118772045
Relativistic ideal Bose gas in Harmonic traps
Using semiclassical approximation method, Bose-Einstein condensation (BEC) of a relativistic ideal boson gas (RIBG) with and without antibosons in three-dimensional (3-D) harmonic traps is investigated. The BEC transition temperature T_{c} and the Helmholtz free energy at T_{c} are calculated. The effect of the rest mass of the boson on the properties of the system is also studied. We find that T_{c} of RIBG is higher than that of the nonrelativistic approximation. The RIBG with antibosons is also investigated and it is found that the Helmholtz free energy of the system with antibosons at T_{c} is lower than that of the system without antibosons. It implies that the system with antibosons is more stable.
120885308
Gravitational Waves from a Pseudo-Newtonian Kerr Field with Halos
A close relation between gravitational waveforms and the types of trajectories in a superposed field between a pseudo-Newtonian Kerr black hole and quadrupolar halos is shown in detail. The gravitational waveforms emitted from circular, KAM tori and chaotic orbits must be periodic, quasiperiodic and stochastic, respectively. The chaotic motion can maximally enhance both the amplitudes and the energy emission rates of the waves.
107530267
Implementation of the Domino Sampling Waveform digitizer in the PIBETA experiment
The Domino Sampling Chip(DSC)-Waveform digitization system is a significant addition to electronics arsenal of PIBETA experiment. It is used to digitize waveforms from every photo tube in the detector. Through carefully programmed offline analysis of its raw data collected during regular runtime, better timing and energy resolution are achieved compared with feast’s results. And more importantly, the geometric character of the digitized waveform which contains information of energy deposition of particle decays can be utilized for particle identification, a great advantage that regular unit could not possess. In addition to fastbus , incorporate DSC data through its offline analysis including timing and energy offset, scale calibration will contribute a final more precise result of PIBETA experiment.
14783506
System-size dependence of transverse momentum correlations at √s NN=62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider
We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\eta$, and the azimuthal angle $\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations.
119221593
THE INFLUENCE OF NET QUARKS ON YIELDS AND RAPIDITY SPECTRA OF IDENTIFIED HADRONS
Within a quark combination model, we study systematically the yields and rapidity spectra of various hadrons in central Au + Au collisions at $\sqrt{s_{\rm NN}} = 200\ {\rm GeV}$. We find that considering the difference in rapidity between net quarks and newborn quarks, the data of multiplicities, rapidity distributions for π±, K±, $p(\bar{p})$ and, in particular, the ratios of charged antihadron to hadron as a function of rapidity, can be well described. The effects of net quarks on various hadrons are analyzed, and the rapidity distributions for $K^{0}_{s}$, $\Lambda(\bar{\Lambda})$, $\Sigma^{+}(\bar{\Sigma}{}^{-})$, $\Xi^{-}(\bar{\Xi}^{+})$ and $\Omega^{-}(\bar{\Omega}^{+})$ are predicted. We discuss the rapidity distribution of net baryons, and find that it reflects exactly the energy loss of colliding nuclei.
119871313
The BESIII muon identification system
The muon identification system of BESIII experiment at the IHEP is described. The muon counter (MUC) is composed of resistive plate chambers (RPCs) working in self-quenching streamer mode with the gas mixture Ar/C(2)F(4)H(2)/C(4)H(10)=50/42/8. The design, the construction, the mass production and the quality control result of the detectors are described in detail. The paper also presents the performance of the bare RPCs and the superlayer modules with cosmic rays. Finally, the subsystems of MUC, including the RPC superlayer modules, the gas systems, the HV and LV system and the readout electronic system, are also presented. (C) 2009 Elsevier B.V. All rights reserved.
396092
The SNS linac RF control system
Development of the Spallation Neutron Source (SNS) continues, with operations beginning in 2004. The SNS is a 1 GeV machine consisting of a combination normal-conducting and super-conducting linac as well as a ring and target area. The RF control system (RFCS) for the linac has been under development for two years, with the first versions of the individual modules under construction and system integration begun. This paper will discuss this stage of the design and its implementation. In addition, it will report on the module variations required to use similar hardware for both the normal conducting (NC) and superconducting (SRF) portions of the linac.
298393
Cosmological constant and advanced gravitational wave detectors
Interferometric gravitational wave detectors could measure the frequency sweep of a binary inspiral (characterized by its chirp mass) to high accuracy. The observed chirp mass is the intrinsic chirp mass of the binary source multiplied by (1+z), where z is the redshift of the source. Assuming a nonzero cosmological constant, we compute the expected redshift distribution of observed events for an advanced LIGO detector. We find that the redshift distribution has a robust and sizable dependence on the cosmological constant; the data from advanced LIGO detectors could provide an independent measurement of the cosmological constant. {copyright} {ital 1997} {ital The American Physical Society}