5 research outputs found
Review of HBT or Bose-Einstein correlations in high energy heavy ion collisions
A brief review is given on the discovery and the first five decades of the
Hanbury Brown - Twiss effect and its generalized applications in high energy
nuclear and particle physics, that includes a meta-review. Interesting and
inspiring new directions are also highlighted, including for example source
imaging, lepton and photon interferometry, non-Gaussian shape analysis as well
as many other new directions. Existing models are compared to two-particle
correlation measurements and the so-called RHIC HBT puzzle is resolved.
Evidence for a (directional) Hubble flow is presented and the conclusion is
confirmed by a successful description of the pseudorapidity dependence of the
elliptic flow as measured in Au+Au collisions by the PHOBOS Collaboration.Comment: 14 pages, 1 figure, 8 sub-figures, invited plenary talk at the
ICPA-QGP 2005 conference in Kolkata, Indi
Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at âs=200ââGeV
We report STAR measurements of the longitudinal double-spin asymmetry ALL, the transverse single-spin asymmetry AN, and the transverse double-spin asymmetries AÎŁ and ATT for inclusive jet production at mid-rapidity in polarized p+p collisions at a center- of-mass energy of âs=200ââGeV. The data represent integrated luminosities of 7.6ââpb-1 with longitudinal polarization and 1.8ââpb- 1 with transverse polarization, with 50%â55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet AN, AÎŁ, or ATT at mid- rapidity. Recent model calculations indicate the AN results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry ALL significantly improves the knowledge of gluon polarization in the nucleon
Pion interferometry of root s(NN)=130 GeV Au+Au collisions at RHIC
Two-pion correlation functions in An + Au collisions at roots(NN) = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in roots(NN)
Transverse single-spin asymmetry and cross section for Ï0 and η mesons at large Feynman x in pâ+p collisions at âs=200ââGeV
Measurements of the differential cross section and the transverse single-spin asymmetry, AN, vs xF for Ï0 and η mesons are reported for 0.40.55, is consistent with a perturbative QCD prediction, and the η/Ï0 cross-section ratio agrees with existing midrapidity measurements. For 0.5