Recent observations indicate that magnetars may reside in merging compact binaries and at least part of fast radio bursts (FRBs) are sourced by magnetar activities. It is natural to speculate that a class of merging neutron star binaries may have FRB emitters. In this work, we study the observational aspects of these binaries—particularly those with FRB repeaters, which are promising multiband and multimessenger observation targets of radio telescopes and ground-based gravitational wave detectors as the former telescopes can probe the systems at a much earlier stage in the inspiral than the latter. We show that observations of FRB repeaters in compact binaries have a significant advantage in pinning down the binary spin dynamics, constraining neutron star equation of state, probing FRB production mechanisms, and testing beyond standard physics. As a proof of principle, we investigate several half-year long mock observations of FRB pulses originating from premerger neutron star binaries, and we find that using the information of FRB arriving times alone, the intrinsic parameters of this system (including the stellar masses, spins, and quadrupole moments) can be measured with high precision, and the angular dependence of the FRB emission pattern can also be well reconstructed. The measurement of stellar masses [with an error of $\mathcal{O}({10}^{-6}–{10}^{-5})$] and quadrupole moments [with an error of $\mathcal{O}(1\%–10\%)$] may be an unprecedented discriminator of nuclear equations of state in neutron stars. In addition, we find the multiband and multimessenger observations of this binary will be sensitive to alternative theories of gravity and beyond standard models, e.g., dynamical Chern-Simons gravity and axion field that is coupled to matter. For example, we find that the effect of gravitational parity violation can be probed much more accurately than existing observations/experiments by combining FRB observations with either gravitational observations or x-ray observations and applying universal relations for neutron stars that do not depend sensitively on the equations of state.

Spinning black holes can transfer a significant fraction of their energy to ultralight bosonic fields via superradiance, condensing them in a corotating structure or “cloud.” This mechanism turns black holes into powerful particle detectors for bosons with extremely feeble interactions. To explore its full potential, the couplings between such particles and the Maxwell field in the presence of plasma need to be understood. In this work, we study these couplings using numerical relativity. We first focus on the coupled axion-Maxwell system evolving on a black hole background. By taking into account the axionic coupling concurrently with the growth of the cloud, we observe for the first time that a new stage emerges: that of a stationary state where a constant flux of electromagnetic waves is fed by superradiance, for which we find accurate analytical estimates. Moreover, we show that the existence of electromagnetic instabilities in the presence of plasma is entirely controlled by the axionic coupling; even for dense plasmas, an instability is triggered for high enough couplings.

We propose a new stellar structure of compact stars, the “cross stars” that consist of a hadronic matter core and a quark matter crust, with an inverted structure compared to the conventional hybrid stars. This distinct stellar structure naturally arises from the quark matter to hadronic matter transition associated with the chemical potential crossing, in the context of the quark matter hypothesis that either strange or up-down quark matter is the ground state of baryonic matter at low pressure. We find that the interplay between the hadronic matter and quark matter compositions of cross stars can help to reconcile the small radii constraints indicated by the LIGO/Virgo GW170817 event, the large radii constraints set for massive compact stars by recent NICER x-ray observations, and the recent observation of the most-massive pulsar PSR J0952-0607. This leaves more space open for the equation of states of both hadronic matter and quark matter.

We study consistently the effects of magnetic field on hot and dense matter. In particular, we look for differences that arise due to assumptions that reproduce the conditions produced in particle collisions or astrophysical scenarios, such as in the core of fully evolved neutron stars (beyond the protoneutron star stage). We assume the magnetic field to be either constant or follow a profile extracted from general relativity calculations of magnetars and make use of two realistic models that can consistently describe chiral symmetry restoration and deconfinement to quark matter, the chiral mean field and the Polyakov-loop extended Nambu-Jona-Lasinio models. We find that net isospin, net strangeness, and weak chemical equilibrium with leptons can considerably change the effects of temperature and magnetic fields on particle content and deconfinement in dense matter. We finish by discussing the possibility of experimentally detecting quark deconfinement in dense and/or hot matter and the possible role played by magnetic fields.

The effective coupling of the Higgs boson to gluons determines the production rate of the Higgs boson at the LHC and plays a crucial role to measure the Higgs properties. In this paper, we propose a novel method to extract the Higgs gluon gauge coupling information at future lepton colliders, by utilizing the jet charge asymmetry of the two leading jets from the Higgs boson decay. Owing to the jet charge correlation nature of the Higgs decay products, we demonstrate that this asymmetry value would be close to one for the signal $H\to gg$, while it is always larger than one for the dominated backgrounds. With the help of the jet charge information, it is possible to constrain the Higgs gluon effective coupling very well in the future Higgs factory, and this conclusion is not sensitive to the jet charge parameter $\kappa$.

We present a formulation of lepton family numbers, based on quantum field theory, for neutrino oscillation phenomenology that can be applied to nonrelativistic and relativistic energies for neutrinos. It is formulated for both types of neutrinos, Dirac and Majorana. The formulation is constructed as the time evolution of a lepton family number density operator. Then, the time evolution of the lepton family number density operator becomes dependent on the mass and new features appear. The expectation value of the density operator is evaluated for the initial state with a Gaussian distribution for the momentum amplitude. This enables us to study wave-packet-like decoherence effects. We show in the nonrelativistic regime, the type of neutrino mass are distinguishable even under the presence of wave-packet-like decoherence effects.

We compute the chiral magnetic effect (CME) in a cylindrical region coaxial with the external magnetic field. As the boundary condition we require vanishing of the radial component of the electric current on the cylinder side wall. We find that when the magnetic length is comparable to or larger than the cylinder radius, the CME is suppressed compared to the corresponding result in an infinite medium. As a result, for a given cylinder radius, the suppression is stronger in weak fields. We argue that the electric current generated by the CME vanishes at the cylinder wall and monotonically increases toward the symmetry axis.

We present scheme-independent calculations of the anomalous dimensions ${\gamma }_{\overline{\psi }\psi ,IR}$ and ${\gamma }_{\overline{\chi }\chi ,IR}$ of fermion bilinear operators $\overline{\psi }\psi$ and $\overline{\chi }\chi$ at an infrared fixed point in an asymptotically free SU($N_c$) gauge theory with massless Dirac fermion content consisting of $N_F$ fermions ${\psi }_i^a$ in the fundamental representation and $N_{A_2}$ fermions ${\chi }_j^{ab}$ in the antisymmetric rank-2 tensor representation, where $i$, $j$ are flavor indices. For the case $N_c=4$, $N_F=4$, and $N_{A_2}=4$, we compare our results with values of these anomalous dimensions measured in a recent lattice simulation and find agreement.

Hyperon nonleptonic decays that change strangeness by two units, such as $\mathrm{\Xi }\to N\pi$ and ${\mathrm{\Omega }}^{-}\to n{K}^{-},\mathrm{\Lambda }{\pi }^{-},{\mathrm{\Sigma }}^{(*)}\pi$, are highly suppressed in the standard model. Only a few of them have been searched for to date, leading to experimental upper bounds that are many orders of magnitude above the expectations of the standard model. This leaves ample opportunity to look for indications of new physics in these processes. At the same time, most, but not all, $\mathrm{\Delta }S=2$ interactions beyond the standard model are severely constrained by kaon-mixing data. We present two scenarios where new physics satisfying the kaon-mixing constraints can enhance the hyperon decay rates to levels that can be probed in future searches by BESIII and LHCb and at the proposed Super Tau-Charm Factory. Both scenarios require significant fine-tuning.

We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, ${\pi }^{+}\to e^{+}{\nu }_e{X}_{\mu }$. In models where the net charge to which $X_{\mu }$ couples to is not conserved, no lepton helicity flip is required for the decay to happen, enhancing the decay rate by factors of $\mathcal{O}(m_{\pi }^4/m_e^2{m}_X^2)$. A past search at the SINDRUM-I spectrometer severely constrains this possibility. In the context of the hypothesized 17 MeV particle proposed to explain anomalous ${}^8\mathrm{Be}$, ${}^4\mathrm{He}$, and ${}^{12}\mathrm{C}$ nuclear transitions claimed by the ATOMKI experiment, this limit rules out vector-boson explanations and poses strong limits on axial-vector ones.

Next-generation large-volume detectors, such as GRAND, POEMMA, Trinity, TAROGE-M, and PUEO, have been designed to search for ultrahigh-energy cosmic rays (UHECRs) and cosmic neutrinos with unprecedented sensitivity. We propose to use these detectors to search for new physics beyond the Standard Model (BSM). By considering the simple case of a right-handed neutrino that mixes exclusively with the active $\tau$ neutrino, we demonstrate that the existence of new physics can increase the probability for ultrahigh-energy (UHE) neutrinos to propagate through the Earth and produce extensive air showers that will be measurable soon. We compare the fluxes of such showers that would arise from various diffuse and transient sources of high-energy neutrinos, both in the Standard Model and in the presence of a right-handed neutrino. We show that detecting events with emergence angles $\gtrsim 10\mathrm{deg}$ is promising to probe the existence of BSM physics, and we study the sensitivities of GRAND and POEMMA in this scenario. In particular, we show that the hypothesis of a right-handed neutrino with a mass of $\mathcal{O}(1–16)\mathrm{GeV}$ may be probed in the future for mixing angles as small as $|U_{\tau N}{|}^2\gtrsim {10}^{-7}$, thus competing with existing and projected experimental limits.

We discuss the role of the top-quark Yukawa coupling $y_t$ concerning the hierarchy problem and construct an alternative scheme to the conventional solutions with top partners. In traditional models, such as supersymmetry or composite Higgs, top partners cancel the top loop contribution to the Higgs quadratic term. The lack of evidence for such colored partners, however, drives these models into more and more fine-tuned regions. Here, an alternative means to mitigate the top loop, allowing for natural electroweak symmetry breaking, is presented. Emphasizing that we have not measured the top-Higgs interactions at high scales yet, we envisage scenarios where this interaction is only approaching its sizable strength in the infrared, but gets strongly suppressed at high scales. We first discuss possible effects via a modification of the running of the top Yukawa coupling. Then, we turn to models where the top Yukawa is generated at the one-loop level. Originated from a dimension-six operator, it drops when crossing the mass threshold of new degrees of freedom. In either case, the top partners are replaced by some new top-philic particles with strong interaction. Thus, a very different phenomenology, such as large top mass running and signals in four top final states, is introduced, which will be discussed in detail. With the assistance of this mechanism, the solution to the hierarchy problem can be pushed to a (well-defined) higher scale, and a final test of naturalness might be deferred to a 100 TeV collider, such as the future circular collider.

We study a doubly bottomed tetraquark state $(bb\overline{u}\overline{d})$ with quantum number $I(J^P)=0(1^{+})$, denoted by $T_{bb}$, in lattice QCD with the nonrelativistic QCD (NRQCD) quark action for $b$ quarks. Employing ($2+1$)-flavor gauge configurations at $a\approx 0.09\mathrm{fm}$ on ${32}^3\times 64$ lattices, we have extracted the coupled-channel potential between $\overline{B}{\overline{B}}^{*}$ and ${\overline{B}}^{*}{\overline{B}}^{*}$ in the HAL QCD method, which predicts an existence of a bound $T_{bb}$ below the $\overline{B}{\overline{B}}^{*}$ threshold. By extrapolating results at $m_{\pi }\approx 410$, 570, 700 MeV to the physical pion mass $m_{\pi }\approx 140\mathrm{MeV}$, we obtain a binding energy with its statistical error as $E_{\text{binding}}^{(\mathrm{single})}=155(17)\mathrm{MeV}$ and $E_{\text{binding}}^{(\mathrm{coupled})}=83(10)\mathrm{MeV}$, where “coupled” means that effects due to virtual ${\overline{B}}^{*}{\overline{B}}^{*}$ states are included through the coupled channel potential, while only a potential for a single $\overline{B}{\overline{B}}^{*}$ channel is used in the analysis for “single.” A comparison shows that the effect from virtual ${\overline{B}}^{*}{\overline{B}}^{*}$ states is quite sizable to the binding energy of $T_{bb}$. We estimate systematic errors to be $\pm 20\mathrm{MeV}$ at most, which are mainly caused by the NRQCD approximation for $b$ quarks.

In this work, we adopt the one-boson-exchange model to study the $Y_c{K}^{(*)}(Y_c={\mathrm{\Lambda }}_c,{\mathrm{\Sigma }}_c)$ interactions. After considering both of the $S-D$ wave mixing effects and the coupled channel effects, we can predict several possible open-charm molecular pentaquarks, i.e., the single ${\mathrm{\Sigma }}_c{K}^{*}$ molecular states with $I(J^P)=1/2(1/2^{-})$, $1/2(3/2^{-})$, and $3/2(1/2^{-})$, the coupled ${\mathrm{\Lambda }}_c{K}^{*}/{\mathrm{\Sigma }}_c{K}^{*}$ molecular states with $1/2(1/2^{-})$ and $1/2(3/2^{-})$, and the coupled ${\mathrm{\Sigma }}_{c}K/{\mathrm{\Lambda }}_c{K}^{*}/{\mathrm{\Sigma }}_c{K}^{*}$ molecular state with $1/2(1/2^{-})$. Meanwhile, we extend our study to the $Y_c{\overline{K}}^{(*)}$ interactions, and our results suggest that the ${\mathrm{\Sigma }}_c\overline{K}$ system with $I(J^P)=1/2(1/2^{-})$, the ${\mathrm{\Sigma }}_c{\overline{K}}^{*}$ systems with $1/2(1/2^{-})$, $1/2(3/2^{-})$, and $3/2(3/2^{-})$, the coupled ${\mathrm{\Lambda }}_c{\overline{K}}^{*}/{\mathrm{\Sigma }}_c{\overline{K}}^{*}$ system with $1/2(1/2^{-})$, and the ${\mathrm{\Sigma }}_c\overline{K}/{\mathrm{\Lambda }}_c{\overline{K}}^{*}/{\mathrm{\Sigma }}_c{\overline{K}}^{*}$ system with $1/2(1/2^{-})$ can be the prime molecular candidates.

We study the axion of quantum chromodynamics in hot and/or dense quark matter, within a Nambu-Jona-Lasinio-like model that includes the coupling of the axion to quarks. First, we compute the effects of the chiral crossover on the axion mass and self-coupling at finite temperature and baryon density, implementing local electrical neutrality and $\beta$-equilibrium. We find that the low energy properties of axion are very sensitive to the phase transition of quantum chromodynamics, in particular, when the bulk quark matter is close to criticality. Then, for the first time in the literature we compute the axion potential at finite quark chemical potential and study the axion domain walls in bulk quark matter. We find that the energy barrier between two adjacent vacuum states decrease in the chirally restored phase: this results in a lower surface tension of the walls. Finally, we comment on the possibility of production of walls in dense quark matter.

The evolution kernels that govern the scale dependence of the generalized parton distributions are invariant under transformations of the $\mathrm{SL}(2,\mathrm{R})$ collinear subgroup of the conformal group. Beyond one loop the symmetry generators, due to quantum effects, differ from the canonical ones. We construct the transformation that brings the full symmetry generators back to their canonical form and show that the eigenvalues (anomalous dimensions) of the new, canonically invariant, evolution kernel coincide with the so-called parity respecting anomalous dimensions. We develop an efficient method that allows one to restore an invariant kernel from the corresponding anomalous dimensions. As an example, the explicit expressions for next-to-next-to-leading order invariant kernels for the twist-two flavor-nonsinglet operators in QCD and for the planar part of the universal anomalous dimension in $\mathcal{N}=4$ supersymmetric Yang-Mills are presented.

A large amount of data on hadronic two-body weak decays of antitriplet charmed baryons $T_{c\overline{3}}$ to an octet baryon $T_8$ and an octet or singlet pseudoscalar meson $P$, $T_{c\overline{3}}\to T_{8}P$, have been measured. The SU(3) flavor symmetry has been applied to study these decays to obtain insights about weak interactions for charm physics. However not all such decays needed to determine the SU(3) irreducible amplitudes have been measured forbidding a complete global analysis. Previously, it was shown that data from measured decays can be used to do a global fit to determine all except one parity-violating and one parity-conserving amplitudes of the relevant SU(3) irreducible amplitudes causing 8 hadronic two body weak decay channels involving ${\mathrm{\Xi }}_c^0$ to $\eta$ or ${\eta }^{\prime }$ transitions undetermined. It is important to obtain information about these decays in order to guide experimental searches. In this work using newly measured decay modes by BESIII and Belle in 2022, we carry out a global analysis and parametrize the unknown amplitudes to provide the ranges for the branching ratios of the eight undetermined decays. Our results indicate that the SU(3) flavor symmetry can explain the measured data exceptionally well, with a remarkable minimal ${\chi }^2/\mathrm{d}.\mathrm{o}.\mathrm{f}.$ of 1.21 and predict 80 observables in 45 decays for future experimental data to test. We then vary the unknown SU(3) amplitudes to obtain the allowed range of branching ratios for the eight undetermined decays. We find that some of them are within reach of near future experimental capabilities. We urge our experimental colleagues to carry out related searches.

The popular waveform templates of extreme-mass-ratio inspirals usually omit the mass-ratio corrections in conservative dynamics, and employ adiabatic approximation to include the radiation reaction. With the help of effective-one-body dynamics, we investigate the influence of mass-ratio corrections in the conservative part on the gravitational waves. We find that for the extra-relativistic orbits, the mass-ratio corrections can produce obvious orbital dephasing even for a very small mass ratio and then affect the waveforms. More importantly, it is noted that omitting the mass-ratio corrections in waveform templates may induce a fake signal of deviation from general relativity.

We derive optimal estimators for the binned two-, three-, and four-point correlators of statistically isotropic tensor fields defined on the sphere, in the presence of arbitrary beams, inpainting, and masking. This is a conceptually straightforward extension of the associated scalar-field estimators [O. H. E. Philcox, Phys. Rev. D 107, 123516 (2023).], but upgraded to include spin-2 fields such as cosmic microwave background polarization and galaxy shear, and parity-violating physics in all correlators. All estimators can be realized using spin-weighted spherical harmonic transforms and Monte Carlo summation and are implemented in the public code polybin, with computation scaling, at most, with the total number of bins. We perform a suite of validation tests verifying that the estimators are unbiased and, in limiting regimes, minimum variance. These facilitate general binned analyses of higher-point functions, and allow constraints to be placed on various pheomena, such as nonseparable inflationary physics (novelly including polarized trispectra), nonlinear evolution in the late Universe, and cosmic parity violation.

We study the neutral pion mass in the presence of an external arbitrary magnetic field in the framework of the linear sigma model coupled to quarks to a quark at finite temperature. In doing so, we have calculated the pion self-energy, constructed the dispersion equation via resummation, and solved the dispersion relation at zero three-momentum limit. In calculating the pion mass, we have included meson self-coupling’s thermal and magnetic contribution and approximate chiral order parameter $v_0$. We report that the ${\pi }^0$ mass decreases with the magnetic field and increases with temperature.