共查询到20条相似文献,搜索用时 15 毫秒
1.
Christina Markert 《Acta Physica Hungarica A》2004,21(2-4):171-177
The recent results from resonance production in central Au+Au and p+p collisions at $\sqrt {s_{NN} } = 200$ GeV from the STAR experiment at RHIC are presented and discussed. 相似文献
2.
Hanna Paulina Zbroszczyk 《Physics of Particles and Nuclei Letters》2011,8(9):931-933
The analysis of two-particle femtoscopy provides a powerful tool to study the properties of matter created in heavy ion collisions.
Applied to identical and nonidentical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic
scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced
from identical pion studies, providing additional information about source characteristics. In this paper we present the correlation
functions obtained for protons and antiprotons for Au + Au collisions √s
NN
= 62.4 and 200 GeV. On the other hand, as STAR experiment participates in Beam Energy Scan program, we present theoretical
predictions of p − p, [`(p)] - [`(p)]\bar p - \bar p and p - [`(p)]p - \bar p femtoscopic measurements, based on UrQMD simulation for √s
NN
= 5–39 GeV. 相似文献
3.
Jens Sören Lange 《Acta Physica Hungarica A》2004,21(2-4):357-364
Results from the search for Γ → e+ e? and $B(\bar B) \to e^ \pm X$ in Au+Au collisions at $\sqrt s = 200$ GeV are presented. 相似文献
4.
Brian Lasiuk 《Acta Physica Hungarica A》2002,15(3-4):205-214
Preliminary results for the production of high transverse momentum hadrons are reported from the STAR detector at the Relativistic Heavy Ion Collider. Negative hadron spectra for 2 < pT < 6 (GeV/c) indicate a suppressed yield compared to expectations from $p\bar p$ collisions at similar energy. The elliptical flow deviates from agreement with predictions based on purely hydrodynamical considerations at pT > 1.5 GeV/c. An initial measurement of the flavor dependence of baryon production at pT ≤ 2.25 GeV/c is also presented and discussed. 相似文献
5.
Haibin Zhang 《The European Physical Journal C - Particles and Fields》2007,49(1):355-358
We report on the measurements of D0 meson production via direct reconstruction through the hadronic decay channel D0→Kπ in minimum bias d+Au and Au+Au collisions at with pT up to ∼3 GeV/c. We derive the charm production total cross-section per nucleon–nucleon collision from a combination of three
measurements: the D0 meson spectra, the non-photonic electron spectra from charm semi-leptonic decays obtained in p+p, d+Au, and Au+Au collisions,
and the charm-decayed single muon (prompt muon) spectra at low pT in Au+Au collisions. The cross-section is found to follow binary scaling, which is a signature of charm production exclusively
at the initial impact. The implications of charm quark energy-loss and thermalization in the strongly interacting matter are
discussed.
PACS 25.75.Dw; 13.20.Fc; 13.25.Ft; 24.85.+p 相似文献
6.
Bedangadas Mohanty 《Pramana》2006,67(5):927-935
We present some of the important experimental results from nucleus-nucleus collision studies carried out by the STAR experiment
at Relativistic Heavy Ion Collider (RHIC). The results suggests that central Au+Au collisions at RHIC has produced a dense
and rapidly thermalizing matter with initial energy densities above the critical values predicted by lattice QCD for establishment
of a quark-gluon plasma (QGP). 相似文献
7.
John W. Harris 《Acta Physica Hungarica A》2001,14(1-4):169-180
The Relativistic Heavy Ion Collider (RHIC) along with its complement of four experiments commenced operation for physics in the summer of 2000. Initial results on detector performance, preliminary physics results on hadron production, and the physics anticipated from the STAR experiment will be reported. 相似文献
8.
F. Retière 《Acta Physica Hungarica A》2004,19(3-4):369-372
Ultra-relativistic heavy-ion collisions produced at RHIC differ significantly from a superposition of proton-proton collisions. Evidence of collective expansion has been gathered. The yield of high transverse momentum particles has been found to be lower in head-on Au?Au collisions than is expected by scaling p-p collisions. Di-jet processes, which are frequent in p-p collisions, are almost absent in head-on Au?Au collisions. The current results from RHIC indicate that Au?Au collisions at $\sqrt {S_{NN} } = 130$ GeV and $\sqrt {S_{NN} } = 200$ GeV yield an expanding system that is opaque to high momentum partons. 相似文献
9.
10.
Jan Kapitán 《Indian Journal of Physics》2011,85(1):177-181
Thermalization is one of the key questions in understanding the matter created in Au+Au collisions at RHIC. Heavy-flavor quark
collectivity could be used to indicate the degree of thermalization of the light-flavor quarks. Heavy quark energy loss could
give important information on color charge density of the medium. Direct reconstruction of open charm hadrons is essential
for these measurements. 相似文献
11.
12.
Yuxi Pan 《Physics of Particles and Nuclei》2014,45(1):105-107
Transverse single spin asymmetries A N are expected to be sensitive to par-ton polarization and orbital angular momentum contributions to the nucleon spin. Significantly large A N has been observed in different collision systems such as semi-inclusive deep inelastic scattering (SIDIS) and polarized proton-proton (pp) collisions, indicating a dominant contribution of partonic interactions in the non-perturbative regime. Therefore it’s critical to measure A N in various channels of polarized pp collisions in order to complement SIDIS data and to constrain theoretical models. We report STAR asymmetry measurements on mid-rapidity hadron-jet and di-hadron correlations at √s = 200 GeV and forward rapidity inclusive hadron production at √s = 500 GeV polarized pp collisions. 相似文献
13.
A. A. P. Suaide 《The European Physical Journal C - Particles and Fields》2005,43(1-4):193-200
The single electron spectrum over a sufficiently broad
range provides an indirect measurement of charm and beauty production at RHIC energies. Heavy-quarks are produced in parton-parton
scattering in the initial phase of the collision and thus provide important information about the initial configuration of
the colliding nuclei. Even more important, the final state spectra reflect the interactions of these heavy partons with the
medium and thus allow us to probe the properties of the hot and dense system created in heavy-ion collisions. We present preliminary
measurements of electron and positron
spectra in pp and d + Au as well as preliminary elliptic flow measurements in Au + Au collisions at
GeV performed by the STAR experiment. We describe the measurement techniques used to discriminate electrons from hadrons
and compare the results with theoretical calculations.
PACS. 25.75.-q
Arrival of the final proofs: 20 June 2005 相似文献
14.
Thomas A. Trainor 《Acta Physica Hungarica A》2002,15(3-4):183-193
I review the first STAR event-by-event analysis of <p p > fluctuations, event multiplicity fluctuations and large-scale two-particle p t correlations. Significant nonstatistical charge-independent and charge-dependent fluctuations and correlations are observed. 相似文献
15.
Helen Caines 《Pramana》2003,60(4):627-638
An overview of the latest results from the STAR experiment at RHIC is presented. Preliminary measurements of π,K,p,Λ and Ξ, plus their respective anti-particles atp
t < 2 GeV/c, where the majority of particle production occurs, allow us to probe the soft processes whilst the harder perturbative
regime can be accessed by studying particle spectra and yields at higher momenta. 相似文献
16.
17.
Gang Wang 《Central European Journal of Physics》2012,10(6):1230-1233
Heavy quarks are produced early in the relativistic heavy ion collisions, and provide an excellent probe into the hot and dense nuclear matter created at RHIC. In these proceedings, we will discuss recent STAR measurements of heavy flavor production, to investigate the heavy quark interaction with the medium. Electromagnetic probes, such as electrons, provide information on the various stages of the medium evolution without modification by final stage interactions. Di-electron production measurements by STAR will also be discussed. 相似文献
18.
M. Tokarev 《Physics of Particles and Nuclei Letters》2018,15(5):478-491
The STAR experiment provides measurements of single and double-spin asymmetries in longitudinally and transversely polarized p + p collisions at \(\sqrt s \) = 200 and 510 GeV to deepen our understanding on the proton spin structure and dynamics of parton interactions over a wide range of collision energy, momentum and rapidity of the various produced probes. Polarized processes with W± production allow us to study the spin-flavor structure of the proton. Recent results obtained by STAR on the double longitudinal asymmetry, ALL, of pion and jet production at \(\sqrt s \) = 200 and 510 GeV, the single longitudinal, AL, and transverse, AN, asymmetry of W± production at \(\sqrt s \) = 510 GeV are overviewed. STAR results on azimuthal single transverse asymmetry of pion in p↑ + (p, Au) and jet + π± in p↑ + p collisions are discussed. The proposed Forward Calorimeter System (FCS) and Forward Tracking System (FTS) upgrades at STAR would significantly improve the capabilities of existing detectors for measurements of observables such as asymmetries of pion, jet, Drell-Yan pairs produced at forward rapidities. 相似文献
19.
Neeraj Gupta M. Sharma S. Dogra S. Singh N. K. Pruthi L. Kumar 《Indian Journal of Physics》2011,85(1):105-110
We present the measurement of multiplicity and pseudorapidity distributions of photons production at forward rapidity (−2.3
≤ η ≤ −3.8) for Cu + Cu collisions at $
\sqrt {S_{NN} }
$
\sqrt {S_{NN} }
= 62.4 and 200 GeV. Photons are measured using the Photon Multiplicity Detector (PMD) in STAR experiment at RHIC. The distributions
of (η−η
beam), where η
beam is beam rapidity is presented. Pseudorapidity distributions of photons at forward rapidities, when ob-served in the frame
of one of the colliding particles show the signature of energy independent scaling at forward rapidities known as Limiting
Fragmentation. Measurement of inclusive photons reflect the distribution for π
0 as most of the photons come from π
0 decay. Gluon saturation at initial conditions of the collisions is one of the possible explanations for this scaling. Study
of system-size and incident energy dependence of this phenomenon help us understand the mechanisms better. The system-size
and energy dependence of the widths of scaling in pseudorapidity and comparison with model predictions are presented. 相似文献
20.
Xin Dong 《Acta Physica Hungarica A》2006,25(2-4):435-442
We report recent measurements on the open charm production in d+Au and p+p collisions at $\sqrt {s_{NN} } = 200$ GeV from the STAR detector at RHIC. The two independent measurements — direct open charm hadron (D0, D* etc.) reconstruction and non-photonic single electron spectrum — provide consistent results. The mid-rapidity charm differential cross section per nucleon-nucleon collision from d+Au collisions at RHIC is $d\sigma _{c\bar c}^{NN} /dy = 0.30 \pm 0.04(stat.) \pm 0.09(syst.)$ mb, which is higher than predictions from most of the NLO pQCD calculations. Implications for charmonium production in Au+Au collisions will also be discussed. 相似文献