Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of...
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![Page 1: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/1.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1
First measurement of the
First measurement of the
- meson production with
- meson production with
PHENIX experiment at RHIC
PHENIX experiment at RHICV
ictor R
yabo
v
for th
e PH
EN
IX C
ollab
oratio
n
![Page 2: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/2.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 2
Measurement of ω-meson production in different decay channels (ωπ0π+π-, π0, e+e-) carries information about possible modification of the media produced in HI collisions.
Measurement of hadronic decays of the ω-mesons in p+p collisions creates a baseline for the comparison to other decay modes and collision systems:
Comparison ωhadrons vs. ωdi-electrons in p+p Comparison of the same ratio in A+A
ω is an important ingredient for calculation of electron cocktails used in various PHENIX analyses.
Vector-to-Pseudoscalar meson ratio (/0) at high pT tells us about the production of q-qbar bound states.
High pT results on ω and K0S add to the picture of the
meson RdA in d+Au interactions measured at RHIC
![Page 3: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/3.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 3
Decays under study
Experimental setup
Analysis details: Acceptances Phase space Systematic errors
Results: Spectra, cross-checks and comparisons RdA
ω/π0 ratio Measurement of the mass peak
Summary and Outlook
![Page 4: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/4.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 4
Charge particles DC-PC1Momentum resolution:
No pID for π+π-
Neutrals particles EMCEnergy and space resolution:
%7.0%1.1 TT
T ppp
%,3%1.8 EE
E
ppL
El z 7.5
55.1PHENIX acceptance : -0.35 < < 0.35
2 x 90o for two arms
π-
π0
π+
(see poster 203 in sec.6)
Run 3
![Page 5: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/5.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 5
+ - 0 decay channel: - meson: m = 548 MeV, BR = 23.1 %
- meson: m = 783 MeV, BR = 88.8 %
0 decay channel: - meson: m = 783 MeV, BR = 8.5 %
0 0 decay channel:K0
S - meson: m = 498 MeV, BR = 31.1 %
Minv, GeV
Minv, GeV
Minv, GeV
Run 3 data
![Page 6: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/6.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 6
K0Sπ0π0 ωπ0π+π-π+π-ωπ0
Geometrical acceptance
Trigger efficiency
Combined
PHENIX has different acceptance and trigger efficiencies for the decays under study
Consistency of the results is a powerful cross check
![Page 7: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/7.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 7
GEANT assumes uniform density of the phase-space
We used measured (e.g.:PRL(1962) 325) density distribution profile resulting in 5%-15% correction depending on pT
Correction applies to ωπ0π+π- while
ωπ0 is unaffected and remains a cross check.
π- E kin π + E
kin
π0 Ekin
1.0
0.53.0 5.0 7.0 9.0 pT [GeV/c]
![Page 8: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/8.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 8
Calorimeter related errors:Geometrical acceptance 4-8 % Energy resolution 1-5 %Energy scale 3-23 %
Tracking related errors: DC-PC1 tracking efficiency negligibleMatching cuts 2 %Momentum cuts for charged tracks
negligible Run by run variation 2-3 %
Trigger related errors:ERT trigger efficiency 3-7 %Trigger efficiency and correction 10 %
Analysis uncertainties:0 selection cuts 3-10 %Conversion correction uncertainty 3-6 %Peak extraction uncertainty 9-13 %Branching ratio uncertainties 0.8-5 %Phase space correction 2-8 %
![Page 9: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/9.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 9
First result on the ω-meson production at RHIC energy.
Broad pT coverage from 2.5-9.5GeV/c
Good agreement between two independent decay modes
![Page 10: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/10.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 10
First result on the ω-meson production in d+Au.
Broad pT coverage from 3 GeV/c to 9 GeV/c
Good agreement between to independent decay modes
![Page 11: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/11.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 11
K0S spectra up to pT of 6.5 GeV/c in p+p and 8.5GeV/c in d+Au
Gap between K0S and K+ K- measurement prevents direct
comparison to Time-of-Flight measurements (talk by Maya Shimomura).
PHENIX results are consistent with measurements of STAR in the region of overlap and go to higher pT. Provides a good cross check for analysis approach
hep-ex/0501059
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Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 12
CERES-TAPS measured ω-meson production in hadronic collisions at lower pT
At √31 GeV (π+Be E706) spectrum have steeper slope
Instead of comparing spectra we can compare ω/π0 ratio
![Page 13: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/13.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 13
p+p
d+Au First result on the Vector/Pseudo-scalar meson ratio at RHIC at high pT
Ratios are similar in p+p and d+Au and close to 1
Ratios do not change in a range of pT from 2 GeV/c to 9 GeV/c within systematic errors
PYTHIA (default) tuned to LEP data at lower √s suggests slightly higher ratio
![Page 14: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/14.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 14
π0 η K0S φ
RdA measured for - mesons is consistent with 1 within the systematic errors
Heavier mesons tend to show higher value of RdA
![Page 15: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/15.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 15
PHENIX can measure position of the centers of ω-meson mass peaks at different pT. Current (run3) measurements are limited by statistics.
Possibility to measure the width of ω is under investigation
In run3 the widths of the peaks is about 22 MeV at natural width of 8.5 MeV
Minv, GeV
0+-
![Page 16: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/16.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 16
Au+Au
miss-ID combinatorics
clear peak
PHENIX can measure - mesons in AuAu at √sNN = 200 GeV
See clear signal in 0 channel at pT > 7 GeV/c
Statistics of Run4 let to measure centrality dependence at high pT
(poster 193, session 6)
0
Co
un
ts
Half of Run4 statistics, loose cuts
![Page 17: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/17.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 17
The first measurement of the ω-meson production at RHIC in p+p and d+Au systems is shown:
The spectra are measured in pT range from 2.5 to 9.5 GeV/c,
Two decay modes for ω-meson give consistent results, RdA = 1.3 ± 0.2 in the range of measurement, ω/π0 (inclusive) = 0.9 ± 0.1 in p+p, Ratio is independent of pT within systematic errors, ω-meson mass is consistent with the PDG value, Clear peaks are seen in Au+Au data at high pT
K-meson measurement is consistent with existing results and extended to substantially higher pT.
Future plans: Run5 p+p with x15 more statistics, Run4 Au+Au with 1.5B events on tape, Run5 Cu+Cu with statistics comparable to Au+Au, Other decay modes.
![Page 18: Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 1 First measurement of the - meson production with PHENIX experiment at.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f2b5503460f94c46891/html5/thumbnails/18.jpg)
Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 18
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Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 19
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Victor Ryabov (PNPI) for the PHENIX Collaboration QM2005 Budapest Aug,06,2005 20
d+Au
cou
nt
s
cou
nt
s
Statistics of Run3 d+Au is sufficient only to see the indication of -meson in e+e- channel. No comparison can be done with hadronic channel
Statistics of Run4 Au+Au allows to produce estimation of the dN/dy
(poster 195, session 6)