Flux compactification of string theory generates an ensemble with a large number of vacua, called the landscape. By using the statistics of various properties of low-energy effective theories in the string landscape, one can therefore hope to provide a scientific foundation to the notion of naturalness. This article discusses how to answer such questions of practical interest by using flux compactification of F-theory. It is found that the distribution is approximately in a factorized form given by distribution on the choice of 7-brane gauge group, that on the number of generations $N_{\text{gen}}$ and that on effective coupling constants. The distribution on $N_{\text{gen}}$ is approximately Gaussian for the range $|N_{\text{gen}}|\lesssim 10$. The statistical cost of higher-rank gauge group is also discussed.

We study the general theory of the Higgs mechanism without assuming Lorentz invariance. In the presence of a finite expectation value of non-Abelian matter charges, gauging those symmetries always results in spontaneous breaking of spatial rotation. If we impose the charge neutrality by assuming a background with the opposite charges, the dynamics of the background cannot be decoupled and has to be fully taken into account. In either case, the spectrum is continuous as the gauge coupling is switched off.

We present rotating wormhole solutions in general relativity, which are supported by a phantom scalar field. These solutions evolve from the static Ellis wormhole, when the throat is set into rotation. As the rotational velocity increases, the throat deforms until, at a maximal value of the rotational velocity, an extremal Kerr solution is encountered. The rotating wormholes attain a finite mass and quadrupole moment. They exhibit ergospheres and possess bound orbits.

In the so-called “Yukawaon” model, the (effective) Yukawa coupling constants $Y_f^{\text{eff}}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (Yukawaons) with $3\times 3$ components. In this brief article, we change VEV forms $⟨Y_f⟩$ in the previous paper into a unified form. Therefore, parameter fitting for quark and lepton masses and mixings is revised. Especially, we obtain predicted values of neutrino mixing ${\sin }^{2}2{\theta }_{13}$ and a leptonic $CP$ violating phase ${\delta }_{CP}^{\ell }$ that are consistent with the observed curve in the $({\sin }^{2}2{\theta }_{13},{\delta }_{CP}^{\ell })$ reported by the T2K group recently.

We show that due to the $\rho$ parameter bound and the Landau pole limit, the reduced 3-3-1 model is unrealistic, while due to the $\rho$ parameter and flavor-changing neutral current bounds, the simple 3-3-1 model is experimentally unfavored. All such conditions strictly constrain the gauge symmetry breaking scales of the minimal 3-3-1 model with three scalar triplets.

We study the quark spectrum at nonzero temperature and density near the critical point (CP) of the chiral phase transition incorporating effects of the scalar- and pseudoscalar-density fluctuations in a chiral effective model with a nonzero current quark mass. It is known that the soft mode associated with the second-order transition at the CP lies in the spacelike region of the scalar-density fluctuation. We find that the soft mode influences the quark spectrum significantly near the CP, resulting in the shift of the quasiquark peak. Effects of the composite stable pions on the quark spectrum near the CP are also discussed.

In this paper the smallest thermal screening mass associated with the correlator of the $CT$-odd operator, $\sim \mathrm{Tr}{F}_{\mu \nu }{\tilde{F}}^{\mu \nu }$, is determined in strongly coupled non-Abelian gauge plasmas which are holographically dual to nonconformal, bottom-up $\mathrm{Einstein}+\mathrm{scalar}$ gravity theories. These holographic models are constructed to describe the thermodynamical properties of $\mathrm{S}\mathrm{U}(N_c)$ plasmas near deconfinement at large $N_c$, and we identify this thermal mass with the Debye screening mass $m_D$. In this class of nonconformal models with a first-order deconfinement transition at $T_c$ the Debye screening mass $m_D$ displays the same behavior found for the expectation value of the Polyakov loop (which we also compute) jumping from zero below $T_c$ to a nonzero value just above the transition. In the case of a crossover phase transition, $m_D/T$ has a minimum similar to that found for the speed of sound squared $c_s^2$. This holographic framework is also used to evaluate $m_D$ as a function of $\eta /s$ in a strongly coupled conformal gauge plasma dual to Gauss–Bonnet gravity. In this case, $m_D/T$ decreases with increasing $\eta /s$ in accordance with extrapolations from weak coupling calculations.

We study the asymmetric nuclear matter using a holographic QCD model by introducing a baryonic charge in the infrared boundary. We first show that, in the normal hadron phase, the predicted values of the symmetry energy and its slope parameter are comparable with the empirical values. We find that the phase transition from the normal phase to the pion condensation phase is delayed compared with the pure mesonic matter: the critical chemical potential is larger than the pion mass which is obtained for the pure mesonic matter. We also show that, in the pion condensation phase, the pion contribution to the isospin number density increases with the chemical potential, while the baryonic contribution is almost constant. Furthermore, the value of chiral condensation implies that the enhancement of the chiral symmetry breaking occurs in the asymmetric nuclear matter as in the pure mesonic matter. We also give a discussion on how to understand the delay in terms of the four-dimensional chiral Lagrangian including the rho and omega mesons based on the hidden local symmetry.

The same-sign diboson process $pp\to W^{\pm }{W}^{\pm }jj$ has been measured at the LHC using leptonic decay channels of $W$ bosons, with production cross sections of two fiducial regions reported to be consistent with the Standard Model expectations within $1\sigma$. These results constrain new physics models with a modified $W^{+}{W}^{+}{W}^{-}{W}^{-}$ vertex. We consider in particular the Georgi-Machacek model in which the quartic $W$ boson vertex is effectively modified due to mediations of new Higgs bosons in the model. The relevant gauge-gauge-scalar couplings are all proportional to the vacuum expectation value of the isospin triplets, which can be of $\mathcal{O}(10)\mathrm{GeV}$ because of custodial vacuum alignment. Using the current 8-TeV data at the LHC, we exclude parameter space on the plane of the triplet vacuum expectation value and the new Higgs boson mass. The expected discovery reach at the 14-TeV LHC is also studied.

We proposed a mechanism in which the lightness of Higgs boson and the smallness of charge parity ($CP$) violation are correlated based on the Lee model, namely, the spontaneous $CP$-violation two-Higgs-doublet model. In this model, the mass of the lightest Higgs boson $m_h$ as well as the quantities $K$ and $J$ are $\propto t_{\beta }{s}_{\xi }$ in the limit $t_{\beta }{s}_{\xi }\to 0$ (see text for definitions of $t_{\beta }$ and $\xi$), namely, the $CP$ conservation limit. Here, $K$ and $J$ are the measures for $CP$-violation effects in scalar and Yukawa sectors, respectively. It is a new way to understand why the Higgs boson discovered at the LHC is light. We investigated the important constraints from both high energy LHC data and numerous low energy experiments, especially the measurements of electric dipole moments of electron and neutron as well as the quantities of B meson and kaon. Confronting all data, we found that this model is still viable. It should be emphasized that there is no standard-model limit for this scenario; thus it is always testable for future experiments. In order to pin down the Lee model, it is important to discover the extra neutral and charged Higgs bosons and measure their $CP$ properties and the flavor-changing decays. At the LHC with $\sqrt{s}=14\mathrm{TeV}$, this scenario is favored if there is significant suppression in the $b\overline{b}$ decay channel or any vector boson fusion, $\mathrm{V}+\mathrm{H}$ production channels. On the contrary, it will be disfavored if the signal strengths are standard-model–like more and more. It can be easily excluded at $(3–5)\sigma$ level with several ${\mathrm{fb}}^{-1}$ at future $e^{+}{e}^{-}$ colliders, via accurately measuring the Higgs boson production cross sections.

We perform a thorough analysis of the parameter space of the minimal left-right supersymmetric model in agreement with the LHC data. The model contains left- and right-handed fermionic doublets, two Higgs bidoublets, two Higgs triplet representations, and one singlet, insuring a charge-conserving vacuum. We impose the condition that the model complies with the experimental constraints on supersymmetric particles masses and on the doubly charged Higgs bosons and require that the parameter space of the model satisfies the LHC data on neutral Higgs signal strengths at $2\sigma$. We choose benchmark scenarios by fixing some basic parameters and scanning over the rest. The lightest supersymmetric particle in our scenarios is always the lightest neutralino. We find that the signals for $H\to \gamma \gamma$ and $H\to V{V}^{\star }$ are correlated, while $H\to b\overline{b}$ is anticorrelated with all of the other decay modes, and also that the contribution from singly charged scalars dominates that of the doubly charged scalars in $H\to \gamma \gamma$ and $H\to Z\gamma$ loops, contrary to type II seesaw models. We also illustrate the range for mass spectrum of the LRSUSY model in light of planned measurements of the branching ratio of $H\to \gamma \gamma$ to 10% level.

We explore possible signatures for heavy neutrinos and a neutral gauge boson, $Z^{\prime }$, in the TeV scale $B-L$ extension of the Standard Model with inverse seesaw mechanisms at the Large Hadron Collider. We show that, due to new decay channels of $Z^{\prime }$ into heavy/inert neutrinos, the LHC stringent bounds imposed on the $Z^{\prime }$ mass can be significantly relaxed. We analyze the pair production of heavy neutrinos decaying to four leptons plus two neutrinos, four jets plus two leptons, or three leptons plus two jets and one neutrino. We show that the $4l+2\nu$ is the most promising decay channel for probing both $Z^{\prime }$ and heavy neutrinos at the LHC.

We present a detailed analysis of the heavy-to-light semileptonic decays of the ${\mathrm{\Lambda }}_b$ and ${\mathrm{\Lambda }}_c$ baryons ${\mathrm{\Lambda }}_b\to p{\ell }^{-}{\overline{\nu }}_{\ell }$ and ${\mathrm{\Lambda }}_c\to n{\ell }^{+}{\nu }_{\ell }$ in the covariant confined quark model. We calculate the invariant and helicity amplitudes of the two processes which are then used to analyze their angular decay distributions, their rates and asymmetry parameters.

We report a measurement of the indirect $CP$-violating asymmetries ($A_{\mathrm{\Gamma }}$) between effective lifetimes of anticharm and charm mesons reconstructed in $D^0\to K^{+}{K}^{-}$ and $D^0\to {\pi }^{+}{\pi }^{-}$ decays. We use the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab experiment and corresponding to $9.7{\mathrm{fb}}^{-1}$ of integrated luminosity. The strong-interaction decay $D^{*+}\to D^0{\pi }^{+}$ is used to identify the meson at production as $D^0$ or ${\overline{D}}^0$. We statistically subtract $D^0$ and ${\overline{D}}^0$ mesons originating from $b$-hadron decays and measure the yield asymmetry between anticharm and charm decays as a function of decay time. We measure $A_{\mathrm{\Gamma }}(K^{+}{K}^{-})=(-0.19\pm 0.15(\text{stat})\pm 0.04(\text{syst}))\%$ and $A_{\mathrm{\Gamma }}({\pi }^{+}{\pi }^{-})=(-0.01\pm 0.18(\text{stat})\pm 0.03(\text{syst}))\%$. The results are consistent with the hypothesis of $CP$ symmetry and their combination yields $A_{\mathrm{\Gamma }}=(-0.12\pm 0.12)\%$.

E-strings arise from M2 branes suspended between an M5 brane and an M9 plane. In this paper we obtain explicit expressions for the elliptic genus of two E-strings using a series of string dualities. Moreover we show how this can be used to recover the elliptic genus of two $E_8\times E_8$ heterotic strings using the Hořava–Witten realization of heterotic strings in M-theory. This involves highly nontrivial identities among Jacobi forms and is remarkable in light of the fact that E-strings are “sticky” and form bound states whereas heterotic strings do not form bound states.

We investigate how isospin affects the geometrical shape and energy of classical soliton solutions of topological charges $B=1–4,8$ in the Skyrme model. The novel approach in our work is that we study classically isospinning Skyrmions beyond the rigid-body approximation; that is, we explicitly allow the soliton solutions to deform and to break the symmetries of the static configurations. Our fully three-dimensional relaxation calculations reveal that the symmetries of isospinning Skyrme solitons can differ significantly from the ones of the static configurations. In particular, isospinning Skyrmion solutions can break up into lower-charge Skyrmions, can deform into new solution types that do not exist at vanishing angular frequency $\omega$ or energy degeneracy can be removed. These types of deformations have been largely ignored in previous work on modeling nuclei by quantized Skyrmion solutions.

Charged plasmas with chirality imbalance are unstable and tend to reduce the imbalance. This chiral plasma instability is, however, not captured in (anomalous) hydrodynamics for high-temperature non-Abelian plasmas. We derive a Langevin-type classical effective theory with anomalous parity-violating effects for non-Abelian plasmas that describes the chiral plasma instability at the magnetic scale. We show that the time scale of the instability is of order $[g^{4}T\ln (1/g){]}^{-1}$ at weak coupling.

We present two new one-parameter families of scheme transformations and apply these to study the scheme dependence of the infrared zero in the beta function of an asymptotically free non-Abelian gauge theory up to four-loop order. Our results provide a further quantitative measure of this scheme dependence, showing that for moderate values of the gauge coupling and the parameter specifying the scheme transformation, this dependence is relatively mild. We also remark on a generalized multi-parameter family of rational scheme transformations.

An investigation of the relativistic effects on the Richtmeyer-Meshkov (RM) instability is presented. It is found that the relativistic effects weaken the RM instability as compared to the nonrelativistic case, both in two and three spatial dimensions. Linear stability is studied analytically and compared with numerical results in the linear growth regime. Finally, based on the numerical results, a general expression characterizing the nonlinear evolution of the instability is proposed.

We systematically examine the properties of an electrically charged black hole in Eddington-inspired Born-Infeld gravity with not only the positive but also the negative coupling constant in the theory. As a result, we numerically find that the black hole solution exists even with the negative coupling constant, where the electric charge of black hole can be larger than the black hole mass. We also clarify the parameter space where the black hole solution exists. On the other hand, to examine the particle motion around such black hole, we derive the geodesic equation. The behavior of the effective potential for the radial particle motion is almost the same as that in general relativity, but the radius of the innermost stable circular orbit and the angular momentum giving the innermost stable circular orbit can be changed, depending on the coupling constant. In particular, we find that the radius of innermost stable circular orbit with the specific value of the coupling constant can be smaller than that for the extreme case in general relativity. Such a particle can release the gravitational binding energy more than the prediction in general relativity, which could be important from the observational point of view.