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

Title: Proton-{lambda} correlations in central Au+Au collisions at {radical}(s{sub NN})=200 GeV

Abstract

We report on p-{lambda},p-{lambda},p-{lambda}, and p-{lambda} correlation functions constructed in central Au-Au collisions at {radical}(s{sub NN})=200 GeV by the STAR experiment at RHIC. The proton and lambda source size is inferred from the p-{lambda} and p-{lambda} correlation functions. It is found to be smaller than the pion source size also measured by the STAR experiment at smaller transverse masses, in agreement with a scenario of a strong universal collective flow. The p-{lambda} and p-{lambda} correlation functions, which are measured for the first time, exhibit a large anticorrelation. Annihilation channels and/or a negative real part of the spin-averaged scattering length must be included in the final-state interactions calculation to reproduce the measured correlation function.

Authors:
; ; ; ; ; ;  [1]; ; ; ; ;  [2]; ; ; ; ; ; ; ;  [3]
  1. University of Birmingham, Birmingham (United Kingdom)
  2. Panjab University, Chandigarh 160014 (India)
  3. Variable Energy Cyclotron Centre, Kolkata 700064 (India) (and others)
Publication Date:
OSTI Identifier:
20864228
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 74; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.74.064906; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ANNIHILATION; BROOKHAVEN RHIC; CORRELATION FUNCTIONS; CORRELATIONS; FINAL-STATE INTERACTIONS; GEV RANGE; GOLD 197 REACTIONS; LAMBDA BARYONS; MULTIPARTICLE SPECTROMETERS; PARTICLE IDENTIFICATION; PIONS; PROTONS; SCATTERING LENGTHS; SPIN

Citation Formats

Adams, J., Barnby, L. S., Blyth, C. O., Gaillard, L., Jones, P. G., Nelson, J. M., Timmins, A. R., Aggarwal, M. M., Bhati, A. K., Bhatia, V. S., Kumar, A., Sharma, M., Ahammed, Z., Chattopadhyay, S., Das, D., Das, S., Mazumdar, M. R. Dutta, Ganti, M. S., Ghosh, P., and Mohanty, B. Proton-{lambda} correlations in central Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States: N. p., 2006. Web. doi:10.1103/PHYSREVC.74.064906.
Adams, J., Barnby, L. S., Blyth, C. O., Gaillard, L., Jones, P. G., Nelson, J. M., Timmins, A. R., Aggarwal, M. M., Bhati, A. K., Bhatia, V. S., Kumar, A., Sharma, M., Ahammed, Z., Chattopadhyay, S., Das, D., Das, S., Mazumdar, M. R. Dutta, Ganti, M. S., Ghosh, P., & Mohanty, B. Proton-{lambda} correlations in central Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States. doi:10.1103/PHYSREVC.74.064906.
Adams, J., Barnby, L. S., Blyth, C. O., Gaillard, L., Jones, P. G., Nelson, J. M., Timmins, A. R., Aggarwal, M. M., Bhati, A. K., Bhatia, V. S., Kumar, A., Sharma, M., Ahammed, Z., Chattopadhyay, S., Das, D., Das, S., Mazumdar, M. R. Dutta, Ganti, M. S., Ghosh, P., and Mohanty, B. Fri . "Proton-{lambda} correlations in central Au+Au collisions at {radical}(s{sub NN})=200 GeV". United States. doi:10.1103/PHYSREVC.74.064906.
@article{osti_20864228,
title = {Proton-{lambda} correlations in central Au+Au collisions at {radical}(s{sub NN})=200 GeV},
author = {Adams, J. and Barnby, L. S. and Blyth, C. O. and Gaillard, L. and Jones, P. G. and Nelson, J. M. and Timmins, A. R. and Aggarwal, M. M. and Bhati, A. K. and Bhatia, V. S. and Kumar, A. and Sharma, M. and Ahammed, Z. and Chattopadhyay, S. and Das, D. and Das, S. and Mazumdar, M. R. Dutta and Ganti, M. S. and Ghosh, P. and Mohanty, B.},
abstractNote = {We report on p-{lambda},p-{lambda},p-{lambda}, and p-{lambda} correlation functions constructed in central Au-Au collisions at {radical}(s{sub NN})=200 GeV by the STAR experiment at RHIC. The proton and lambda source size is inferred from the p-{lambda} and p-{lambda} correlation functions. It is found to be smaller than the pion source size also measured by the STAR experiment at smaller transverse masses, in agreement with a scenario of a strong universal collective flow. The p-{lambda} and p-{lambda} correlation functions, which are measured for the first time, exhibit a large anticorrelation. Annihilation channels and/or a negative real part of the spin-averaged scattering length must be included in the final-state interactions calculation to reproduce the measured correlation function.},
doi = {10.1103/PHYSREVC.74.064906},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • We report on p-{Lambda}, p-{bar {Lambda}}, {bar p}-{Lambda}, and {bar p}-{bar {Lambda}} correlation functions constructed in central Au-Au collisions at {radical}s{sub NN} = 200 GeV by the STAR experiment at RHIC. The proton and lambda source size is inferred from the p-{Lambda} and {bar p}-{bar {Lambda}} correlation functions. It is found to be smaller than the pion source size also measured by the STAR experiment at smaller transverse masses, in agreement with a scenario of a strong universal collective flow. The p-{bar {Lambda}} and {bar p}-{Lambda} correlation functions, which are measured for the first time, exhibit a large anticorrelation. Annihilationmore » channels and/or a negative real part of the spin-averaged scattering length must be included in the final-state interactions calculation to reproduce the measured correlation function.« less
  • Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at = {radical}s{sub NN} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.
  • Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at {radical}{ovr S{sub NN}}=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.
  • We report charged particle pair correlation analyses in the space of {Delta}{phi} (azimuth) and {Delta}{eta} (pseudorapidity), for central Au+Au collisions at {radical}s{sub NN} = 200 GeV in the STAR detector. The analysis involves unlike-sign charged pairs and like-sign charged pairs, which are transformed into charge-dependent (CD) signals and charge-independent (CI) signals. We present detailed parametrizations of the data. A model featuring dense gluonic hot spots as first proposed by Van Hove predicts that the observables under investigation would have sensitivity to such a substructure should it occur, and the model also motivates selection of transverse momenta in the range 0.8more » < p{sub T} < 2.0 GeV/c. Both CD and CI correlations of high statistical significance are observed, and possible interpretations are discussed.« less
  • We report charged particle pair correlation analyses in the space of {delta}{phi} (azimuth) and {delta}{eta} (pseudorapidity), for central Au+Au collisions at {radical}(s{sub NN})=200 GeV in the STAR detector. The analysis involves unlike-sign charged pairs and like-sign charged pairs, which are transformed into charge-dependent (CD) signals and charge-independent (CI) signals. We present detailed parametrizations of the data. A model featuring dense gluonic hot spots as first proposed by Van Hove predicts that the observables under investigation would have sensitivity to such a substructure should it occur, and the model also motivates selection of transverse momenta in the range 0.8<p{sub t}<2.0 GeV/c.more » Both CD and CI correlations of high statistical significance are observed, and possible interpretations are discussed.« less