Heavy weakly interacting massive particle (WIMP) effective field theory is used to compute the WIMP-nucleon scattering rate for general heavy electroweak multiplets through order $m_W/M$, where $m_W$ and $M$ denote the electroweak and WIMP mass scales. The lightest neutral component of such an electroweak multiplet is a candidate dark matter particle, either elementary or composite. Existing computations for certain representations of electroweak ${\mathrm{SU}(2)}_W\times {\mathrm{U}(1)}_Y$ reveal a cancellation of amplitudes from different effective operators at leading and subleading orders in $1/M$, yielding small cross sections that are below current dark matter direct-detection experimental sensitivities. We extend those computations and consider all low-spin (spin-0, spin-$1/2$, spin-1, spin-$3/2$) heavy electroweak multiplets with arbitrary ${\mathrm{SU}(2)}_W\times {\mathrm{U}(1)}_Y$ representations and provide benchmark cross section results for dark matter direct detection experiments. For most self-conjugate TeV WIMPs with isospin $\le 3$ the cross sections are below current experimental limits but within reach of next-generation experiments. An exception is the case of pure electroweak doublet, where WIMPs are hidden below the neutrino floor.

We study the properties of the shear viscosity coefficient of quark matter near the chiral phase transition at finite temperature and chemical potential, and the kinds of high temperature, high density, and strong magnetic field background. The strong magnetic field induces anisotropy, that is, the quantization of Landau energy levels in phase space. If the magnetic field is strong enough, it will interfere with significant QCD phenomena, such as the generation of dynamic quark mass, which may affect the transport properties of quark matter. The inclusion of the anomalous magnetic moments of the quarks at finite density into the Nambu-Jona-Lasinio model gives rise to additional spin polarization magnetic effects. It is found that both the ratio $\eta /s$ of shear viscosity coefficient to entropy and the collision relaxation time $\tau$ show similar trend with temperature, both of which reach minima around the critical temperature. The shear viscosity coefficient of the dissipative fluid system can be decomposed into five different components as the strong magnetic field exists. The influences of the order of chiral phase transition and the critical end point on dissipative phenomena in such a magnetized medium are quantitatively investigated. It is found that ${\eta }_1$, ${\eta }_2$, ${\eta }_3$, and ${\eta }_4$ all increase with temperature. For first-order phase transitions, ${\eta }_1$, ${\eta }_2$, ${\eta }_3$, and ${\eta }_4$ exhibit discontinuous characteristics.

We discuss the status of $b\to s{\ell }^{+}{\ell }^{-}$ decays in the post-$R_{K^{(*)}}$ era. The recent LHCb update of $R_K$ and $R_{K^{*}}$ measurements, which are now compatible with the Standard Model, constrain new physics contributions to be lepton-flavor universal, allowing only small deviations from this limit. In addition to the latest LHCb measurements of $R_K$ and $R_{K^{*}}$, we also include the recent CMS measurements of $R_K$ and of the branching ratio of $B^{+}\to K^{+}{\mu }^{+}{\mu }^{-}$. We present a model-independent analysis of the $b\to s{\ell }^{+}{\ell }^{-}$ data and investigate the implications of the different sets of observables. In addition, we consider multidimensional fits and discuss the significance of more complex new physics scenarios compared to one- and two-dimensional scenarios.

The $W$ boson mass $m_W$ in the grand unified theory inspired $SO(5)\times U(1)\times SU(3)$ gauge-Higgs unification in the Randall-Sundrum (RS) warped space is evaluated. The muon decay ${\mu }^{-}\to e^{-}{\overline{\nu }}_e{\nu }_{\mu }$ proceeds by the exchange of not only the zero mode of the $W$ boson $(W^{(0)})$ but also Kaluza-Klein (KK) excited modes $W^{(n)}$ and $W_R^{(n)}$ ($n\ge 1$) at the tree level. The anti–de Sitter curvature of the RS space also affects the relationship among the gauge couplings and the ratio of $m_W$ to the $Z$ boson mass $m_Z$. The $W$ couplings of leptons and quarks also change. With the given KK mass scale $m_{\mathrm{KK}}$ the range of the Aharonov-Bohm phase ${\theta }_H$ in the fifth dimension is constrained. For $m_{\mathrm{KK}}=13\mathrm{TeV}$, $0.085\lesssim {\theta }_H\lesssim 0.11$ and $80.381\lesssim m_W\lesssim 80.407\mathrm{GeV}$. The predicted value of $m_W$ for $13\le m_{\mathrm{KK}}\le 20\mathrm{TeV}$ lies between $m_W^{\mathrm{SM}}=80.354\pm 0.007\mathrm{GeV}$ in the standard model and $m_W^{\mathrm{CDF}}=80.4335\pm 0.0094\mathrm{GeV}$, the value reported by the CDF Collaboration in 2022.

We show for the first time that a common solution to dark matter and the flavor problem of the standard model can be obtained in the framework of the ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavor symmetry where the flavonic Goldstone boson of this flavor symmetry acts as a good dark matter candidate through the misalignment mechanism. A hierarchical mass pattern of quarks and charged leptons naturally follows from the discrete symmetry. For light active neutrinos, we construct the Dirac-type mass matrix which is preferred to fit the observed neutrino oscillation data with normal hierarchy. Our model predicts the axionlike photon coupling characteristically different from the standard QCD axion, which could be probed by the future x-ray or radio observations.

Lattice gauge field theories may suffer from unphysical “bulk” phase transitions at strong lattice gauge coupling. We introduce a one-parameter family of lattice $\mathrm{SU}(N)$ gauge actions which, when used in combination with a hybrid Monte Carlo (HMC) update algorithm, prevents the appearance of the bulk phase transition. We briefly discuss the (presumed) mechanism behind the prevention of the bulk transition and present test results for different $\mathrm{SU}(N)$ gauge groups.

In the framework of nonrelativistic QCD (NRQCD) factorization, we compute both the polarized and the unpolarized decay widths for the processes ${\eta }_b({\chi }_{bJ})\to J/\psi J/\psi$, accurate up to next-to-next-to-leading order (NNLO) in ${\alpha }_s$. For the first time, we confirm that the NRQCD factorization does hold at NNLO for the process involving triple quarkonia. We find that the radiative corrections are considerable. In particular, for ${\chi }_{b2}$, both the $\mathcal{O}({\alpha }_s)$ and $\mathcal{O}({\alpha }_s^2)$ corrections are sizable and negative, and both can significantly reduce the leading-order prediction. At NNLO, the branching fractions are $8.2\times {10}^{-7}$, $6.2\times {10}^{-6}$, $7.2\times {10}^{-7}$, and $2.7\times {10}^{-6}$ for ${\eta }_b$, ${\chi }_{b0}$, ${\chi }_{b1}$, and ${\chi }_{b2}$ decay, respectively. Our theoretical predictions are consistent with the upper limits measured by the Belle Collaboration. Moreover, we investigate the dependence of the theoretical predictions on the ratio of the charm quark mass and the bottom quark mass—i.e., $r=m_c/m_b$. By fixing $m_b$ and varying $m_c$ from 1.25 to 1.9 GeV, we find that the branching fraction can change by factors of 2, 3, and 6 for ${\eta }_b$, ${\chi }_{b0}$, and ${\chi }_{b1}$, respectively. Although the branching fraction for ${\chi }_{b2}$ decreases with the increase of $r$ at leading order and next-to-leading order, it is almost independent of $r$ at NNLO. In the phenomenological analysis, with the integrated luminosity $\mathcal{L}=100{\mathrm{fb}}^{-1}$, we expect about $(5-10)\times {10}^3$ ${\eta }_b({\chi }_{bJ})\to J/\psi J/\psi \to \ell \overline{\ell }\ell \overline{\ell }$ events to be produced at the Large Hadron Collider; thus, it might be helpful to search for these processes. On the other hand, there are fewer than 100 ${\eta }_b({\chi }_{bJ})\to J/\psi J/\psi$ signal events at the B Factory, so it seems that the experimental measurements on these channels are quite challenging based on the current dataset. Nevertheless, with the designed $50{\mathrm{ab}}^{-1}$ integrated luminosity at Belle 2, the observation prospects of ${\eta }_b({\chi }_{bJ})\to J/\psi J/\psi$ may be promising in the foreseeable future.

According to general understanding, the proton as one of the main ingredients of the nucleus is composed of one down and two up quarks bound together by gluons, described by quantum chromodynamics (QCD). In this view, heavy quarks do not contribute to the primary wave function of the proton. Heavy quarks arise in the proton perturbatively by gluon splitting and the probability gradually increases as $Q^2$ increases (extrinsic heavy quarks). In addition, the existence of nonperturbative intrinsic charm quarks in the proton has also been predicted by QCD. In this picture, the heavy quarks also exist in the proton’s wave function. In fact, the wave function has a five-quark structure $|uudc\overline{c}⟩$ in addition to the three-quark bound state $|uud⟩$. So far, many studies have been done to confirm or reject this additional component. One of the recent studies has been done by the NNPDF Collaboration. They established the existence of an intrinsic charm component at the 3-standard-deviation level in the proton from the structure function measurements. Most of the studies performed to calculate the contribution of the intrinsic charm so far have been based on the global analyses of the experimental data. In this article, for the first time we directly calculate this contribution by an analytic method. We estimate a $x^{c\overline{c}}=(1.36\pm 0.67)\%$ contribution for the $|uudc\overline{c}⟩$ component of the proton.

Neutrino experiments in a Forward Physics Facility at the Large Hadron Collider can measure neutrino and antineutrino cross sections for energies up to a few TeV. For neutrino energies below 100 GeV, the inelastic cross section evaluations have contributions from weak structure functions at low momentum transfers and low hadronic final state invariant mass. To evaluate the size of these contributions to the neutrino cross section, we use a parametrization of the electron-proton structure function, adapted for neutrino scattering, augmented with a correction to account for the partial conservation of the axial vector current, and normalized to structure functions evaluated at next-to-leading order in QCD, with target mass corrections and heavy quark corrections. We compare our results with other approaches to account for this kinematic region in the neutrino cross section for energies between 10–1000 GeV on isoscalar nucleon and iron targets.

Progress in neutrino-nucleus cross section models is being driven by the need for highly accurate predictions for the neutrino oscillation community. These sophisticated models are being developed within a microscopic description of the nucleus with the goal of encompassing all reaction modes relevant for the accelerator neutrino program. The disconnect between these microscopic models and the event generators that will be used in the next generation of experiments represents a critical obstacle that must be overcome in order to precisely measure the neutrino oscillation parameters. To this end we have developed a hadron tensor interface for lepton-nucleus quasielastic (QE) scattering within the GENIE event generator as a proof of principle, with the broader goal of creating an efficient pipeline for incorporating advanced theoretical models in event generators. As a demonstration of this interface we have implemented the spectral function model into GENIE by connecting theorist provided fortran code through the hadron tensor interface. The spectral function model offers a more complete description of the nuclear ground state, as well as the ability to provide quantifiable theoretical uncertainties. We validate this implementation and compare its predictions against data and against QE models already available in GENIE.

Using a sample of $(27.12\pm 0.14)\times {10}^8\psi (3686)$ events collected with the BESIII detector, the decay $\psi (3686)\to \mathrm{\Lambda }\overline{\mathrm{\Lambda }}{\eta }^{\prime }$ with ${\eta }^{\prime }$ subsequently decaying into $\gamma {\pi }^{+}{\pi }^{-}$ and $\eta {\pi }^{+}{\pi }^{-}$ is observed for the first time. The branching fraction of $\psi (3686)\to \mathrm{\Lambda }\overline{\mathrm{\Lambda }}{\eta }^{\prime }$ is measured to be $(7.34\pm 0.94(\mathrm{stat})\pm 0.43(\mathrm{sys}))\times {10}^{-6}$. No resonant structures are evident in the $\mathrm{\Lambda }{\eta }^{\prime }$, $\overline{\mathrm{\Lambda }}{\eta }^{\prime }$ and $\mathrm{\Lambda }\overline{\mathrm{\Lambda }}$ mass spectra.

The quantum nature of neutrino oscillations would be reflected in the mismatch between the neutrino survival probabilities with and without an intermediate observation. We propose this quantum mismatch as a measure of quantumness in neutrino oscillations. For two neutrino flavors, it inevitably performs better than the Leggett-Garg measure. For three flavors, we devise modified definitions of these two measures, which would be applicable for experiments that measure neutrino survival probabilities with negligible matter effects. The modified definitions can be used to probe deviations from expected classical behavior, even for systems with an unknown number of states. For neutrino experiments like DUNE, MINOS, and JUNO, we identify the energies where these modified measures can probe quantumness efficiently.

Electromagnetic and gravitational perturbations on Kerr spacetime can be reconstructed from solutions to the Teukolsky equations. We study the canonical quantization of solutions to these equations for any integer spin. Our quantization scheme involves the analysis of the Hertz potential and one of the Newman-Penrose scalars, which must be related via the Teukolsky-Starobinsky identities. We show that the canonical commutation relations between the fields can be implemented if and only if the Teukolsky-Starobinsky constants are positive, which is the case both for gravitational perturbations and Maxwell fields. We also obtain the Hadamard parametrix of the Teukolsky equation, which is the basic ingredient for a local and covariant renormalization scheme for nonlinear observables. We also discuss the relation of the canonical energy of Teukolsky fields to that of gravitational perturbations.

We investigate the second Rényi entropy of two intervals in the massless Thirring model describing a self-interacting Dirac fermion in two dimensions. Boson-fermion duality relating this model to a free compact boson theory enables us to simplify the calculation of the second Rényi entropy, reducing it to the evaluation of the partition functions of the bosonic theory on a torus. We derive exact results on the second Rényi entropy, and examine the dependence on the sizes of the intervals and the coupling constant of the model both analytically and numerically. We also explore the mutual Rényi information, a measure quantifying the correlation between the two intervals, and find that it generally increases as the coupling constant of the Thirring model becomes larger.

It was recently found that, in certain flavors of scalar-Gauss-Bonnet gravity, linearly stable bald black holes can coexist with stable scalarized solutions. The transition between both can be ignited by a large nonlinear perturbation, thus the process was dubbed nonlinear scalarization, and it happens with a jump that leads to interesting astrophysical implications. Generalizing these results to the case of nonzero scalar field potential is important because a massive self-interacting scalar field can have interesting theoretical and observational consequences, e.g., reconcile scalar-Gauss-Bonnet gravity with binary pulsar observation, stabilize black hole solutions, etc. That is why, in the present paper, we address this open problem. We pay special attention to the influence of a scalar field mass and self-interaction on the existence of scalarized phases and the presence of a jump between stable bald and hairy black holes. Our results show that both the addition of a mass and positive self-interaction of the scalar field result in suppression or quenching of the overall scalarization phenomena. A negative scalar field self-interaction results in an increase of the scalarization. The presence and the size of the jump, though, are not so sensitive to the scalar field potential.

General relativity (GR) exists in different formulations, which are equivalent in pure gravity. Once matter is included, however, observable predictions generically depend on the version of GR. In order to quantify the resulting ambiguity, we employ metric-affine gravity, which encompasses as special cases the metric, Palatini, Einstein-Cartan, and Weyl formulations. We first discuss the interaction of fermions with torsion and nonmetricity, also commenting on projective symmetry. With a view toward the Standard Model, we then construct a generic model of (complex) scalar, fermionic, and gauge fields coupled to GR and derive an equivalent metric theory, which features numerous new interaction terms. As a first observable consequence, we point out that a gravitational mechanism for producing dark matter in the form of singlet fermions can be used to distinguish between metric gravity and other formulations of GR.

This study explores the gravitational collapse of a massless scalar field within quadratic gravity treated as a dimension-four operator effective field theory extension to general relativity. The additional degrees of freedom associated with the higher derivatives in this theory are removed by an order reduction approach, where the truncated expansion nature of the theory is exploited. Through simulations, we find scenarios where solutions remain within the bounds of the effective field theory while displaying significant deviations from general relativity in the dynamics of curvature invariants during the collapse. Limitations of the approach taken, the effective field theory approximation, and the appearance of instabilities are also discussed.

In previous work we analyzed the linear stability of nonrelativistic $\ell$-boson stars with respect to radial modes and showed that ground state configurations are stable with respect to these modes, whereas excited states are unstable. In this work we extend the analysis to nonspherical linear mode perturbations. To this purpose, we expand the wave function in terms of tensor spherical harmonics which allows us to decouple the perturbation equations into a family of radial problems. By using a combination of analytic and numerical methods, we show that ground state configurations with $\ell >1$ possess exponentially in time growing nonradial modes, whereas only oscillating modes are found for $\ell =0$ and $\ell =1$. This leads us to conjecture that nonrelativistic $\ell$-boson stars in their ground state are stable for $\ell =1$ as well as $\ell =0$, while ground state and excited configurations with $\ell >1$ are unstable.

The Laser Interferometer Space Antenna (LISA) will detect gravitational waves (GWs) emitted by massive black hole binaries (MBHBs) in the low-frequency ($\sim \mathrm{mHz}$) band. Low-mass lenses, such as low-mass dark matter halos or subhalos, have sizes comparable to the wavelength of these GWs. Encounters with these lenses produce wave-optics (WO) effects that alter waveform phase and amplitude. Thus, a single event with observable WO effects can be used to probe the lens properties. In this paper, we first compute the probability of observing WO effects in a model-agnostic way. We perform information-matrix analyses over $\mathcal{O}(1000)$ MBHBs with total mass, mass ratio, and redshift spanning the ranges relevant to LISA. We then calculate lensing rates using three semianalytical models of MBHB populations. In both cases, we use a waveform model that includes merger, ringdown, and higher-order modes. We use two lens population models: the theory-based Press-Schechter halo mass function and an observation-based model derived from Sloan Digital Sky Survey. We find that the probability of detecting WO effects can be as large as $\sim 3\%$, $\sim 1.5\%$, and $\sim 1\%$ at $1\sigma$, $3\sigma$, and $5\sigma$ confidence levels, respectively. The most optimistic MBHB population model yields $\sim 8$, $\sim 4$, and $\sim 3$ events with detectable WO effects at the same confidence levels, while the rates drop to $\sim 0.01$ in the more pessimistic scenarios. The most likely lens masses probed by LISA are in the range $({10}^3,{10}^8)M_{\odot }$, and the most probable redshifts are in the range (0.3, 1.7). Therefore, LISA observations of WO effects can probe low-mass DM halos, complementing strong lensing and other observations.

We argue that observations of the reionization history can be used as a probe of primordial density fluctuations, particularly on small scales. Although the primordial curvature perturbations are well constrained from measurements of cosmic microwave background (CMB) anisotropies and large-scale structure, these observational data probe the curvature perturbations only on large scales, and hence, its information on smaller scales will give us further insight on primordial fluctuations. Since the formation of early galaxies is sensitive to the amplitude of small-scale perturbations, and then, in turn, gives an impact on the reionization history, one can probe the primordial power spectrum on small scales through observations of reionization. In this work, we focus on the running spectral indices of the primordial power spectrum to characterize the small-scale perturbations and investigate their impact on the reionization history using the numerical code 21cmfast, which adopts a simple but commonly used reionization model. We also derive the constraints on the running spectral indices from observations of the reionization history indicated by the luminosity function of the Lyman-$\alpha$ emitters. We show that the reionization history, in combination with large-scale observations such as CMB, would be a useful tool to investigate primordial density fluctuations.