We compute the relaxation times for massive quarks and antiquarks to align their spins with the angular velocity in a rigidly rotating medium at finite temperature and baryon density. The rotation effects are implemented using a fermion propagator immersed in a cylindrical rotating environment. The relaxation time is computed as the inverse of the interaction rate to produce an asymmetry between the quark (antiquark) spin components along and opposite to the angular velocity. For conditions resembling heavy-ion collisions, the relaxation times for quarks are smaller than for antiquarks. For semicentral collisions, the relaxation time for quarks is within the possible lifetime of the QGP for all collision energies. However, for antiquarks, this happens only for collision energies $\sqrt{s_{NN}}\gtrsim 50\mathrm{GeV}$. The results are quantified in terms of the intrinsic quark and antiquark polarizations, namely, the probability to build the spin asymmetry as a function of time. Our results show that these intrinsic polarizations tend to 1 with time at different rates given by the relaxation times with quarks reaching a sizable asymmetry at a faster pace. These are key results to further elucidate the mechanisms of hyperon polarization in relativistic heavy-ion collisions.

We investigate the production of spin-$3/2$ hadrons in semi-inclusive deep inelastic lepton-nucleon scatterings. The complete differential cross section is derived through the kinematic analysis and expressed in terms of 288 structure functions, corresponding to all polarization configurations and azimuthal modulations. For an unpolarized lepton beam, half of the 192 structure functions have nonzero leading order contributions in the parton model, among which 42 are from rank-3 tensor polarized fragmentation functions of the hadron. For a polarized lepton beam, one third of the 96 structure functions contribute at the leading order and 14 of them are from rank-3 tensor polarized fragmentation functions. In addition to the formalism, we perform a model estimation of the spin transfer to a $S_{hLLL}$ polarized hadron and sizable asymmetry is expected. Therefore, these newly defined observables for the production of a spin-$3/2$ hadron in a deep inelastic scattering process can be explored in future experiments to understand nucleon spin structures and spin-dependent fragmentation functions.

Generalized distribution amplitudes (GDAs) of mesons can be probed by the reactions $e^{-}{e}^{+}\to M_1{M}_2\gamma$, which are accessible at electron-positron colliders such as BESIII and Belle II. After discussing the neutral meson production case in our previous paper, we discuss here the complementary case of the charged meson ($M^{+}{M}^{-}$) production, where one can extract the complete information on GDAs from the interference of the amplitudes of the two competing processes where the photon is emitted either in the initial or in the final state. Considering the importance of the charged meson production, we present a complete expression for the interference term of the cross section, which is experimentally accessible thanks to its charge conjugation specific property. We adopt two types of models for leading-twist $\pi \pi$ GDAs to estimate the size of the interference term in the process $e^{-}{e}^{+}\to {\pi }^{+}{\pi }^{-}\gamma$ numerically, namely, a model extracted from previous experimental results on ${\gamma }^{*}\gamma \to {\pi }^0{\pi }^0$ at Belle and the asymptotic form predicted by QCD evolution equations. We include in the calculation the kinematical power suppressed (sometimes called kinematical higher-twist) corrections up to $1/Q^2$ for the helicity amplitudes. Both models of GDAs indicate that the kinematical corrections are not negligible for the interference term of the cross section measured at BESIII, thus it is necessary to include them if we try to extract the GDAs precisely. On the other side, the kinematical corrections are very tiny for the measurements at Belle II, and the leading twist-two formula of the interference term will be good enough to describe the charge conjugation odd part of the differential cross section.

Abundant phenomenology suggests that strong decays from relatively low-excitation hadrons into other hadrons proceed by the creation of a light quark-antiquark pair with zero total angular momentum, the so called ${}^3{P}_0$ mechanism originating from a scalar bilinear. Yet the quantum chromodynamics (QCD) interaction is perturbatively mediated by gluons of spin one, and QCD presents a chirally symmetric Lagrangian. Such scalar decay term must be spontaneously generated upon breaking chiral symmetry. We attempt to reproduce this with the help of the quark-gluon vertex in Landau gauge, whose nonperturbative structure has been reasonably elucidated in the last years, and insertions of a uniform, constant chromoelectric field. This is akin to Schwinger pair production in quantum electrodynamics (QED), and we provide a comparison with its two field-insertions diagram. We find that, the symmetry being cylindrical, the adequate quantum numbers to discuss the production are rather ${{}^3\mathrm{\Sigma }}_0$, ${{}^3\mathrm{\Sigma }}_1$, and ${{}^3\mathrm{\Pi }}_0$ as in diatomic molecules, and we indeed find a sizeable contribution of the third decay mechanism, which may give a rationale for the ${}^3{P}_0$ phenomenology, as long as the momentum of the produced pair is at or below the scale of the bare or dynamically generated fermion mass. On the other hand, ultrarelativistic fermions are rather ejected with ${{}^3\mathrm{\Sigma }}_1$ quantum numbers. In QED, our results suggest that ${{}^3\mathrm{\Sigma }}_0$ dominates, whereas the constraint of producing a color singlet in QCD leads to ${{}^3\mathrm{\Pi }}_0$ dominance at sub-GeV momenta.

Recently, the LHCb Collaboration has observed the decays ${\mathrm{\Xi }}_b^0\to {\mathrm{\Xi }}_c^{+}{D}_s^{-}$ and ${\mathrm{\Xi }}_b^{-}\to {\mathrm{\Xi }}_c^0{D}_s^{-}$. They measured the relative branching fractions times the ratio of beauty-baryon production cross sections $\mathcal{R}(\frac{{\mathrm{\Xi }}_b^0}{{\mathrm{\Lambda }}_b})\equiv \frac{\sigma ({\mathrm{\Xi }}_b^0)}{\sigma ({\mathrm{\Lambda }}_b^0)}\times \frac{B({\mathrm{\Xi }}_b^0\to {\mathrm{\Xi }}_c^{+}{D}_s^{-})}{B({\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{D}_s^{-})}$ and $\mathcal{R}(\frac{{\mathrm{\Xi }}_b^{-}}{{\mathrm{\Lambda }}_b})\equiv \frac{\sigma ({\mathrm{\Xi }}_b^{-})}{\sigma ({\mathrm{\Lambda }}_b^0)}\times \frac{B({\mathrm{\Xi }}_b^{-}\to {\mathrm{\Xi }}_c^0{D}_s^{-})}{B({\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{D}_s^{-})}$. Once the ratio $\frac{\sigma ({\mathrm{\Xi }}_b^0)}{\sigma ({\mathrm{\Lambda }}_b^0)}$ or $\frac{\sigma ({\mathrm{\Xi }}_b^{-})}{\sigma ({\mathrm{\Lambda }}_b^0)}$ is known, one can determine the relative branching fractions which can be used to exam the mixing of ${\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_c^{\prime }$. In previous literature, ${\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_c^{\prime }$ were assumed to belong to ${\mathrm{SU}(3)}_F$ antitriple and sextet, respectively. However, recent experimental measurements, such as the ratio $\mathrm{\Gamma }({\mathrm{\Xi }}_{cc}\to {\mathrm{\Xi }}_c{\pi }^{+})/\mathrm{\Gamma }({\mathrm{\Xi }}_{cc}\to {\mathrm{\Xi }}_c^{\prime }{\pi }^{+})$, indicate the spin-flavor structures of ${\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_c^{\prime }$ are a mixture of ${\mathrm{\Xi }}_c^{\overline{3}}$ and ${\mathrm{\Xi }}_c^6$. The exact value of mixing angle $\theta$ is still under debate. In theoretical models, the mixing angle was fitted to be about $16.27°\pm 2.30°$ or $85.54°\pm 2.30°$ based on decay channels ${\mathrm{\Xi }}_{cc}\to {\mathrm{\Xi }}_c^{{(}^{\prime })}$. While in lattice calculation, a small angle ($1.2°\pm 0.1°$) is preferred. To address such discrepancy and test the mixing of ${\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_c^{\prime }$, here we propose the analysis of semileptonic and nonleptonic decays of ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c^{\prime }$. We calculate the decay rate of ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c^{\prime }$ based on the light-front quark model and study the effect of the mixing angle on the ratios of weak decays ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c$ and ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c^{\prime }$. In particular, we find the transition ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c^{\prime }$ can be an ideal channel to verify the mixing and extract the mixing angle because in theory, the decay rate would be extremely tiny without mixing. Our calculation suggests a measurement of ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c^{\prime }$ can be feasible in the near future, which will help to test flavor mixing angle $\theta$ and elucidate the mechanism of decay of heavy baryons.

Based on $4.5{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data accumulated at center-of-mass energies between 4599.53 and 4698.82 MeV with the BESIII detector, we measure the absolute branching fraction of the Cabibbo-favored decay ${\mathrm{\Lambda }}_c^{+}\to n{K}_S^0{\pi }^{+}$ with the precision improved by a factor of 2.8 and report the first evidence for the singly-Cabibbo-suppressed decay ${\mathrm{\Lambda }}_c^{+}\to n{K}_S^0{K}^{+}$. The branching fractions for ${\mathrm{\Lambda }}_c^{+}\to n{K}_S^0{\pi }^{+}$ and ${\mathrm{\Lambda }}_c^{+}\to n{K}_S^0{K}^{+}$ are determined to be $(1.86\pm 0.08\pm 0.04)\times {10}^{-2}$ and $(3.9_{-1.4}^{+1.7}\pm 0.3)\times 10^{-4}$, respectively, where the first uncertainties are statistical and the second ones are systematic.

Axion dark matter (DM) constitutes an oscillating background that violates parity and time-reversal symmtries. Inside piezoelectric crystals, where parity is broken spontaneously, this axion background can result in a stress. We call this new phenomenon “the piezoaxionic effect.” When the frequency of axion DM matches the natural frequency of a bulk acoustic normal mode of the piezoelectric crystal, the piezoaxionic effect is resonantly enhanced and can be read out electrically via the piezoelectric effect. We explore all axion couplings that can give rise to the piezoaxionic effect—the most promising one is the defining coupling of the QCD axion, through the anomaly of the strong sector. We also point our another, subdominant phenomenon present in all dielectrics, namely the “electroaxionic effect.” An axion background can produce an electric displacement field in a crystal which in turn will give rise to a voltage across the crystal. The electroaxionic effect is again largest for the axion coupling to gluons. We find that this model-independent coupling of the QCD axion may be probed through the combination of the piezoaxionic and electroaxionic effects in piezoelectric crystals with aligned nuclear spins, with near-future experimental setups applicable for axion masses between ${10}^{-11}\mathrm{eV}$ and ${10}^{-7}\mathrm{eV}$, a challenging range for most other detection concepts.

A substantial fraction of systematic uncertainties in neutrino oscillation experiments stem from the lack of precision in modeling the nuclear target in neutrino-nucleus interactions. Whilst this has driven significant progress in the development of improved nuclear models for neutrino scattering, it is crucial that the models used in neutrino data analyses be accompanied by parameters and associated uncertainties that allow the coverage of plausible nuclear physics. Based on constraints from electron scattering data, we propose such a set of parameters, which can be applied to nuclear shell models, and test their application to the Benhar et al. [Nucl. Phys. A579, 493 (1994)] spectral function model. The parametrization is validated through a series of maximum likelihood fits to cross section measurements made by the T2K and MINERvA experiments, which also permit an exploration of the power of near-detector data to provide constraints on the parameters in neutrino oscillation analyses.

We propose a novel method for renormalization group improvement of thermally resummed effective potential. In our method, $\beta$-functions are temperature dependent as a consequence of the divergence structure in resummed perturbation theory. In contrast to the ordinary $\overline{\mathrm{MS}}$ scheme, the renormalization group invariance of the resummed finite-temperature effective potential holds order by order, which significantly mitigates a notorious renormalization scale dependence of phase transition quantities such as a critical temperature even at the one-loop order. We also devise a tractable method that enables one to incorporate temperature-dependent higher-order corrections by fully exploiting the renormalization group invariance.

We present an action for minimal massive gravity (MMG) in three dimensions in terms of a dreibein and an independent spin connection. Furthermore, the construction provides an action principle for an infinite family of so-called third-way consistent generalizations of the three-dimensional Einstein field equations, including exotic massive gravity and new higher-order generalizations. It allows us to systematically construct the matter couplings for these models, including the couplings to fermions, depending on the spin connection. In particular, we construct different supersymmetric extensions of MMG, and derive their second order fermionic field equations. This establishes a new class of three-dimensional supergravity theories and we discuss their limit to topological massive supergravity. Finally, we identify the landscape of (anti–)de Sitter vacua of the supersymmetric models. We analyze the spectrum and the unitarity properties of these vacua. We recover the known AdS vacua of MMG which are bulk and boundary unitary.

It is well known that the Kerr-Newmann-Unti-Tamburino-anti–de Sitter spacetimes possess hidden symmetries encoded in the so-called principal Killing-Yano tensor. In this paper, focusing on the four-dimensional case, we obtain a number of symmetry operators for scalar, vector, and tensor perturbations, that are of degree 2 (to be defined below) and homogeneous in the principal tensor. In particular, by considering homogeneous operators that are linear, quadratic, and cubic in the principal tensor, we recover a complete set of four mutually commuting operators for scalar perturbations, underlying the separability of (massive) scalar wave equation. Proceeding to vector and tensor perturbations of the Kerr-Newmann-Unti-Tamburino-anti–de Sitter spacetimes, we find a set of seven and eight commuting operators, respectively. It remains to be seen whether such operators can be used to separate the corresponding spin 1 and spin 2 test field equations in these spacetimes.

We study phase structures of Lorentzian Dyonic Taub-NUT-AdS spacetimes for different horizon geometries, which could be spherical, flat, or hyperbolic. We check the consistency of our extended thermodynamics approach through satisfying the first law, the Gibbs-Duhem relation, and the generalized Smarr’s relation. Although we study the phase structure for the three cases, we give special attention to the flat and hyperbolic cases since they are known to show no phase transitions and were not studied before. Working in a mixed ensemble, we found that the behaviors of the flat and hyperbolic cases are different from those of a charged black hole. In the latter case, a continuous phase transition occurs at high temperatures and pressures, i.e., above the critical point, but in our cases it occurs at low temperatures and pressures, i.e., below the critical point! Generically, the spherical case is characterized by two critical points with continuous phase transition between them.

Dynamical captures of black holes may take place in dense stellar media due to the emission of gravitational radiation during a close passage. Detection of such events requires detailed modeling, since their phenomenology qualitatively differs from that of quasicircular binaries. Very few models can deliver such waveforms, and none includes information from numerical relativity (NR) simulations of nonquasicircular coalescences. In this study we present a first step towards a fully NR-informed effective-one-body (EOB) model of dynamical captures. We perform 14 new simulations of single and double encounter mergers, and use this data to inform the merger-ringdown model of the TEOBResumS-Dalì approximant. We keep the initial energy approximately fixed to the binary mass, and vary the mass-rescaled, dimensionless angular momentum in the range (0.6, 1.1), the mass ratio in (1, 2.15), and aligned dimensionless spins in $(-0.5,0.5)$. We find that the model is able to match NR to 97%, improving previous performances, without the need of modifying the baseline template. Upon NR informing the model, this improves to 99% with the exception of one outlier corresponding to a direct plunge. The maximum $\mathrm{EOB}/\mathrm{NR}$ phase difference at merger for the uninformed model is of 0.15 radians, which is reduced to 0.1 radians after the NR information is introduced. We outline the steps towards a fully informed EOB model of dynamical captures, and discuss future improvements.

The Auger Collaboration has recently published the precise energy spectrum of cosmic rays above 1 EeV, which exhibits rich and interesting features. These features provide an opportunity to investigate the Galactic propagation and interaction of ultrahigh energy cosmic rays (UHECRs). While the classic dip model, which describes the UHECR propagation and interaction with cosmic microwave background in extragalactic space by theoretical calculation, well explains the cutoff behavior of the highest high energy spectrum of Auger, it fails to describe the low energy features. It indicates that the Galactic propagation and interaction of UHECRs might play an important role in modulating the low energy side of the Auger spectrum. With the disk-halo diffusion model, this work demonstrates excellent agreement with the energy spectrum measured by Auger and supports that the diffusion coefficient follows a power law with an index of ${1.81}_{-0.04}^{+0.05}$ in the Galaxy, at least above $5\times {10}^{18}\mathrm{eV}$. The inferred diffusion coefficient is 1 to 2 orders of magnitude smaller than these extrapolated from low energy studies when conventional model parameters are adopted. The study of the modulation effect at a cluster of the Galaxy level might be needed.

The search for sub-GeV dark matter via scattering on electrons has ramped up in the last few years. Like in the case of dark matter scattering on nuclei, electron-recoil-based searches also face an ultimate background in the form of neutrinos. The so-called “neutrino fog” refers to the range of open dark matter parameter space where the background of neutrinos can potentially prevent a conclusive discovery claim of a dark matter signal from being made. In this study, we map the neutrino fog for a range of electron recoil experiments based on silicon, germanium, xenon, and argon targets. In analogy to the nuclear recoil case, we also calculate the “edge” to the neutrino fog, which can be used as a visual guide to determine where neutrinos become an important background—this boundary excludes some parts of the key theory milestones used to motivate these experiments.

We introduce a graph neural network architecture designed to extract novel phenomena in the standard model effective field theory (SMEFT) context from LHC collision data. The proposed infrared- and collinear-safe architecture is sensitive to the angular orientation of radiation patterns in jets from hadronic decays of highly energetic massive particles. Equivariance with respect to rotations around the jet axis allows for extracting the information on the angular orientation decoupled from the jet substructure. We demonstrate the robustness of the approach and its potential for future probes of the SMEFT at the LHC through toy studies and with realistic event simulations of the associated production of a W and a Z boson in the semileptonic decay channel.

We assess proton decay signatures in the simplest viable $SU(5)$ model with regard to constraints on parameters governing the Standard Model fermion mass spectrum. Experimental signals for all eight two-body proton decay processes result from exchange of two gauge bosons, a single scalar leptoquark, or their combination. Consequently, it enables us to delve into an in-depth anatomy of proton decay modes and anticipate future signatures. Our findings dictate that observing a proton decay into $p\to {\pi }^0{e}^{+}$ indicates gauge boson mediation, with the potential for observation of $p\to {\eta }^0{e}^{+}$ mode. Alternatively, if decay is through the $p\to K^{+}\overline{\nu }$ process, it is mediated by a scalar leptoquark, possibly allowing the observation of $p\to {\pi }^0{\mu }^{+}$. Detection of both $p\to {\pi }^0{e}^{+}$ and $p\to K^{+}\overline{\nu }$ could enhance $p\to {\pi }^0{\mu }^{+}$ through constructive interference. The model predicts inaccessibility of $p\to {\pi }^{+}\overline{\nu }$, $p\to {\eta }^0{\mu }^{+}$, $p\to K^0{e}^{+}$, and $p\to K^0{\mu }^{+}$, regardless of the dominant mediation type, in the coming decades. In summary, through a comprehensive analysis of proton decay signals, gauge coupling unification, and fermion masses and mixing, we both accurately and precisely constrain the parameter space of the $SU(5)$ model in question.

The two-Higgs doublet model (2HDM) is a well understood alternative to the Standard Model of particle physics. If the new particles included in the 2HDM are at an energy scale much greater than the weak scale, the theory can be matched to the Standard Model effective field theory (SMEFT). We compute for the first time the complete one-loop matching at dimension-6. We compare its numerical impact with that of tree-level matching at dimension-8 by performing a global fit to single Higgs and precision electroweak measurements, and we emphasize the importance of comparing one-loop SMEFT results with corresponding one-loop results in the full 2HDM model. In the SMEFT, we consider the relative importance of both one-loop matching and the inclusion of renormalization group evolution. Our results demonstrate the necessity of studying the impact of various expansions to quantify the uncertainties of the SMEFT matching.

We consider an experiment to search for dark sector particles in invisible (or semi-invisible) decays of neutral mesons $M^0={\pi }^0$, $\eta$, ${\eta }^{\prime }$, $\omega$, $f_2(1270)$, which produced the charge-exchange reactions ${\pi }^{-}+(A,Z)\to M^0+(A,Z-1);M^0\to$ invisible of high-energy pions (or kaons) on a nuclei target in the NA64 experiment at the CERN SPS. This reaction chain would lead to a striking signature of the signal event—the complete disappearance of the beam energy in the setup [Phys. Rev. D 91, 015004 (2015)]. Using data obtained from the measurements at IHEP (Protvino) and Fermilab (Batavia) we show that the integral cross sections $\sigma$ for the production of the $M^0\mathrm{s}$ slightly deviate from the phenomenological formula $\sigma \sim Z^{2/3}$, where $Z$ is the nuclei charge. In particular, we present the formulas for the differential and integral cross sections that explicitly depend on the Mandelstam and $Z$ variables. Derived formulas are used to predict the $M^0$ yield as a function of beam energy for several target nuclei, and to estimate the projection sensitivity for the proposed search in the dark vector portal model. Sensitivity to different decay modes of $M^0\mathrm{s}$ is explored.

We present a numerical calculation of the Lee-Yang and Fisher zeros of the 2D Ising model using multipoint Padé approximants. We perform simulations for the 2D Ising model with ferromagnetic couplings both in the absence and in the presence of a magnetic field using a cluster spin-flip algorithm. We show that it is possible to extract genuine signature of Lee-Yang and Fisher zeros of the theory through the poles of magnetization and specific heat, using the multipoint Padé method. We extract the poles of magnetization using Padé approximants and compare their scaling with known results. We verify the circle theorem associated to the well known behavior of Lee-Yang zeros. We present our finite volume scaling analysis of the zeros done at $T=T_c$ for a few lattice sizes, extracting to a good precision the (combination of) critical exponents $\beta \delta$. The computation at the critical temperature is performed after the latter has been determined via the study of Fisher zeros, thus extracting both ${\beta }_c$ and the critical exponent $\nu$. Results already exist for extracting the critical exponents for the Ising model in two and three dimensions making use of Fisher and Lee-Yang zeros. In this work, multipoint Padé is shown to be competitive with this respect and thus a powerful tool to study phase transitions.