skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High Transverse Momentum {eta} Meson Production in p+p,d+Au and Au+Au Collisions at sqrt(s NN) = 200 GeV

Abstract

Inclusive transverse momentum spectra of {eta} mesons in the range p{sub T}{approx}2-12 GeV/c have been measured at midrapidity (|{eta}|<0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at {radical}R{sub NN}=200 GeV. The eta mesons are reconstructed through their {eta}{yields}{gamma} {gamma} channel for the three colliding systems as well as through the {eta}{yields}{pi}{sup 0}{pi}{sup +}{pi}{sup -} decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, RdAu(p{sub T}){approx}1.0-1.1, suggests at most only modest pT broadening ('Cronin enhancement'). In central Au+Au reactions, the eta yields are significantly suppressed, with RAuAu(p{sub T}){approx}0.2. The ratio of {eta} to {pi}{sup 0} yields is approximately constant as a function of pT for the three colliding systems in agreement with the high-pT world average of R{sub {eta}}/{pi}{sup 0}{approx}0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies {radical}R{sub NN}{approx}3-1800 GeV as well as, for high scaled momentum xp, in e{sup +}e{sup -} annihilations at {radical}R=91.2 GeV. These results are consistent with a scenario where high-pT eta production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons ({pi}{sup 0},{eta}) are equally suppressed due to final-state interactions ofmore » the parent partons in the dense medium produced in Au+Au reactions.« less

Authors:
 [1];  [2];  [3];  [2];  [3];  [2];  [2];  [2];  [4];  [2];  [2];  [3];  [5]
  1. Brookhaven National Laboratory (BNL)
  2. ORNL
  3. University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
  4. University of Tennessee, Knoxville (UTK)
  5. The
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
930888
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review C; Journal Volume: 75; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 74 ATOMIC AND MOLECULAR PHYSICS; DECAY; ETA MESONS; FINAL-STATE INTERACTIONS; HEAVY IONS; MESONS; MODIFICATIONS; PRODUCTION; SPECTRA; TRANSVERSE MOMENTUM

Citation Formats

Adler, S. S., Awes, Terry C, Batsouli, Sotiria, Cianciolo, Vince, Efremenko, Yuri, Plasil, F, Read Jr, Kenneth F, Silvermyr, David O, Sorensen, Soren P, Stankus, Paul W, Young, Glenn R, Zhang, Chun, and PHENIX, Collaboration. High Transverse Momentum {eta} Meson Production in p+p,d+Au and Au+Au Collisions at sqrt(sNN) = 200 GeV. United States: N. p., 2007. Web. doi:10.1103/PhysRevC.75.024909.
Adler, S. S., Awes, Terry C, Batsouli, Sotiria, Cianciolo, Vince, Efremenko, Yuri, Plasil, F, Read Jr, Kenneth F, Silvermyr, David O, Sorensen, Soren P, Stankus, Paul W, Young, Glenn R, Zhang, Chun, & PHENIX, Collaboration. High Transverse Momentum {eta} Meson Production in p+p,d+Au and Au+Au Collisions at sqrt(sNN) = 200 GeV. United States. doi:10.1103/PhysRevC.75.024909.
Adler, S. S., Awes, Terry C, Batsouli, Sotiria, Cianciolo, Vince, Efremenko, Yuri, Plasil, F, Read Jr, Kenneth F, Silvermyr, David O, Sorensen, Soren P, Stankus, Paul W, Young, Glenn R, Zhang, Chun, and PHENIX, Collaboration. Mon . "High Transverse Momentum {eta} Meson Production in p+p,d+Au and Au+Au Collisions at sqrt(sNN) = 200 GeV". United States. doi:10.1103/PhysRevC.75.024909.
@article{osti_930888,
title = {High Transverse Momentum {eta} Meson Production in p+p,d+Au and Au+Au Collisions at sqrt(sNN) = 200 GeV},
author = {Adler, S. S. and Awes, Terry C and Batsouli, Sotiria and Cianciolo, Vince and Efremenko, Yuri and Plasil, F and Read Jr, Kenneth F and Silvermyr, David O and Sorensen, Soren P and Stankus, Paul W and Young, Glenn R and Zhang, Chun and PHENIX, Collaboration},
abstractNote = {Inclusive transverse momentum spectra of {eta} mesons in the range p{sub T}{approx}2-12 GeV/c have been measured at midrapidity (|{eta}|<0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at {radical}R{sub NN}=200 GeV. The eta mesons are reconstructed through their {eta}{yields}{gamma} {gamma} channel for the three colliding systems as well as through the {eta}{yields}{pi}{sup 0}{pi}{sup +}{pi}{sup -} decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, RdAu(p{sub T}){approx}1.0-1.1, suggests at most only modest pT broadening ('Cronin enhancement'). In central Au+Au reactions, the eta yields are significantly suppressed, with RAuAu(p{sub T}){approx}0.2. The ratio of {eta} to {pi}{sup 0} yields is approximately constant as a function of pT for the three colliding systems in agreement with the high-pT world average of R{sub {eta}}/{pi}{sup 0}{approx}0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies {radical}R{sub NN}{approx}3-1800 GeV as well as, for high scaled momentum xp, in e{sup +}e{sup -} annihilations at {radical}R=91.2 GeV. These results are consistent with a scenario where high-pT eta production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons ({pi}{sup 0},{eta}) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.},
doi = {10.1103/PhysRevC.75.024909},
journal = {Physical Review C},
number = 2,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Inclusive transverse momentum spectra of {eta} mesons in the range p{sub T}{approx_equal}2-12 GeV/c have been measured at midrapidity (|{eta}|<0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. The {eta} mesons are reconstructed through their {eta}{yields}{gamma} {gamma} channel for the three colliding systems as well as through the {eta}{yields}{pi}{sup 0}{pi}{sup +}{pi}{sup -} decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R{sub dAu}(p{sub T}){approx_equal}1.0-1.1, suggests at most only modest p{sub T} broadening (''Cronin enhancement''). In central Au+Au reactions, the {eta} yields are significantly suppressed, with R{sub AuAu}(p{sub T}){approx_equal}0.2. Themore » ratio of {eta} to {pi}{sup 0} yields is approximately constant as a function of p{sub T} for the three colliding systems in agreement with the high-p{sub T} world average of R{sub {eta}/{pi}{sup 0}}{approx_equal}0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies ({radical}(s{sub NN}){approx_equal}3-1800 GeV) as well as, for high scaled momentum x{sub p}, in e{sup +}e{sup -} annihilations at {radical}(s)=91.2 GeV. These results are consistent with a scenario where high-p{sub T} {eta} production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons ({pi}{sup 0},{eta}) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.« less
  • We report a measurement of high-p{sub T} inclusive pi{sup 0}, eta, and direct photon production in p+p and d+Au collisions at sq root(s{sub NN})=200 GeV at midrapidity (0<eta<1). Photons from the decay pi{sup 0}->gammagamma were detected in the barrel electromagnetic calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The eta->gammagamma decay was also observed and constituted the first eta measurement by STAR. The first direct photon cross-section measurement by STAR is also presented; the signal was extracted statistically by subtracting the pi{sup 0}, eta, and omega(782) decay background from the inclusive photon distribution observed in the calorimeter.more » The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading-order perturbative QCD calculations.« less
  • We report a measurement of high-p{sub T} inclusive {pi}{sup 0}, {eta}, and direct photon production in p+p and d+Au collisions at {radical}s{sub NN} = 200 GeV at midrapidity (0 < {eta} < 1). Photons from the decay {pi}{sup 0} {yields} {gamma}{gamma} were detected in the barrel electromagnetic calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The {eta} {yields} {gamma}{gamma} decay was also observed and constituted the first {eta} measurement by STAR. The first direct photon cross-section measurement by STAR is also presented; the signal was extracted statistically by subtracting the {pi}{sup 0}, {eta}, and {omega}(782) decay backgroundmore » from the inclusive photon distribution observed in the calorimeter. The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading-order perturbative QCD calculations.« less
  • We report a measurement of high-p{sub T} inclusive {pi}{sup 0}, {eta}, and direct photon production in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV at midrapidity (0 < {eta} < 1). Photons from the decay {pi}{sup 0} {yields} {gamma}{gamma} were detected in the Barrel Electromagnetic Calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The {eta} {yields} {gamma}{gamma} decay was also observed and constituted the first {eta} measurement by STAR. The first direct photon cross section measurement by STAR is also presented, the signal was extracted statistically by subtracting the {pi}{sup 0},more » {eta}, and {omega}(782) decay background from the inclusive photon distribution observed in the calorimeter. The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading order perturbative QCD calculations.« less
  • The dependence of transverse momentum spectra of neutral pions and {eta} mesons with p{sub T}<16 GeV/c and p{sub T}<12 GeV/c, respectively, on the centrality of the collision has been measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) in d+Au collisions at {radical}(s{sub NN})=200 GeV. The measured yields are compared to those in p+p collisions at the same {radical}(s{sub NN}) scaled by the number of underlying nucleon-nucleon collisions in d+Au. At all centralities, the yield ratios show no suppression, in contrast to the strong suppression seen for central Au+Au collisions at RHIC. Only amore » weak p{sub T} and centrality dependence can be observed.« less