CP-odd WWZ couplings induced by vector-like quarks

A minimal extension of the standard model includes extra quarks with charges 2/3 and/or , whose left-handed and right-handed components are both SU(2) singlets. This model predicts new interactions of the flavor-changing neutral current at the tree level, which also violate CP invariance. We study CP-odd anomalous couplings for the W, W, and Z gauge bosons induced by the new interactions at the one-loop level. These couplings become non-negligible only if both up-type and down-type extra quarks are incorporated. Their form factors are estimated to be maximally of order . Such magnitudes are larger than those predicted in the standard model, though smaller than those in certain other models. Received: 26 February 1999 / Published oinline: 12 August 1999     

Testing the standard model by precision measurement of the weak charges of quarks

In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low energy. The precision of this new result, combined with earlier atomic parity-violation measurements, places tight constraints on the size of possible contributions from physics beyond the standard model. Consequently, this result improves the lower-bound on the scale of relevant new physics to approximately 1 TeV.     

Confinement model for quarks

A confinement model of hadron with its constituent quarks bound in a strong gravitational field is presented. The gravitational field plays the role of a medium having, as if, space dependent permeabilities from a fixed centre. The massless Dirac equation modified by the gravitational field is solved. The solution for the wavefunction of the quarks obtained shows the characteristic features of confinement, i.e., (i) wavefunction with higher energy states lying closer to the centre, (ii) equispaced energy levels without continuum, (iii) the quark orbits lying within a distance ∼ 10⁻¹⁴ cm, the characteristic radius of a typical hadron.     

On the properties of heavy quarks

This work is the first attempt to define charmed, beautiful, and true quarks, that is, c-, b-, and t-quarks. The operators charma, bottoma, and topa are determined using the Okubo matrix A ₁ ¹ , A ₂ ² , and A ₃ ³ and eigenfunctions and eigenvalues of these operators are also found. The decay width was estimated to be t → Wb (≈10⁻⁶). __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 86–89, November, 2005.     

Decay of quarks in the Pati-Salam model

We discuss, within the framework of the basic Pati-Salam model, the feasibility of the hypothesis that quarks are unconfined, integer-charged, relatively light (mass ～2?3 GeV) and short-lived (τ_q?10^?12s). Our estimates for the quark life-times vary between 10^?12s and 10⁺¹¹ s for the white and blue quarks and between 10^?12 s and 10⁺¹⁶ s for the red quarks. The life-times depend very sensitively, and it is shown why, on the values of the Salam-Weinberg mixing angle and the quark-gluon coupling constant.     

On the invariant regularization of the standard model

We show that the gauge invariant regularization of the Standard Model proposed by Frolov and Slavnov describes a nonlocal theory with quite simple Lagrangian.     

On physics beyond standard model

In this review we do not try to cover all the aspects of physics besnd tile standard model （BSM）, instead our latest understanding on tile BSM will be presented： i） Tile Higgs sector is likely related to BSM, which can be confirmed at current running large hadron collider （LHC） or tile fllture eolliders. Furthermore we pointed out that spontaneous CP violation can be closely related to the lightness of the Higgs boson, ii） Top quark forward-backward asymmetry, which was mea.sured by Tewttron, might be the sign of BSM.2; proposed a new color-octet particle Zcr to account fi）r the observation and Z can be fllrther studied at the LHC. iii） If dark matter （DM） is utilized to accommodate astrophysical obserwtions, it ought to be observed at the high energy LttC and DM produced at colliders should be tile slnoking gun signal, iv） Lithium puzzle might also be the sign of the BSM. We briefly review tile newly proposed solution to Lithium puzzle, i.e.. the existonce of non-thermal component during the big bang nuclei-synthesis （BBN）. The possible origins of the non-thermal coinponent can be dark matter or the new accelerating mechanism of normal particles.     

On the excited quarks and leptons

Using a duality-like finite energy sum rule, we discuss the assumption of having excited fermions at the W scale in a supersymmetric(SUSY) and non-supersymmetric hypercolour theory where quarks and leptons are bound states of fermion and scalar preon constituents. We conclude that a SUSY-like composite model cannot have excited fermions having a mass smaller than 0.5 TeV. A non-SUSY composite model having composite fermions but elementary W bosons can produce an excited fermion mass of the order of M_W provided that the scalar vacuum condensate is of the order of the (TeV)² scale of compositeness.     

On the mass function of light quarks

A mass function model of light quarks based on non-perturbative solutions of the Schwinger-Dyson equations is considered. According to this model, for small arguments the mass function has a constant value close to the constituent quark mass and then quickly decreases entering into the perturbative regime. It is demonstrated that this behavior of the mass function allows good agreement with experimental value of weak pion decay constant {ie730-01} and phenomenological value of the chiral condensate {ie730-02} to be obtained. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 64–68, July, 2008.     

A composite model of leptons and quarks

A heuristic model is presented, treating leptons and quarks as composites of spin $\text{1}\text{2}$ fields with charges 0, $\text{±}\text{e}\text{3}$. A distinguishability assumption leads to the emergence of three quark colors. The model is extended to consideration of the force-mediating bosons.     

On the oscillatory modes of quarks in baryons

The color bond structure of a quark-antiquark system is extended, in the long-range approximation, self-consistently to the baryonic three-quark bond structure for SU(3)_c and generally to the N-quark bond structure for SU(N)_c. The universal (N-independent) mass square eigenvalues for massless quarks are

$\text{M}{}^2\text{=(H}{}_{\mathrm{N}}\text{)}{}^2\text{?2m}{}_{\mathrm{\rho }}{}^2\text{∑}\text{α=1}\text{3N?3}\text{ν}{}_{\mathrm{\alpha }}\text{+}\text{constant}\text{, ν}{}_{\mathrm{\alpha }}\text{=0,1,2,…}$

.     

Bag model of hadrons with massive quarks

We generalize the bag model of hadrons to include massive quarks and investigate in particular the properties of the l = 0 octet and decimet baryons with m_p = m_n = 0, m_λ = 270 MeV (obtained by fitting the decimet). The magnetic moments and weak axial vector/vector transition moments are calculated and compared with experimental data for cases in which data exists. We also speculate on the mechanism by which the remaining degeneracies in the baryons are lifted and on modifications which are necessary to construct a bag model of mesons.     

On the fragmentation functions of heavy quarks into hadrons

An explicit form for the charmed quark fragmentation function D^C_c(z) into hadrons has been obtained with the help of the “reciprocity relation” and the c-quark distribution function in charmed mesons (the function calculated in terms of the Kuti-Weisskopf model). D^C_c(z) turns out to peak mainly at z close to 1. The analysis of new data on muon pair production in neutrino reactions points to such a behaviour of the D^C_c(z) function. The obtained fragmentation function, contrary to those, used earlier, leads to a charmed particle (average) multiplicity in e⁺e^?-annihilation independent of energy.