An ultralight axion with $CP$ violating interactions with a dark sector and $CP$ preserving interactions with the visible sector can act as a novel portal between dark matter and the Standard Model. In such theories, dark matter sources an axion field extending over the entire galaxy, the gradient of which can be searched for with precise spin precession experiments. A reinterpretation of existing co-magnetometer data already constrains theories that are consistent with astrophysical bounds, and near-future experiments will begin probing well-motivated models. The required interactions can arise from a confining hidden sector without necessitating fine-tuning of the axion’s mass.

Neutrino oscillation experiments have provided direct evidence for the existence of neutrino masses. The seesaw mechanism explains the smallness of these masses through the introduction of heavy right-handed neutrino (RHN) states. The RHN states can also generate Dirac neutrino masses at tree or loop level. These heavy states can exist at the electroweak scale, approximately in the $\mathcal{O}(\mathrm{GeV})$ range, and can be investigated through current and future collider experiments. This scenario, where other new physics interactions occur at scales much higher than the RHN scale, can be described using an effective field theory (EFT) framework known as $N_R$-EFT. This study focuses on constraining the Wilson coefficients of $N_R$-EFT operators, which primarily contribute to trilepton production and missing energy signals at the LHC. We examine both the scenarios where the RHN mass $M_N$ is less than and greater than the $W$ boson mass $M_W$, and provide predictions for the High-Luminosity run of the LHC.

The vector boson dark matter particles which stem from some broken gauge symmetries usually require some unbroken symmetries to keep them stable. In previous literature, some simplest cases have been discussed, in which the unbroken symmetry is provided by a remnant subgroup of the gauge group. It would be interesting to ask whether all the possible remnant subgroups as well as all the possible coupling forms can be enumerated. Classifying all the Higgs components into different mass degenerate representations to simplify the diagonalization processes is also necessary. Rather than the ambitious target of providing a general solution to all kinds of gauge groups configured with all forms of the Higgs multiplets, in this paper, we concentrate on the case of the ${\mathrm{SU}(2)}_{\mathrm{D}}$ gauge group together with a single Higgs multiplet. We enumerate all possible discrete subgroups that can survive up to $n=21$, where $n$ is the dimension of the Higgs multiplet. We also provide the general algorithms to enumerate all possible renormalizable operators, to write the general forms of the vacuum expectation value (VEV) configurations, and to give the detailed results of all the mass degenerate irreducible representations embedded in the Higgs multiplet.

Lattice QCD results for isospin $I=\frac{1}{2}$ $D\pi$ scattering are presented. Utilizing a series of $N_{\mathrm{f}}=2+1$ Wilson-Clover ensembles with pion masses of $m_{\pi }\approx 133$, 208, 305, and 317 MeV, various two-particle operators are constructed, and the corresponding finite-volume spectra are determined. The $S$- and $P$-wave scattering phase shifts are extracted using the Lüscher approach. A clear trend for the motion of the $D_0^{*}(2300)$ pole is identified. With the physical pion mass configurations also included, this calculation constitutes the first lattice calculation in which the pion mass dependence of the $D_0^{*}(2300)$ pole is investigated and the scattering lengths are extrapolated/interpolated to the physical pion mass in $D\pi$ scattering.

The quantum numbers of monopoles in $R^3$ in the presence of massless fermions have been analyzed using a uniform flux background in $S^2\times R$ coupled to fermions. An analogous study in $T^2\times R$ is performed by studying the discrete symmetries of the Dirac Hamiltonian in the presence of a static uniform field on $T^2$ with a total flux of $Q$ in the continuum. The degenerate ground states are classified based on their transformation properties under $\frac{\pi }{2}$ rotations of $T^2$ that leave the background field invariant. We find that the lattice analysis with overlap fermions exactly reproduces the transformation properties of the single-particle zero modes in the continuum. Whereas the transformation properties of the single-particle negative energy states can be studied in the continuum and the lattice, we are also able to study the transformation properties and the particle number (charge) of the many-body ground state on a finite lattice, and we show that the contributions from the fully filled single-particle states cannot be ignored.

The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment, $(g-2)/2$, is computed in the infinite volume QED framework with lattice QCD. We report $a_{\mu }^{\text{HLbL}}=12.47(1.15)(0.95)\times {10}^{-10}$ where the first error is statistical and the second systematic. The result is mainly based on the $2+1$ flavor Möbius domain wall fermion ensemble with inverse lattice spacing $a^{-1}=1.73\mathrm{GeV}$, lattice size $L=5.5\mathrm{fm}$, and $m_{\pi }=139\mathrm{MeV}$, generated by the RBC-UKQCD collaborations. The leading systematic error of this result comes from the lattice discretization. This result is consistent with previous determinations.

We consider dijet production in deep inelastic scattering at small $x$, on a purely gluonic unpolarized target. Starting from earlier results obtained at next-to-eikonal accuracy in the high-energy limit, we perform the expansion in the back-to-back dijet limit, at next-to-leading power accuracy. We rewrite our results in the language of transverse-momentum-dependent (TMD) factorization, in terms of twist-2 and twist-3 TMD gluon distributions (gluon TMDs). Among the next-to-eikonal corrections, we find in particular twist-2 contributions corresponding to the $x$ dependent phase of the twist-2 gluon TMDs. We also find two types of twist-3 unpolarized gluon TMDs, as well as correlators of three gluon field strength tensors.

The vector meson-baryon interaction in a coupled channel scheme is revisited within the correlation function framework. As illustrative cases to reveal the important role played by the coupled channels, we focus on the $\varphi \mathrm{p}$ and ${\rho }^0\mathrm{p}$ systems given their complex dynamics and the presence of quasibound states or resonances in the vicinity of their thresholds. We show that the $\varphi \mathrm{p}$ femtoscopic data provide novel information about a $N^{*}$ state present in the experimental region and anticipate the relevance of a future ${\rho }^0\mathrm{p}$ correlation function measurement in order to pin down the $S=0,Q=+1$ vector meson-baryon interaction as well as to disclose the characterizing features of the $N^{*}(1700)$ state.

In this work, we have investigated the transverse and spatial structure of light (${\pi }^{+}(u\overline{d})$, $K^{+}(u\overline{s})$) and heavy (${\eta }_c(c\overline{c})$, ${\eta }_b(b\overline{b})$, $B$ and $D$) pseudoscalar mesons using the light-cone quark model. The transverse structure of these particles have been studied using the transverse momentum dependent parton distribution (TMDs). The leading twist unpolarized $f_1(x,{\mathbf{k}}_{\perp }^2)$ TMD has been solved using the quark-quark correlator. We have predicted the average momenta carried by the quark and antiquark of the considered mesons. For a complete description of mesons, we have also computed the leading twist unpolarized $H(x,0,-t)$ generalized parton distribution (GPD). Further, electromagnetic form factors (EMFFs), along with gravitational form factors (GFFs) have been derived by taking the zeroth and first moments of the unpolarized GPD. These EMFFs are found to be compatible with available lattice simulation results. Further, we have also calculated the parton distribution functions (PDFs) for both the quarks and the antiquarks of these mesons. The PDF sum rule has also been verified.

Hidden-charm strong decays of the spin-2 partner $X_2(4014)$ of the charmoniumlike state $X(3872)$ have been studied in the framework of the covariant confined quark model. The exotic state $X_2$ has been interpreted as a four-quark state with molecular-type interpolating current. We have considered the decay widths of $X_2$ on the level of two-petal quark loops. The partial widths of the strong decays $X_2\to \omega J/\mathrm{\Psi }$ and $X_2\to {\rho }^{0}J/\mathrm{\Psi }$ have been calculated and the related branching ratio has been analyzed.

The Nambu–Jona-Lasinio (NJL) model and specifically its extension to color superconductivity (CSC) is a popular effective model for investigating dense quark matter. However, the reliability of its results is challenged by cutoff artifacts, which emerge if temperature or chemical potential are of the order of the cutoff energy scales. In this work, we generalize an idea from Braun et al. [SciPost Phys. 6, 056 (2019)], which is based on the requirement of renormalization-group (RG) consistency and has successfully been applied to the two-flavor quark-meson-diquark model, to the NJL model for electrically and color-neutral three-flavor color-superconducting quark matter. To this end, we analyze the medium divergences of the model and eliminate them by appropriate counterterms, introducing three different schemes. We show that the RG consistent treatment removes the cutoff artifacts of the conventional regularization and enables the investigation of CSC matter at higher densities by the model. Our studies reveal the emergence of a so-called $d$-quark superconducting (dSC) phase within the melting pattern of the color-flavor locked phase at high chemical potentials, consistent with earlier Ginzburg-Landau analyses.

Motivated by the LHCb measurement of the hyperon decay mode ${\mathrm{\Sigma }}^{+}\to p{\mu }^{+}{\mu }^{-}$ and prospects for improvement, we revisit the estimates for the rate and muon forward-backward asymmetry within the standard model and beyond. The standard model prediction has a fourfold ambiguity, and we suggest ways to resolve it with other measurements, including possible studies of ${\mathrm{\Sigma }}^{+}\to p{e}^{+}{e}^{-}$ in the BESIII and LHCb experiments. We use the recent BESIII measurements of ${\mathrm{\Sigma }}^{+}\to p\gamma$ and ${\mathrm{\Sigma }}^{+}\to N\pi$ to reduce the uncertainty in the long-distance contribution to ${\mathrm{\Sigma }}^{+}\to p{\mu }^{+}{\mu }^{-}$. Beyond the standard model, we consider a general effective Hamiltonian at low energy with ten operators whose Wilson coefficients parametrize the new physics. We derive expressions for the ${\mathrm{\Sigma }}^{+}\to p{\mu }^{+}{\mu }^{-}$ rate and the associated muon forward-backward asymmetry in terms of these coefficients. Finally, we present the constraints on these Wilson coefficients that result from both kaon and hyperon decays and emphasize their complementarity.

We study the axial-vector and the induced pseudoscalar form factors associated with the weak transitions between the octet baryon members in nuclear medium, using a covariant constituent quark model. We extend previous calculations of the axial transition form factors from the vacuum (free space) to the nuclear medium (symmetric nuclear matter). The extension of the model to the nuclear medium takes into account the modifications of the properties of hadrons in the medium (masses and coupling constants), as determined by the quark-meson coupling model. The axial-vector ($G_A$) and the induced pseudoscalar ($G_P$) form factors are evaluated for different values of the nuclear density $\rho$ in terms of the square transfer momentum $q^2=-Q^2$. We conclude that, in general, the $G_A$ and $G_P$ form factors are reduced in the nuclear medium. The reduction is stronger for light baryons and high densities. The medium modifications are milder for the heavier octet baryons, particularly at large $Q^2$. The calculations presented here can be used to estimate the cross sections of neutrino and antineutrino scattering with nucleus, and neutrino and antineutrino scattering with hyperons bound to a nucleus, as well as those in the cores of compact stars.

We investigate the phase transition within an extremely strong magnetic background field, employing a holographic quantum chromodynamics (QCD) model with a focus on the entropy, pressure, and Polyakov loop properties. At relatively modest magnetic field strengths, our study discerns a crossover transition between the normal phase and the quark-gluon plasma (QGP) phase as the temperature rises. In contrast, under the influence of an extremely strong magnetic field, a first-order phase transition is observed. A critical point is identified at $(e{B}_c,T_c)\approx (2.8623{\mathrm{GeV}}^2,0.1191\mathrm{GeV})$, which corresponds to a second-order phase transition. This phase structure is found to be in qualitative agreement with lattice simulation predictions reported in D’Elia et al. [Phys. Rev. D 105, 034511 (2022)]. Furthermore, we explore the impact of the magnetic field on the jet quenching parameter across various phases. At zero magnetic field ($eB=0$), the normalized jet quenching parameter $\widehat{q}/T^3$ exhibits a monotonic increase with temperature. However, in the presence of a magnetic background field, the normalized jet quenching parameters not only display directional anisotropy but also experience a universal enhancement, particularly in the vicinity of the critical temperature region. This observation suggests that the jet quenching parameter could potentially act as an indicator of phase transitions.

Gravitational effects are inevitable as photons propagate in curved spacetime, and especially gravitational redshift can cause the distortion of photon wave packets, so it is very meaningful and necessary to study the controllable parameter estimation under the gravitational-redshift effect. Here, in correlated noisy channels under the effect of gravitational redshift, we analyze the precision of phase estimation of two-qubit system states which is introduced by a symplectic matrix for two-mode entangled states (two types of Werner-like states). We find that the gravitational redshift could decrease the precision of phase estimation of these two-qubit system states. Interestingly, by adjusting the correlation parameter of the channels and the initial entanglement, the precision of phase estimation in noisy channels under the influence of gravitational redshift could be enhanced. The larger the initial entanglement and the stronger the correlation of the channels, the higher the precision of phase estimation obtained. Particularly, for two types of Werner-like initial states, the phase estimation of the system is more robust for the Werner-like initial state $\cos (\frac{\alpha }{2})|01⟩+e^{i\varphi }\sin (\frac{\alpha }{2})|10⟩$ as the strong enough gravitational-redshift effect.

We introduce a tensor network designed to faithfully simulate the $\mathrm{AdS}/\mathrm{CFT}$ correspondence, akin to the multiscale entanglement renormalization ansatz (MERA), following hyperinvariant tensor network. The proposed construction integrates bulk indices within the network architecture to uphold the key features of the HAPPY code, including complementary recovery. This framework accurately reproduces the boundary conformal field theory’s (CFT) two- and three-point correlation functions, while considering the image of any bulk operator. Furthermore, we provide an explicit methodology for calculating the correlation functions in an efficient manner. Our findings highlight the physical aspects of the relation between bulk and boundary within the tensor network models, contributing to the understanding and simulation of holographic principles in quantum information.

In Minkowski spacetime quantum field theory, each stationary motion is associated with an effective, energy-dependent notion of temperature, which generalizes the familiar Unruh temperature of uniform linear acceleration. Motivated by current experimental interest in circular motion, we analyze the effective temperature for drifted Rindler motion, generated by a boost and a spacelike translation (drift), and the way in which drifted Rindler motion can be smoothly (and in fact real analytically) deformed to circular motion through a third type of motion known as parator. For an Unruh-DeWitt detector coupled linearly to a massless scalar field in $2+1$ and $3+1$ spacetime dimensions, we establish analytic results in the limits of large gap, small gap and large drift speed. For fixed proper acceleration, the drifted Rindler temperature remains bounded in the large gap limit, in contrast to the circular motion temperature, which can be arbitrarily large in this limit. Finally, in $2+1$ dimensions, we trace the vanishing of the circular motion temperature in the small gap limit to the weak decay of the Wightman function, and we show that, among all types of stationary motion in all dimensions, this phenomenon is unique to $2+1$ dimensions and therein to circular and parator motion.

We construct static axisymmetric multisolitons in the Einstein-Friedberg-Lee-Sirlin model. This theory features a complex scalar field which gains mass through its interaction with a real scalar field that has a nonzero vacuum expectation value. By performing three-dimensional numerical relativity simulations, we identify stable dipolar boson stars in specific regions of the parameter space. Based on the dipole results, nonrotating odd-parity chains with and without gravity can also be constructed when the mass of the real scalar field is sufficiently small. However, chains beyond the dipole case are found to be unstable.

In a series of recent papers it was shown that several aspects of dark matter (DM) phenomenology, such as the velocity profiles of individual dwarfs and spiral galaxies, the scaling relations observed in the latter, and the pressure and density profiles of galaxy clusters, can be explained by assuming the DM component in virialized halos to feel a nonlocal fractional interaction mediated by gravity. Motivated by the remarkable success of this model, in a recent work we have looked for a general relativistic extension, proposing a theory, dubbed relativistic scalar fractional gravity or RSFG, in which the trace of the DM stress-energy tensor couples to the scalar curvature via a nonlocal operator constructed with a fractional power of the d’Alembertian. In this work we construct an extension of that model in which also a nonlocal coupling between the Ricci tensor and the DM stress energy tensor is present. In the action we encode the normalization between these scalar and tensorial term into two operators ${\mathcal{F}}_0(\square )$ and ${\mathcal{F}}_2(\square )$, and we derive the general field equations. We then take the weak field limit of the latter, showing that they reduce to general relativity sourced by an effective stress energy tensor, featuring a nonlocal isotropic pressure and anisotropic stress, even if one starts with the assumption of a pressureless DM fluid. Finally, after having worked out the lensing theory in our setup, we test particularly interesting realizations of our framework against the measured convergence profiles of the individual and stacked clusters of the CLASH sample, finding remarkable consistency with the data.

Based on the hyperboloidal framework, we research the dynamical process of charged de Sitter black holes scattered by a charged scalar field. From the linear perturbation analysis, with the coupling strength within a critical interval, the charged scalar field with a superradiance frequency can induce the instability of the system. To reveal the real-time dynamics of such an instability, the nonlinear numerical simulation is implemented. The results show that the scalar field grows exponentially in the early stages and drastically extracts the charge from the black hole due to the superradiance, analogous to the charged black hole in a closed system. Differently, after saturation, the scalar field cannot coexist with the central black hole stably and dissipates beyond the cosmological horizon slowly, leaving behind a bald black hole.