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Title: High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV

Abstract

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. The 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}) aremore » equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]
  1. Brookhaven National Laboratory, Upton, New York 11973-5000 (United States) (and others)
Publication Date:
OSTI Identifier:
20991035
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevC.75.024909; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANNIHILATION; BROOKHAVEN RHIC; CENTER-OF-MASS SYSTEM; COLLISIONS; D QUARKS; ELECTRONS; ETA MESONS; FINAL-STATE INTERACTIONS; GEV RANGE; NUCLEI; PIONS MINUS; PIONS NEUTRAL; POSITRONS; TRANSVERSE MOMENTUM; U QUARKS

Citation Formats

Adler, S. S., Aronson, S. H., Chujo, T., David, G., Desmond, E. J., Drees, K. A., Ewell, L., Franz, A., Guryn, W., Haggerty, J. S., Harvey, M., Johnson, B. M., Kistenev, E., Kroon, P. J., Makdisi, Y. I., Mioduszewski, S., Mitchell, J. T., Morrison, D. P., O'Brien, E., and Pinkenburg, C. High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.024909.
Adler, S. S., Aronson, S. H., Chujo, T., David, G., Desmond, E. J., Drees, K. A., Ewell, L., Franz, A., Guryn, W., Haggerty, J. S., Harvey, M., Johnson, B. M., Kistenev, E., Kroon, P. J., Makdisi, Y. I., Mioduszewski, S., Mitchell, J. T., Morrison, D. P., O'Brien, E., & Pinkenburg, C. High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States. doi:10.1103/PHYSREVC.75.024909.
Adler, S. S., Aronson, S. H., Chujo, T., David, G., Desmond, E. J., Drees, K. A., Ewell, L., Franz, A., Guryn, W., Haggerty, J. S., Harvey, M., Johnson, B. M., Kistenev, E., Kroon, P. J., Makdisi, Y. I., Mioduszewski, S., Mitchell, J. T., Morrison, D. P., O'Brien, E., and Pinkenburg, C. Thu . "High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV". United States. doi:10.1103/PHYSREVC.75.024909.
@article{osti_20991035,
title = {High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV},
author = {Adler, S. S. and Aronson, S. H. and Chujo, T. and David, G. and Desmond, E. J. and Drees, K. A. and Ewell, L. and Franz, A. and Guryn, W. and Haggerty, J. S. and Harvey, M. and Johnson, B. M. and Kistenev, E. and Kroon, P. J. and Makdisi, Y. I. and Mioduszewski, S. and Mitchell, J. T. and Morrison, D. P. and O'Brien, E. and Pinkenburg, C.},
abstractNote = {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. The 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.},
doi = {10.1103/PHYSREVC.75.024909},
journal = {Physical Review. C, Nuclear Physics},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • 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}more » 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.« 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
  • 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
  • Inclusive transverse momentum spectra of {eta} mesons have been measured within p{sub T}=2-10 GeV/c at midrapidity by the PHENIX experiment in Au+Au collisions at {radical}(s{sub NN})=200 GeV. In central Au+Au the {eta} yields are significantly suppressed compared to peripheral Au+Au, d+Au, and p+p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p{sub T} dependence of the suppression is common, within errors, for {eta} and {pi}{sup 0}. The ratio of {eta} to {pi}{sup 0} spectra at high p{sub T} amounts to 0.40<R{sub {eta}/{pi}{sup 0}}<0.48 for the three systems, in agreement with the world average measured inmore » hadronic and nuclear reactions and, at large scaled momentum, in e{sup +}e{sup -} collisions.« less
  • The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2 < p{sub T} < 10 GeV/c) in p+p, d+Au, and Au+Au collisions at {radical}s{sub NN} = 200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p{sub T}, suggesting substantial heavy-quark energy loss at RHIC. The centrality and p{sub T} dependences of the suppression provide constraints on theoretical models of suppression.