中介子

The superconducting solenoid magnet is one of the key equipment in the muon ionization cooling experiment.

超导耦合螺线管磁体为μ介子离子化冷却实验装置中的关键设备，其线圈内径1 500 mm，长度285 mm，采用截面1.65 mm×1.00 mm的NbTi复合超导线，励磁到210 A时，峰值磁场可达7.4 T。

The nonsymmetry effects can explain the problem appearing in the extention of the life time for the secondary cosmic ray,μ mesons; they also can explain the controversial problem who is more young in the famous twin paradox.

不对称性效应能解释次级宇宙线μ介子出现寿命延长的问题；也解释了著名的孪生子佯谬中谁年轻的争论问题。

Two photons are created in the decay of the neutral pion.

双光子是在中性兀介子衰变中产生的。

Meanwhile, pion also achieved highly concentrations for it has been largely produced in high energy heavy collisions recently.

而π介子由于在近来高能重离子碰撞实验中大量产生，也吸引了人们的研究兴趣。

When treat-ing the spectra, transition, scattering problems, we must use the semi-microscopicapproach. The main new conclusions in this thesis are following:We found the different shrinking effect in ∧ hypernuclei and 〓 hypernuclei, the shrink-ing effect in ∧ hypernuclei are confirmed in a recent experiment;We also found a new approach to treat the configuration mixing of ∧∧ hypernuclei and〓 hypernuclei and that the conversion process may change the spectra and widths of〓 hypernuclei;For the first time, we investigate the neutron star matter without the ∑ hyperon butwith the new meson 〓(975) and φ(1020), we found the contribution of 〓 and φ canmake the equation of state of neutron star soften, and the maximum mass of neutronstar reduces;we extract a set of optimum parameters of the optical potential for the scattering of 〓with nucleus, we found that the 〓 nucleus optical potential need a bigger imaginarypart.

本论文所取得的主要新成果是：独立揭示∧超核和〓超核的不同的收缩效应，其中∧超核的收缩效应被最新实验证实；提出了处理∧∧超核与〓超核混合态的新方法，并发现conversion过程使〓超核能谱和宽度改变；首次在中子星研究中在不包含∑超子的同时考虑新介子〓(975)和φ(1020)，并发现这可使中子星物质的状态方程变软、中子星半径变大、质量变小；独立提取了〓核光学势的一组最佳参数，并证明〓+核光学势要求一个较大的虚部。

This implies that the negative energy projectors'contributions are important in light pseudoscalar bound states.

这说明负能投影贡献在轻赝标介子系统中十分重要，为进一步做更加深入的工作指出了解决问题的途径。

The new introduced physics mechanisms in PYTHIA version6.3 indicate that the complicated string junction may contribute to this splitting effect between mesons and baryons.

在PYTHIA6.3版本中引入的新的物理机制表明复杂的弦纠缠形式可能是这种重子一介子差异的主要原因。

In the high energy physics laboratory called CERN, just outside Geneva in Switzerland, unstable muons (a type of fundamental particle that normally undergoes radioactive disintegration after about one millionth of a second) have been found to live longer by factor of thirty when travelling at high speed around a circular machine shaped like a large hollow doughnut.

在一个叫做 CERN 的高能量物理实验室，这个实验室在瑞士的日内瓦郊外，不稳定的μ介子（一种基本粒子，在百万分之一秒内会进行放射性衰变。）在绕着一个外形像中空的炸面圈形状的圆形机器中高速运行时，它的存在时间已经可以延长30倍了。

The BEijing Spectrometer is an only large general purpose solenoidal detector at the BEPC, on which the physics is to study e+e- collide physics in 2-5GeV region , the emphasis is in the τ-charm physics and the topics include J/ψ physics,ψ(2S) physics, T physics, Ds physics, D physics and hadrons generation mechanism as well as the test of QCD in 2-5GeV.

经过中外科学家的共同努力，在北京谱仪上已作出了包括"τ轻子质量的精密测量"、"2-5GeV能区的R值测量"，以及在J／ψ、ψ(2S)、Ds介子等物理研究中的多项国际领先水平的重要科研成果，引起了国际高能物理界的普遍重视和广泛关注。

In this thesis, we study the weak decays of B mesons in the RPV SUSY.

本论文是在R宇称破缺超对称模型中，我们系统研究了B介子弱衰变。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。