共查询到20条相似文献,搜索用时 15 毫秒
1.
A dynamical scheme for composite quarks and leptons is proposed in which the observed fermions are Goldstone particles of spontaneously broken supersymmetry. Their residual interactions are described by a minimal effective lagrangian which invokes a non-linear realization of sypersymmetry. Possible experimental consequences are studied and it is found that the most conspicuous signature of this scheme would be a dramatic increase in the lepton pair production in hadronic collisions, particularly in scattering, at high energy. 相似文献
2.
《中国物理C(英文版)》2016,(10)
The Review summarizes much of particle physics and cosmology.Using data from previous editions,plus 3,062 new measurements from 721 papers,we list,evaluate,and average measured properties of gauge bosons and the recently discovered Higgs boson,leptons,quarks,mesons,and baryons.We summarize searches for hypothetical particles such as supersymmetric particles,heavy bosons,axions,dark photons,etc.All the particle properties and search limits are listed in Summary Tables.We also give numerous tables,figures,formulae,and reviews of topics such as Higgs Boson Physics,Supersymmetry,Grand Unified Theories,Neutrino Mixing,Dark Energy,Dark Matter,Cosmology,Particle Detectors,Colliders,Probability and Statistics.Among the 117 reviews are many that are new or heavily revised,including new reviews on Pentaquarks and Inflation. 相似文献
3.
George L. Strobel 《International Journal of Theoretical Physics》2000,39(1):115-126
The Roper resonances of the nucleon are described as transverse vibrations of astretched flux tube between the three quarks. The proton is modeled using currentmass quarks interacting with a confining linear flux tube potential plus thespin-dependent parts of a one-gluon exchange potential. The proton ground state hasno vibrations and the confining flux tube has the minimum length required toconnect the three quarks. The flux tube has a V or Y shape of two or threesegments, depending on the locations of the quarks. The vibrations of the fluxtube have nodes at the quarks and at the apex of the Y-shaped configuration andprovide the vibrational excitation energy to describe the proton excitations. Theamplitude of the transverse vibrations is found from a geometric analysis, anddepends on the string constant of the flux tube potential. The Roper 1. 440-GeVresonance energy is very nearly reproduced by the vibration with mode number1 acting in only one segment of the flux tube. The vibration with mode number2 in one segment of the flux tube closely reproduces the second proton excitationat 1.710 GeV. The D excited states are also well reproduced by these modes ofa vibrating flux tube. 相似文献
4.
5.
6.
N. I. Maksyukov 《Russian Physics Journal》1974,17(3):300-302
The basic parameters — mass and radius — of the quark configurations having central densities from 1019 to 1032 g/cm3 are obtained. It is shown that similar objects should have large gravitational mass defects. The curve of the stable configurations is extended to the region of densities substantially exceeding those of the nucleus. 相似文献
7.
Hagen Kleinert 《Nuclear Physics B》1974,79(3):526-545
We propose a new algebra which will hopefully contribute to the joint understanding of electromagnetic and weak structure functions and of Regge couplings. It involves an infinite number of form factors of arbitrary complex spin J (with Re(J?1) > 0) and definite signature. The algebra holds exactly in a quark-gluon model when quantized canonically on equal light fronts. If all form factors have k = 0 and J = 1, the algebra closes and becomes U(6) × U(6), with the connecting subgroups being associated with pure quarks and pure antiquark currents, respectively. This doubling of the group leads to exact exchange degeneracy if baryons and mesons consist of qqq and q wave functions only.To some lowest approximation, Regge couplings can be calculated by representing U(6) × U(6) on properly mixed quark wave functions. With the mixing parameters fixed by the chiral subgroup, these couplings are determined up to an overall normalization.As an illustration, the coupling of the trajectories ?, ω; A2, f; A1, D; Z, Zsg; π, η; B, H trajectories are estimated for the meson resonances ?, ω; π, η; A2, f; A1, D; B, H; A0, σ. The trajectories π, η; B, H are not in the algebra initially but can be inferred from an extension of PCAC to the bilocal currents (“PCBC”). 相似文献
8.
Haim Harari 《Physics Reports》1978,42(4):235-309
We review the physics of quarks and leptons within the framework of gauge theories for the weak and electromagnetic interactions. The Weinberg-Salam SU(2) × U(1) theory is used as a “reference point” but models based on larger gauge groups, especially SU(2)L × SU(2)R × U(1), are discussed. We distinguish among thre “generations” of fundamental fermions: The first generation (e?, νe, u, d), the second generation (μ?, νμ, c, s) and the third generation (τ?, ντ, t, b). For each generation we discuss the classification of all fermions, the charged and neutral weak currents, possible right-handed currents, parity and CP-violation, fermion masses and Cabibbo-like angles and related problems. We review theoretical ideas as well as experimental evidence, emphasizing open theoretical problems and possible experimental tests. The possibility of unifying the weak, electromagnetic and strong interactions in a grand unification scheme is reviewed. The problems and their possible solutions are presented, generation by generation, but a brief subject-index (following the table of contents) enables the interested reader to follow any specific topic throughout the three generations. 相似文献
9.
An adequate canonical transformation of the hamiltonian permitted the full observance of the specific Pauli commutation relations and the elimination of the main quasiparticle non-conservative term. This will allow a correct treatment of the kinematic part of the interaction in many problems. 相似文献
10.
11.
12.
C. V. Westenholz 《Annalen der Physik》1970,480(4):337-346
We discuss the concept of Schwinger, which starts with the hypothesis of the existence of magnetical monopoles and results in a baryon model with magnetically charged constituents. Especially we analyse the mathematical consistency of such a theory. which admits a connection between some magnetically charged “quarks” and the homogeneous Maxwell-equations ?v*Fμv(xu) = 0, which, displaying a lack of symmetry with respect to the inhomogeneous one, ?vFμv(xu) = 4?jμ, are replaced by ?*jμv. Here *jμ(xμ) means a conserved magnetic current which provides a monopole source for the magnetic field. 相似文献
13.
Yu. R. Musin 《Russian Physics Journal》2018,61(1):146-149
14.
The last few years have seen a dramatic improvement in our knowledge of the strange form factors of the nucleon. With regard to the vector from factors the level of agreement between theory and experiment gives us considerable confidence in our ability to calculate with non-perturbative QCD. The calculation of the strange scalar form factor has moved significantly in the last 2 years, with the application of new techniques which yield values considerably smaller than believed for the past 20 years. These new values turn out to have important consequences for the detection of neutralinos, a favourite dark matter candidate. Finally, very recent lattice studies have resurrected interest in the famed H-dibaryon, with modern chiral extrapolation of lattice data suggesting that it may be only slightly unbound. We review some of the major sources of uncertainty in that chiral extrapolation. 相似文献
15.
16.
17.
Russian Physics Journal - 相似文献
18.
夸克是人类目前所知道的最基本的粒子.所有强子(包括构成原子核的质子、中子)都是由夸克组成的.夸克的运动变化遵守什么规律呢?它们之间的强相互作用有什么特点?物理学家用量子色动力学描写夸克之间的强相互作用.本文拟对量子色动力学作个扼要介绍. 相似文献
19.
Based on Dyson-Schwinger equations in “rainbow“ approximation, fully dressed confining quark propagator is obtained, and then the masses of light quarks (mu, md, and ms) are derived from the fully dressed confining quark propagator. At the same time, the local and non-local quark vacuum condensates as well as the quark-gluon mixed condensate are also predicted. Furthermore, the quark masses are also deduced from the Gell-Mann-Oakes-Renner relation and chiral perturbative theory. The results from different methods are consistent with each other. 相似文献
20.
Production and collective motion ofq \(\bar q\) and gluon pairs in strong color fields is studied using boost-invariant version of collisionless Boltzmann-Vlasov transport equations. It is shown that, for realistic fields, the effective formation time for pair production according to Schwinger mechanism is a small fraction of 1 fermi. Collective oscillations of quarkgluon gas, although damped by pair production and expansion of the system, remain an important feature of the process. The considered mechanism produces quark and gluons in a state which is rather far from equilibrium and thus strong collision effects (collision time ?1 fm) are needed to achieve equilibrated distributions at formation time. Finally, it is observed that, if such equilibrated distribution is produced at later times, the expansion of the system modifies dramatically its properties, as is explicitly shown for small oscillations of quark-gluon plasma in a weak external field. 相似文献