Modern Physics Letters A

We obtain Bargmann–Michel–Telegdi equations of motion of classical spinning particle using Lagrangian variational principle with Grassmann variables.

The gauge invariance of the muonium–antimuonium oscillation time scale is explicitly demonstrated in the Standard Model modified only by the inclusion of singlet right-handed neutrinos and allowing for general renormalizable interactions. The seesaw mechanism is exploited resulting in three light Majorana neutrinos and three heavy Majorana neutrinos with mass scale M_R≫M_W. The leading order matrix element contribution to the oscillation process is computed in R_ξ gauge and shown to be ξ-independent thereby establishing the gauge invariance to this order. Present experimental limits resulting from the non-observation of the oscillation process sets a lower limit on M_R roughly of order 600 GeV.

We consider SU(N) Yang–Mills theory on the space ℝ × S³ with Minkowski signature (-+++). The condition of SO(4)-invariance imposed on gauge fields yields a bosonic matrix model which is a consistent truncation of the plane wave matrix model. For matrices parametrized by a scalar ϕ, the Yang–Mills equations are reduced to the equation of a particle moving in the double-well potential. The classical solution is a bounce, i.e. a particle which begins at the saddle point ϕ = 0 of the potential, bounces off the potential wall and returns to ϕ = 0. The gauge field tensor components parametrized by ϕ are smooth and for finite time, both electric and magnetic fields are nonvanishing. The energy density of this non-Abelian dyon configuration does not depend on coordinates of ℝ × S³ and the total energy is proportional to the inverse radius of S³. We also describe similar bounce dyon solutions in SU(N) Yang–Mills theory on the space ℝ × S² with signature (-++). Their energy is proportional to the square of the inverse radius of S². From the viewpoint of Yang–Mills theory on ℝ^1,1 × S² these solutions describe non-Abelian (dyonic) flux tubes extended along the x³-axis.

We have obtained the creation and annihilation operators directly from the eigenfunction for the general deformed morse potential in one-dimensional Klein–Gordon equation with equally mixed vector and scalar potentials and also in the Schrödinger equation, we show that these operators satisfy the commutation relation of the SU(1, 1) group. Then we have expressed the Hamiltonian in terms of the su(1, 1) algebra.

In this paper, a parametrized deceleration parameter q(a) = q₀+q₁(1-a) is constrained by using the current cosmic observational data from type Ia Supernova (Sne Ia) and Cosmic Microwave Background Radiation (CMB). When the CMB dataset is added as a strong constraint, it is found that the 1σ error is largely reduced. The values of transition redshift z_T from decelerated expansion to accelerated expansion and current deceleration parameter q₀ are larger than that obtained from the case where Sne Ia dataset is used alone. With comparison to the case of Sne Ia 182 dataset used,¹⁵ it is found that the value of transition redshift is smaller than that in Sne 192 dataset case. This is the so-called dataset dependence.

We predict the contribution of scalar unparticle to the branching ratios of the lepton flavor conserving Z → l⁺l^- decays and we study the discrepancy between the experimental and the QED corrected standard model branching ratios. We observe that these decays are sensitive to the unparticle scaling dimension d_u for its small values, especially for heavy lepton flavor output.

The Casimir force on two-dimensional pistons for massive scalar fields with both Dirichlet and hybrid boundary conditions is computed. The physical result is obtained by making use of generalized ζ-function regularization technique. The influence of the mass and the position of the piston in the force is studied graphically. The Casimir force for massive scalar field is compared to that for massless scalar field.