Modern Physics Letters A

The phrase “Yang–Mills” can be used (1) to refer to the specific theory proposed by Yang and Mills in 1954; or (2) as shorthand for any non-Abelian gauge theory. The 1954 version, physically speaking, had a famous show-stopping defect in the form of what might be called the “Pauli snag,” or the requirement that, in the Lagrangian for non-Abelian gauge theory the mass term for the gauge field has to be zero. How, then, was it possible for (1) to turn into (2)? What unfolding sequence of events made this transition possible, and what does this evolution say about the nature of theories in physics? The transition between (1) and (2) illustrates what historians and philosophers a century from now might still find instructive and stimulating about the development of Yang–Mills theory.

Incorporating the generalized uncertainty principle (GUP) into the tunneling mechanism, we have studied the tunneling radiation of the scalar particles and fermions from the five-dimensional Schwarzschild–Tangherlini black hole. The results showed that the GUP corrected temperatures do not only depend on the mass of ST black hole, but are also affected by the gravity effects correction $\beta$. Besides, the $\beta$ slows down the Hawking temperature increasing and causes the existence of remnants in black hole evaporation.

Vacuum polarization of charged massless fermions is investigated in the superposition of Coulomb and Aharonov–Bohm (AB) potentials in 2 + 1 dimensions. For this purpose, we construct the Green function of the two-dimensional Dirac equation with Coulomb and AB potentials (via the regular and irregular solutions of the radial Dirac equation) and then calculate the vacuum polarization charge density in the so-called subcritical and supercritical regimes. In the supercritical regime, the Green function has a discontinuity in the complex plane of “energy” due to the singularities on the negative energy axis; these singularities are situated on the unphysical sheet and related to the creation of infinitely many quasistationary fermionic states with negative energies. We expect that our results will be helpful in gaining deeper understanding of the fundamental problem of quantum electrodynamics which can be applied to the problems of charged impurity screening in graphene taking into consideration the electron spin.

We examine the possibility of observing the Kaluza–Klein (KK) gluons in gauge-Higgs unification models at the LHC with the energy $\sqrt{s}$=14 TeV. We consider a benchmark model with the gauge symmetry SU(3)${}_C\times$SU(3)_W in five-dimensional spacetime, where SU(3)_C is the gauge symmetry of the strong interaction and SU(3)_W is that for the electroweak interaction and a Higgs doublet field. It is natural in general to introduce SU(3)_C gauge symmetry in five-dimensional spacetime as well as SU(3)_W gauge symmetry in gauge-Higgs unification (GHU) models. Since the fifth dimension is compactified to $S^1/Z_2$ orbifold, there are KK modes of gluons in low-energy effective theory in four-dimensional spacetime. We investigate the resonance contribution of the first KK gluon to dijet invariant mass distribution at the LHC, and provide signal-to-noise ratios in various cases of KK gluon masses and kinematical cuts. Although the results are given in a specific benchmark model, we discuss their application to general GHU models with KK gluons. GHU models can be verified or constrained through the physics of the strong interaction, though they are proposed to solve the naturalness problem in electroweak symmetry breaking.

We construct wormhole-like solutions in type IIA string theory. These solutions represent wormholes in four dimensions and are given by the D2-branes within appropriated backgrounds fields. We present the conditions on these fields which lead to the four-dimensional wormholes. In the special case, we show how the particular solution in type IIA theory leads to the dynamic wormhole. We also speculate about the number of universes and the cosmological constant.

In this paper, the width of the decay $\tau \to K^{-}{\pi }^0{\nu }_{\tau }$ is calculated in the framework of the Nambu–Jona-Lasinio (NJL) model. The contributions of the intermediate vector $K^{\ast }(892)$ and scalar $K_0^{\ast }(800)$ mesons are taken into account. It is shown that the main contribution to the width of this decay is given by the subprocesses with the intermediate $W$-boson and vector $K^{\ast }(892)$ meson. The scalar channel with the intermediate $K_0^{\ast }(800)$ meson gives an insignificant contribution. In Appendix A, it is shown that the contribution of the subprocess with the intermediate ${K^{\ast }}^{\prime }(1410)$ meson is negligible as well. The obtained results are in satisfactory agreement with the experimental data.

We examine in detail the cosmology based on quantal (Bohmian) trajectories as suggested in a recent study [A. F. Ali and S. Das, Phys. Lett. B 741, 276 (2014)]. We disagree with the conclusions regarding predicting the value of the cosmological constant $\mathrm{\Lambda }$ and evading the Big Bang singularity. Furthermore, we show that the approach of using a quantum corrected Raychaudhuri equation (QRE), as suggested in A. F. Ali and S. Das, Phys. Lett. B 741, 276 (2014), is unsatisfactory, because, essentially, it uses the Raychaudhuri equation (RE), which is a kinematical equation, in order to predict dynamics. In addition, even within this inconsistent framework, the authors have adopted unjustified assumptions and carried out incorrect steps leading to doubtful conclusions.

Cluster radioactivity is a rare cold nuclear process which is intermediate between alpha decay and spontaneous fission. The present work is a theoretical investigation of the feasibility of alpha decay and cluster radioactivity from proton rich Osmium (Os) isotopes with mass number ranging from 162–190. Osmium forms a part of the transition region between highly deformed and spherical nuclei. Calculations have been done using unified fission model and Hartree–Fock–Bogoliubov (HFB) theory. We have chosen only those decays with half-lives falling in measurable range. Geiger–Nuttall plot has been successfully reproduced. The isotope which is most favorable to each decay mode has a magic daughter nucleus.