Previous studies demonstrate that the inflaton, when coupled to the hypercharge Chern-Simons density, can source an explosive production of helical hypermagnetic fields. Then, in the absence of fermion production, those fields have the capability of preheating the Universe after inflation and triggering a successful baryogenesis mechanism at the electroweak phase transition. In the presence of fermion production, however, we expect a strong damping of the gauge fields production from the fermion backreaction, a phenomenon called Schwinger effect, thus jeopardizing their original capabilities. Using numerical methods, we study the backreaction on the generated gauge fields and revisit the processes of gauge preheating and baryogenesis in the presence of the Schwinger effect. We have found that gauge preheating is very unlikely, while still having a sizable window in the parameter space to achieve the baryon asymmetry of the Universe at the electroweak phase transition.

We construct nonlinear inflaton potential-energy densities that describe not necessarily very slowly rolling closed and open inflation models, and compute tilted primordial spatial inhomogeneity power spectra that follow from quantum-mechanical fluctuations during inflation in these models. Earlier nonflat inflation model power spectra computations assumed an inflaton potential-energy density with a linear slope that resulted in very slow roll during inflation and untilted power spectra. These new tilted power spectra differ from those that have previously been used to study cosmological data in nonflat cosmological models.

We study the impact of rotation on the multimessenger signals of core-collapse supernovae (CCSNe) with the occurrence of a first-order hadron-quark phase transition (HQPT). We simulate CCSNe with the flash code starting from a $20M_{\odot }$ progenitor with different rotation rates, and using the RDF equation of state from Bastian 2021 that prescribes the HQPT. Rotation is found to delay the onset of the HQPT and the resulting dynamical collapse of the protocompact star (PCS) due to the centrifugal support. All models with the HQPT experience a second bounce shock which leads to a successful explosion. The oblate PCS as deformed by rotation gives rise to strong gravitational-wave (GW) emission around the second bounce with a peak amplitude larger by a factor of $\sim 10$ than that around the first bounce. The breakout of the second bounce shock at the neutrinosphere produces a ${\overline{\nu }}_e$-rich neutrino burst with a luminosity of serveral ${10}^{53}\mathrm{erg}{\mathrm{s}}^{-1}$. In rapidly rotating models the PCS pulsation following the second bounce generates oscillations in the neutrino signal after the burst. In the fastest rotating model with the HQPT, a clear correlation is found between the oscillations in the GW and neutrino signals immediately after the second bounce. In addition, the HQPT-induced collapse leads to a jump in the ratio of rotational kinetic energy to gravitational energy ($\beta$) of the PCS, for which persistent GW emission may arise due to secular nonaxisymmetric instabilities.

We present the first numerical analysis of causal, stable first-order relativistic hydrodynamics with ideal gas microphysics, based in the formalism developed by Bemfica, Disconzi, Noronha, and Kovtun (BDNK theory). The BDNK approach provides definitions for the conserved stress-energy tensor and baryon current, and rigorously proves causality, local well-posedness, strong hyperbolicity, and linear stability (about equilibrium) for the equations of motion, subject to a set of coupled nonlinear inequalities involving the undetermined model coefficients (the choice for which defines the “hydrodynamic frame”). We present a class of hydrodynamic frames derived from the relativistic ideal gas “gamma-law” equation of state which satisfy the BDNK constraints, and explore the properties of the resulting model for a series of $(0+1)\mathrm{D}$ and $(1+1)\mathrm{D}$ tests in 4D Minkowski spacetime. These tests include a comparison of the dissipation mechanisms in Eckart, BDNK, and Müller-Israel-Stewart theories, as well as investigations of the impact of hydrodynamic frame on the causality and stability properties of Bjorken flow, planar shockwave, and heat flow solutions.

Many astronomical studies model stars like radiating blackbodies with unit emissivity. Their conclusions should be reconsidered if the stellar spectral emissivity, ${ϵ}_{\lambda }$, were to be proven to be appreciably smaller. However, determining ${ϵ}_{\lambda }$ from raw observational data poses serious technical challenges. Here, using a machine learning technique, we implemented an inverse model for calculating the stellar spectral radiation flux in a given spectral band emissivity. Radiation flux data in some spectral bands serve as input to determine the unknown model parameters. To this purpose, we chose 411 stars (361 from the Midcourse Space Experiment (MSX) catalog and 50 from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) catalog) as training samples of a stochastic particle swarm optimization algorithm. The mean values of the emissivity estimates thus obtained deviate significantly from the ideal blackbody value. Knowledge of the model parameters then enabled us to calculate the radiation fluxes in other spectral bands to compare with the existing observational data and thus validate our approach. Finally, based on the trained algorithm, we discuss our predictions for spectral bands where astronomical data are unavailable. Besides providing direct evidence against modeling stars as emitting blackbodies, our conclusions also call for more direct investigations of the stellar emissivity.

A precise and model-independent determination of the neutron distribution radius $R_n$ and thus the neutron skin thickness $R_{\mathrm{skin}}$ of atomic nuclei is of fundamental importance in nuclear physics, particle physics, and astrophysics but remains a big challenge in terrestrial labs. We argue that the nearby core-collapse supernova (CCSN) in our Galaxy may render a neutrino flux with unprecedentedly high luminosity, offering the perfect opportunity to determine the $R_n$ and $R_{\mathrm{skin}}$ through the coherent elastic neutrino-nucleus scattering ($\mathrm{CE}\nu \mathrm{NS}$). We evaluate the potential of determining the $R_n$ of lead (Pb) via $\mathrm{CE}\nu \mathrm{NS}$ with the nearby CCSN neutrinos in the RES-NOVA project which is designed to hunt CCSN neutrinos using an array of archaeological Pb based cryogenic detectors. We find that an ultimate precision of $\sim 0.1\%$ for the $R_n$ ($\sim 0.006\mathrm{fm}$ for the $R_{\mathrm{skin}}$) of Pb can be achieved via RES-NOVA in the most optimistic case that the CCSN explosion were to occur at a distance of $\sim 1\mathrm{kpc}$ from the Earth.

TeV halos are regions of enhanced photon emissivity surrounding pulsars. While multiple sources have been discovered, a self-consistent explanation of their radial profile and spherically symmetric morphology remains elusive due to the difficulty in confining high-energy electrons and positrons within $\sim 20\mathrm{pc}$ regions of the interstellar medium. One proposed solution utilizes anisotropic diffusion to confine the electron population within a “tube” that is auspiciously oriented along the line of sight. We show that while such models may explain a unique source such as Geminga, the phase space of such solutions is very small and they are unable to simultaneously explain the size and approximate radial symmetry of the TeV halo population.

Satellite galaxies of the Milky Way with high mass-to-light ratios and little baryon content, i.e., dwarf spheroidal galaxies (dSphs), are among the most promising targets to detect or constrain the nature of dark matter (DM) through its final annihilation products into high-energy photons. Previously, the assumption that DM emission from dSphs is pointlike has been used to set strong constraints on DM candidates using data from the Fermi Large Area Telescope (LAT). However, due to their high DM densities and proximity, dSphs actually have sufficient angular extension to be detected by the Fermi-LAT. Here, we perform a comprehensive analysis about the impact of accounting for angular extension in the search for gamma-ray DM signals toward known dSphs with Fermi-LAT. We show that, depending on the dSph under consideration, limits on the DM cross section can be weakened by up to a factor of 2–2.5, while the impact on the stacked, i.e., combined, limits is at most 1.5–1.8 depending on the annihilation channel. This result is of relevance when comparing dSph limits to other multimessenger DM constraints and for testing the DM interpretation of anomalous “excesses.”

We embed Feynman integrals in the subvarieties of Grassmannians through homogenization of the integrands in projective space, then obtain Gel’fand-Kapranov-Zelevinsky systems satisfied by those scalar integrals. The Feynman integral can be written as linear combinations of the hypergeometric functions of a fundamental solution system in neighborhoods of regular singularities of the Gel’fand-Kapranov-Zelevinsky system, whose linear combination coefficients are determined by the integral on an ordinary point or some regular singularities. Taking some Feynman diagrams as examples, we elucidate in detail how to obtain the fundamental solution systems of Feynman integrals in neighborhoods of regular singularities. Furthermore we also present the parametric representations of Feynman integrals of the two-loop self-energy diagrams that are convenient to embed in the subvarieties of Grassmannians.

The connection between Standard Model (SM) particles and dark matter (DM) can be introduced via a hidden spin-2 massive mediator. In the present paper we consider the simplified benchmark link between the charged lepton sector of SM and DM particles, which are considered to be hidden Dirac fermions from the dark sector. The regarding couplings are established through the dimension-five operators involving spin-2 mediator field and the energy-momentum tensors of both SM and DM sectors. We study in detail the implication of this scenario for the lepton fixed-target facilities, such as $\mathrm{NA}64e$, LDMX, $\mathrm{NA}64\mu$, and ${\mathrm{M}}^3$; in particular, for the specific experiment we discuss in detail, the missing energy signatures of spin-2 boson production followed by its invisible decay into stable DM pairs. Moreover, we derive the expected reaches of these experiments for the projected statistics of the leptons accumulated on the target. We also discuss the implication of both nuclear and atomic form-factor parametrizations for the differential spectra of hidden spin-2 boson emission, the total cross section of its production, and the experimental reach of the fixed-fixed-target facilities for probing hidden spin-2 DM mediator. We briefly discuss the DM relic abundance parameter space that can be probed by these experiments.

We investigate the prospects for probing asymmetric dark matter models through their gravitational wave signatures. We concentrate on a theory extending the Standard Model gauge symmetry by a non-Abelian group, under which leptons form doublets with new fermionic partners, one of them being a dark matter candidate. The breaking of this new symmetry occurs at a high scale and results in a strong first order phase transition in the early universe. The model accommodates baryogenesis in an asymmetric dark matter setting and predicts a gravitational wave signal within the reach of near-future experiments.

Within an effective-field-theory framework, we present a model-independent analysis of the potential of discovering new physics by searching for lepton flavor violation in heavy quarkonium decays and, more in general, we study the phenomenology of lepton-flavor-violating (LFV) 2 quark-2 lepton ($2q2\ell$) operators with two charm or bottom fields. We compute the constraints from LFV muon and tau decays on the new-physics operators that can induce LFV processes involving $c\overline{c}$ and $b\overline{b}$ systems, thus providing a comprehensive list of indirect upper limits on processes such as $J/\psi \to \ell {\ell }^{\prime }$, $\mathrm{\Upsilon }(nS)\to \ell {\ell }^{\prime }$, $\mathrm{\Upsilon }(nS)\to \ell {\ell }^{\prime }\gamma$ etc., which can be sought at BESIII, Belle II, and the proposed super tau-charm factory. We show that such indirect constraints are so stringent that they prevent the detection of quarkonium decays into $e\mu$. In the case of decays of quarkonia into $\ell \tau$ ($\ell =e$, $\mu$), we find that an improvement by 2-3 orders of magnitude on the current sensitivities is in general required in order to discover or further constrain new physics. However, we show that cancellations among different contributions to the LFV tau decay rates are possible, such that $\mathrm{\Upsilon }(nS)\to \ell \tau$ can saturate the present experimental bounds. We also find that, interestingly, searches for LFV $Z$ decays, $Z\to \ell \tau$, at future $e^{+}{e}^{-}$ colliders are complementary probes of $2q2\ell$ operators with third generation quarks.

The long-standing muon $g-2$ anomaly can be explained by heavy new physics particles through chirally enhanced contributions. It has been recently proposed that a muon collider running at center-of-mass energies of several TeV could test these new physics scenarios in a model-independent way, through the study of high-energy processes such as ${\mu }^{+}{\mu }^{-}\to h\gamma$. In this work, we validate these findings, based on effective field theories, by considering selected renormalizable simplified models and by computing this one-loop process in full generality. Furthermore, we explore the interplay of direct and indirect high-energy searches to pin down the details of the underlying new physics model accommodating the muon $g-2$ anomaly.

Weakly interacting massive particles (WIMPs) can be captured by the Sun and annihilate in the core, which may result in production of kaons that can decay at rest into monoenergetic 236 MeV neutrinos. Several studies of detection of these neutrinos at DUNE have been carried out. It has been shown that if the WIMP mass is below 4 GeV, then they will evaporate prior to annihilation, suppressing the signal. Since Jupiter has a cooler core, WIMPs with masses in the 1–4 GeV range will not evaporate and can thus annihilate into kaons which decay at rest into monoenergetic neutrinos. We calculate the flux of these neutrinos near the surface of Jupiter and find that it is comparable to the flux of neutrinos from the Sun at DUNE for masses above 4 GeV and substantially greater in the 1–4 GeV range. Of course, detecting these neutrinos would require a neutrino detector near Jupiter. Obviously, it will be many decades before such a detector can be built, but should direct detection experiments find a WIMP with a mass in the 1–4 GeV range, it may be one of the few ways to learn about the annihilation process. A liquid hydrogen time projection chamber might be able to get precise directional information and energy of these neutrinos (and hydrogen is plentiful in the vicinity of Jupiter). We speculate that such a detector could be placed on the far side of one of the tidally locked Amalthean moons; the moon itself would provide substantial background shielding and the surface would allow easier deployment of solar panels for power generation.

We discuss the use of quantum simulation to study an $N$-flavor theory of interacting relativistic fermions in ($1+1$) dimensions on noisy intermediate-scale quantum (NISQ)-era machines. The case of two flavors is particularly interesting as it can be mapped to the Hubbard model. We derive the appropriate qubit Hamiltonians and associated quantum circuits. We compare classical simulation and density matrix renormalization group/time-evolving blocked decimation calculations with the results of quantum simulation on various platforms for $N=2$ and 4-flavors. We demonstrate that the four steps needed for calculations of real-time scattering can be implemented using current NISQ devices.

We present a new QCD analysis of parton distribution functions (PDFs) at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO). In the present paper, the role of special types of experimental measurements for extracting PDFs is investigated, and simultaneously the values of the strong coupling constant are determined. Essential elements of this QCD analysis are the HERA combined data as a base, heavy-quark cross-section measurement together with Tevatron data on jet production and H1 and ZEUS jet cross sections as “non-LHC” data, and especially the “LHC” dataset for top-quark and jet cross sections. These different datasets have allowed detailed information at low $x$, providing worthwhile information on the nucleon’s flavor, and have played an important role for some PDFs at large-$x$ and strong coupling constant. Since the large-$x$ gluon PDF benefits from an accurate determination of quark PDFs, we have enough motivation to focus on the top-quark production and jet cross-section measurements from LHC to find the impact of these data on the gluon PDF and strong coupling constant. These experimental data have an impact on the relative uncertainties of PDF. The gluon PDF at large $x$ and the values of ${\alpha }_s(M_Z^2)$ are affected significantly. Although the main motivation of this paper is to focus on the gluon PDF and its uncertainty at large-$x$, giving notice to heavy PDF behavior in this region is also very important. We study the intrinsic charm (IC) using the BHPS model together with our extracted extrinsic charm PDF at large $x$, which can be very worthwhile for future experiments at the LHC.

We carry out an analysis of the multibody decay cascade ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_J^{*}J/\psi \to p{K}^{-}J/\psi$ with the ${\mathrm{\Lambda }}_J^{*}$ resonance, including ${\mathrm{\Lambda }}_{1520}^{*}$, ${\mathrm{\Lambda }}_{1600}^{*}$, and ${\mathrm{\Lambda }}_{1800}^{*}$, and $J/\psi$ reconstructed by the lepton pair final state. Using the helicity amplitude technique, we derive a compact form for the angular distributions for the decay chain, from which one can extract various one-dimensional distributions. Using the ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_J^{*}$ form factors from lattice QCD and quark model, we calculate the differential and integrated partial widths. Decay branching fractions are found as $\mathcal{B}({\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_J^{*}(pK)J/\psi ({\ell }^{+}{\ell }^{-}))=(1.35\pm 0.28)\times {10}^{-5}$. In addition, we also explore forward-backward asymmetry and various polarizations. Results in this work will serve a calibration for the study of $b\to s{\ell }^{+}{\ell }^{-}$ decays in ${\mathrm{\Lambda }}_b$ decays in future and provide useful information toward the understanding of the properties of the ${\mathrm{\Lambda }}_J^{*}$ baryons.

We obtain the masses, the electromagnetic properties, and the parton distribution functions (PDFs) of $\mathrm{\Lambda }$, ${\mathrm{\Lambda }}_c$, and their isospin triplet baryons, i.e., ${\mathrm{\Sigma }}^0$, ${\mathrm{\Sigma }}^{+}$, ${\mathrm{\Sigma }}^{-}$ and ${\mathrm{\Sigma }}_c^0$, ${\mathrm{\Sigma }}_c^{+}$, ${\mathrm{\Sigma }}_c^{++}$ from a light-front effective Hamiltonian in the leading Fock sector in the basis light-front quantization framework. The light-front wave functions of these baryons are given by the eigenstates of the effective Hamiltonian consisting of a three-dimensional confinement potential and a one-gluon exchange interaction with fixed coupling. The masses of these baryons in our approach are in the experimental range, while isospin-dependent mass differences are too small. Meanwhile, the electromagnetic properties are in agreement with the available experimental data, the lattice QCD simulations, and other theoretical calculations. We also present the gluon and the sea quark PDFs, which we generate dynamically from the QCD evolution of the valence quark distributions.

We evaluate the three-gluon vertex with one vanishing external momentum within the Curci-Ferrari (CF) model at two-loop order and compare our results to Landau-gauge lattice simulations of the same vertex function for the SU(2) and SU(3) gauge groups in four dimensions. This extends previous works [J. A. Gracey et al., Phys. Rev. D 100, 034023 (2019); N. Barrios et al., Phys. Rev. D 102, 114016 (2020)] that considered similarly the two-loop ghost and gluon two-point functions as well as the two-loop ghost-antighost-gluon vertex (with vanishing gluon momentum). With the parameters of the model being adjusted by fitting the two-point functions to available lattice data, our evaluation of the three-gluon vertex arises as a pure prediction. We find that two-loop corrections systematically improve the agreement between the model and the lattice data as compared to earlier one-loop calculations, with a better agreement in the SU(3) case as already seen in previous studies. We also analyze the renormalization scheme dependence of our calculation. In all cases, this dependence diminishes when two-loop corrections are included, which is consistent with the perturbative CF paradigm. In addition, we study the low momentum regime of the three-gluon vertex in relation with the possibility of zero crossing. Within the CF model, we show that the leading infrared behavior of the exact vertex is given by the same linear logarithm that arises at one-loop order, multiplied by the all orders cubic ghost dressing function at zero momentum (we provide similar exact results for other vertex functions). We argue that this property remains true within the Faddeev-Popov framework under the assumption that the resummed gluon propagator features a decoupling behavior. This shows that the zero crossing is a property of the exact three-gluon vertex function. Within the CF model, we find however that the scale of the zero crossing is considerably reduced when going from one- to two-loop order. This seems consistent with some recent lattice simulations [G. T. R. Catumba et al., EPJ Web Conf. 258, 02008 (2022)]. Finally, our analysis also allows us to support recent claims about the dominance of the tree-level tensor component [F. Pinto-Gómez et al., arXiv:2208.01020].

We perform an analysis of lattice QCD data in the open-charm sector based on the chiral SU(3) Lagrangian. The low-energy constants are adjusted to recover the open-charm meson masses on lattice QCD ensembles from HPQCD, ETMC, and HSC with pion and kaon masses smaller than 550 MeV. A significant set of low-energy parameters is obtainable only if the most recent information from HSC on scattering observables is included in our global fit. For the first time our analysis considers the effect of left-hand cuts as developed in terms of a generalized potential approach previously by one of the authors. Here we use coupled-channel interaction terms at the one-loop level. The elastic s-wave and p-wave $D\pi$, $DK$, and $D\overline{K}$ scattering phase shifts on ensembles with nominal pion masses of about 239 and 391 MeV are reproduced faithfully. Based on such low-energy parameters we predict s- and p-wave phase shifts and inelasticities at physical quark masses, where the statistical uncertainties in the phase shifts are smaller than 1 degree always. Most striking would be the exotic s-wave $D_s\pi$ channel, for which we predict a resonance state at about 2.287 GeV where the phase shift passes through 90 degrees.