STARYear 2001 Data and Analysis

• RHIC performance• STAR Trigger• Recorded Event Statistics• Offline Production• pp Running• Summary/Outlook

Thomas Ullrich, Nov 30, 2001

11/30/2001 2STAR

RHIC – Performance 2001 compared to 2000

Run 2000s = 130 GeV6 56 bunches* ~ 5 mL 2·1025 (10% design)

Run 2001s = 200 GeV56 bunches* ~ 5 3 m L 2·1026

STAR 2000

~ 8.5 106 sec

L dt 19 year 2000

11/30/2001 3STAR

Event Selection – The STAR Trigger in 2001

Considerably more complex than in 2000: New detectors and components

TDC in ZDC estimate of z-vertex [cut |z| < (25) 35 cm] SVT noise ~ 2 MB for empty events low rates at low Nch

L3 trigger (rare probes) ToF, FTPC, EMC no impact on event selection (almost for EMC) Optimization of event selection

Cope with 3½ orders of multiplicity: UPC (1) central (5000) Maximize “useful” events (in terms of physics analysis) Trigger setup depends on rates (e.g. L3 only useful at high intensities) Minimize bias: ZDC z-vertex cut (L0), L3, etc. Rate studies and tests before implementation of triggers

Trigger Board (chair Tonko) addresses the technical questions (see http://www.star.bnl.gov/protected/trgboard/index.html)

11/30/2001 4STAR

STAR Trigger (continued)

The setup of the trigger was a learning process! The following trigger sets (aka trigger group or trigger configurations) were used in Au+Au:

15PerCTB 15PerCTBVertex Central centralTopo combinedPedestal Cosmic ctbSum CTBWindow emcPedestal EMCtierTEST hanks hanks_emc L3Central L3Central1200 L3Central1200UPC L3Central600 L3Central600UPC

pedTest

laser MediumBias MinBias MinBiasPreVertex MinBiasSvtPulser MinBiasVertex MinBiasVertexCTB100SVT MinBiasVertexSVTTest2 MinBiasVtxCTB75noSVT MinBiasVtxCTB75noSVT33k MinBiasVtxMip15noSVT pedAsPhys

pedestal

pedestal-obs-7-24

physics physics-obs-7-24 productionCentral productionCentral600

productionCentral1200productionCentralKiller productionCentralNoUPC ProductionMinBias pulser SMDTest SVTRawPulser test testCentral topology trgPed UncalibratedMix

Trigger set contains several triggers (trigger mix)

11/30/2001 5STAR

STAR Trigger: two examples

Trigger Set: productionCentralhi-mult & ZDC 1102hi-mult 1101Hadronic central 1100TOPO 3001TOPO & ZDC 3002TOPO Efficiency 3011pulserSVT F101Laser F200

Trigger Set: productionMinBiashi-mult 1101UPC minbias 1001Hadronic minbias 1000pulserSVT F101Laser F200

In RED: counted for “physics” stats

11/30/2001 6STAR

STAR Trigger: Usage in Analysis Check and understand the trigger definitions of the type of events you want

to study Run log browser: http://online.star.bnl.gov/RunLog2001/

You might need more than one trigger word to your assemble dataset In few cases the trigger word changed meaning Do not assume the same trigger word describes the same in all trigger sets In few cases the vertex cut and other parameters changed in the same trigger set

(same configuration name) – this cannot be detected via the offline trigger info Central triggers with L3 are biased

L3 group has lots of info on this on their web pages, also methods in StEvent Dedicated web page:

http://www.star.bnl.gov/STAR/html/all_l/trigger2001/ Contains description and details on trigger 2001 FAQ (describing pitfalls), useful links and more Please help adding useful info

And for the real critical stuff (cross-sections, multiplicity distributions etc) talk to the experts: Hank, Jeff, Tonko, Zhangbu, Falk

11/30/2001 7STAR

Run 2001: “hadronic central” events

Trigger Set Field A (+1) Field ½A (+½) Field ½B (-½) Field B (-1)

central 98,569 0 0 1,561

productionCentral 1,315,474 0 267,417 1,447,612

productionCentral600 204,163 0 0 181,921

productionCentral1200 63,597 0 0 28,311

Summary 1,681,803 0 267,417 1,659,405

Total Sum: 3,608,625 events (72% of the initially planned 5·106)

Used ZDC cut at 10% centrality (720 mbarn) 5 b-1

RHIC: L dt (hadronic) 34 b-1 max 24 ·106 events

We recorded 15% of all (10%) central collisions delivered by RHIC(consider we run central only half the time and with |z|<35 cm)

Nov 14 – Nov 24: 1.3 ·106 events Record day 11/23/2001: 211k hadronic central events

11/30/2001 8STAR

Run 2001: “hadronic minimum bias” events

Trigger Set Field A (+1) Field ½A (+½) Field ½B (-½) Field B (-1)

MinBias

Corrected (0.7 0.2)

29,244

4,094

46,088

6,452

84,862

11,880

556,260

77,876

MinBiasVertex

Corrected (0.7)

0

0

0

0

825,136

577,595

1,747,058

1,237,724

productionMinBias 1,033,580 0 0 1,768,178

Summary 1,037,674 6,452 589,475 3,083,778

Total Sum: 4,717,379 events (94% of the initially planned 5·106)Note: these are useful events, i.e. |z|<35 cm and vertex can be found

Assume observ 0.94 7.2 b = 6.7 b 0.7 b-1

RHIC: L dt (hadronic) 34 b-1 max 227 ·106 events

We recorded 2% of all ‘observable’ hadronic interactions delivered by RHIC(observable means: vertex can be found offline but no |z| range)

…. 0.5 ·106 min bias events with zero field and ?? usable events from 19.6 GeV run

11/30/2001 9STAR

Run 2001: Things to keep in mind Lots of important info is not in the run log (sparse comments)

Volunteers needed: log book run log Detectors in data stream

TPC – always RICH – always FTPC – mostly pToF – mostly SVT – with interruptions EMC – only towards the end SMD – no FPD – rarely

Detector hiccups TPC:

# of dead channels varies in time (RDO boards) FTPC

sometimes only FTPC-West sometimes with missing sector in FTPC-East

SVT see Rene’s talk earlier

EMC see Alex’s talk earlier

11/30/2001 10STAR

Example: Bad Sectors

230 < day < 253 RDO 21-3 bad254 < day < 266 RDO 9-3 and 21-3 bad266 < day RDO 9-3 bad

Run 2266012 Art Poskanzer

11/30/2001 11STAR

Fast Offline

Purpose: complete reconstruction of parts of the recorded events processed in a timely fashion (hours) for QA

Setup, maintained, petted, and cursed by Jerome Use 7 nodes (14 CPUs) out of 124 CRS nodes Use up to 60% of reserved 1 TB disk (purged frequently) Of 12 · 106 recorded events, 11% processed over the entire time Not always timely (days) depending on RCF

Long term: use online cluster sitting in DAQ-room Fast Offline runs with the “dev” version

Latest status but also with the most recent bug

Please Note: results from fast offline are NOT publishable(no stable chain, bugs in chain, calibration pass not reliable)

11/30/2001 12STAR

Offline Test Runs

• Short (test) productions as requested by detector subgroups via period-coordinators or SAC (e.g. for ToF, L3, EMC, FTPC, calibration studies, 19.6 GeV run)

• Managed by Lidia and Jerome

• Competes with “standard” production on 117 (of 124) CRS nodes

• So far ~ 2M events processed

• Sometimes run in “dev”, sometimes in “pro” depending on needs

Parts of Jerome’s TO

DO

List

Please Note: results from offline test runs are NOT

publishable(no stable chain, bugs in chain,

calibration pass not reliable)

11/30/2001 13STAR

Year 2001 Au+Au Reconstruction Current ‘official’ production version is P01gk Original plan: produce only parts and have people check data quality Reconstruction of TPC, RICH, L3 only (ToF raw data on DST) So far: ~ 106 events minimum bias Up to now no requests from PWGs for more …

Next round: might be the one for QM2001 in Nantes aim for complete production (i.e. all y2001 data) include FTPC (at least let’s try hard) require RICH to provide PID which can be used directly by any user

(StRichPidTraits) possibly new corrections for TPC (see Jamies talk) might be the last big production before ITTF comes in (see Mikes talk)

We need to fix TRS (“loving owner” issue) a.s.a.p Still problems with disks at RCF, need solution soon ITTF evaluation will need some resources Near future: need coordination of all slow simulators (simulation leader)

11/30/2001 14STAR

Preparation for pp Analysis So far:

Reconstruction optimized for heavy-ions making use of:

very precise vertex lots of tracks/event for

calibration

pp spin program focus on the lower end in Nch

worse vertex resolution

many small events (I/O vs CPU)

need to keep track of polarization

handling pile-up events new trigger configurations

pp software workshop on 11/19

• Event vertex resolution ppLMV has a sigma of about 2 cm for

x,y,z Need to do much better (new code,

EVR?) How stable is beam spot in x,y ?

• pp-production chain needs to be finalized Currently big memory leaks that kill the

jobs after ~200 events

• Trigger info. trigger scalers info in Db, work in

progress

• Drift velocity calibration Present algorithm is not useful for pp rely more on laser runs

All minutes and some (important) slides posted on reco pages:

http://www.star.bnl.gov/STARAFS/comp/reco/

11/30/2001 15STAR

Summary and OutlookWe have plenty of data on tape

min bias: y2001 10 y2000 central: y2001 7 y2000

Reach new physics High-pt

h spectra and anisotropy out to 12 GeV/c, (?), ratios at high-pt (RICH)

Strangeness , (width, mass-shifts), higher reach in

pT for (multi-) strange baryons, (1520), K*(1430), (1385)

HBT 3D K-K, K- w/ greater resolution, K-p,

-p, K0s-K0

s, pt dependence of R()

Spectra , He4, particle ration

EbyE , K* flow, K/

… and much more …

Lots of work to do to get analysis chain fully functional

Need more help on: TRS Embedding production Code development and maintenance pp chain

First steps for analysis: normalized multiplicity distribution Define common multiplicity classes

Future ITTF Reshape chain (tables -> StEvent) DAQ100