STAR Analysis Meeting

June 5-7, 2003

New Physics ResultsNew Physics Results

from the FTPCfrom the FTPC

Joern Putschke

for the STAR FTPC group

June 2003 Joern Putschke / STAR Analysis Meeting 2

FTPC calibration finshed :-)

Thanks to all who helped us !

Special thanks toJerome, Lidia and Jeff

June 2003 Joern Putschke / STAR Analysis Meeting 3

Outline

• AuAu calibration quality

• Flow news v1 (Aihong)

• AuAu minbias spectra– <pt> vs. centrality– multiplicity FTPC/TPC

• Forward / backward <pt> correlation

• dAu centrality definition

• dAu spectra

• Outlook & toDo– analysis plans– dAu / pp calibration status

June 2003 Joern Putschke / STAR Analysis Meeting 4

AuAu calibration qualityr s

tep [c

m]

hardware sector

uncorrectedcorrected

For more details on calibration look at (under construction) :http://wwwstar.mppmu.mpg.de/ftpc_calibration_page/index.html

Inner cathode shift correction appliedand works with reasonable precision.

Vertex reconstruction with FTPC trackswith respect to TPC vertex :

x,y +- 200 muz +- 0.5 cm

June 2003 Joern Putschke / STAR Analysis Meeting 5

Flow news (v1)

(Aihong Tang)

v1 signal improvedwith final calibrated FTPC AuAu minbiasdataset !

v2 on the way ...

Flow with FTPCs looks very promising !

June 2003 Joern Putschke / STAR Analysis Meeting 6

AuAu minbias pt distribution1/

Nev

ent d

N/(

p t d

p t)

[1/G

eV2 ]

pt [GeV]

AuAu minbias68k (47K)

no corrections

dca<2cm0.1<=pt<13<=y_pion<3.2n_hits>=5|vertex_z|<=25

<pt>west=0.409 GeV<pt>east=0.394 GeV

June 2003 Joern Putschke / STAR Analysis Meeting 7

<pt> vs. centrality

centrality bin

<p t

> [G

eV]

FTPC westFTPC east

Only slight centralitydependence of <pt>for charged hadronsvisible in the FTPCs.

Same behaviour as for pions in the TPC.

June 2003 Joern Putschke / STAR Analysis Meeting 8

Multiplicity FTPC/TPC

FTPC westFTPC east

centrality bin

<dN

/dN

ch>

Nch,FTPC

Nch

ref

,TP

Cdca<2cm0.1<=pt<12.9<=eta<3.5n_hits>=5|vertex_z|<=25

dummy

June 2003 Joern Putschke / STAR Analysis Meeting 9

String fusion modell

June 2003 Joern Putschke / STAR Analysis Meeting 10

Forward / backward <pt> correlation

with string fusion, no resc.

without string fusion, no resc.

AuAu minbias

June 2003 Joern Putschke / STAR Analysis Meeting 11

Impact parameter vs. multiplicity FTPC east

50k dAu minbias Hijing

z-Vertex <= |60| cm

June 2003 Joern Putschke / STAR Analysis Meeting 12

dAu Multiplicity FTPC east

|vertexz| <= 50cm

dca <= 3cm

2.8 <= || < 3.8

nhits >= 5

triggerID cut (minbias)

# primary tracks FTPC east

1/N

even

tsdN

/dN

ch

June 2003 Joern Putschke / STAR Analysis Meeting 13

Multiplicity FTPC east vs. vertex-z

# prim. tracks FTPC east

dca [cm]

Slight Vertex-z dependence of FTPC east multiplicity for vz>30 cm could be explained due to <dca> shift and useddca cut < 3cm to minimize backgroundand fake tracks.

<dca> shift due to missalignement of FTPCs(not calibrated yet) !

June 2003 Joern Putschke / STAR Analysis Meeting 14

run day

perc

ent

of e

vent

sCentrality FTPC east

|vertexz| <= 50cmdca <= 3cm2.8 <= || < 3.8nhits >= 5triggerID cut (minbias)

nch (east) % of events

<=11 40-100

12-17 20-40

>=18 0-20

June 2003 Joern Putschke / STAR Analysis Meeting 15

dAu pt distribution

dAu minbias1.2 M (370K)

no corrections

dca<2cm0.1<=pt<13<=y_pion<3.2n_hits>=5|vertex_z|<=25

<pt>west=0.36 GeV<pt>east=0.367 GeV

1/N

even

t dN

/(p t

dp t

) [1

/GeV

2 ]

pt [GeV]

June 2003 Joern Putschke / STAR Analysis Meeting 16

FTPC east multiplicity neutron tag

minBiaszdcw<=17zdcw>17

# primary tracks FTPC east

1/N

even

tsdN

/dN

ch

June 2003 Joern Putschke / STAR Analysis Meeting 17

dAu pt distribution neutron tag

FTPC east FTPC west

1/N

eve

nt d

N/(

p t d

p t)

[1/G

eV

2]

1/N

eve

nt d

N/(

p t d

p t)

[1/G

eV

2]

pt [GeV] pt [GeV]

<pt>zdcw>17 =0.352 GeV<pt>zdcw<=17=0.369 GeV

<pt>zdcw>17 =0.359 GeV<pt>zdcw<=17=0.360 GeV

dummy

June 2003 Joern Putschke / STAR Analysis Meeting 18

Outlook & toDo

• Analysis plans– AuAu minbias spectra, flow ...

June 2003 Joern Putschke / STAR Analysis Meeting 19

The STAR FTPC group

• Volker Eckardt• Peter Maierbeck• Maria Mora Corral• Markus Oldenburg • Joern Putschke• Janet Seyboth• Peter Seyboth• Frank Simon

June 2003 Joern Putschke / STAR Analysis Meeting 20

FTPC pion acceptance

June 2003 Joern Putschke / STAR Analysis Meeting 21

AuAu efficiency

June 2003 Joern Putschke / STAR Analysis Meeting 22

dAu efficiency

|vertexz| < 20cm