电子回旋加速器粒子稳定加速的模拟计算

用MAFIA程序计算了电子回旋加速器加速腔上加速孔、阴极孔、辅助孔 (第Ⅱ加速型 )对加速场分布的影响。计算结果表明 :进行粒子动力学模拟计算时 ,忽略这种影响是合理的。另用对电子加速到最终能量跟踪计算的方法 ,同时以能散度为依据 ,计算电子稳定加速的参数范围 ,并给出S波段电子回旋加速器工作参数的计算结果。计算用C语言编制的程序在微机上进行。

Recent development of hydrodynamic modeling in heavy-ion collisions

We present a concise review of the recent development of relativistic hydrodynamics and its applications to heavy-ion collisions.Theoretical progress on the extended formulation of hydrodynamics toward out-ofequilibrium systems is addressed,with emphasis on the socalled attractor solution.Moreover,recent phenomenological improvements in the hydrodynamic modeling of heavy-ion collisions with respect to the ongoing beam energy scan program,the quantitative characterization of transport coefficients in three-dimensionally expanding quark–gluon plasma,the fluid description of small colliding systems,and certain other interdisciplinary connections are discussed.

Dynamically Exploring the QCD Matter at Finite Temperatures and Densities:A Short Review

We provide a concise review on recent theory advancements towards full-fledged(3+1)D dynamical descriptions of relativistic nuclear collisions at finite baryon density.Heavy-ion collisions at different collision energies produce strongly coupled matter and probe the QCD phase transition at the crossover,critical point,and first-order phase transition regions.Dynamical frameworks provide a quantitative tool to extract properties of hot QCD matter and map fireballs to the QCD phase diagram.Outstanding challenges are highlighted when confronting current theoretical frameworks with current and forthcoming experimental measurements from the RHIC beam energy scan programs.

First large scale application of novel Si stripixel detector in real large experiment: Si VTX in PHENIX upgrade at RHIC

2D position sensitive, single-sided Si stripixel detector was selected as the one of the two main components of the Si vertex tracker (Si SVX) in the upgraded PHENIX detector at RHIC (relativistic heavy ion collider) in Brookhaven National Laboratory (BNL). This is the first large scale application of the novel Si stripixel detector in a real large experiment after many years of research and development at BNL. The first and second prototype fabrication runs of the SVX stripixel detectors were carried out successfully in BNL’s Si detector development and processing Lab. The processing of these stripixel detectors is similar to that for the standard single-sided strip detectors: one-sided processing, single implant for the pixel (strip) electrodes, etc. The only additional processing step is the double metal process, a technology that is simple and well matured by many Si detector processing industries and labs, including BNL. The laser and beam tests on those prototype detectors show the 2D position sensitivity and good position resolution in both X and U coordinates (about 25 μm for 80 μm pitch). For the mass production of 400 sensors needed for the Si SVX, the processing technology has been successfully transferred to the industrial: Hamamatsu Photonics (HPK). HPK has produced a pre-production run of stripixel sensors with the full PHENIX SVX specification on 150 mm diameter wafers. The laser tests on these pre-production wafers show good signal to noise ratio (about 20∶1).

Consistency of Perfect Fluidity and Jet Quenching in Semi-Quark-Gluon Monopole Plasmas

We utilize a new framework, CUJET3.0, to deduce the energy and temperature dependence of the jet trans- port parameter, q （E 〉 10 GeV, T）, from a combined analysis of available data on nudear modification factor and azimuthal asymmetries from high energy nuclear collisions at RHIC/BNL and LHC/CERN. Extending a previous perturbative-QCD based jet energy loss model （known as CUJET2.0） with （2＋1）D viscous hydrody- namic bulk evolution, this new framework includes three novel features of nonperturbative physics origin; （i） the Polyakov loop suppression of color-electric scattering （aka ＇semi-QGP＇ of Pisarski et al.）, （ii） the enhancement of jet scattering due to emergent magnetic monopoles near Tc （aka ＇magnetic scenario＇ of Liao and Shuryak）, and Oii） thermodynamic properties constrained by lattice QCD data. CUJET3.0 reduces to v2.0 at high tem- peratures T 〉400 MeV, while greatly enhances ~ near the QCD deconfinement transition temperature range. This enhancement accounts well for the observed elliptic harmonics of jets with pT 〉10 GeV. Extrapolating our data-constrained q down to thermal energy scales, E-2 GeV, we find for the first time a remarkable consistency between high energy jet quenching and bulk perfect fluidity with η/s^T3/q^0.1 near To.

Two Kinds of Deep Hole-Traps in Bi_(4)Ge_(3)O_(12) Crystal

This paper presents the thermoluminescence(TL)and the absorption spectra of a series of doped Bi_(4)Ge_(3)O_(12)(BGO)crystal irradiated by ultraviolet light.By the representation of Fe:BGO and Mn:BGO,the formation mechanism of two kinds of deep TL traps was discussed,and also their association with the stability of color center.

Impact of Vector-Current Interactions on the QCD Phase Diagram

Using a nonlocal version of the Polyakov-loop-extended Nambu-Jona-Lasinio model, we investigate effects of a nonderivative vector-current interaction (relating to the quark-number density) at both real and imaginary chemical potentials. This repulsive vector interaction between quarks has the following impact on the chiral first-order phase transition: at imaginary chemical potential it sharpens the transition at the Roberge-Weiss (RW) end point and moves this critical point toward lower temperatures;at real chemical potential, the critical end point moves on a trajectory towards larger chemical potentials and lower temperatures with increasing vector coupling strength. The conditions are discussed at which the first-order phase transition disappears and turns into a smooth crossover.

淡积云中夹卷混合机制的参数化及二次混合的影响

夹卷混合过程影响着低云中降水的形成、气溶胶间接效应的评估、低云和气候之间的反馈以及雷达遥感云水含量的准确度。淡积云中夹卷混合过程的参数化对改进大尺度模式中云的参数化方案是至关重要的，但日前仍处于起步阶段。本文利用淡积云的飞机观测结果，对夹卷混合过程的参数化进行探索。并利用砸式混合气泡模式（EMPM）进行数值模拟研究。

一个区分和联系层积云中夹卷混合过程与碰并过程的方法

暖云中的夹卷混合过程及碰并过程紧密相关,因为非均匀夹卷混合并随后抬升过程中产生的大滴能启动碰并机制.区分这两个过程并寻找它们之间的联系对于理解暖云中的＂降水之谜＂至关重要.本文提出了一个区分这两个过程,并建立两者之间联系的方法.

Entrainment-mixing parameterization in shallow cumuli and effects of secondary mixing events

Parameterization of entrainment-mixing processes in cumulus clouds is critical to improve cloud parameterization in models,but is still at its infancy.For this purpose,we have lately developed a formulation to represent a microphysical measure defined as homogeneous mixing degree in terms of a dynamical measure defined as transition scale numbers,and demonstrated the formulation with measurements from stratocumulus clouds.Here,we extend the previous work by examining data from observed cumulus clouds and find positive correlations between the homogeneous mixing degree and transition scale numbers.These results are similar to those in the stratocumulus clouds,but proved valid for the first time in observed cumulus clouds.The empirical relationships can be used to parameterize entrainmentmixing processes in two-moment microphysical schemes.Further examined are the effects of secondary mixing events on the relationships between homogeneous mixing degree and transition scale numbers with the explicit mixing parcel model.The secondary mixing events are found to be at least partially responsible for the larger scatter in the above positive correlations based on observations than that in the previous results based on numerical simulations without considering secondary mixing events.

Recursive method for opacity expansion at finite temperature

Using a reaction operator approach, we derive the multiple-scattering induced gluon number distribution function to all orders in powers of opacity at finite temperature. The detailed balance effect is analyzed by taking into account both gluon emission and absorption in a thermal medium. We also calculate virtual corrections and show that the infrared divergence cancels out in the gtuon distribution function at finite temperature.

ANGULAR DISTRIBUTIONS FOR ^(13)C(K^-,π^-)_Λ^(13)C REACTIONS

The study of hypernuclear states produced in （K-, π-） reactions on nuclei has obtained valuable information on the A-nucleus system and has attracted much interest. Recently, the excitation spectra of A13C have been measured for the first time in the experiments at BNL. Different hypernuclear states are excited preferentially

THE MUON ANOMALOUS MAGNETIC MOMENT

The Dirac equation predicts a muon magnetic moment, M→=gμe/2mμS^→, with gyromagnetic ratio gμ = 2. Quantum loop effects lead to a small calculable deviation from gμ = 2, parameterized by the anomalous magnetic moment

RARE KAON DECAYS

A. Introduction： There are several useful reviews on rare kaon decays and related topics [1-17]. Activity in rare kaon decays can be divided roughly into four categories：1. Searches for explicit violations of the Standard Model 2. Measurements of Standard Model parameters 3. Searches for direct CP violation 4. Studies of strong interactions at low energy.

Vud, Vus, THE CABIBBO ANGLE, AND CKM UNITARITY

The Cabibbo-Kobayashi-Maskawa （CKM） [1,2] threegeneration quark mixing matrix written in terms of the Wolfenstein parameters （λ, A, p, η） [3] nicely illustrates the orthonormality constraint of unitarity and central role played by λ.

Status of the chiral magnetic effect and collisions of isobars

In this review, we examine the current theoretical and experimental status of the chiral magnetic effect.We discuss possible future strategies for resolving uncertainties in interpretation including recommendations for theoretical work, recommendations for measurements based on data collected in the past five years, and recommendations for beam use in the coming years of RHIC. We specifically investigate the case for colliding nuclear isobars（nuclei with the same mass but different charge） and find the case compelling. We recommend that a program of nuclear isobar collisions to isolate the chiral magnetic effect from background sources be placed as a high priority item in the strategy for completing the RHIC mission.

Symmetry properties of nonlocal quark bilinear operators on a Lattice(LP~3 Collaboration)

Using symmetry properties, we determine the mixing pattern of a class of nonlocal quark bilinear operators containing a straight Wilson line along a spatial direction.We confirm the previous study that mixing among the lowest dimensional operators, which have a mass dimension equal to three, can occur if chiral symmetry is broken in the lattice action.For higher dimensional operators, we find that the dimension-three operators will always mix with dimension-four operators, even if chiral symmetry is preserved.Also, the number of dimension-four operators involved in the mixing is large, and hence it is impractical to remove the mixing by the improvement procedure.Our result is important for determining the Bjorken-xdependence of the parton distribution functions using the quasi-distribution method on a Euclidean lattice.The requirement of using large hadron momentum in this approach makes the control of errors from dimension-four operators even more important.