency for LUT start to drop after PC2 resolution > 10cm.


Beam related backgrounds: RPC timing resolution!

• Outgoing beam background (attenuated by PHENIX absorber)

• Incoming beam background (out of time)

• Neutron background (out of time)

Three beam background components:

Scintillator Pair

• Scintillator study of background time structure in run 2004 (Wei Xie)


New PHENIX Experiment Specific Shielding –

(final configuration in progress)Typical Background

iron 4’ thick, 10.5' tallPlan View

Elevation View

Blue beam Yellow beam

MuIDMuID

Beam Background simulationsVasily Dzhordzhadze


-+p

+ - e+e-

n

Particles reached MuID

Gap 5 absorber

10K 100 GeV protonsincident on Q03Integrated overallEnergies


100K Incident Protons scrapping Magnet

GAP 5

MARS Study shows that Shielding will reduce background only by factor of 3-4


Pattern Recognition for Muon Tracking?

U-Tracker

Muon fromhadron decays

Muon from W

D-II-Tracker

Silicon endcap

•Muon triggerMuon trigger– Upstream tracker (pad chamber or RPC)– Downstream tracker I (pad chamber or RPC)– Downstream tracker II with timing resolution (RPC)

David Slivermyr, Vince Cianciolo

D-I-TrackerUtilize and upgrade (LL1 output) existing pad-chamber front end electronics (90k channels) pad-size upstream: 1cm2

downstream: 10 cm2


R&D and test data

Matthias Grosse Perdekamp, RBRC and UIUC

Evaluation of muID LL1 Wei Xie, Ken Barish: using run 03 data (UCR)

Background Hiroki Sato: run 02 (Kyoto)

Ken Read, Vasily Dzhordzahdze, Vince Cianciolo: run 03, run04 (UT, ORNL) Wei Xie, Hiro Hiejima, MGP (RBRC, UIUC)

Cherenkov Kazuya Aoki, Naohito Saito, Atsushi Taketani: run 03 (Kyoto, RIKEN)

Nosecone Mikhail Merkin, Edward Kistenev, Richard Seto, Gianluigi Sampa (MSU, BNL, UCR, INFN Trieste)

MuTr Kazuya Aoki, Hiroki Sato, Naohito Saito, Doug Fields (Kyoto, UNM)

RLT/RPC Hiro Hiejima, Alex Linden Levy, Cody McCain, Jen-Chieh Peng, Joshua Rubin, Wei Xie, Matthias Grosse Perdekamp (UIUC, RBRC)


Introduce RPC technology: RPC

o The relative luminosity analysis requires two luminosity monitors which can be scaled to high rates. o ZDC is fine but BBC and NTC have large acceptance and will saturate At L=2x1032cm-2s-1 we expect on average 1.2 interactions/bunch-crossing!

RLT : New 3-station telescope located vertically above the interaction region.

o longitudinal segmentation with ability to a) reject (to a certain degree) non-vertex related background b) monitor luminosity for different vertex cuts.

o azimuthal segmentation to select different momenta and to scale acceptance with luminosity.


Introduce RPC technolgoy: RLT

nosecone80cm

MA-PMT

x

x

x

x

x

x

FEM

LL1

STAR-Scalers

Technology: RPC vs Scinitillators?

HBD/TPC/Silicon

LUT corresponding todifferent vertex cutsand pT bins.


RLT test during run 04

Analysis ongoing, RPC tests at UIUC


CMS-RPCCMS-RPC Project: Project: RPC system at CMS detectorRPC system at CMS detector

China’s share of task: • RE1/2, RE1/3 of end-cap RPC (totally 144 detectors);

• RB1(in,out) of Barrel RPC (totally 120 detectors);

From Yong Ban


Cosmic ray test of the RPC prototype at Peking Cosmic ray test of the RPC prototype at Peking UniversityUniversity

The RPC prototype was being tested by cosmic rays: 3 layers of scintillator construct the cosmic-ray telescope. s small percentage of SF6 killed the streamer signal .

cosmic rays trigger.

avalance signal

Streamer signal

From Yong Ban


Beam test of Chinese RPC prototype at GIF of Beam test of Chinese RPC prototype at GIF of CERNCERN GIF(Gamma Irradiation Facility): simulate the irradiation environment at

LHC.

Chinese RPC prototype was being tested at GIF

From Yong Ban


Beam test results of Chinese RPC Beam test results of Chinese RPC prototypeprototype

Conclusion:The Chinese RPC prototype has good mechanical strength,gas-tightness and HV performances;The efficiency and time resolution are satisfactory;The efficiency at very high irradiation is limited due to the high resistivity of the bakelite.

The PKU-RPC group accumulated experience and technical know-how of

RPC.

From Yong Ban


Laboratory construction at PKULaboratory construction at PKU

Build laboratory for RPC R&D, assembly and test (shared by nuclear experiment group): area of the hall of the workshop ~150m2.

From Yong Ban


Goals and Schedule for 2004

o RLT background tests analysis ongoing o RLT as test bench for RPCs and front end electronics test stand at UIUC obtained first RPC prototype from Tsinghua U. o Tap into Peking experience with CMS trigger chambers. complete performance evaluation available. evaluate to what extend the CMS design can be adapted for PHENIX. noise rate? Front end electronics? o Independent of technology: production in China, NuTech (STAR TOF RPCs, excellent company!!). o RPC FEEs ??


Summary

RPCs are well explored cheap technology for muon trigger applications at the LHC. Good timing resolution will proof efficient in rejection incomingbeam backgrounds and neutrons.

Potential to support the muon tracking.

Possibility to build on CMS experience through the Peking group.

RLT may serve as first step in mastering technology locally.


Muon Trigger: Physics Motivation

d

d

d

d

u

u

u

uWW

, , , A ,L

A-dependence of nucleon structure

-Spectroscopy

Study color screening effects associated with QGP production in quarkonia withdifferent binding energies. RHIC IIluminosities in combination with beambackgrounds may require level 1 trigger.

Measure the A-dependence of the gluon distribution at small x:

o Drell Yan

o Heavy flavors

does this require a muon trigger upgrade?

/

)(xGA

pp dA AA

ΔG to small x: measure ∫ ΔG(x)dx?

Quark polarizations

What is the impact of high statisticsmeasurements of ALL in open heavyflavor production at 500 GeV on ∆Gat small x. Is there anything the triggerUpgrade can add to doing this in the “e-mu-coincidence” channel…

Flavor separation of quark and anti-quark polarizations in W-production:

Open Heavy Flavor?

Precision study of heavy quark energyloss and fragmentation in the final stateformed in HI collisions at RHIC.


The Importance of x-coverage uncertainty in low-x extrapolation!

Example: Measuring the Quark Spin Contribution to the Proton Spin SLAC (E80 and E130) vs CERN (EMC)

0.1<xSLAC<0.7

A1(x)

x-Bjorken x-Bjorken

∫g1(x)dx=∫A1(x)*F2(x)/

[2x(1+R(x))]dxEllis-Jaffe sum ruleProton spin crisis:

Proton Spin = 1/2h = Quark Spin + Gluon Spin + Orbital Angular Momentum≈0.1 EMC, Phys.Lett.B206:364,1988: 1200 citations!

E130, Phys.Rev.Lett.51:1135,1983: 382 citations.

Documents

RPCs in the PHENIX Muon Trigger