In this paper we investigate the parallel texture structures containing texture zeros in the charged lepton mass matrix $M_l$ and cofactor zeros in the neutrino mass matrix $M_{\nu }$. These textures are interesting since they are related to the $Z_n$ flavor symmetries. Using the weak basis permutation transformation, the 15 parallel textures are grouped as 4 classes (class I, II, III, and IV), with the matrices in each class sharing the same physical implications. Under the current experimental data, the classes I and III with inverted mass hierarchy and class II with normal mass hierarchy are phenomenologically acceptable. The correlations between some important physical variables are presented, which are essential for the model selection and can be tested by future experiments. The model realization is illustrated by means of $Z_4\times Z_2$ flavor symmetry.

A search for $WV\gamma$ triple vector boson production is presented based on events containing a $W$ boson decaying to a muon or an electron and a neutrino, a second $V$ ($W$ or $Z$) boson, and a photon. The data correspond to an integrated luminosity of $19.3{\mathrm{fb}}^{-1}$ collected in 2012 with the CMS detector at the LHC in $pp$ collisions at $\sqrt{s}=8\mathrm{TeV}$. An upper limit of 311 fb on the cross section for the $WV\gamma$ production process is obtained at 95% confidence level for photons with a transverse energy above 30 GeV and with an absolute value of pseudorapidity of less than 1.44. This limit is approximately a factor of 3.4 larger than the standard model predictions that are based on next-to-leading order QCD calculations. Since no evidence of anomalous $WW\gamma \gamma$ or $WWZ\gamma$ quartic gauge boson couplings is found, this paper presents the first experimental limits on the dimension-eight parameter $f_{T,0}$ and the $CP$-conserving $WWZ\gamma$ parameters ${\kappa }_0^W$ and ${\kappa }_C^W$. Limits are also obtained for the $WW\gamma \gamma$ parameters $a_0^W$ and $a_C^W$.

Rapidly rotating black holes are a prime arena for understanding corrections to Einstein’s theory of general relativity (GR). We construct solutions for rapidly rotating black holes in dynamical Chern-Simons (dCS) gravity, a useful and motivated example of a post-GR correction. We treat dCS as an effective theory and thus work in the decoupling limit, where we apply a perturbation scheme using the Kerr metric as the background solution. Using the solutions to the scalar field and the trace of the metric perturbation, we determine the regime of validity of our perturbative approach. We find that the maximal spin limit may be divergent, and the decoupling limit is strongly restricted for rapid rotation. Rapidly rotating stellar-mass black holes can potentially be used to place strong bounds on the coupling parameter $\ell$ of dCS. In order for the black hole observed in GRO J1655-40 to be within the decoupling limit, we need $\ell \lesssim 22\mathrm{km}$, a value 7 orders of magnitude smaller than present Solar System bounds on dynamical Chern-Simons gravity.

In general relativity, the rotation of a gravitating body like the Earth influences the motion of orbiting test particles or satellites in a non-Newtonian way. This causes, e.g., a precession of the orbital plane known as the Lense-Thirring effect and a precession of the spin of a gyroscope known as the Schiff effect. Here, we discuss a third effect first introduced by Cohen and Mashhoon called the gravitomagnetic clock effect. It describes the difference in proper time of counterrevolving clocks after a revolution of $2\pi$. For two clocks on counterrotating equatorial circular orbits around the Earth, the effect is about ${10}^{-7}\mathrm{s}$ per revolution, which is quite large. We introduce a general relativistic definition of the gravitomagnetic clock effect which is valid for arbitrary pairs of orbits. This includes rotations in the same direction and different initial conditions, which are crucial if the effect can be detected with existing satellites or with payloads on nondedicated missions. We also derive the post-Newtonian expansion of the general relativistic expression and calculate the effect for the example of a satellite of a global navigation satellite system compared to a geostationary satellite.

The IceCube observation of cosmic neutrinos with $E_{\nu }>60\mathrm{TeV}$, most of which are likely of extragalactic origin, allows one to severely constrain Lorentz invariance violation (LIV) in the neutrino sector, allowing for the possible existence of superluminal neutrinos. The subsequent neutrino energy loss by vacuum $e^{+}{e}^{-}$ pair emission (VPE) is strongly dependent on the strength of LIV. In this paper we explore the physics and cosmology of superluminal neutrino propagation. We consider a conservative scenario for the redshift distribution of neutrino sources. Then by propagating a generic neutrino spectrum, using Monte Carlo techniques to take account of energy losses from both VPE and redshifting, we obtain the best present constraints on LIV parameters involving neutrinos. We find that ${\delta }_{\nu e}={\delta }_{\nu }-{\delta }_e\le 5.2\times 10^{-21}$. Taking ${\delta }_e\le 5\times 10^{-21}$, we then obtain an upper limit on the superluminal velocity fraction for neutrinos alone of $1.0\times 10^{-20}$. Interestingly, by taking ${\delta }_{\nu e}=5.2\times 10^{-21}$, we obtain a cutoff in the predicted neutrino spectrum above 2 PeV that is consistent with the lack of observed neutrinos at those energies, and particularly at the Glashow resonance energy of 6.3 PeV. Thus, such a cutoff could be the result of neutrinos being slightly superluminal, with ${\delta }_{\nu }$ being $(0.5\text{to}1.0)\times 10^{-20}$.

We examine the issue of whether a magnetic field can be amplified in a background matter consisting of electrons and positrons self-interacting within the Fermi model. For this purpose, we compute the antisymmetric contribution to the photon polarization tensor in this matter having nonzero temperature and chemical potential. It is shown that this contribution is vanishing in the static limit. Then we study a particular case of a degenerate relativistic electron gas present in a magnetar. We demonstrate that a seed magnetic field is attenuated in this case. Thus, contrary to the recent claim, we show that there is no magnetic field instability in such a system, which can lead to the magnetic field growth. Therefore, the recently proposed mechanism cannot be used for the explanation of strong magnetic fields of magnetars.

The process $e^{+}{e}^{-}\to p\overline{p}{\pi }^0$ has been studied by analyzing data collected at $\sqrt{s}=3.773\mathrm{GeV}$, at $\sqrt{s}=3.650\mathrm{GeV}$, and during a $\psi (3770)$ line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of $p\overline{p}{\pi }^0$ in the vicinity of the $\psi (3770)$ is measured, and the Born cross section of $\psi (3770)\to p\overline{p}{\pi }^0$ is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of $1.5\sigma$ are found. The solutions for the Born cross section of $\psi (3770)\to p\overline{p}{\pi }^0$ are $33.8\pm 1.8\pm 2.1\mathrm{pb}$ and ${0.06}_{-0.04-0.01}^{+0.10+0.01}\mathrm{pb}$ ($<0.22\mathrm{pb}$ at a 90% confidence level). Using the estimated cross section and a constant decay amplitude approximation, the cross section $\sigma (p\overline{p}\to \psi (3770){\pi }^0)$ is calculated for the kinematic situation of the planned $\overline{\mathrm{P}}\text{ANDA}$ experiment. The maximum cross section corresponding to the two solutions is expected to be less than 0.79 nb at 90% confidence level and $122\pm 10\mathrm{nb}$ at a center-of-mass energy of 5.26 GeV.

The claimed detection of the BICEP2 experiment on the primordial B-mode of cosmic microwave background polarization suggests that cosmic inflation possibly takes place at the energy around the grand unified theory scale given a constraint on the tensor-to-scalar ratio, i.e., $r\simeq 0.20$. In this report, we revisit single-field (slow-roll) composite inflation and show that, with the proper choice of parameters and sizeable number of $e$-foldings, a large tensor-to-scalar ratio consistent with the recent BICEP2 results can be significantly produced with regard to the composite paradigms.

We investigate a mass deformation effect on the renormalized entanglement entropy (REE) near the UV fixed point in ($2+1$)-dimensional field theory. In the context of the gauge/gravity duality, we use the Lin-Lunin-Maldacena geometries corresponding to the vacua of the mass-deformed ABJM theory. We analytically compute the small mass effect for various droplet configurations and show in holographic point of view that the REE is monotonically decreasing, positive, and stationary at the UV fixed point. These properties of the REE in ($2+1$)-dimensions are consistent with the Zamolodchikov $c$-function proposed in ($1+1$)-dimensional conformal field theory.

We construct exact solutions with the bubble of nothing in the Dvali-Gabadadze-Porrati braneworld model. The configuration with a single brane can be constructed, unlike in the Randall-Sundrum braneworld model. The geometry on the single brane looks like the Einstein-Rosen bridge. We also discuss the junction of multibranes. Surprisingly, even without any artificial matter fields on the branes such as three-dimensional tension of the codimension-two objects, two branes can be connected in certain configurations. We investigate solutions of multibranes too. The presence of solutions may indicate the semiclassical instability of the models.

Using large-N technique at fixed dimension ($d=3$), I examine the multicritical behavior of a $U(N/2)\times U(N/2)$ Ginzburg-Landau theory of two multicomponent complex fields interacting through gauge fields described by Maxwell terms and a mixed Chern-Simons term. This model is relevant to the dynamics of Cooper pairs and vortices in a self-dual Josephson junction array system near its superconductor-insulator quantum transition. I present calculations of the various critical exponents including $1/N$ corrections to the $N=\infty$ saddle point. I investigate in the scaling region the behavior of the renormalized zero-momentum four-point quartic couplings $u$ and $w$ in the action, and I calculate the $1/N$ correction to the $\beta$-functions and their fixed-point values. It is shown that the decoupled fixed point is destabilized in the presence of the mixed Chern-Simons term at the next-to-leading order. Finally, I examine the universal character of the conductivity at the critical point up to the next-to-leading order in $1/N$ expansion.

We investigate the vacuum polarization and Casimir energy of a Dirac field coupled to a scalar potential in one spatial dimension. Both of these effects have a common cause, which is the distortion of the spectrum of the Dirac field due to its coupling with the background field. Choosing the potential to be a symmetrical square well renders the problem exactly solvable, and we can obtain the whole spectrum of the system analytically. We show that the total number of states and the total density remain unchanged as compared with the free case, as one expects. Furthermore, since there is a reflection symmetry between positive- and negative-energy eigenstates of the fermion, the total density and the total number of negative and positive states remain unchanged, separately. This, along with the fact that there is no zero mode, mandate that the vacuum polarization in this model is zero for any choice of the parameters of the potential. It is important to note that although the vacuum polarization is zero due to the symmetries of the model, the Casimir energy of the system is not zero in general. In the graph of the Casimir energy as a function of the depth of the well, there is a maximum approximately when the bound energy levels change direction and move back towards their continuum of origin. The Casimir energy for a fixed value of the depth is an almost linear increasing function of the width. Moreover, the Casimir energy density (the energy density of all the negative-energy states) and the energy density of all the positive-energy states are exactly the mirror images of each other. Finally, we compute the total energy of a valence fermion present in the lowest positive-energy fermionic bound state. We find that taking into account the Casimir energy does not result in the appearance of any local minima in the graphs of the total energy as a function of the parameters of the model, and this is in sharp contrast to the cases where there are levels crossing the line $E=0$.

We investigate the cause of the divergence of the entanglement entropy for the free scalar fields in $(1+1)$ and $(D+1)$ dimensional space-times. In a canonically equivalent set of variables, we show explicitly that the divergence in the entanglement entropy of the continuum field in $(1+1)$ dimensions is due to the accumulation of a large number of near-zero frequency modes as opposed to the commonly held view of divergence having UV origin. The feature revealing the divergence in zero modes is related to the observation that the entropy is invariant under a hidden scaling transformation even when the Hamiltonian is not. We discuss the role of dispersion relations and the dimensionality of the space-time on the behavior of entanglement entropy.

We study the triple points and phase diagrams in the extended phase space of the charged Gauss-Bonnet black holes in $d$-dimensional anti-de Sitter space, where the cosmological constant appears as a dynamical pressure of the system and its conjugate quantity is the thermodynamic volume of the black holes. Employing the equation of state $T=T(v,P)$, we demonstrate that the information of the phase transition and behavior of the Gibbs free energy are potential encoded in the $T-v$ ($T-r_h$) line with fixed pressure $P$. We get the phase diagrams for the charged Gauss-Bonnet black holes with different values of the charge $Q$ and dimension $d$. The result shows that the small/large black hole phase transitions appear for any $d$, which is reminiscent of the liquid/gas transition of a Van der Waals type. Moreover, the interesting thermodynamic phenomena, i.e., the triple points and the small/intermediate/large black hole phase transitions are observed for $d=6$ and $Q\in (0.1705,0.1946)$.

Previously it was shown that imposing a Petrov-like boundary condition on a hypersurface may reduce the Einstein equation to the incompressible Navier-Stokes equation, but all these correspondences are established in the near-horizon limit. In this paper, we demonstrate that this strategy can be extended to an arbitrary finite cutoff surface which is spatially flat, and the Navier-Stokes equation is obtained by employing a nonrelativistic long-wavelength limit.

A new cellular automaton (CA) model is presented for the self-organized criticality (SOC) in recurrent bursts of soft gamma repeaters (SGRs), which are interpreted as avalanches of reconnection in the magnetosphere of neutron stars. The nodes of a regular dodecahedron and a truncated icosahedron are adopted as spherically closed grids enclosing a neutron star. It is found that the system enters the SOC state if there are sites where the expectation value of the added perturbation is nonzero. The energy distributions of SOC avalanches in CA simulations are described by a power law with a cutoff, which is consistent with the observations of SGR $1806–20$ and SGR $1900+14$. The power-law index is not universal and depends on the amplitude of the perturbation. This result shows that the SOC of SGRs can be illustrated not only by the crust quake model but also by the magnetic reconnection model.

In this paper we present a computation of the thermally generated acceleration of the Cassini probe during its solar conjunction experiment, obtained from a model of the spacecraft. We build a thermal model of the vehicle and perform a Monte Carlo simulation to find a thermal acceleration with a main component of $(3.01\pm 0.33)\times 10^{-9}\mathrm{m}/{\mathrm{s}}^2$. This result is in close agreement with the estimates of this effect performed through Doppler data analysis.

Motivated by the LHCb’s recent confirmation of $Z_1(4475)$ as the $J^P=1^{+}$ resonance, we investigate various exotic interpretations of $Z_1(4475)$, which may be an axial vector tetraquark state, the P-wave excitation of the S-wave $D_1{\overline{D}}^{*}$ or $D_2{\overline{D}}^{*}$ molecule, the S-wave molecule composed of a $D$ or $D^{*}$ meson and a D-wave vector $D$ meson, or the cousin molecular state of $Z_c(3900)$ and $Z_c(4020)$ composed of a $D$ or $D^{*}$ meson and their radial excitations. With the help of the heavy quark symmetry, we predict the typical radiative and hidden-charm and open-charm strong decay patterns of $Z_1(4475)$, which are crucial to further identify the molecular state assignment of $Z_1(4475)$.