The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description? To investigate this, we explicitly construct an ensemble containing $N$ individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large $N$, the differences are small.

A first application of the equation of state (EoS) in the quark-meson-coupling (QMC) model in thermodynamic scenarios corresponding to stationary and rotating isentropic protoneutron stars (PNS), producing results in agreement with recent observation, was published recently. In addition, a tabulated form of the EoS in the parameter space suitable for use in simulations of cold binary neutron star mergers (BNS) and their time development, has been deposited for public use in the CompOSE database. However, the theoretical background of the QMC EoS of hot hyperonic matter has not yet been presented. In this work, we report, for the first time, details of the QMC theory of dense matter, including nucleons, leptons, and the full hyperon octet, extended to particle number density from $n_B=0$ up to $1.2{\mathrm{fm}}^{-3}$, over the temperature range 0–100 MeV, with the entropy per particle between $\mathrm{S}/\mathrm{A}=0$ and $2{\mathrm{k}}_B$ and lepton fraction from ${\mathrm{Y}}_L=0$ to 0.6. The main objective of this work is to explore the effect of the exchange (Fock) terms at finite temperature, when they are self-consistently incorporated in the fully relativistic QMC Lagrangian. As already mentioned above, these terms are missing in most relativistic mean field models of hot dense hyperonic matter. We show that they have a non-negligible effect on observables of astrophysical objects and that it is essential they are included in realistic mean field calculations.

In previous works we derived equations for the average momentum of high-energy electrons experiencing quantum radiation reaction in strong electromagnetic plane-wave background fields. In this paper we derive similar equations for the momentum spectrum. We formulate the equations in terms of the cumulative function and study the relation between the equations for the spectrum and the equations for the moments, analyze the structure of the low-energy expansions, and finally explain how our formulation is essentially in terms of a “Green’s function” which allows us to study the dynamics without choosing a specific initial wave packet (or particle-bunch distribution).

We construct $Q$-ball solutions from a model consisting of one massive scalar field $\xi$ and one massive complex scalar field $\varphi$ interacting via the cubic couplings $g_1\xi {\varphi }^{*}\varphi +g_2{\xi }^3$, typical of Henon-Heiles-like potentials. Although being formally simple, these couplings allow for $Q$-balls. In one spatial dimension, analytical solutions exist, either with vanishing or nonvanishing $\varphi$. In three spatial dimensions, we numerically build $Q$-ball solutions and investigate their behaviors when changing the relatives values of $g_1$ and $g_2$. For $g_1<g_2$, two $Q$-balls with the same frequency exist, while $\omega =0$ can be reached when $g_1>g_2$. We then extend the former solutions by gauging the U(1) symmetry of $\varphi$ and show that charged $Q$-balls exist.

We study the light right-handed slepton bulk regions for dark matter from the generalized minimal supergravity (GmSUGRA) in the minimal supersymmetric Standard Model. In our comprehensive numerical studies, we show that ${\mathcal{R}}_{\tilde{\varphi }}\gtrsim 10\%$ is a conservative criterion to formulate bulk region, where ${\mathcal{R}}_{\tilde{\varphi }}\equiv (m_{\tilde{\varphi }}-m_{{\tilde{\chi }}_1^0})/m_{{\tilde{\chi }}_1^0}$. For right-handed stau as the next-to-the-lightest supersymmetric particle (NLSP), we find a large viable parameter space, consistent with the current LHC constraints, Planck2018 dark matter relic density bounds, and direct bounds on neutralino-nucleons scattering cross section that naturally supports the right-handed stau bulk regions for dark matter. In particular, the upper bounds on the masses of the lightest supersymmetric particle neutralino and right-handed stau are about 120.4 and 138 GeV, respectively. This bulk region may be beyond the current LHC reach and could be probed at LUX-ZEPLIN, a next-generation dark matter direct-detection experiment, the Future Circular Collider at CERN, and the Circular Electron Positron Collider. However, the scenario with the right-handed selectron as the NLSP is excluded by the LHC supersymmetry searches.

In this work, we extend the analysis of the pion axioproduction, $aN\to \pi N$, to include the impact of the Roper resonance $N^{*}(1440)$ together with the previously studied $\mathrm{\Delta }(1232)$ resonance. Our theoretical framework is a chiral Lagrangian approach with explicit resonance fields to account for their respective impacts. We find that the $N^{*}(1440)$ also leads to an enhancement of the cross section within its energy range for various axion models. This enhancement given by the $N^{*}(1440)$ maintains stability even when the parameter ${\sin }^2\beta$ of the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) model undergoes variations. In contrast, the enhancement given by the $\mathrm{\Delta }(1232)$ gradually diminishes and finally disappears as ${\sin }^2\beta$ approaches 1. Furthermore, the resonance peaks given by the $\mathrm{\Delta }(1232)$ are approximately the same in both the Kim-Shifman-Vainstein-Zakharov (KSVZ) model and the DFSZ model with ${\sin }^2\beta =\frac{1}{2}$, while the resonance peak given by the $N^{*}(1440)$ in the former model is much more pronounced.

The origin of the excess of low-energy events observed by the MiniBooNE experiment remains a mystery, despite exhaustive investigations of backgrounds and a series of null measurements from complementary experiments. One intriguing explanation is the production of beyond-the-Standard-Model particles that could mimic the experimental signature of additional ${\nu }_e$ appearance seen in MiniBooNE. In one proposed mechanism, muon neutrinos up-scatter to produce a new “dark neutrino” state that decays by emitting highly collimated electron-positron pairs. We propose high-energy neutrinos produced from $W$ boson decays at the Large Hadron Collider as an ideal laboratory to study such models. Simple searches for a low-mass, boosted dilepton resonance produced in association with a high-$p_{\mathrm{T}}$ muon from the $W$ decay with run 2 data would already provide unique sensitivity to a range of dark neutrino scenarios, with prompt and displaced searches providing complementarity. Looking farther ahead, we show how the unprecedented sample of $W$ boson decays anticipated at the HL-LHC, together with improved lepton acceptance would explore much of the parameter space most compatible with the MiniBooNE excess.

Strongly supercooled first-order phase transitions (FOPTs) can produce primordial black hole (PBH) dark matter (DM) along with observable gravitational waves (GWs) from bubble collisions. Such FOPTs may also produce coherent magnetic fields generated by bubble collisions and by turbulence in the primordial plasma. Here we find that the requirement for PBH DM can produce large primordial magnetic fields which subsequently yield intergalactic magnetic fields in the present Universe (with magnitude $\lesssim 20\mathrm{pG}$ across coherence length scales of $\simeq 0.001–0.01\mathrm{Mpc}$, assuming maximally helical magnetic fields) that easily exceed lower bounds from blazar observations. We follow a largely model-independent approach and highlight the possibility of producing DM and observable multimessenger magnetic fields and GW signals visible in next generation experiments.

It is well-established now that the generalized parton distributions (GPDs) at zero skewness are playing important roles in some physical process such as elastic electron-nucleon scattering, elastic (anti)neutrino-nucleon scattering, and wide-angle Compton scattering (WACS) via various types of form factors (FFs). In this study, we are going to utilize the recent JLab measurements of the elastic electron-nucleon scattering reduced cross section, namely GMp12, as a touchstone to unravel the tension observed between the measurements of the WACS cross section and the data of the proton magnetic FF $G_M^p$. We also investigate the impact of GMp12 data on valence unpolarized GPDs $H_v^q$ and $E_v^q$ at zero skewness by performing some ${\chi }^2$ analyses of the related experimental data. By calculating the electric and scalar quadrupole ratios, $R_{\mathrm{EM}}$ and $R_{\mathrm{SM}}$, and magnetic transition FF $G_M^{*}/3G_D$ related to the nucleon-to-delta ($N\to \mathrm{\Delta }$) transition using the extracted GPDs and comparing the results with corresponding experimental measurements, we show that our results are in an excellent consistency with experiments, indicating the universality property of GPDs. We emphasize that the inclusion of these data in the future analysis of GPDs can significantly affect the extracted GPDs especially their uncertainties at smaller values of $Q^2$.

We investigate the possibility of deuteronlike ${\mathrm{\Sigma }}_c^{*}\overline{\mathrm{\Sigma }}$ bound states within the one-boson-exchange model and systematically analyze the effects of the contact range ${\delta }^3(\overrightarrow{r})$ potential, the tensor term from the vector-meson exchange, and nonlocal potentials due to the dependence on the sum of the initial and final state center-of-mass momenta. We find that the pion-exchange potential including the ${\delta }^3(\overrightarrow{r})$ term and the tensor term of the $\rho$-exchange potential exhibit comparable magnitudes but opposite signs for any $S$-wave baryon-antibaryon systems. For the ${\mathrm{\Sigma }}_c^{*}\overline{\mathrm{\Sigma }}$ system, it is most likely to form bound states with mass around 3.7 GeV in the $I(J^P)=0(2^{-})$ and $1(2^{-})$ channels.

It is long known that interference effects play an important role in understanding the shape of the ${\pi }^{+}{\pi }^{-}$ spectrum of resonances near the threshold. In this manuscript, we investigate the role of the $\rho \text{−}\omega$ interference in the study of semileptonic $B\to {\pi }^{+}{\pi }^{-}\ell {\overline{\nu }}_{\ell }$ decays. We determine for the first time the strong phase difference between $B\to {\rho }^0\ell {\overline{\nu }}_{\ell }$ and $B\to \omega \ell {\overline{\nu }}_{\ell }$ from a recent Belle measurement of the $m_{\pi \pi }$ spectrum of $B\to {\pi }^{+}{\pi }^{-}\ell {\overline{\nu }}_{\ell }$. We find ${\varphi }_{\rho \text{−}\omega }=(-46_{-67}^{+155})°$ and extract the branching fraction of $\mathcal{B}(B\to {\rho }^0\ell {\overline{\nu }}_{\ell })=(1.41_{-0.38}^{+0.49})\times {10}^{-4}$. In addition, we set a limit on the $S$-wave component within an $m_{\pi \pi }$ window ranging from $2m_{\pi }$ to 1.02 GeV of $\mathrm{\Delta }\mathcal{B}(B\to [{\pi }^{+}{\pi }^{-}{]}_S\ell {\overline{\nu }}_{\ell })<0.51\times {10}^{-4}$ at 90% CL. We also determine the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element of $|V_{ub}{|}_{\rho \text{−}\omega }=(3.03_{-0.44}^{+0.49})\times {10}^{-3}$, which takes into account the $\rho \text{−}\omega$ interference.

Until recently the spin-flip processes in the deep inelastic scatterings are thought to be suppressed in the high energy. We found a positive intercept for the spin-flip generalized transverse momentum-dependent parton distribution (GTMDs) $\mathrm{Re}(F_{1,2})$ as $\mathrm{Re}(F_{1,2})\sim {(\frac{1}{x})}^{{\overline{\alpha }}_s(4\ln 2-8/3)}(\cos 3{\varphi }_{k\mathrm{\Delta }}+\cos {\varphi }_{k\mathrm{\Delta }}).$ This is done by analytically solving the integro-differential evolution equation for $\mathrm{Re}(F_{1,2})$, recently proposed by Hatta and Zhou, in the dilute regime. Interestingly, the surviving solution corresponds to conformal spin $n=2$ and carries an explicit $\cos 3{\varphi }_{k\mathrm{\Delta }}+\cos {\varphi }_{k\mathrm{\Delta }}$ azimuthal dependence. As the imaginary part of $F_{1,2}$, is related to the spin-dependent odderon or gluon Siver function and scales as $\mathrm{Im}(F_{1,2})\sim x^0$, the positive intercept for $\mathrm{Re}(F_{1,2})$ implies that it is expected to dominate over the gluon Siver function in the small-$x$ limit and may directly impact the modeling of unpolarized GTMDs and associated spin-flip processes.

In a previous publication [Benić et al., Phys. Rev. D 104, 094027 (2021)], we have computed the perturbative QCD contribution to transverse single spin asymmetries (SSAs) in semi-inclusive deep inelastic scattering (SIDIS) involving the $g_T(x)$ distribution. In this paper, we first present a more efficient derivation of the asymmetries which is applicable to both transverse and longitudinal SSAs and correct some inconsistencies in our previous calculation. We then adapt the method to compute transverse SSAs in the Drell-Yan process proportional to $g_T(x)$ and its gluonic counterpart and discuss the crossing symmetry between the results for SIDIS and the Drell-Yan process. Finally, we present numerical results for various asymmetries measurable at the EIC, RHIC, COMPASS, and Fermilab (SpinQuest), including also part of the genuine twist-three corrections to $g_T(x)$ from a recent global analysis. We find that the asymmetries can reach percent-level magnitude, if the kinematics predominantly probes the large-$x$ (valence) region of the polarized proton, but remain at subpercent levels otherwise.

We investigate the speed of sound and polytropic index of quantum chromodynamics (QCD) matter in the full phase diagram based on a three-flavor Polyakov-looped Nambu-Jona-Lasinio (PNJL) model. The speed of sound and polytropic index in isothermal and adiabatic cases all have a dip structure at the low chemical potential side of the chiral phase transition boundary, and these quantities reach their global minimum values at the critical end point (CEP) but are not completely zero, where the values in adiabatic are lightly greater than those in isothermal. Different from the speed of sound, the polytropic index rapidly form a peak after crossing the chiral phase transition boundary, which is observed for the first time. Along the hypothetical chemical freeze-out lines, the speed of sound rapidly decreases near the CEP, followed by a small spinodal behavior, while the polytropic index, especially in isothermal, exhibits a more pronounced and nearly close to zero dip structure as it approaches the CEP.

The available world deep-inelastic scattering (DIS) data on proton and deuteron structure functions $F_2^p$, $F_2^d$, and their ratios are leveraged to extract the free neutron $F_2^n$ structure function, the $F_2^n/F_2^p$ ratio, and associated uncertainties using the latest nuclear effect calculations in the deuteron. Special attention is devoted to the normalization of the proton and deuteron experimental datasets and to the treatment of correlated systematic errors, as well as the quantification of procedural and theoretical uncertainties. The extracted $F_2^n$ dataset is utilized to evaluate the $Q^2$ dependence of the Gottfried sum rule and the nonsinglet $F_2^p-F_2^n$ moments. To facilitate replication of our study, as well as for general applications, we provide a comprehensive DIS database including all recent Jefferson Lab 6 GeV measurements, the extracted $F_n^2$, a modified CTEQ-JLab global parton distribution function fit named CJ15nlo_mod, and grids with calculated proton, neutron, and deuteron DIS structure functions.

We construct an extended version of the linear sigma model in such a way as to describe spin-1 hadrons as well as spin-0 hadrons in two-color QCD (${\mathrm{QC}}_2\mathrm{D}$) by respecting the Pauli-Gürsey $SU(4)$ symmetry. Within a mean-field approximation, we therefrom examine a mass spectrum of the spin-1 hadrons at finite quark chemical potential (${\mu }_q$) and zero temperature. Not only mean fields of scalar mesons and scalar-diquark baryons but also of vector mesons and vector-diquark baryons are incorporated. As a result, we find that, unless all of those four types of mean fields are taken into account, neither lattice result for the critical ${\mu }_q$ that corresponds to the onset of baryon superfluidity nor for ${\mu }_q$ dependence of the pion mass can be reproduced. We also find that a slight suppression of the $\rho$ meson mass in the superfluid phase, which was suggested by the lattice simulation, is reproduced by subtle mixing effects between spin-0 and spin-1 hadrons. Moreover, we demonstrate the emergence of an axial-vector condensed phase and possibly of a vector condensed phase by identifying the values of ${\mu }_q$ at which the corresponding hadron masses vanish. The possible presence of isotriplet $1^{-}$ diquarks that may be denoted by a tensor-type quark bilinear field is also discussed.

Observing matter effects in atmospheric neutrinos traveling through the entire mantle and core of the Earth is a promising way of enhancing our understanding of Earth’s density structure. In that context we study the prospects of Earth tomography with the ICAL detector at the India-based Neutrino Observatory. While this experiment is smaller in size in comparison to some of the other larger detectors being proposed, it is the only planned neutrino experiment with charge-identification sensitivity. In particular, ICAL can see matter effects separately in neutrinos and antineutrinos. This has been seen to enhance ICAL’s sensitivity to earth matter effects and hence the mass ordering sensitivity for both normal and inverted mass orderings. It is therefore pertinent to see if the ICAL sensitivity to earth tomography is competitive or better with respect to other experiments, especially for the inverted mass ordering, where other experiments suffer reduced sensitivity. We present the sensitivity of ICAL to earth tomography by taking into consideration both the Earth’s mass constraint as well as the hydrostatic equilibrium constraints.

Based on $(2712.4\pm 14.1)\times {10}^6$ $\psi (3686)$ events collected with the BESIII detector, we study the decays $h_c\to 3({\pi }^{+}{\pi }^{-}){\pi }^0$, $h_c\to 2({\pi }^{+}{\pi }^{-})\omega$, $h_c\to 2({\pi }^{+}{\pi }^{-}){\pi }^0\eta$, $h_c\to 2({\pi }^{+}{\pi }^{-})\eta$, and $h_c\to p\overline{p}$ via $\psi (3686)\to {\pi }^0{h}_c$. The decay channel $h_c\to 3({\pi }^{+}{\pi }^{-}){\pi }^0$ is observed for the first time, and its branching fraction is determined to be $(9.28\pm 1.14\pm 0.77)\times {10}^{-3}$, where the first uncertainty is statistical and the second is systematic. In addition, first evidence is found for the modes $h_c\to 2({\pi }^{+}{\pi }^{-}){\pi }^0\eta$ and $h_c\to 2({\pi }^{+}{\pi }^{-})\omega$ with significances of $4.8\sigma$ and $4.7\sigma$, and their branching fractions are determined to be $(7.55\pm 1.51\pm 0.77)\times {10}^{-3}$ and $(4.00\pm 0.86\pm 0.35)\times {10}^{-3}$, respectively. No significant signals of $h_c\to 2({\pi }^{+}{\pi }^{-})\eta$ and $h_c\to p\overline{p}$ are observed, and the upper limits of the branching fractions of these decays are determined to be $<6.19\times {10}^{-4}$ and $<4.40\times {10}^{-5}$ at the 90% confidence level, respectively.

Combining multiple gravitational-wave observations allows for stringent tests of general relativity, targeting effects that would otherwise be undetectable using single-event analyses. We highlight how the finite size of the observed catalog induces a significant source of variance. If not appropriately accounted for, general relativity can be excluded with arbitrarily large credibility even if it is the underlying theory of gravity. This effect is generic and holds for arbitrarily large catalogs. Moreover, we show that it cannot be suppressed by selecting “golden” observations with large signal-to-noise ratios. We present a mitigation strategy based on bootstrapping (i.e. resampling with repetition) that allows assigning uncertainties to one’s credibility on the targeted test. We demonstrate our findings using both toy models and real gravitational-wave data. In particular, we quantify the impact of the catalog variance on the ringdown properties of black holes using the latest LIGO/Virgo catalog.

We consider thermodynamics of the Universe within a quasiparticle approach where the collective dynamics of a system is governed by the thermal mass of the constituents. The spacetime dependence of this thermal mass leads to a negative contribution to the pressure and a positive contribution to the energy density, similar to the effect due to dark energy. We propose a mechanism based on thermodynamic arguments to quantify this contribution from the thermal vacuum of the system. For a sufficiently large spacetime variation of the thermal mass, the effective pressure can become negative and could mimic a dark energy equation of state. We validate our framework using results from renormalizable interacting scalar field theory and demonstrate an application on QCD axion.