Year -2

• topics

• simulations needs for these

Barbara Jacak

March 2, 2001

Year -2 physics topics

• This year’s analyses at s = 200– multiplicity, ET, flow

– single particle spectra, ratios– HBT

• higher pT

• electron pairs and K+K-

• muons and e-• direct • spin

For analyses like this year

• HIJING events for Nch, ET, 0 corrections– ~100K events adequate, as this year

• single particles for correction functions & embedding– as this year, but higher statistics

– few days - a week CPUs usage

Charged singles corrections• Throw single particles

– flat in pT, weight for correct spectrum

– physics processes in PISA yield decay, interaction corrections

• Tracking as in data– get geom. Acceptance & tracking efficiency

– rely upon DC,PC simul/data agreement

– correct for match, TOF cuts via cut – TOF simulation being worked on now - will

allow same cuts on MC & data

• Make corrections vs. pT

– fit to remove statistical fluctuations

• Separate Nch dependence– by embedding tracks into real events

– check that pT and Nch effects factorize

completeEvaluation ntuple

Event Vertex: eventxvtx, eventyvtx, eventzvtx

Pc Vertex:

Reconstructed: pc13vtxr

GEANT: pc13vtxm

Bbc Vertex and t0: bbcvtx, bbct0

Dc charged particle track:Reconstructed: recoQual, momentumR, theta0R, phi0R, xhits, uvhits ,chi2, numHitsFit

Evaluation: sumfound, solution, . . .

GEANT: momentumG, theta, phi, theta0G, phi0G, alphaG, betaG, zedG

Pc1 and Pc3 hits:Reconstructed: xpc1r,ypc1r,zpc1r,xpc3r,ypc3r,zpc3r

Projected: xpc1pro, ypc1pro, zpc1pro, xpc3pro, ypc3pro, zpc3pro

GEANT: xpc1m, ypc1m, zpc1m, pc3mcid, xpc3m, ypc3m, zpc3m

Particle generation, decay vertex, ID: generation, particleID, parentID, primaryID, rvtx, zvtx

Emc shower position and energy:Reconstruced: xemcreco, yemcreco, zemcreco, emcecore, emcecorr,. . .

Projected: xemcproj,yemcproj,zemcproj,pathlemc

GEANT: xemcmc,yemcmc,zemcmc,. .

Crk PMTs/pathlength:Reconstructed: crkacc, crknpmt0, crknpmt1, crknpmt3, crknpe0, crknpe1, crknpe3, crkchi2, crkdisp

Projected: crkpath

Tof time-of-flight:Reconstructed: xtofr, ytofr, ztofr, toftofr, elosstofr, pidtofr

Projected: xtofpro, ytofpro, ztofpro, tofpath

GEANT: xtofm, ytofm, ztofm, toftofm,elosstofm, pidtofm

completeEvaluation ntuple. . .

Pairs• Factorize corrections• Throw single parent distribution

– according to physical distribution

– events have 2 instead of 1 particle• corrections as for singles

• Denominator in corrections– daughters within acceptance &

kinematic cuts

– separate correction for this• analytical for resonances with known decay

kinematics

• cannot do w/o model dependence for continuum

• impose geometry/kinematic cuts on theory

• Relation to singles corrections– 2D space, fit function to corrections

– exchange systematic for statistics

HBT

• Single particle corrections cancel

• MC corrections for 2-particle acceptance, efficiency cutting into q space

• MC to study residual correlation effects

Higher pT needs

• Full simulation of TEC tracking– tune as was done for DC

• Modeling to optimize outer detector cuts– further response tuning?

• Single particle events with full history– develop cleanup for pT>5 GeV/c

– recall S/B now ~1 at 5 GeV/c

• Separate check of multiplicity dependence

Direct photons• Calorimeter analysis

– understand showers to few %– embed showers/high statistics– systematic studies

• specialized simulations

• by the analyzers themselves

• requires CPU availability

• Via conversions– special runs in both data and MC

• magnetic field

• extra converter

– systematics on e ID, kinematic cuts• described already by Akiba

• Some full HIJING events for background study

Summary

• Few 100K central arm full HIJING events– also need muon full events…

– but muon embedding important!

• Many single particle runs– centralize generation & reco?

– Common embedding study?

• Pair acceptance studies

• Resources for systematic studies– by analyzers themselves