Stellar energy loss rates associated with photoneutrino processes in the minimal extension of the standard model

Using the minimal extension of the standard model and considering the charge radius and the anapole moments of a neutrino, we derive analytical expressions for the stellar energy loss rates associated with the production of a neutrino pair \begin{document}$ e^- + \gamma \rightarrow e^- + \nu_e +\overline{\nu_e} $\end{document} in hot plasma under three limiting regimes (nondegenerate, intermediate, and degenerate electrons) of the temperature, electron chemical potential, and plasma energy. The obtained results reveal the presence of an extra contribution of approximately \begin{document}$10$\end{document}% based on the considered calculations.     

Enhanced electron–positron pair production by frequency chirping in one-and two-color laser pulse fields

Enhanced electron–positron pair production by frequency chirping in one- and two-color laser pulse fields is investigated by solving the quantum Vlasov equation. A small frequency chirp shifts the momentum spectrum along the momentum axis. The positive and negative frequency chirp parameters play the same role in increasing the pair number density. The sign change of the frequency chirp parameter at the moment t = 0 leads the pulse shape and momentum spectrum to be symmetric, and the number density to be increased. The number density of produced pairs in the two-color pulse field is much higher than that in the one-color pulse field and the larger frequency chirp pulse field dominates more strongly. In the two-color pulse fields, the relation between the frequency ratio of two colors and the number density is not sensitive to the parameters of small frequency chirp added in either a low frequency strong field or a high frequency weak field but sensitive to the parameters of large frequency chirp added in a high frequency weak field.     

New results on the hadronic vacuum polarization contribution to the muon g-2

Results on the lowest-order hadronic vacuum polarization contribution to the muon magnetic anomaly are presented.They are based on the latest published experimental data used as input to the dispersion integral.Thus recent results on τ→ντππ0 decays from Belle and on e+e-annihilation to π+π-from BABAR and KLOE are included.The new data,together with improved isospin-breaking corrections for τ decays,result into a much better consistency among the different results.A discrepancy between the Standard Model prediction and the direct g-2 measurement is found at the level of 3σ.     

Evidence for further charmonium vector resonances

We discuss the shape of threshold signals in production cross sections of the reaction e<'+>e<,-> → D<'*>D<'*>, at the opening of the D<,s><'*>D<,s><'*> and Λ<,c><'+>Λ<,c><'-> channels. Furthermore, evidence for the ψ(3D), ψ(5S), ψ(4D), ψ(6S), ψ(5D), ψ(7S), ψ(6D), and ψ(8S) new charmonium vector resonances is presented, on the basis of data recently published by the BABAR Collaboration. Central masses and resonance widths are estimated. Confirmation of these resonances would be a huge step in lifting the precision level of hadron spectroscopy towards that of atomic spectroscopy, with far-reaching consequences for theory.     

强激光场中真空极化效应

通过求解狄拉克方程,对强激光场下真空极化问题进行了研究。理论计算结果表明：在仅随时间变化的电场下,要激发狄拉克海中负能级的电子,需要两个阈值条件,即激光场的电场强度大于等于1016 V/cm和激光场的持续时间大于等于10-21 s。前者主要保证负能态电子有足够的能量跃迁到正能态,后者主要是保证电子在跃迁过程中动量亏损得以补偿。     

中国超级陶粲装置

在粒子物理研究领域,陶粲能区具有独特的性质、丰富的前沿物理课题和重大的科学发现潜力,是该领域重点关注的能区之一。为了使我国在该研究领域继续引领世界,依托中国科学技术大学的国家同步辐射实验室,核探测与核电子学国家重点实验室等研究平台,科学家提出建设一台新一代的正负电子对撞机——超级陶粲装置。新一代的超级陶粲装置的设计亮度大于0.5×10³⁵ cm^-2 s^-1,对撞的质心能量覆盖2—7 GeV,相关性能比当前正在运行的北京正负电子对撞机BEPCII 有大幅度的提升。该装置将为探索宇宙中正反物质的不对称性(CP破缺)、深入研究强子内部结构及非微扰强相互作用本质、寻找奇异物质和超越标准模型的新物理现象等前沿重大课题提供关键平台。陶粲装置的预研和建设对我国现有已掌握的高能加速器和探测器相关关键技术提出了重大挑战,对我国的基础科学研究、高新技术的发展以及相关综合性人才的培养等方面具有重要的科学意义和战略地位。     

Electron-Positron Pair Production in a Strong Laser Field Enhanced by an Assisted High Frequency Weak Field

Electron-positron pair production in a strong laser field enhanced by an assisted high frequency weak field is investigated by solving the quantum Vlasov equation.The average and residual pair number densities are obtained for sinusoid electric field and it is found that the high frequency assisted weak field will enhance pair production significantly.There exists an optimal frequency of assisted field that makes the pair production number density get a maximum one,which is a few orders of higher than that without assisted field.We also discuss the other possible assisted fields.     

Approximated Vector Potential of Intense Laser Pulses in a Pair Plasma

A （3＋1 ）-dimensional Kadomtse-Petviashvili （KP） equation for nonlinearly interacting intense laser pulses with an electron-positron （e-p） plasma is derived. Taking into account the combined action of the relativistic particle mass increase and the relativistic light ponderomotive force, using the perturbation method, and allowing different types solution, we discuss the analytical solution of （3＋1）-dimensional KP-I equation, and give the approximate solutions of vector potential of the intense laser pulse in e-p plasma. Our results may be significantly useful in understanding the nonlinear wave propagation and interaction of intense laser beams in an e-p plasma.     

Seed and vacuum pair production in strong laser field

Researches on the electron-positron pair production in the presence of the intense laser field are reviewed, motivated by the theoretical importance of the nonperturbative QED problem and the worldwide development of high power laser facilities. According to the distinct experimental requirements and theoretical methods, two types of pair production are elaborated, which are, respectively, pair production in the combination of a seed particle and the strong laser, and vacuum pair production without a seed particle. The origin of the nonperturbative problem caused by the strong field is analyzed. The main ideas, realisation, achievements, validity, challenges and bottleneck problems of the nonperturbative methods developed for each type of the pair production problem are discussed.     

光的真实本性与未来科技飞跃发展预测

物理学史上,有三大主宰着物理学发展的跨世纪大论战,其中前两次论战的主题是光的概念,第三次论战的主题关系整个现代物理,但整个第三次论战被光的概念所主宰.错误的光子概念与第三次论战占了上风的超距心灵作用结合形成物理学最严重的百年大错.研究发现了三大跨世纪论战中造成真理失败的根源.关于光的本性,论文提供了九项证据证明光只是波...