亚夸克模型,轻子型夸克和一种简单的夸克-轻子结构模型

基于最简洁的 rishon亚夸克模型 ,讨论了由此可以组成的各种玻色子和费米子 .这可以导出轻子型夸克及一些新粒子 .进而提出一种简单的夸克 -轻子复合结构的动力学模型 ,如此可以不引入色 ,并与已知的粒子质量关系 ,衰变道一致 .最后 ,简单探讨了中微子有质量的某些问题 。

可能存在的轻子型夸克态

最近在德国汉堡发现了一种轻子与夸克相结合的新物质－－轻子夸克。本文根据焦－－宫亚夸克模型及亚夸克对的产生与重组合机制，探讨了可能存在的轻子型夸克态。

质量m′>50m_p的奇异粒子与(q′,q^-′)复合态

最近实验研究显示 :发现了一种质量m′>5 0mp、与 4种自然力不发生作用 ,并支持超对称模型的奇异粒子 .通过分析 ,编外夸克 q′(b,g ,g)和 q′的复合态 (q′, q′)也具有这些性质 .我们认为 ,质量m′>5 0mp 的奇异粒子可能就是“轻子型夸允”q′和 q′的复合粒子 (q′ , q′) .

编内、“编外”粒子的超对称性和SU_f(3)表示

据焦一宫提出的夸克、轻子的亚克三体结构模型和推广后的Preon模型 ,讨论了超对称性的数学和物理基础 ,分析了编内费米子和“编外”玻色子间具有的正、反两界粒子一一对应的超对称关系 ,且正、反两界粒子分别满足SUf(3 )群和SUf(3 )亚群对称 .从而认为最近观测到的质量m′ >5 0mp 的奇异粒子是“编外”轻子型夸克q′及 q′的复合态H′(q′, q′) .发现 l- -q共振是“编外”玻色子中存在“反轻子型夸克”S+ 23c (bc , g)的必然结果 。

编外粒子及可能存在的新物质态

从亚夸克物理中允许存在的编外粒子出发，探索了可能存在的双夸克态，双轻子态以及轻子夸克等新物质态，给出了它们的结构性和ＳＵ（３）对称表示。

A Study on Radiative Dileptonic Decays B^0（Bs）→γe^＋e^-

We study the rare radiative dileptonlc decays B^0（Bs）→γe^＋e^- （e = e, μ） in the standard model By using the B meson wave function constrained by non-leptonic decays, the branching ratios turn out to be of the order of 10^-9 for Bs→γe^＋e^-, γe^＋e^-, and 10^-10 for Bs→γe^＋e^-, γe^＋e^-. Based on the study, these decays are accessible at the near future LHC-b experiment, which are useful to determine the B（B,） wave function.

Perturbation Effects of Ion Screening to Leptons in Type-Ⅱ Supernova

Based on the new progenitor stars model, the influence of ion screening is investigated. The simulation results show that ion screening has weak perturbation effects to the leptons in type-II supernova explosion. Ion screening decreases slightly the fraction of leptons and prolongs slightly the shock propagation time. Moreover, simulation results are shown that ion screening increases the total energy loss and reduces the shock energy, eventually decreasing of explosion energy and becomes a negative factor to supernova explosion. In addition, comparison of slight perturbated variation of ion screening to leptons, but simulation results＂ show that ion screening affects obviously explosion energy of type-II supernova, hence, it can also confirm that the variation of leptons is very sensitive to energy in supernova explosion.

亚夸克粒子的B分布、Γ分布和超对称性

据实验、理论分析认为 :在高能下F -D统计和B -E统计将统一被B分布或Γ分布替代 .给出了价-海亚夸克混合模型中的B分布和Γ分布函数 ,与超对称的要求相符 .讨论了轻子型夸克q′和其反粒子 q′的复合粒子 (q′ , q′)是促成费米子和玻色子相互转变———超对称的中介 。

A Shell Model Mass Formula for Exotic Light Nuclei

An analytic phenomenological shell model mass formula for light nuclei is constructed. The formula takes into account the non locality of the self consistent single particle potential and the special features of light nuclei, namely： （a） charge and mass distributions are closer to a Gaussian shape than to the shape characteristic in medium and heavy nuclei; （b） the central charge and mass densities are larger than, and decrease towards, the ＂asymptotic＂ values that are the reference parameters for nuclear matter; and （c） after a shell closure, the next level has a larger orbital angular momentum and a noticeably larger mean square radius. Only then a good numerical fit is obtained with parameters consistent with optical model analysis and empirical spin-orbit couplings. A correlation between the ＂skin effect＂ and the symmetry dependence of the optical potential is established. Towards the neutron drip line the potential well depth, the spin-orbit splitting of the single particle levels and the gap between major shells decrease, as has been observed. The ensuing shift and contraction of the single particle level scheme may lead to： （a） to strong configuration mixing and new magic numbers, and （b） the onset of the halo effect, to avoid the expulsion of single particle levels to the continuum.

System design of a dexterous lightweight robot arm with remote control

This paper presents a novel remote controlled dexterous robot arm with 6 degrees of freedom （DOF）. As a highly integrated mechatronics system, sensors and their signal processing system are integrated inside each joint. To lighten the weight, almost all mechanical parts are made of aluminum and the robot control system is placed outside. The modular concept is adopted during the robot design process for time and cost saving. Considering the much greater torque acted on the two shoulder joints, the joint shells are strengthened in the design to increase joint stiffness and suppress system vibration. Meanwhile, to simplify the maintenance, a new spring pins electronic connector is designed to disassemble every joint, connector and link independently without cutting any cables. The teleoperation technology enables the robot to offer more convenient service definitely for people＇ s daily life. Virtual reality technology is used to solve the time delay problem during teleoperation. Finally, two typical daily chore experiments are implemented to prove the manipulation ability of the dexterous robot arm.

A common origin of muon g-2 anomaly,Galaxy Center GeV excess and AMS-02 anti-proton excess in the NMSSM

The supersymmetric model is one of the most attractive extensions of the Standard Model of particle physics.In light of the most recently reported anomaly of the muon g-2 measurement by the FermiLab E989 experiment,and the excesses of gamma rays at the Galactic center observed by Fermi-LAT space telescope,as well as the antiproton excess observed by the Alpha Magnetic Spectrometer,we propose to account for all these anomalies or excesses in the Next-to-Minimal Supersymmetric Standard Model(NMSSM).Considering various experimental constraints including the Higgs mass,B-physics,collider data,dark matter relic density and direct detections,we find that a~60 GeV bino-like neutralino is able to successfully explain all these observations.Our scenario can be sensitively probed by future direct detection experiments.

Experimental investigation on the wing-wake interaction at the mid stroke in hovering flight of dragonfly

This paper focuses on flow structures of the wing-wake interaction between the hind wing and the wake of the forewing in hovering flight of a dragonfly since there are arguments whether the wing-wake interaction is useful or not.A mechanical flapping model with two tandem wings is used to study the interaction.In the device,two identical simplified model wings are mounted to the flapping model and they are both scaled up to keep the Reynolds number similar to those of dragonfly in hovering flight since our experiment is conducted in a water tank.The kinetic pattern of dragonfly(Aeschna juncea) is chosen because of its special interesting asymmetry.A multi-slice phase-locked stereo particle image velocimetry(PIV) system is used to record flow structures around the hind wing at the mid downstroke(t/T=0.25) and the mid upstroke(t/T=0.75).To make comparison of the flow field between with and without the influence of the wake,flow structures around a single flapping wing(hind wing without the existence of the forewing) at these two stroke phases are also recorded.A local vortex identification scheme called swirling strength is applied to determine the vortices around the wing and they are visualized with the iso-surface of swirling strength.This paper also presents contour lines of z at each spanwise position of the hind wing,the vortex core position of the leading edge vortex(LEV) of hind wing with respect to the upper surface of hind wing,the circulation of the hind wing LEV at each spanwise position and so on.Experimental results show that dimension and strength of the hind wing LEV are impaired at the mid stroke in comparison with the single wing LEV because of the downwash from the forewing.Our results also reveal that a wake vortex from the forewing traverses the upper surface of the hind wing at the mid downstroke and its distance to the upper surface is about 40% of the wing chord length.At the instant,the distance of the hind wing LEV to the upper surface is about 20% of the wing chord length.Thus,there must be a wing-wake interaction mechanism that makes the wake vortex become an additional LEV of the hind wing and it can partly compensate the hind wing for its lift loss caused by the downwash from the forewing.

Lepton Electric Charge Swap at the 10 TeV Energy Scale

We investigate the nature of the dark matter by proposing a mechanism for the breaking of local rotational symmetry between ordinary third family leptons and proposed non-regular leptons at energy scales below 10 TeV. This symmetry breaking mechanism involves electric charge swap between ordinary families of leptons can and produces highly massive non-regular leptons of order 0 （1 TeV） mass unobservable at energy scales below 10 TeV （the scale of LEP Ⅰ, Ⅱ and neutrino oscillation experiments）. Electric charge swap between ordinary families of leptons produces heavy neutral non-regular leptons with order 0 （1 TeV） masses, which may form cold dark matter. The existence of these proposed leptons can be tested once the Large Hadron Collider （LHC） becomes operative at 10 TeV energy-scales. This proposition may have far reaching applications in astrophysics and cosmology.

Improved Light-Cone QCD Sum Rule Analysis of Rare Decays Λ_b → Λ_γ and Λ_b → Λl^+ l^-

We present a systematic light-cone QCD sum rule study of the exclusive rare radiative decay Ab → Aγ and rare semileptonic decay Ab→ Al＋ l- within the framework of the standard model. Although some light-cone sum rule （LCSR） studies on these rare processes can be found in different literatures, it is necessary to reanalyze them systematically for the reason that either the baryonic distribution amplitudes are improved or different interpolating currents for the Ab baryon may lead to quite different results. In addition, the rare process Ab →Aγ has not yet been analyzed by LCSR with the Ioffe-type current. Taking all these reasons into account, we perform LCSR calculations of both the processes with two types of interpolating currents. Our calculations show that the choice of the interpolating current for the Ab baryon can affect the predictions significantly, especially for the rare radiative decay process.

t→cγ and t→cg in Local Gauged Baryon and Lepton Numbers

In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that the branching ratios of t →cγ and t →cg can reach 10^-6 and 10^-5 respectively, which can be detected in near future.

Exclusive Semi-leptonic Decays b → s(d)ν in the Standard Model with Fourth Generation

We consider the effects of the fourth generation quarks on the rare B decay processes described by the b → s（d）vv processes at the quark level. We find that the values of the branching ratios for some of these rare decay processes are much larger than the standard model （SM） predictions. These processes can be used to constrain the relevant free parameters.

Two Higgs Doublet Model Ⅲ and Double-Lepton Polarization Asymmetries in Λ_b →Λμ^+μ^- Decays

Using the form factors calculated both in lattice QCD and HQET, we analyze the branching ratio, doublelepton polarization asymmetries and averaged double-lepton polarization asymmetries of Λ_b →Λμ^+μ^- decay in the2 HDM Ⅲ, respectively. Combining the experimental constrains on the 2HDM Ⅲ parameters, we take two set of representative parameter spaces in our calculations. For the branching ratio of Λ+b →Λμμ-decay, considering the uncertainties of the form factors and input parameters, we find the results of both SM and 2HDM Ⅲ can satisfy the current experimental data in the framework of lattice QCD, but not in HQET. Then we calculate the double-lepton polarization asymmetries Pij and their averaged values Pij, we find the double-lepton polarization asymmetries PLT,PNN, and PTT are sensitive to the 2HDM Ⅲ. However, PLN, PNL, PNT, and PTN show the opposite results. The contribution of the 2HDM Ⅲ to their averaged values have similar results.

B^0-B^0 Mixing in Local Gauged Baryon and Lepton Numbers

Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model （SM） where baryon number and lepton number are local gauge symmetries. The numerical results indicate the correction from the extra particles to the mass difference ArnB is significant. There is a 60% enhancement compared to the SM prediction for AraB at most, which agrees with the current experimental result.