We introduce a novel method to generate a bank of gravitational-waveform templates of binary black hole (BBH) mergers for matched-filter searches in LIGO, Virgo, and Kagra data. We derive a novel expression for the metric approximation to the distance between templates, which is suitable for precessing BBHs and/or systems with higher-order modes (HM) imprints and we use it to meaningfully define a template probability density across the parameter space. We employ a masked autoregressive normalizing flow model which can be conveniently trained to quickly reproduce the target probability distribution and sample templates from it. Thanks to the normalizing flow, our code takes a few hours to produce random template banks with millions of templates, making it particularly suitable for high-dimensional spaces, such as those associated to precession, eccentricity and/or HM. After validating the performance of our method, we generate a bank for precessing black holes and a bank for aligned-spin binaries with HMs: with only 5% of the injections with fitting factor below the target of 0.97, we show that both banks cover satisfactorily the space. Our publicly released code mbank will enable searches of high-dimensional regions of BBH signal space, hitherto unfeasible due to the prohibitive cost of bank generation.

We show that testing Bell inequalities in $W^{\pm }$ pair systems by measuring their angular correlation suffers from the ambiguity in kinetical reconstruction of the dilepton decay mode. We further propose a new set of Bell observables based on the measurement of the linear polarization of the $W$ bosons that can be used in the semileptonic decay mode of $W^{\pm }$ pair, and we analyze the prospects of testing the violation of Bell inequalities at $e^{+}{e}^{-}$ colliders.

We systematically compute the ${\mathrm{\Lambda }}_b(p,s_b)\to {\mathrm{\Lambda }}_c(2595{)}^{+}$ and ${\mathrm{\Lambda }}_b(p,s_b)\to {\mathrm{\Lambda }}_c(2625{)}^{+}$ form factors within the heavy quark effective theory (HQET) framework including $\mathcal{O}(1/m_c^2)$. Besides taking into account the Standard Model–like vector and axial contributions, we further determine tensor and pseudotensor form factors. Our work constitutes a step forward with respect to previous analyses allowing for a comprehensive study of the matrix element parametrization stemming from the HQET formalism. Finally, we demonstrate that the resulting form factors agree well with lattice quantum chromodynamics determinations stressing the need and relevance of the newly derived $1/m_c^2$ corrections.

In order to solve the Bethe-Salpeter equation (BSE) in the Minkowski space, we first introduce the Nakanishi integral representations of the Bethe-Salpeter amplitude and the Bethe-Salpeter wave function. We then derive the explicit integral equations for the corresponding spectral functions from the BSE for states of two scalar particles bound by a scalar-particle exchange interaction, where the propagators of constituents are allowed to be fully dressed. These integral equations are subsequently solved numerically in the variation of the Wick-Cutkosky model with massive exchange particles, where an algorithm of adaptive mash grid is proposed. The equations and algorithm we develop here serve as the foundation of Minkowski-space formulation of BSE for bound states of fermions.

We present a systematic treatment of non-Gaussianity in stochastic systems using the Schwinger-Keldysh effective field theory framework, in which the non-Gaussianity is realized as nonlinear terms in the fluctuation field. We establish two stochastic formulations of the Schwinger-Keldysh effective field theory, with those nonlinear terms manifested as multiple non-Gaussian noises in the Langevin equation and as higher order diffusive terms in the Fokker-Planck equation. The equivalence of the stochastic formulations with the original Schwinger-Keldysh effective field theory is demonstrated with nontrivial examples for arbitrary non-Gaussian parameters. The stochastic formulations will be more flexible and effective in studying nonequilibrium dynamics. We also reveal an ambiguity when coarse-graining timescale and non-Gaussian parameters vanish simultaneously, which may be responsible for the unphysical divergence found in perturbative analysis.

Motivated by the most recent measurement of tau polarization in $Z\to {\tau }^{+}{\tau }^{-}$ by CMS, we have introduced a new $U(1{)}_X$ gauge boson field $X$, which can have renormalizable kinetic mixing with the standard model $U(1{)}_Y$ gauge boson field $Y$. In addition to the kinetic mixing of the dark photon, denoted as $\sigma$, there may also be mass mixing introduced by the additional Higgs doublet with a vacuum expectation value participating in $U(1{)}_X$ and electroweak symmetry breaking simultaneously. The interaction of the $Z$ boson with the SM leptons is modified by the introduction of the mixing ratio parameter $\epsilon$, which quantifies the magnitude of both the mass and kinetic mixing of the dark photon. Initially, we use the tau lepton as an example to explore the $Z$-boson phenomenology of the dark photon model with both kinetic and mass mixing. The goal is to determine the allowed parameter regions by taking into account constraints from the vector and axial-vector couplings $g_{V,A}^{\tau }$, the decay branching ratio $\mathrm{Br}(Z\to {\tau }^{-}{\tau }^{+})$ and tau-lepton polarization in $Z\to {\tau }^{-}{\tau }^{+}$. We found that the mixing ratio plays important role in the $Z$-boson features by choosing different $\epsilon$ values. Furthermore, we aim to generalize our analysis from the tau-lepton case to include all fermions by conducting global fits. This allows us to identify viable regions by incorporating relevant fermion constraints and the $W/Z$ mass ratio. Correspondingly, we obtain the fit results with the kinetic mixing parameter $\sigma =0.074\pm 0.021$, mixing ratio $\epsilon =-1.37\pm 0.46$, and dark photon mass $m_X=275\pm 39\mathrm{GeV}$. Our global analysis indicates a preference for a dark photon mass larger than $m_Z$.

Modular symmetries offer a dynamic approach to understanding the flavor structure of leptonic mixing. Using the modular ${\mathcal{A}}_4$ flavor symmetry integrated in a type-II seesaw, we propose a simple and minimalistic model that restricts the neutrino oscillation parameter space and, most importantly, introduces a sum rule in the physical neutrino masses. When combined with the mass squared differences observed in neutrino oscillations, this sum rule determines the absolute neutrino mass scale. This has significant implications for cosmology, neutrinoless double beta decay experiments, and direct neutrino mass measurements. In particular, the model predicts ${\sum }_i{m}_i\approx 0.1\mathrm{eV}$ for both normal and inverted ordering, and thus can be fully probed by the current generation of cosmological probes in the upcoming years.

We determine the fine-tuning of the Yukawa couplings of supersymmetric QCD, discretized on a lattice. We use perturbation theory at one-loop level. The modified minimal subtraction scheme ($\overline{\mathrm{MS}}$) is employed; by its definition, this scheme requires perturbative calculations, in the continuum and/or on the lattice. On the lattice, we utilize the Wilson formulation for gluon, quark, and gluino fields; for squark fields we use naive discretization. The sheer difficulties of this study lie in the fact that different components of squark fields mix among themselves at the quantum level and the action’s symmetries, such as parity and charge conjugation, allow an additional Yukawa coupling. Consequently, for an appropriate fine-tuning of the Yukawa terms, these mixings must be taken into account in the renormalization conditions. All Green’s functions and renormalization factors are analytic expressions depending on the number of colors, $N_c$, the number of flavors, $N_f$, and the gauge parameter, $\alpha$, which are left unspecified. Knowledge of these renormalization factors is necessary in order to relate numerical results, coming from nonperturbative studies, to the renormalized, “physical” Green’s functions of the theory.

We propose a new method toward distinguishing the Dirac versus Majorana nature of neutrino masses from the spectrum of gravitational waves (GWs) associated with neutrino mass genesis. Motivated by the principle of generating small neutrino masses without tiny Yukawa couplings, we assume generic seesaw mechanisms for both Majorana and Dirac neutrino masses. For Majorana neutrinos, we further assume a spontaneously broken gauged $U(1{)}_{B-L}$ symmetry, independently of the type of Majorana seesaw mechanism, which gives a cosmic string induced GW signal flat over a wide range of frequencies. For Dirac neutrinos, we assume the spontaneous breaking of a $Z_2$ symmetry, the minimal symmetry choice associated with all Dirac seesaw mechanisms, which is softly broken, generating a peaked GW spectrum from the annihilation of the resulting domain walls. In fact, the GW spectra for all types of Dirac seesaws with such a broken $Z_2$ symmetry are identical, subject to a mild caveat. As an illustrative example, we study the simplest respective type-I seesaw mechanisms, and show that the striking difference in the shapes of the GW spectra can help differentiate between these Dirac and Majorana seesaws, complementing results of neutrinoless double beta decay experiments. We also discuss detailed implications of the recent NANOGrav data for Majorana and Dirac seesaw models.

Imaginary chemical potentials serve as a useful tool to constrain the QCD phase diagram and to gain insight into the thermodynamics of strongly interacting matter. In this study, we report on the first determination of the phase diagram for arbitrary imaginary baryon and isospin chemical potentials at high temperature using one-loop perturbation theory, revealing a nontrivial structure of Roberge-Weiss (RW) phase transitions in this plane. Subsequently, this system is simulated numerically with $N_{\mathrm{f}}=2$ unimproved staggered quarks on $N_{\tau }=4$ lattices at a range of temperatures at one of the RW phase transitions. We establish a lower bound for the light quark mass, where the first-order transition line terminates in a tricritical point. It is found that this tricritical mass is increased as compared to the case of purely baryonic imaginary chemical potentials, indicating that our setup is more advantageous for identifying critical behavior toward the chiral limit. Finally, the dynamics of local Polyakov loop clusters is also studied in conjunction with the RW phase transition.

The $SU(3)\otimes SU(2)\otimes U(1)$ standard model maps smoothly onto a conventional lattice gauge formulation, including the parity violation of the weak interactions. The formulation makes use of the pseudoreality of the weak group and requires the inclusion a full generation of both leptons and quarks. As in continuum discussions, chiral eigenstates of the Dirac operator generate known anomalies, although with rough gauge configurations these are no longer exact zero modes of the Dirac operator.

Lattice QCD spectra can be used to constrain partial-wave scattering amplitudes that, while satisfying unitarity, do not have to respect crossing symmetry and analyticity. This becomes a particular problem when extrapolated far from real energies, e.g. in the case of broad resonances like the $\sigma$, leading to large systematic uncertainties in the pole position. In this manuscript, we will show how dispersion relations can implement the additional constraints, using as input lattice-determined $\pi \pi$ partial-wave scattering amplitudes with isospin–0,1,2. We will show that only certain combinations of amplitude parametrizations satisfy all constraints, and that when we restrict to these, the $\sigma$ pole position is determined with minimal systematic uncertainty. The evolution of the now well-constrained $\sigma$ pole with varying light quark mass is presented, showing how it transitions from a bound-state to a broad resonance.

We present the first fully consistent calculation of inclusive ${\pi }^0$ production at forward rapidities at next-to-leading order (NLO) accuracy in proton-lead collisions at $\sqrt{s}=8.16\mathrm{TeV}$ within the color glass condensate approach. The center-of-mass energy dependence is determined by the Balitsky-Kovchegov equation with the initial condition constrained at NLO accuracy by the proton structure function measurements. We find that the LHCb data further constrain this nonperturbative input, and that both the NLO corrections to the evolution equation and to the impact factor have significant effects on the nuclear modification factor $R_{p\mathrm{Pb}}$. The complete NLO calculation is shown to be in qualitative agreement with the LHCb data, and the predictions are found to be sensitive to the details of the applied deep inelastic scattering (DIS) fit. These results demonstrate the need to perform global analyses of DIS and LHC data in order to probe gluon saturation phenomena at precision level at very small momentum fraction $x$.

In this work, we investigate the isospin breaking decay $X_b\to {\pi }^0{\chi }_{bJ}$ and the isospin conserved decay $X_b\to \pi \pi {\chi }_{bJ}$, where $X_b$ is taken to be the heavy quark flavor symmetry counterpart of $X(3872)$ in the bottomonium sector as a $B^{*}\overline{B}$ molecule candidate. Since the mass of this state may be far below the $B{\overline{B}}^{*}$ threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the $X_b$, the isospin-violating decay channel $X_b\to {\pi }^0{\chi }_{bJ}$ would be highly suppressed. The calculated partial width of $X_b\to \pi \pi {\chi }_{b1}$ is found to be about tens of keVs, 1–2 order(s) of magnitude larger than those of $X_b\to \pi \pi {\chi }_{b2}$ and $X_b\to \pi \pi {\chi }_{b0}$. Taking into account the fact that the total width of $X_b$ may be smaller than a few MeV like $X(3872)$, the calculated branching ratios $X_b\to \pi \pi {\chi }_{b1}$ may reach to orders of ${10}^{-2}$, which makes it a possible channel for the experimental searching of the $X_b$.

Inclusive differential cross sections for various $eA$ and $\nu A$ reactions are analyzed within the GiBUU theoretical framework and code. The treatment of electron-nucleus reactions has been improved by implementing a parametrized description of electron-nucleon interactions for a nucleon. Using the momentum of a nucleon inside the Fermi sea the electron-nucleon cross sections are then Lorentz-boosted to obtain the electron structure functions for nuclei. The neutrino structure functions are obtained from the ones for electrons by a transformation that involves the axial form factors and kinematical factors that account for the difference of vector and axial currents. Special emphasis is put on analyzing data from various different experiments in different neutrino energy regimes with one and the same theoretical input. Good agreement is reached for a wide kinematical regime, from MicroBooNE to the medium energy MINERvA experiment.

We propose a Rydberg-atom-based single-photon detector for signal readout in dark matter haloscope experiments between $40\mathrm{\mu }\mathrm{eV}$ and $200\mathrm{\mu }\mathrm{eV}$ (10 GHz and 50 GHz). At these frequencies, standard haloscope readout using linear amplifiers is limited by quantum measurement noise, which can be avoided by using a single-photon detector. Our single-photon detection scheme can offer scan rate enhancements up to a factor of ${10}^4$ over traditional linear amplifier readout, and is compatible with many different haloscope cavities. We identify multiple haloscope designs that could use our Rydberg-atom-based single-photon detector to search for QCD axions with masses above $40\mathrm{\mu }\mathrm{eV}$ (10 GHz), currently a minimally explored parameter space.

In this study, we use rational-quadratic neural spline flows, a sophisticated parametrization of normalizing flows, for inferring posterior probability distributions in scenarios where direct evaluation of the likelihood is challenging at inference time. We exemplify this approach using the T2K near detector as a working example, focusing on learning the posterior probability distribution of neutrino flux binned in neutrino energy. The predictions of the trained model are conditioned at inference time by the momentum and angle of the outgoing muons released after neutrino-nuclei interaction. This conditioning allows for the generation of personalized posterior distributions, tailored to the muon observables, all without necessitating a full retraining of the model for each new dataset. The performances of the model are studied for different shapes of the posterior distributions.

We show via explicit construction that for six or more parties, there exist extreme rays of the subadditivity cone that can be realized by quantum states, but not by holographic states. This is a counterexample to a conjecture first formulated in Hernández-Cuenca et al. [The holographic entropy cone from marginal independence, J. High Energy Phys. 09 (2022) 190.], and implies the existence of deep holographic constraints that restrict the allowed patterns of independence among various subsystems beyond the universal quantum mechanical restrictions.

We analyze the energy density spectrum of scalar induced gravitational waves (SIGWs) using the NANOGrav 15-year data set, thereby constraining the primordial non-Gaussian parameter $f_{\mathrm{NL}}$. For the first time, we calculate the seventeen missing two-loop diagrams proportional to $f_{\mathrm{NL}}{A}_{\zeta }^3$ that correspond to the two-point correlation function $⟨h_{\mathbf{k}}^{\lambda ,(3)}{h}_{{\mathbf{k}}^{\prime }}^{{\lambda }^{\prime },(2)}⟩$ for local-type primordial non-Gaussianity. The total energy density spectrum of SIGWs can be significantly suppressed by these two-loop diagrams. If SIGWs dominate the stochastic gravitational wave backgrounds observed in pulsar timing array experiments, the parameter interval $f_{\mathrm{NL}}\in [-5,-1]$ is notably excluded based on NANOGrav 15-year data set. After taking into account abundance of primordial black holes and the convergence of the cosmological perturbation expansion, we find that the only possible parameter range for $f_{\mathrm{NL}}$ might be $-1\le f_{\mathrm{NL}}<0$.