International Journal of Modern Physics A

We show that a simultaneous explanation for fermionic mass hierarchy among and within the fermionic families, quark-mixing, can be obtained in an extension of the Standard Model, with real singlet scalar fields, which are UV completed by vector-like fermions and a strongly interacting sector.

We calculate the shape Rényi and generalized Rényi complexity of a noncommutative anisotropic harmonic oscillator in a homogeneous magnetic field. To do so, we first obtain the Rényi entropy in position and momentum spaces of the exact normalized wave functions. We observe that shape Rényi and generalized Rényi complexities are monotone functions of noncommutative parameter ($𝜃$) in some short range in position space. We analyze the effect of the noncommutative parameter, the magnetic field and the anisotropy on shape Rényi and generalized Rényi complexities.

We propose a model to explain several muon-related experimental anomalies and the abundance of dark matter. We introduce a vector-like exotic lepton that form an iso-doublet and three right-handed Majorana fermions as an iso-singlet. A real/complex scalar field is added as a dark matter candidate. We impose a global $U{(1)}_{\mu }$ symmetry under which fields associated with the SM muon are charged. To stabilize the dark matter, we impose a $Z_2$ (or $Z_3$) symmetry under which the exotic lepton doublet and the real (or complex) scalar field are charged. We find that the model can simultaneously explain the muon anomalous magnetic dipole moment and the dark matter relic density in no conflict with any lepton flavor-violating/conserving observables, with some details depending upon whether the scalar field is real or complex. Besides, we extend the framework to the quark sector in a way similar to the lepton sector, and find that the recent anomalies associated with the $b\to s{\mu }^{+}{\mu }^{-}$ transition can also be accommodated while satisfying constraints such as the $B_{s(d)}\to {\mu }^{+}{\mu }^{-}$ decays and neutral meson mixings.

In this paper, we analyze the fermionic Casimir effects associated with a massless quantum field in the context of Lorentz symmetry violation approach based on Horava–Lifshitz methodology. In order to obtain these observables, we impose the standard MIT bag boundary condition on the fields on two large and parallel plates. Our main objectives are to investigate how the Casimir energy and pressure depend on the parameter associated with the breaking of Lorentz symmetry.

The aim of this work is to analyze and to verify the effects of the charge and cosmological constant on the temperature oscillations that occur in a gas in a circular motion close to geodesic under the action of a Reissner–Nordström–de Sitter metric. The temperature oscillations are determined from Tolman’s law written in Fermi normal coordinates for a comoving observer. The temperature oscillations are calculated for a theoretical model obtained in the literature. Comparing the different configurations analyzed, it is possible to verify that the cosmological constant term causes a small displacement in the oscillation peaks. We also calculated the ratio between frequencies for some particular cases of the Reissner–Nordström–de Sitter metric and verified that the cases with null cosmological constant are closer of the 3/2 value found in QPOs. In another hand, the addition of the cosmological constant causes a direct increase of the ratio between frequencies.

In this paper, we tentatively assign the $Z_c(4600)$ to be the ${[dc]}_P{[ū\bar{c}]}_A-{[dc]}_A{[ū\bar{c}]}_P$ type vector tetraquark state and study its two-body strong decays with the QCD sum rules based on solid quark–hadron duality, the predictions for the partial decay widths $\mathrm{\Gamma }(Z_c^{-}\to J/\psi {\pi }^{-})=41.4_{-14.9}^{+20.5}\mathrm{\text{MeV}}$, $\mathrm{\Gamma }(Z_c^{-}\to {\eta }_c{\rho }^{-})=41.6_{-22.2}^{+32.7}\mathrm{\text{MeV}}$, $\mathrm{\Gamma }(Z_c^{-}\to J/\psi a_0^{-}(980))=10.2_{-6.7}^{+11.3}\mathrm{\text{MeV}}$, $\mathrm{\Gamma }(Z_c^{-}\to {\chi }_{c0}{\rho }^{-})=3.5_{-3.0}^{+6.7}\mathrm{\text{MeV}}$, $\mathrm{\Gamma }(Z_c^{-}\to D^{\ast 0}{D}^{\ast -})=39.5_{-19.3}^{+29.6}\mathrm{\text{MeV}}$, $\mathrm{\Gamma }(Z_c^{-}\to D^0{D}^{-})=6.6_{-3.0}^{+4.6}\mathrm{\text{MeV}}$ and $\mathrm{\Gamma }(Z_c^{-}\to D^{\ast 0}{D}^{-})=1.0_{-0.6}^{+1.0}\mathrm{\text{MeV}}$ can be compared to the experimental data in the future to diagnose the nature of the $Z_c(4600)$.

We consider the formalism of small-$x$ effective action for reggeized gluons${}^{1\text{–}10}$ and, following the approach developed in Refs. 11–17, calculate the classical gluon field to NNLO precision with fermion loops included. It is demonstrated that for each perturbative order, the self-consistency of the equations of motion is equivalent to the transversality conditions applied to the solution of the equations, these conditions allow to construct the general recursive scheme for the solution’s calculation. The one fermion loop contribution to the classical solutions and application of the obtained results are also discussed.