期刊：
HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,2004年28(1):1-10 ISSN：0254-3052
通讯作者：
Bai, JZ
作者机构：
[Bai, JZ] CAS, Inst High Energy Phys, Beijing 100039, Peoples R China.;Univ Sci & Technol China, Dept Modern Phys, Hefei 230027, Peoples R China.;Shandong Univ, Dept Phys, Jinan 250100, Peoples R China.;Zhejiang Univ, Dept Phys, Hangzhou 310028, Peoples R China.;Shanghai Jiao Tong Univ, Dept Appl Phys, Shanghai 200030, Peoples R China.
通讯机构：
[Bai, JZ] C;CAS, Inst High Energy Phys, Beijing 100039, Peoples R China.
关键词：
BES;BEPC;D-0 meson;branching fraction
摘要：
We report the results of an experimental study of the exclusive hadronic decays for D-0 --> K(s)(0)pi(+) pi(-) and (KsK+K-)-K-0 and their resonant structures using BES-I detector at the BEPC Collider. Using the data sample of 22.3 pb(-1) collected at the center-of-mass energy roots = 4.03 GeV, we measured the branching fraction for D-0 --> (K) over bar (0) pi(+) pi(-) to be (5.32 +/- 0.53 +/- 0.40)%, the branching fractions for the decays D-0 --> K* - pi(+), D-0 --> and D-0 --> (K) over bar (0) (pi(+) pi(-))(non-resonant) to be (6.05 +/- 0.32 +/- 0.49)%, (1.17 +/- 0.17 +/- 0.13)% and (1.35 +/- 0.22 +/- 0.17)% respectively. We measured the branching fractions Br(D-0 --> f) to be (1.04 +/- 0.24 +/- 0.16)% for f = (K) over bar (0) K+ K-, (1.12 +/- 0.34 +/- 0.15)% for f = (K) over bar (0)phi and (0.27 +/- 0.13 +/- 0.03)% for f = (K) over bar (0) (K+ K-)(non-phi).
期刊：
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT,2004年522(3):252-273 ISSN：0168-9002
通讯作者：
Llope, W
作者机构：
Rice Univ, TW Bonner Nucl Lab, Houston, TX 77005 USA.;NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Huazhong Normal Univ, Dept Phys, Wuhan 430070, Peoples R China.;Inst High Energy Phys, Beijing 100039, Peoples R China.;Kent State Univ, Kent, OH 44242 USA.
通讯机构：
[Llope, W] R;Rice Univ, TW Bonner Nucl Lab, MS 315,6100 S Main St, Houston, TX 77005 USA.
关键词：
particle identification;time of flight;STAR
摘要：
A time-of-flight system was constructed for the STAR Experiment for the direct identification of hadrons produced in 197Au+197Au collisions at RHIC. The system consists of two separate detector subsystems, one called the Pseudo Vertex Position Detector (pVPD, the “start” detector) and the other called the Time of Flight Patch (TOFp, the “stop” detector). Each detector is based on conventional scintillator/phototube technology and includes custom high-performance front-end electronics and a common CAMAC-based digitization and read-out. The design of the system and its performance during the 2001 RHIC run will be described. The start resolution attained by the pVPD was 24 ps, implying a pVPD single-detector resolution of 58 ps. The total time resolution of the system averaged over all detector channels was 87 ps, allowing direct π/K/p discrimination for momenta up to ∼1.8 GeV/c, and direct (π+K)/p discrimination up to ∼3 GeV/c.
作者机构：
[Adams, J] Univ Birmingham, Birmingham, W Midlands, England.;Argonne Natl Lab, Argonne, IL 60439 USA.;Univ Bern, CH-3012 Bern, Switzerland.;Brookhaven Natl Lab, Upton, NY 11973 USA.;CALTECH, Pasadena, CA 91125 USA.
通讯机构：
[Adams, J] U;Univ Birmingham, Birmingham, W Midlands, England.
摘要：
The pseudorapidity asymmetry and centrality dependence of charged hadron spectra in d+Au collisions at roots(NN)=200 GeV are presented. The charged particle density at midrapidity, its pseudorapidity asymmetry, and centrality dependence are reasonably reproduced by a multiphase transport model, by HIJING, and by the latest calculations in a saturation model. Ratios of transverse momentum spectra between backward and forward pseudorapidity are above unity for p(T) below 5 GeV/c. The ratio of central to peripheral spectra in d+Au collisions shows enhancement at 2<p(T)<6 GeV/c, with a larger effect at backward rapidity than forward rapidity. Our measurements are in qualitative agreement with gluon saturation and in contrast to calculations based on incoherent multiple partonic scatterings.
摘要：
Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au + Au collisions at root(s)NN = 130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are K+/pi(-) = 0.161 +/- 0.002(stat) +/-0.024(syst) and K-/pi(-) = 0. 146 +/- 0.002(stat) +/-0.022(syst) for the most central collisions. The K+/pi(-) ratio is lower than the same ratio observed at the SPS while the K-/pi(-) is higher than the SPS result. The ratios are enhanced by about 50% relative to p + p and 0 + p collision data at similar energies. (C) 2004 Elsevier B.V. All rights reserved.
作者机构：
[Adams, J] Univ Birmingham, Birmingham, W Midlands, England.;Argonne Natl Lab, Argonne, IL 60439 USA.;Univ Bern, CH-3012 Bern, Switzerland.;Brookhaven Natl Lab, Upton, NY 11973 USA.;CALTECH, Pasadena, CA 91125 USA.
通讯机构：
[Adams, J] U;Univ Birmingham, Birmingham, W Midlands, England.
摘要：
Azimuthal anisotropy and correlations at large transverse momenta were presented for Au + Au collisions at √sNN = 200 GeV. Two and four particle correlations as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy was also presented. The elliptic anisotropy v2 was found to reach its maximum at pt ∼ 3 GeV/c, then decrease slowly and remain significant up to pt ≈7-10 GeV/c. The centrality dependence of v2 at intermediate pt was compared to simple models based on jet quenching.
作者机构：
[Adams, J] Univ Birmingham, Birmingham, W Midlands, England.;Argonne Natl Lab, Argonne, IL 60439 USA.;Brookhaven Natl Lab, Upton, NY 11973 USA.;Univ Calif Berkeley, Berkeley, CA 94720 USA.;Univ Calif Davis, Davis, CA 95616 USA.
通讯机构：
[Adams, J] U;Univ Birmingham, Birmingham, W Midlands, England.
摘要：
We report inclusive photon measurements about midrapidity (\y\<0.5) from Au-197+Au-197 collisions at roots(NN)=130 GeV at RHIC. Photon pair conversions were reconstructed from electron and positron tracks measured with the Time Projection Chamber (TPC) of the STAR experiment. With this method, an energy resolution of DeltaE/Eapproximate to2% at 0.5 GeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum (p(t)) spectra of pi(0) mesons about midrapidity (\y\<1) via the pi(0)-->gammagamma decay channel. The fractional contribution of the pi(0)-->gammagamma decay to the inclusive photon spectrum decreases by 20%+/-5% between p(t)=1.65 GeV/c and p(t)=2.4 GeV/c in the most central events, indicating that relative to pi(0)-->gammagamma decay the contribution of other photon sources is substantially increasing.
作者机构：
[Adams, J] Univ Birmingham, Birmingham, W Midlands, England.;Argonne Natl Lab, Argonne, IL 60439 USA.;Brookhaven Natl Lab, Upton, NY 11973 USA.;Univ Calif Berkeley, Berkeley, CA 94720 USA.;Univ Calif Davis, Davis, CA 95616 USA.
通讯机构：
[Adams, J] U;Univ Birmingham, Birmingham, W Midlands, England.
摘要：
We present the results of charged particle fluctuations measurements in Au+Au collisions at rootS(NN)=130 GeV using the STAR detector. Dynamical fluctuations measurements are presented for inclusive charged particle multiplicities as well as for identified charged pions, kaons, and protons. The net charge dynamical fluctuations are found to be large and negative providing clear evidence that positive and negative charged p article production is correlated within the pseudorapidity range investigated. Correlations are smaller than expected based on model-dependent predictions for a resonance gas or a quark-gluon gas which undergoes fast hadronization and freeze-out. Qualitative agreement is found with comparable scaled p+p measurements and a heavy ion jet interaction generation model calculation based on independent particle collisions, although a small deviation from the 1/N scaling dependence expected from this model is observed.
摘要：
Values of the ratios in the mid-rapidity yields of (Lambda) over bar/Lambda = 0.71 +/- 0.01(stat.) +/- 0.04(sys.), (Xi) over bar (+)/Xi(-) = 0.83 +/- 0.04(stat.) +/- 0.05(sys.), (Omega) over bar (+)/Omega(-) = 0.95 +/- 0.15(stat.) +/- 0.05(sys.) and K+/K- = 1.092 +/- 0.023(combined) were obtained in central,rootS(NN) = 130 GeV Au + An collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over antihyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models. (C) 2003 Published by Elsevier B.V.
作者机构：
[Liu, ZX] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.
通讯机构：
[Liu, ZX] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
