Self-induced flavor conversions of supernova neutrinos have been characterized in the spherically symmetric “bulb” model, reducing the neutrino evolution to a one-dimensional problem along a radial direction. We lift this assumption, presenting a two-dimensional toy model where neutrino beams are launched in many different directions from a ring. We find that self-interacting neutrinos spontaneously break the spatial symmetries of this model. As a result the flavor content and the lepton number of the neutrino gas would acquire sizable direction-dependent variations, breaking the coherent behavior found in the symmetric case. This finding would suggest that the previous results of the self-induced flavor evolution obtained in one-dimensional models should be critically reexamined.

Massive higher spin fields on de Sitter space exhibit enhanced gauge symmetries at special values of the mass. These fields are known as “partially massless.” We study the structure of the charges and Gauss laws which characterize sources for the partially massless spin-2. Despite having a simple scalar gauge symmetry, there is a rich structure of gauge charges. The charges come in electric and magnetic varieties, each taking values in the fundamental representation of the de Sitter group. We find two invariant electriclike charges and two invariant magneticlike charges and we find the pointlike monopole solutions which carry these charges, analogous to the electric point-charge solution and Dirac monopole solution of Maxwell electrodynamics. These solutions are related by partially massless duality, analogous to the electromagnetic duality that relates electric to magnetic charges.

Twisted deformations of the conformal symmetry in the Hopf algebraic framework are constructed. The first one is obtained by a Jordanian twist built up from dilatation and momenta generators. The second is the lightlike $\kappa$-deformation of the Poincaré algebra extended to the conformal algebra, obtained by a twist corresponding to the extended Jordanian $r$-matrix. The $\kappa$-Minkowski spacetime is covariant quantum space under both of these deformations. The extension of the conformal algebra by the noncommutative coordinates is presented in two cases. The differential realizations for $\kappa$-Minkowski coordinates, as well as their left-right dual counterparts, are also included.

We discuss the helicity spinors interpolating between the instant form dynamics (IFD) and the front form dynamics, or the light-front dynamics (LFD), and present the interpolating helicity amplitudes as well as their squares for the scattering of two fermions, and the annihilation of fermion and antifermion. We parametrize the interpolation between the two dynamics, IFD and LFD, by an interpolation angle and derive not only the generalized helicity spinors in the $(0,J)\oplus (J,0)$ chiral representation that links naturally the two typical IFD vs LFD helicity spinors but also the generalized Melosh transformation that relates these generalized helicity spinors to the usual Dirac spinors. Analyzing the directions of the particle momentum and spin with the variation of the interpolation angle, we inspect the whole landscape of the generalized helicity intermediating between the usual Jacob-Wick helicity in the IFD and the light-front helicity in the LFD. Our analysis clarifies the characteristic difference of the helicity amplitudes between the IFD and the LFD. In particular, we find that the behavior of the angle between the momentum direction and the spin direction bifurcates at a critical interpolation angle and the IFD and the LFD separately belong to the two different branches bifurcated at this critical interpolation angle. This finding further clarifies any conceivable confusion in the prevailing notion of the equivalence between the infinite momentum frame and the LFD. The existence of the universal J-curve found in our previous works of scalar field theory and the sQED theory is confirmed in the present work of interpolating helicity amplitudes for the fermion scattering and annihilation processes. In conjunction with the bifurcation of branches, the two boundaries appear in the interpolating helicity amplitudes and interestingly the J-curve persists within these two boundaries.

The saddle point approximation of the path integral partition functions is an important way of deriving the thermodynamical properties of black holes. However, there are certain black hole models and some mathematically analog mechanical models for which this method cannot be applied directly. This is due to the fact that their action evaluated on a classical solution is not finite and its first variation does not vanish for all consistent boundary conditions. These problems can be dealt with by adding a counterterm to the classical action, which is a solution of the corresponding Hamilton-Jacobi equation. In this work we study the effects of polymer quantization on a mechanical model presenting the aforementioned difficulties and contrast it with the above counterterm method. This type of quantization for mechanical models is motivated by the loop quantization of gravity, which is known to play a role in the thermodynamics of black hole systems. The model we consider is a nonrelativistic particle in an inverse square potential, and we analyze two polarizations of the polymer quantization in which either the position or the momentum is discrete. In the former case, Thiemann’s regularization is applied to represent the inverse power potential, but we still need to incorporate the Hamilton-Jacobi counterterm, which is now modified by polymer corrections. In the latter, momentum discrete case, however, such regularization could not be implemented. Yet, remarkably, owing to the fact that the position is bounded, we do not need a Hamilton-Jacobi counterterm in order to have a well-defined saddle point approximation. Further developments and extensions are commented upon in the discussion.

Binary black-hole systems are expected to be important sources of gravitational waves for upcoming gravitational-wave detectors. If the spins are not colinear with each other or with the orbital angular momentum, these systems exhibit complicated precession dynamics that are imprinted on the gravitational waveform. We develop a new procedure to match the precession dynamics computed by post-Newtonian (PN) theory to those of numerical binary black-hole simulations in full general relativity. For numerical relativity (NR) simulations lasting approximately two precession cycles, we find that the PN and NR predictions for the directions of the orbital angular momentum and the spins agree to better than $\sim 1°$ with NR during the inspiral, increasing to 5° near merger. Nutation of the orbital plane on the orbital time scale agrees well between NR and PN, whereas nutation of the spin direction shows qualitatively different behavior in PN and NR. We also examine how the PN equations for precession and orbital-phase evolution converge with PN order, and we quantify the impact of various choices for handling partially known PN terms.

In this article we study the geodesic motion of test particles and light in the Einstein-Maxwell-dilaton-axion black hole spacetime. We derive the equations of motion and present their solutions in terms of the Weierstraß $\wp$, $\sigma$ and $\zeta$ functions. With the help of parametric diagrams and effective potentials we analyze the geodesic motion and give a list of all possible orbit types.

To determine the frequencies of magnetic oscillations in neutron stars with highly tangled magnetic fields, we derive the perturbation equations. We assume that the field strength of the global magnetic structure is so small that such fields are negligible compared with tangled fields, which may still be far from a realistic configuration. Then, we systematically examine the spectra of the magnetic oscillations, as varying the magnetic field strength and stellar mass. The frequencies without crust elasticity are completely proportional to the strength of the magnetic field, whose proportionality constant depends strongly on the stellar mass. On the other hand, the oscillation spectra with crust elasticity become more complicated, where the frequencies even for weak magnetic fields are different from the crustal torsional oscillations without magnetic fields. For discussing spectra, the critical field strength can play an important role, and it is determined in such a way that the shear velocity is equivalent to the Alfvén velocity at the crust basis. Additionally, we find that the effect of the crust elasticity can be seen strongly in the fundamental oscillations with a lower harmonic index, $\ell$. Unlike the stellar models with a pure dipole magnetic field, we also find that the spectra with highly tangled magnetic fields become discrete, where one can expect many of the eigenfrequencies. Maybe these frequencies could be detected after the violent phenomena breaking the global magnetic field structure.

We present a new method for constructing operators in loop quantum gravity. The construction is an application of the general idea of “coherent state quantization,” which allows one to associate a unique quantum operator with every function on a classical phase space. Using the heat kernel coherent states of Hall and Thiemann, we show how to construct operators corresponding to functions depending on holonomies and fluxes associated with a fixed graph. We construct the coherent state versions of the fundamental holonomy and flux operators, as well as the basic geometric operators of area, angle, and volume. Our calculations show that the corresponding canonical operators are recovered from the coherent state operators in the limit of large spins.

We propose a novel theory of dark matter (DM) superfluidity that matches the successes of the $\mathrm{\Lambda }$ cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) model on cosmological scales while simultaneously reproducing the modified Newtonian dynamics (MOND) phenomenology on galactic scales. The DM and MOND components have a common origin, representing different phases of a single underlying substance. DM consists of axionlike particles with mass of order eV and strong self-interactions. The condensate has a polytropic equation of state $P\sim {\rho }^3$ giving rise to a superfluid core within galaxies. Instead of behaving as individual collisionless particles, the DM superfluid is more aptly described as collective excitations. Superfluid phonons, in particular, are assumed to be governed by a MOND-like effective action and mediate a MONDian acceleration between baryonic matter particles. Our framework naturally distinguishes between galaxies (where MOND is successful) and galaxy clusters (where MOND is not); due to the higher velocity dispersion in clusters, and correspondingly higher temperature, the DM in clusters is either in a mixture of superfluid and the normal phase or fully in the normal phase. The rich and well-studied physics of superfluidity leads to a number of observational signatures: an array of low-density vortices in galaxies; merger dynamics that depend on the infall velocity vs phonon sound speed; distinct mass peaks in bulletlike cluster mergers, corresponding to superfluid and normal components; and interference patters in supercritical mergers. Remarkably, the superfluid phonon effective theory is strikingly similar to that of the unitary Fermi gas, which has attracted much excitement in the cold atom community in recent years. The critical temperature for DM superfluidity is of order mK, comparable to known cold atom Bose–Einstein condensates. Identifying a precise cold atom analog would give important insights on the microphysical interactions underlying DM superfluidity. Tantalizingly, it might open the possibility of simulating the properties and dynamics of galaxies in laboratory experiments.

The Zhitnitsky and Dine, Fischler and Srednicki (DFSZ) model is a natural extension of the two-Higgs-doublet model containing an additional singlet, endowed with a Peccei-Quinn symmetry, and leading to a physically acceptable axion. In this paper we reexamine this model in the light of some new developments. For generic couplings the model reproduces the minimal Standard Model showing only tiny deviations (extreme decoupling scenario) and all additional degrees of freedom (with the exception of the axion) are very heavy. Recently it has been remarked that the limit where the coupling between the singlet and the two doublets becomes very small is technically natural. Combining this limit with the requirement of exact or approximate custodial symmetry, we may obtain an additional $0^{+}$ Higgs at the weak scale, accompanied by relatively light charged and neutral pseudoscalars. The mass spectrum would then resemble that of a generic two-Higgs-doublet model, with naturally adjustable masses in spite of the large scale that the axion introduces. However, the couplings are nongeneric in this model. We use the recent constraints derived from the Higgs-$WW$ coupling together with oblique corrections to constrain the model as much as possible. As an additional result, we work out the nonlinear parametrization of the DFSZ model in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale.

Scale setting for QCD with two flavors of staggered quarks is examined using Wilson flow over a factor of four change in both the lattice spacing and the pion mass. The statistics needed to keep the errors in the flow scale fixed is found to increase approximately as the inverse square of the lattice spacing. Tree level improvement of the scales $t_0$ and $w_0$ is found to be useful in most of the range of lattice spacings we explore. The scale uncertainty due to remaining lattice spacing effects is found to be about 3%. The ratio $w_0/\sqrt{t_0}$ is $N_f$ dependent and we find its continuum limit to be $1.106\pm 0.007(\text{stat})\pm 0.005(\mathrm{syst})$ for $m_{\pi }{w}_0\simeq 0.3$.

We compute masses of $D$ mesons, $D_s$ mesons and charmonium states using Wilson twisted mass lattice QCD. We present results for spin $J=0$, 1, 2, 3, parity $\mathcal{P}=-$, $+$ and in case of charmonium also charge conjugation $\mathcal{C}=-$, $+$. Computations are based on quark-antiquark creation operators and performed at three different unphysically heavy $u/d$ quark masses allowing an extrapolation to the physical $u/d$ quark mass. Within combined statistical and systematic errors, which are around $2\%\dots 3\%$, our results agree with available experimental results. Particular focus is put on the $J^{\mathcal{P}}=1^{+}$ mesons $D_1(2430)$ and $D_1(2420)$. We separate and classify these close-by states according to the total angular momentum of their light degrees of freedom, $j\approx 1/2$ and $j\approx 3/2$. This is a first important step to study decays $B^{(*)}\to D_1+l+\nu$, for which a long-standing conflict between theory and experiment exists.

Within the factorization-assisted topological-amplitude approach, we study the two-body charmed $B$ meson decays $B_{u,d,s}\to D^{(*)}M$, with $M$ denoting a light pseudoscalar (or vector) meson. The meson decay constants and transition form factors are factorized out from the hadronic matrix element of topological diagrams. Therefore, the effect of SU(3) symmetry breaking is retained, which is different from the conventional topological diagram approach. The number of free nonperturbative parameters to be fitted from experimental data is also much less. Only four universal nonperturbative parameters ${\chi }^C$, ${\varphi }^C$, ${\chi }^E$ and ${\varphi }^E$ are introduced to describe the contribution of the color-suppressed tree and $W$-exchanged diagrams for all the decay channels. With the fitted parameters from 31 decay modes induced by $b\to c$ transition, we then predict the branching fractions of 120 decay modes induced by both $b\to c$ and $b\to u$ transitions. Our results are well consistent with the measured data or to be tested in the LHCb and Belle-II experiments in the future. Besides, the SU(3) symmetry breaking, isospin violation and $CP$ asymmetry are also investigated.

In this paper, we consider a solution to explain the three discrepancies with the standard model (SM) predictions in flavor observables, i.e., anomalies in $B\to K^{*}{\mu }^{+}{\mu }^{-}$ and $R_K=\mathcal{B}(B\to K{\mu }^{+}{\mu }^{-})/\mathcal{B}(B\to K{e}^{+}{e}^{-})$ at the LHCb and an excess in $h\to \mu \tau$ at the CMS in the context of R-parity violating (RPV) supersymmetry. We demonstrate that these anomalies can be explained within a unified framework: the minimal supersymmetry model (MSSM) extended with $5+\overline{5}$ vectorlike (VL) particles. The new trilinear RPV couplings involving VL particles in our model can solve the $b\to s$ anomalies, and the mixing between the SM-like Higgs boson and the VL sneutrino can yield the extra $h\to \mu \tau$ decay mode.

We consider single-diffractive (SD) Higgs production in association with heavy flavor in proton-proton collisions at the LHC. The main focus of our study is a reliable estimate of SD/inclusive ratio, not a precision computation of the cross sections. The calculations are performed within the framework of the phenomenological dipole approach, which includes by default the absorptive corrections, i.e., the gap survival effects at the amplitude level. The dominant mechanism is the diffractive production of heavy quarks, which radiate a Higgs boson (Higgsstrahlung). Although diffractive production of $t$-quarks is grossly suppressed as $1/m_t^2$, the large Higgs-top coupling compensates this smallness and the Higgsstrahlung by $t$-quarks becomes the dominant contribution at large Higgs boson transverse momenta. We computed the basic observables such as the transverse momentum and rapidity distributions of the diffractively produced Higgs boson in association with the bottom and top quark pair. Finally, we discuss a potential relevance of the diffractive Higgsstrahlung in comparison to the Higgsstrahlung off intrinsic heavy flavor at forward Higgs boson rapidities.

We explore beyond-standard-model (BSM) physics signatures in the $l+\text{jets}$ channel of the $t\overline{t}$ pair production process at the Tevatron and the LHC. We study the effects of BSM physics scenarios on the top-quark polarization and on the kinematics of the decay leptons. To this end, we construct asymmetries using the lepton energy and angular distributions. Further, we find their correlations with the top polarization, net charge asymmetry and top forward-backward asymmetry. We show that when used together, these observables can help discriminate effectively between SM and different BSM scenarios, which can lead to varying degrees of top polarization at the Tevatron as well as the LHC. We use two types of colored mediator models to demonstrate the effectiveness of proposed observables, an $s$-channel axigluon and a $u$-channel diquark.

We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at $\sim {10}^{13}–{10}^{14}\mathrm{GeV}$. Together with a somewhat enhanced quartic coupling arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. This is a “next-to-minimal” dynamical electroweak symmetry breaking scheme.

We present a study of the process $e^{+}{e}^{-}\to {\pi }^{\pm }(D{\overline{D}}^{*}{)}^{\mp }$ using data samples of $1092{\mathrm{pb}}^{-1}$ at $\sqrt{s}=4.23\mathrm{GeV}$ and $826{\mathrm{pb}}^{-1}$ at $\sqrt{s}=4.26\mathrm{GeV}$ collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the $D$ meson pair and the bachelor ${\pi }^{\pm }$ in the final state, we confirm the existence of the charged structure $Z_c(3885{)}^{\mp }$ in the $(D{\overline{D}}^{*}{)}^{\mp }$ system in the two isospin processes $e^{+}{e}^{-}\to {\pi }^{+}{D}^0{D}^{*-}$ and $e^{+}{e}^{-}\to {\pi }^{+}{D}^{-}{D}^{*0}$. By performing a simultaneous fit, the statistical significance of $Zc(3885{)}^{\mp }$ signal is determined to be greater than $10\sigma$, and its pole mass and width are measured to be $M_{\mathrm{pole}}=(3881.7\pm 1.6(\mathrm{stat})\pm 1.6(\mathrm{syst}))\mathrm{MeV}/c^2$ and ${\mathrm{\Gamma }}_{\mathrm{pole}}=(26.6\pm 2.0(\mathrm{stat})\pm 2.1(\mathrm{syst}))\mathrm{MeV}$, respectively. The Born cross section times the $(D{\overline{D}}^{*}{)}^{\mp }$ branching fraction ($\sigma (e^{+}{e}^{-}\to {\pi }^{\pm }{Z}_c(3885{)}^{\mp })\times Br(Z_c(3885{)}^{\mp }\to (D{\overline{D}}^{*}{)}^{\mp })$) is measured to be $(141.6\pm 7.9(\mathrm{stat})\pm 12.3(\mathrm{syst}))\mathrm{pb}$ at $\sqrt{s}=4.23\mathrm{GeV}$ and $(108.4\pm 6.9(\mathrm{stat})\pm 8.8(\mathrm{syst}))\mathrm{pb}$ at $\sqrt{s}=4.26\mathrm{GeV}$. The polar angular distribution of the ${\pi }^{\pm }-Z_c(3885{)}^{\mp }$ system is consistent with the expectation of a quantum number assignment of $J^P=1^{+}$ for $Z_c(3885{)}^{\mp }$.