Modern Physics Letters A

An increasing number of anomalous experimental results are emerging, which cannot be described within the standard three-neutrino framework. We present a concise discussion of the most popular phenomenological interpretation of such findings, based on a hypothetical flavor conversion phenomenon of the ordinary "active" neutrinos into new light "sterile" species having mass .

In a dielectric black hole background, photons will be radiated via Hawking evaporation mechanism. In this paper, we calculate the entanglement entropy associated with a static dielectric black hole by employing 't Hooft's brick-wall model. It is found that the lowest energy of radiated particles is coordinate dependent. The resulted entanglement entropy is composed of three parts: a parameter independent leading constant term , a logarithmic correction term and some series terms. The convergency of the series terms is also discussed.

We estimate the baryon–photon ratio in the Universe via the leptogenesis scenario in the framework of the minimal seesaw model with a minimally modified bipair neutrino mixing. We assume that one of the elements of the 3 × 2 Dirac mass matrix m_D is exactly zero. It turns out that the lepton asymmetry as well as baryon number of the Universe definitely depends on the reactor neutrino mixing angle in the cases of (m_D)₁₁ = 0 and (m_D)₁₂ = 0. The allowed region of the Majorana CP phase is separated into three regions related to the assumption of either (m_D)₁₁ = 0, (m_D)_{21, 31} = 0 or (m_D)₁₂ = 0.

This paper supplements a recent work [B. Lampe, Int. J. Theor. Phys.51, 3073 (2012)] in which it was pointed out that the observed spectrum of quarks and leptons can arise as quasi-particle excitations in a discrete internal space. The latter paper concentrated on internal vibrational modes and it was only noted in the end that internal spin waves ("mignons") might do the same job. Here it will be shown how the mignon-mechanism works in detail. In particular the Shubnikov group A₄ + S (S₄ - A₄) will be used to describe the spectrum and the mignetic ground state is explicitly given.

We study the conserved quantities of the generalized Heisenberg magnet (GHM) model. We derive the nonlocal conserved quantities of the model using the iterative procedure of Brezin et al. [Phys. Lett. B82, 442 (1979).] We show that the nonlocal conserved quantities Poisson commute with local conserved quantities of the model.

We conjecture that weak interactions are peculiar manifestations of quantum gravity at the Fermi scale, and that the Fermi constant is related to the Newtonian constant of gravitation. In this framework one may understand the violations of fundamental symmetries by the weak interactions, in particular parity violations, as due to fluctuations of the spacetime geometry at a Planck scale coinciding with the Fermi scale. As a consequence, gravitational phenomena should play a more important role in the microworld, and experimental settings are suggested to test this hypothesis.

The Fierz transformations (Ft) for SU(2) and SU(3) operators in eighth-order fermion interactions are derived. These terms appear in expansions in terms of fermion currents of the following form: I₁ I₂ I₃ I₄ and also the composite , where Γ⁽ⁱ⁾ are either the SU(2) Pauli matrices or SU(3) Gell-Mann matrices. The calculation is carried out using the exchange projector operators.