NCC simulation update DC meeting Oct 3, 2007 BNL

Summary Schedule –date for NCC Cost-schedule review ~mid Jan- date not finalized –we must have our document to DOE by end of Nov –We must have our document to the collaboration for review by ~mid-Nov A new CVS area set up: offline/analysis/NCCDOCS/NCCsimudoe –The committee (the same previous committee) must pass us on the physics review before the Cost and Schedule review but the scheduling of that review is being done now –The cost and schedule committee will be a new committee Status –angular dependence, pi0, chic things work from PISA to reconstruction etc in pp working on higher multiplicities –Successful test beam run able to read out detector using full electronics chain Axel asked for a full simulation status so some items are repeated from last time

Tasks Each detector group should demonstrate and document scientific feasibility for two or more topics of high importance –Pi’0’s (figure of merit R_AA vs centrality) –Chic_C (figure of merit – R_AA vs centrality [question of S/B] –Simulation from generation, embedding, pisa, reconstruction and pattern recognition, analysis, signal extraction (figure of merit) The NCC group should demonstrate by simulations that the non- projective geometry and shower digitization does not preclude the ability to eliminate background at the level necessary to accomplish the proposed physics goals. –eff of reconstrucing photons/pi0 vs angle –do this vs multiplicity –put in digitization Note: other things will come out but these are icing on the cake –jet reconstruction –direct photons

NCC detector simulation Geant implemented into pisa –Design change move SM detector from gap 9 to gap 3 –(note it went gap 7,9,3) Merge working Major work now – energy calibration

show all ncc, and brick

Change of geometry moved SM Tungsten 4 mm (EM) & 12mm (HAD) 500 um pitch Strips (“StriPixels”) EM1 electromagnetic EM2 electromagnetic HAD hadron identifier SM “shower max ” PS “pre-shower ” Depth: 42X 0 (1.6 λ ABS ) Silicon pads 1.5x1.5 cm 2

Analysis status Extensive shower shape study done to parameterize the showers (decided on 1/r – as a rough 1 st step.) Detector energy “calibrations” had to be done (and now redone with correct pisa.par file) –This turns out to be important – and angle dependent (see later slides) Optimization of the pi0 code is being done (at the moment there are many different ways to calculate the mass) Cuts need to be figured out to optimize the chic –NCC shower cuts –FVTX cuts on DCA

Simulation running AuAu – basically done pp for spin studies about ¼ done 170 more jobs at ~5/day=28 more days

Pattern recognition and reconstruction Detector gives towers (1x1 pad) in EM1 EM2 HAD take highest energy tower as a seed and form clusters Start in EM2, take highest energy cluster –draw line to vertex –match clusters from EM1 EM2 and HAD to form a “track” Iterate until all clusters used –clusters can be shared between tracks – this is where1/r parameterization is used Energy is calculated from ADC sum+angle (sampling fraction) Note – Pi0 study may be done at the GEANT level and not at the PISA level –Need to add magnet yoke and FVTX material in front

10 GeV e- y=1.1 y=1.5 y=2.5 EM1 HAD

Angle studies 10 GeV electron y=1 center of gravity of cluster Like pixel tracking three layers+vertex iteration assuming parameterization of shower shape for cluster sharing etc vertex EM1EM2 HAD photon “track”

eff vs y for 5 GeV Showers Delta E cut required 1 sigma (so max ~94%) need to do vs multiplicity

delta E/E for GeV sigma~23% mean=0.13 Photons

14 E measured / E initial Problem seems to be in calibration in general

Energy correction is rapidity dependent Edouard is working on this

ChiC first energy resolution for NCC then J/psi from FVTX then Chic some numbers

before after quick and dirty energy correction (needs to be done MUCH more carefully – function of angle etc) Ondrej is doing this Edouard found some problems in code

Width of chic ~100 MeV with Energy recal from TDR

Rich analysis, now on to pp pythia events cheat – use know photon for chic Procedure –use known photon (closest one) Cuts –Chisq_ncc<10 –E_ncc(correcte d)>0.5GeV chic_real background all events

harder cuts Cuts –chisq_ncc<20 –E_ncc>1 –pt_photon>0. 5

Sky analysis -Now for real Mixed and Real Events chic embedded in pp min bias Require J/psi and gamma to be in same NCC using rapidity cuts. Apply cuts suggested by Rich, Ephoton>0.5GeV, and chisq_photon <10 Normalize events using inv. mass tails Minv >3.8. Working further on energy calibs – not certain that my analysis had same energy recal Edouard a problem in his code

(  c - J/ψ) Mixed Mass dAu Minbias Plots show Pt slices from 0- 5GeV In 1.25GeV increments. Data sample 50K dAu minbias

(  c - J/ψ) Background Subtracted Plots show Pt slices from 0- 5GeV In 1.25GeV increments. Data sample 50K dAu minbias

Counting question Should get 10K chic in central events in 1 yr run Real question is what is will S/B be? Things that help –dN/dy of pi0 ~1/2 –J/psi width reduced by FVTX by 1.5 –rejection of hadronic decay-DCA cut (needs to be studied)

J/psi width ~100 MeV with fvtx stuff from melynda need to work on additional clean up cuts

What is it? The parts of the NCC Silicon pads 1.5x1.5 cm 2 Tungsten 4 mm (EM) & 12mm (HAD) HAD hadron identifier SM “shower max ” PS “pre-shower ” Depth: 42X 0 (1.6 λ ABS ) 30 GeV π 0 The PS and SM Detectors: identifying π 0 s 500 um pitch Strips (“StriPixels”) SM Total Energy – from pads Opening angle – from PS Energy asymmetry – from SM  invariant mass old slide of illustration

single π 0 simulations PS Total Energy – from pads Opening angle – from PS Energy asymmetry – from SM  invariant mass SM old slide of illustration 2-track single-track new simulation old slide of illustration

merged into pp two track, 5-10Gev two track, 10-15Gev single track, 10-15Gev Signal – pi0’s with pt spectrum put in by hand background – pythia with “real” pi0’s concentrated at low energy

pp merged – single track pi0’s GeV GeV GeV GeV

 0 now merged in 10 min bias pythia events On to higher multiplicites (from edourd) EK 09/25/2007

Track momenta P [GeV/c} PT [GeV/c}

 0’s vs  0’s with 10 MB events single track pi0’s Test particle merged with 10 min bias events just pi0, black – total colors are momentum bins red is lowest (ask edouard what the bins are –get the pt range)

cable fixed 100 GeV e width 5%

Theory Getting pi0 suppression Theory plots form V Topor Pop (Hijing) Will be contacting Ivan Vitev Also running hijing changing MFP and energy loss

Some predictions from Vasile Pop Central 10% y=0 SCF (strong color fluctuati ons)

ncc rapidity Less suppression predicted by SCF model in forward than central rapidity