Histogram-based template fits are the main technique used for estimating parameters of high energy physics Monte Carlo generators. Parametrized neural network reweighting can be used to extend this fitting procedure to many dimensions and does not require binning. If the fit is to be performed using reconstructed data, then expensive detector simulations must be used for training the neural networks. We introduce a new two-level fitting approach that only requires one dataset with detector simulation and then a set of additional generation-level datasets without detector effects included. This simulation-level fit based on reweighting generator-level events with neural networks (SRGN) is demonstrated using simulated datasets for a variety of examples including a simple Gaussian random variable, parton shower tuning, and the top quark mass extraction.

We study a new class of signals where fermionic dark matter is absorbed by bound electron targets. Fermionic absorption signals in direct detection and neutrino experiments are sensitive to dark matter with sub-MeV mass, probing a region of parameter space in which dark matter is otherwise challenging to detect. We calculate the rate and energy deposition spectrum in xenon-based detectors, making projections for current and future experiments. We present two possible models that display fermionic absorption by electrons and study the detection prospects in light of other constraints.

In this work, we systematically study the mass spectrum of the fully heavy tetraquark in an extended chromomagnetic model, which includes both color and chromomagnetic interactions. Numerical results indicate that the energy level is mainly determined by the color interaction, which favors the color-sextet $|(QQ{)}^{6_c}(\overline{Q}\overline{Q}{)}^{{\overline{6}}_c}⟩$ configuration over the color-triplet $|(QQ{)}^{{\overline{3}}_c}(\overline{Q}\overline{Q}{)}^{3_c}⟩$ one. The chromomagnetic interaction mixes the two color configurations and gives small splitting. The ground state is always dominated by the color-sextet configuration. We find no stable state below the lowest heavy quarkonium pair thresholds. Most states may be wide since they have at least one $S$-wave decay channel into two $S$-wave mesons. One possible narrow state is the $1^{+}$ $bb\overline{b}\overline{c}$ state with a mass 15719.1 MeV. It is just above the ${\eta }_b{\overline{B}}_c$ threshold. But this channel is forbidden because of the conservation of the angular momentum and parity.

While the Polyakov loop is an order parameter of the deconfinement transition in the heavy quark mass regime of QCD, its sensitivity to the deconfinement of light, dynamical quarks in QCD is not apparent. On the other hand, the quark mass dependence of the Polyakov loop is sensitive to the appearance of a chiral phase transition. Using lattice QCD calculations in the staggered fermion discretization scheme at finite values of the lattice spacing, $aT=1/8$, we show here, for the first time, that the Polyakov loop expectation value, and the heavy quark free energy extracted from it, behaves like an energylike observable in the vicinity of the chiral phase transition temperature $T_c$. Consistent with scaling behavior of energylike observables in the $3d$, $\text{O}(2)$ universality class, the quark mass derivatives diverge in the chiral limit at $T_c$ while the temperature derivatives stay finite. The latter will develop a characteristic spike at $T_c$. This, however, may be resolved only in calculations with quark masses being 2 orders of magnitude smaller than those currently accessible in lattice QCD calculations.

The shape and dynamics of the nonrelativistic gauge vortex string in the parity-broken media is considered, upon reducing the problem to finding the extremum of the Abelian Higgs model effective action with the fixed B-type helicity of the gauge field. It is shown that in contrast with the case of the fixed A-type helicity, the static solution of the Ginzburg-Landau energy functional in the London limit is the helix with the specific relation between the curvature and torsion of the vortex line depending on the strength of the space parity violating contribution of the Lifshitz invariant. A nonlinear dynamical equation is linearized in case of small oscillations around the helical contour, and the polarization and dispersion law of the propagated waves are obtained.

Effective field theories describing gravity coupled to matter are investigated, allowing for operators of arbitrary mass dimension. Terms violating local Lorentz and diffeomorphism invariance while preserving internal gauge symmetries are included. The theoretical framework for violations of local Lorentz and diffeomorphism invariance and associated conceptual issues are discussed, including transformations in curved and approximately flat spacetimes, the treatment of various types of backgrounds, the implications of symmetry breaking, and the no-go constraints for explicit violation in Riemann geometry. Techniques are presented for the construction of effective operators, and the possible terms in the gravity, gauge, fermion, and scalar sectors are classified and enumerated. Explicit expressions are obtained for terms containing operators of mass dimension six or less in the effective action for general relativity coupled to the Standard Model of particle physics. Special cases considered include Einstein-Maxwell effective field theories and the limit with only scalar coupling constants.

Gravitational waves are rapidly becoming a very reliable tool for testing alternative theories of gravity. In particular, features in the gravitational wave emission during the black hole ringdown phase provide a direct probe of the spacetime outside the black hole. In this article, we consider the Schwarzschild–de Sitter black hole solution in ghost-free massive gravity. These black holes generically have scalar hair. We found that a simple coupling between gravitational perturbations and this scalar hair can change the quasinormal ringing of the black hole and, in particular, produce echoes in the emitted gravitational waves. This finding suggests a possible method for testing massive gravity using gravitational wave observations.

A new spinorial strategy for the construction of geometric inequalities involving the Arnowitt-Deser-Misner mass of black hole systems in general relativity is presented. This approach is based on a second order elliptic equation (the approximate twistor equation) for a valence 1 Weyl spinor. This has the advantage over other spinorial approaches to the construction of geometric inequalities based on the Sen-Witten-Dirac equation that it allows us to specify boundary conditions for the two components of the spinor. This greater control on the boundary data has the potential of giving rise to new geometric inequalities involving the mass. In particular, it is shown that the mass is bounded from below by an integral functional over a marginally outer trapped surface (MOTS) which depends on a freely specifiable valence 1 spinor. From this main inequality, by choosing the free data in an appropriate way, one obtains a new nontrivial bounds of the mass in terms of the inner expansion of the MOTS. The analysis makes use of a new formalism for the $1+1+2$ decomposition of spinorial equations.

Two sources of geometric information are encoded in the galaxy power spectrum: the sound horizon at recombination and the horizon at matter-radiation equality. Analyzing the BOSS 12th data release galaxy power spectra using perturbation theory with ${\mathrm{\Omega }}_m$ priors from Pantheon supernovae but no priors on ${\mathrm{\Omega }}_b$, we obtain constraints on $H_0$ from the second scale, finding $H_0={65.1}_{-5.4}^{+3.0}\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$; this differs from the best fit of SH0ES at 95% confidence. Similar results are obtained if ${\mathrm{\Omega }}_m$ is constrained from uncalibrated baryon acoustic oscillations: $H_0={65.6}_{-5.5}^{+3.4}\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$. Adding the analogous lensing results from Baxter and Sherwin from 2020, the posterior shifts to ${70.6}_{-5.0}^{+3.7}\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$. Using mock data, Fisher analyses, and scale cuts, we demonstrate that our constraints do not receive significant information from the sound horizon scale. Since many models resolve the $H_0$ controversy by adding new physics to alter the sound horizon, our measurements are a consistency test for standard cosmology before recombination. A simple forecast indicates that such constraints could reach ${\sigma }_{H_0}\simeq 1.6\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ in the era of Euclid.

An excess $\gamma$-ray signal toward the outer halo of M31 has recently been reported. Although other explanations are plausible, the possibility that it arises from dark matter (DM) is valid. In this work we interpret the excess in the framework of DM annihilation, using as our representative case WIMP DM annihilating to bottom quarks, and we perform a detailed study of the systematic uncertainty in the $J$-factor for the M31 field. We find that the signal favors a DM particle with a mass of $\sim 45–72\mathrm{GeV}$. While the mass is well constrained, the systematic uncertainty in the cross section spans 3 orders of magnitude, ranging from $\sim 5\times {10}^{-27}–5\times {10}^{-24}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$. This high uncertainty is due to two main factors, namely, an uncertainty in the substructure nature and geometry of the DM halos for both M31 and the Milky Way (MW), and correspondingly, an uncertainty in the contribution to the signal from the MW’s DM halo along the line of sight. However, under the conditions that the minimum subhalo mass is $\lesssim {10}^{-6}{M}_{\odot }$ and the actual contribution from the MW’s DM halo along the line of sight is at least $\sim 30\%$ of its total value, we show that there is a large overlap with the DM interpretations of both the Galactic center (GC) excess and the antiproton excess, while also being compatible with the limits for the MW dwarf spheroidals. More generally, we summarize the results from numerous complementary DM searches in the energy range 10 GeV–300 GeV corresponding to the GC excess and identify a region in parameter space that still remains viable for discovery of the DM particle.

In this work, we study the strong decays of $\varphi (2170)$ to final states involving the kaonic resonances $K(1460)$, $K_1(1270)$, and $K_1(1400)$, on which experimental data have recently been extracted by the BESIII Collaboration. The formalism developed here is based on interpreting $\varphi (2170)$ and $K(1460)$ as states arising from three-hadron dynamics, which is inspired by our earlier works. For $K_1(1270)$ and $K_1(1400)$, we investigate different descriptions, such as a mixture of states belonging to the nonet of axial resonances, or the former one as a state originating from the vector-pseudoscalar dynamics. The ratios among the partial widths of $K^{+}(1460)K^{-}$, $K_1^{+}(1400)K^{-}$, and $K_1^{+}(1270)K^{-}$ obtained are compatible with the experimental results, reinforcing the three-body nature of $\varphi (2170)$. Within our formalism, we can also explain the suppressed decay of $\varphi (2170)$ to $K^{*}(892){\overline{K}}^{*}(892)$, as found by the BESIII Collaboration. Furthermore, our results can be useful in clarifying the properties of $K(1460)$, $K_1(1270)$, and $K_1(1400)$ when higher statistics data are available.

Direct $CP$ asymmetries (${\mathcal{A}}_{CP}$) in the inclusive decays of $\overline{B}\to X_s\gamma$ and $\overline{B}\to X_{s+d}\gamma$ of the order of 1% will be probed at the BELLE II experiment. In this work, three such asymmetries are studied in the context of a three-Higgs-doublet model (3HDM), and it is shown that all three ${\mathcal{A}}_{CP}$ can be as large as the current experimental limits. Of particular interest is the ${\mathcal{A}}_{CP}$ for $\overline{B}\to X_{s+d}\gamma$, which is predicted to be effectively zero in the Standard Model (SM). A measurement of 2.5% or more for this observable with the full BELLE II data would give $5\sigma$ evidence for physics beyond the SM. We display parameter space in the 3HDM for which such a clear signal is possible.

We present a mechanism wherein the QCD axion coupling to nucleons, photons, or electrons can be enhanced selectively without increasing the axion mass. We focus in particular on the axion-nucleon couplings that are generally considered to be largely model independent, and we show how nucleophilic axion models can be constructed. We discuss the implications of a nucleophilic axion for astrophysics, cosmology, and laboratory searches. We present a model with enhanced axion couplings to nucleons and photons that can provide an excellent fit to the anomalous emission of hard x-rays recently observed from a group of nearby neutron stars, and we argue that such a scenario can be thoroughly tested in forthcoming axion-search experiments.

Rare $|\mathrm{\Delta }c|=|\mathrm{\Delta }u|=1$ transitions into dineutrinos are strongly Glashow-Iliopoulos-Maiani-suppressed and constitute excellent null tests of the standard model. While branching ratios of $D\to P\nu \overline{\nu }$, $D\to P^{+}{P}^{-}\nu \overline{\nu }$, $P=\pi$, $K$, baryonic ${\mathrm{\Lambda }}_c^{+}\to p\nu \overline{\nu }$, and ${\mathrm{\Xi }}_c^{+}\to {\mathrm{\Sigma }}^{+}\nu \overline{\nu }$ and inclusive $D\to X\nu \overline{\nu }$ decays are experimentally unconstrained, signals of new physics can be just around the corner. We provide model-independent upper limits on branching ratios reaching few $\times {10}^{-5}$ in the most general case of arbitrary lepton flavor structure, $\sim {10}^{-5}$ for scenarios with charged lepton conservation and few $\times {10}^{-6}$ assuming lepton universality. We also give upper limits in $Z^{\prime }$ and leptoquark models. The presence of light right-handed neutrinos can affect these limits, a possibility that can occur for lepton number violation at a TeV, and that can be excluded with an improved bound on $\mathcal{B}(D^0\to \text{invisibles})$ at the level of $\sim {10}^{-6}$, about two orders of magnitude better than the present one. Signatures of $c\to u\nu \overline{\nu }$ modes contain missing energy and are suited for experimental searches at $e^{+}{e}^{-}$–facilities, such as BES III, Belle II and future $e^{+}{e}^{-}$–colliders, such as the FCC-ee running at the $Z$.

We present the first lattice-QCD calculation of the kaon valence-quark distribution functions using the large-momentum effective theory (LaMET) approach. The calculation is performed with multiple pion masses with the lightest one around 220 MeV, 2 lattice spacings $a=0.06$ and 0.12 fm, $(M_{\pi }{)}_{\min }L\approx 5.5$, and high statistics ranging from 11,600 to 61,312 measurements. We also calculate the valence-quark distribution of pion and find it to be consistent with the FNAL E615 experimental results, and our ratio of the $u$ quark PDF in the kaon to that in the pion agrees with the CERN NA3 experiment. We also make predictions of the strange-quark distribution of the kaon.

Using the classical description of spin degrees of freedom, we extend recent formulation of the perfect-fluid hydrodynamics for spin-polarized fluids to the case including dissipation. Our work is based on the analysis of classical kinetic equations for massive particles with spin $1/2$, with the collision terms treated in the relaxation time approximation. The kinetic-theory framework determines the structure of viscous and diffusive terms and allows to explicitly calculate a complete set of new kinetic coefficients that characterize dissipative spin dynamics.

We extend our relativistic theory of electroweak properties of composite systems to describe simultaneously the gravitational form factors of hadrons. The approach is based on a version of the instant-form relativistic quantum mechanics and makes use of the modified impulse approximation. We exploit the general method of the relativistic invariant parametrizaton of local operators to write the energy-momentum tensor of a particle with an arbitrary spin. We use the obtained results to calculate the gravitational form factors of the pion assuming pointlike constituent quarks. All but one parameters of our first-principle model were fixed previously in works on electromagnetic form factors. The only free parameter, $D_q$, is a characteristic of the gravitational form factor of a constituent quark. The derived form factors of the pion satisfy the constraints given by the general principles of the quantum field theory of hadron structure. The calculated gravitational form factors and gravitational mean-square radius are in a reasonable agreement with known results.

We establish the nonperturbative validity of the gauge anomaly cancellation condition in an effective electroweak theory of massless fermions with finite momentum cutoff and Fermi interaction. The requirement that the current is conserved up to terms smaller than the energy divided by the cutoff scale, which is the natural condition as gauge invariance is only emerging, produces the same constraint on charges as in the Standard Model. The result holds at a nonperturbative level as the functional integrals are expressed by convergent power series expansions and are analytic in a finite domain.

Using a sample of $1.31\times {10}^{9}J/\psi$ events collected with the BESIII detector, we perform a study of $J/\psi \to \gamma \eta \eta {\eta }^{\prime }$ to search for the $X(2370)$ and ${\eta }_c$ in the $\eta \eta {\eta }^{\prime }$ invariant mass distribution. No significant signal for the $X(2370)$ is observed, and we set an upper limit for the product branching fraction of $\mathcal{B}(J/\psi \to \gamma X(2370)·\mathcal{B}(X(2370)\to \eta \eta {\eta }^{\prime })<9.2\times {10}^{-6}$ at the 90% confidence level. A clear ${\eta }_c$ signal is observed for the first time, yielding a product branching fraction of $\mathcal{B}(J/\psi \to \gamma {\eta }_c)·\mathcal{B}({\eta }_c\to \eta \eta {\eta }^{\prime })=(4.86\pm 0.62(\mathrm{stat})\pm 0.45(\mathrm{sys}))\times {10}^{-5}$.

We analyze the generalized uncertainty principle (GUP) impact onto the nonextensive black hole thermodynamics by using Rényi entropy. We show that when introducing GUP effects, both Rényi entropy and temperature associated with black holes have finite values at the end of the evaporation process. We also study the sparsity of the radiation, associated with Rényi temperature, and compare it with the sparsity of Hawking radiation. Finally, we investigate GUP modifications to the sparsity of the radiation when GUP effects are introduced into Rényi temperature.