Minijet deformation and charge-independent angular correlations on momentum subspace (η,ϕ) in Au-Au collisions at √sNN=130 GeV

Scientific paper - Original scientific paper

• Author: J. Adams
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: J. X. Zuo
• Collaboration: STAR Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Measurements of two-particle correlations on angular difference variables η_1−η_2 (pseudorapidity) and ϕ1−ϕ2 (azimuth) are presented for all primary charged hadrons with transverse momentum 0.15≤p_t≤2 GeV/c and |η|≤1.3 from Au-Au collisions at √sNN=130 GeV. Large-amplitude correlations are observed over a broad range in relative angles where distinct structures appear on the same-side and away-side (i.e., relative azimuth less than π/2 or greater than π/2). The principal correlation structures include that associated with elliptic flow plus a strong, same-side peak. It is hypothesized that the latter results from correlated hadrons associated with semi-hard parton scattering in the early stage of the heavy-ion collision which produces a jet-like correlation peak at small relative angles. The width of the jet-like peak on η_1−η_2 increases by a factor 2.3 from peripheral to central collisions, suggesting strong coupling of semi-hard scattered partons to a longitudinally-expanding medium. The new methods of jet analysis introduced here provide access to scattered partons at low transverse momentum well below the kinematic range where perturbative quantum chromodynamics and standard fragmentation models are applicable.

• Keywords (english): Minijet; STAR
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C - Nuclear Physics
• Numbering: vol. 73, no. 6, 064907
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.73.064907
• URN:NBN: urn:nbn:hr:217:310162
• Publication: 2006
• Document URL: http://link.aps.org/doi/10.1103/PhysRevC.73.064907
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2006) by the American Physical Society.
• Created on: 2019-10-15 18:42:05