We show that string moduli have axionphilic nature owing to the model-insensitive derivative interactions arising from the Kähler potential. The decay of a modulus into stringy axions occurs without suppression by the mass of final states. Interestingly, it turns out to hold in general not only for the scalar partner of the stringy axion but also for any other moduli. The decay into (pseudo)-Nambu-Goldstone bosons (NGBs) also avoids such mass suppression if the modulus is lighter than or similar in mass to the scalar partner of the NGB. Such axionphilic nature makes string moduli a natural source of an observable amount of dark radiation in string compactifications involving ultralight stringy axions, and possibly in extensions of the Standard Model that include a cosmologically stable NGB such as the QCD axion. In the latter case, the fermionic superpartner of the NGB can also contribute to the dark matter as a feebly interacting massive particle.

We develop a cosmographic framework for analyzing redshift drift signals of nearby sources model independently, i.e., without making assumptions about the metric description of the Universe. We show that the Friedmann-Lemaître-Robertson-Walker (FLRW) prediction is altered nontrivially by regional anisotropies and inhomogeneities. In particular, we find that the position drift of the sources is nontrivially linked to the redshift drift signal. The redshift drift signal for nearby sources might be formulated in terms of an effective deceleration parameter, which reduces to the FLRW deceleration parameter in the homogeneous and isotropic limit. The presented cosmographic framework can be used for model-independent data analysis, exploiting the fact that the exact anisotropic redshift drift signal at lowest order in redshift is given by a finite set of physically interpretable coefficients. We discuss physical limits of interest as well as challenges related to the framework.

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to address this problem, we propose a novel approach to construct parameter estimators with a quantifiable bias using an order expansion of highly compressed deep summary statistics of the observed data. These summary statistics are learned automatically using an information maximising loss. Given an observation, we further show how one can use the constructed estimators to obtain approximate Bayes computation (ABC) posterior estimates and their corresponding uncertainties that can be used for parameter inference using Gaussian process regression even if the likelihood is not tractable. We validate our method with an application to the problem of cosmological parameter inference of weak lensing mass maps. We show in that case that the constructed estimators are unbiased and have an almost optimal variance, while the posterior distribution obtained with the Gaussian process regression is close to the true posterior and performs better or equally well than comparable methods.

Based on the recently formulated chiral radiation transport theory for left-handed neutrinos, we study the chiral transport of neutrinos near thermal equilibrium in core-collapse supernovae. We first compute the near-equilibrium solution of the chiral radiation transport equation under the relaxation time approximation, where the relaxation time is directly derived from the effective field theory of the weak interaction. By using such a solution, we systematically derive analytic expressions for the nonequilibrium corrections of the neutrino energy-momentum tensor and neutrino number current induced by magnetic fields via the neutrino absorption on nucleons. In particular, we find the nonequilibrium neutrino energy current proportional to the magnetic field. We also discuss its phenomenological consequences such as the possible relation to pulsar kicks.

The stochastic gravitational-wave background (SGWB) created by astrophysical sources in the nearby Universe is likely to be anisotropic. Upper limits on SGWB anisotropy have been produced for all major data-taking runs by the ground-based laser interferometric detectors. However, due to the challenges involved in numerically inverting the pixel-to-pixel noise covariance matrix, which is necessary for setting upper limits, the searches accounted for angular correlations in the map by using the spherical harmonic basis, where regularization was relatively easier. This approach is better suited though for extended sources. Moreover, the upper-limit maps produced in the two different bases are seemingly different. While the upper limits may be consistent within statistical errors, it was important to check whether the results would remain consistent if the full noise covariance matrix was used in the pixel basis. Here, we use the full pixel-to-pixel Fisher information matrix to create upper-limit maps of SGWB anisotropy. We first perform an unmodeled search for persistent, directional gravitational-wave sources using folded data from the first (O1) and second (O2) observing runs of Advanced LIGO and show that the results are consistent with the upper limits published by the LIGO-Virgo Collaboration (LVC). We then explore various ways to account for the pixel-to-pixel Fisher information matrix using singular-value decomposition and Bayesian regularization schemes. We do not find evidence for any SGWB signal in the data and the upper limits are consistent with the LVC results within statistical errors. Through an injection study, we show that they are all valid 95% upper limits, that is, the upper limit in a pixel is less than the injected signal strength in less than 5% of the pixels. Remarkably, we find that, due to nuances involved in the regularization schemes, the simplest method of using the convolved (dirty) map with a normalized variance, which was used in the LVC analysis, provides as good upper limits as the elaborate schemes with the full noise covariance matrix. Hence, we recommend continuing to use this simple method, though more regularization schemes may be explored to obtain stronger upper limits.

The HAWC Collaboration has reported the detection of an extended $\gamma$-ray emission around the Geminga and Monogem pulsars of a few degree extension. Very recently, the LHAASO Collaboration released also the data for an extended $\gamma$-ray emission around the pulsar PSR J0622+3749. This flux can be explained with electrons and positrons injected from these sources and their inverse Compton scattering on the interstellar radiation fields. So far the size of such $\gamma$-ray halos has been interpreted as the result of the diffusion coefficient around the sources being about 2 orders of magnitude smaller than the average in the Galaxy. However, this conclusion is driven by the assumption that particles propagate diffusively right away after the injection without taking into account the ballistic propagation. The propagation of cosmic-ray leptons in the proximity of the Geminga, Monogem and PSR J0622+3749 pulsars is examined here considering the transition from the quasiballistic, valid for the most recently injected particles, to the diffusive transport regime. For typical interstellar values of the diffusion coefficient, the quasiballistic regime dominates the lepton distribution up to distances of a few tens of parsec from the pulsar for particle energies above $\sim 10\mathrm{TeV}$. In this regime the resulting $\gamma$-ray source tends to be rather compact, despite particles traveling a long distance. Indeed, for larger values of the diffusion coefficient, particles propagate ballistically up to larger distances with the result of a more pointlike $\gamma$-ray source. When such transition is taken into account, a good fit to the HAWC and LHAASO $\gamma$-ray data around Geminga, Monogem and PSR J0622+3749 is obtained without the need to invoke a strong suppression of the diffusion coefficient.

Paleodetectors are a proposed experimental technique to search for dark matter by reading out the damage tracks caused by nuclear recoils in small samples of natural minerals. Unlike a conventional real-time direct detection experiment, paleodetectors have been accumulating these tracks for up to a billion years. These long integration times offer a unique possibility: by reading out paleodetectors of different ages, one can explore the time-variation of signals on megayear to gigayear timescales. We investigate two examples of dark matter substructure that could give rise to such time-varying signals. First, a dark disk through which the Earth would pass every $\sim 45\mathrm{Myr}$, and second, a dark matter subhalo that the Earth encountered during the past gigayear. We demonstrate that paleodetectors are sensitive to these examples under a wide variety of experimental scenarios, even in the presence of substantial background uncertainties. This paper shows that paleodetectors may hold the key to unraveling our Galactic history.

We have conducted a new search for the diffuse supernova neutrino background (DSNB) flux at Super-Kamiokande (SK), with a $22.5\times 2970\text{−}\mathrm{kton}·\mathrm{day}$ exposure from its fourth operational phase IV. With the new analysis we improve on the existing background reduction techniques and systematic uncertainties and take advantage of an improved neutron tagging algorithm to lower the energy threshold compared to the previous phases of SK. This allows for setting the world’s most stringent upper limit on the extraterrestrial ${\overline{\nu }}_e$ flux, for neutrino energies below 31.3 MeV. The SK-IV results are combined with the ones from the first three phases of SK to perform a joint analysis using $22.5\times 5823\mathrm{kton}·\mathrm{days}$ of data. This analysis has the world’s best sensitivity to the DSNB ${\overline{\nu }}_e$ flux, comparable to the predictions from various models. For neutrino energies larger than 17.3 MeV, the new combined 90% CL upper limits on the DSNB ${\overline{\nu }}_e$ flux lie around $2.7{\mathrm{cm}}^{-2}·{\sec }^{-1}$, strongly disfavoring the most optimistic predictions. Finally, potentialities of the gadolinium phase of SK and the future Hyper-Kamiokande experiment are discussed.

We investigate the possibility of studying the strange hidden-charm pentaquark state $P_{cs}(4459)$ by photon-induced reactions on a proton target in an effective Lagrangian approach. The production process is described by the $t$-channel $K^{-}$ exchange, the $u$-channel $\mathrm{\Lambda }$ exchange, the contract term, and the $s$- channel nucleon pole. Our theoretical approach is based on the assumption that $P_{cs}(4459)$ with $J^P=1/2^{-}$ or $J^P=3/2^{-}$ can be interpreted as a molecule composed of ${\overline{D}}^{*}{\mathrm{\Xi }}_c$. Using the coupling constants of the $P_{cs}^{J^P}$ to $\gamma \mathrm{\Lambda }$ and $K^{-}p$ channels obtained from molecule picture of the $P_{cs}^{J^P}(4459)$, the total cross-sections of the process $\gamma p\to P_{cs}^{J^P}{K}^{+}$ is evaluated. Our calculation indicates that the cross-section for $\gamma p\to P_{cs}^{1/2^{-}}{K}^{+}$ and $\gamma p\to P_{cs}^{3/2^{-}}{K}^{+}$ are of the order of 10.0 pb and 5.0 pb, respectively. In addition, we compute the cross section by assuming $P_{cs}(4459)$ as a compact pentaquark and find it is quite different from the results of ${\overline{D}}^{*}{\mathrm{\Xi }}_c$ molecule. Those results can be measured in future experiments, such as the Electron-Ion Collider in China and the United States, and can be used to test the nature of the $P_{cs}$.

We propose an SU(6) unified theory that solves the strong $CP$ problem with a high-quality axion. This is achieved by an automatic global Peccei-Quinn $\mathrm{U}(1{)}_{\mathrm{PQ}}$ symmetry and the gauged discrete ${\mathbb{Z}}_{4\mathcal{R}}$ symmetry. With the axion mass predictions of $m_a\sim \mathcal{O}({10}^{-3})-\mathcal{O}(0.1)\mathrm{eV}$, as well as a universal axion-photon coupling in the unification models, the QCD axion can be probed in the upcoming experiments of IAXO. An intermediate gauge symmetry breaking scale characterized by the axion decay constant is obtained by the Peccei-Quinn quality argument, which is likely to achieve a successful leptogenesis through the type-I seesaw mechanism. The Higgs sector at the electroweak scale is a type-II two-Higgs-doublet model. The gauge coupling unification is possible with the supersymmetric extension.

New gauge bosons coupling to leptons are simple and well-motivated extensions of the Standard Model. We study the sensitivity to gauged $L_{\mu }-L_e$, $L_e-L_{\tau }$ and $L_{\mu }-L_{\tau }$ both with the existing beam dump mode data of MiniBooNE and with the DUNE near detector. We find that including bremsstrahlung and resonant production of $Z^{\prime }$ which decays to $e^{\pm }$ and ${\mu }^{\pm }$ final states leads to a significant improvement in existing bounds, especially for $L_{\mu }-L_e$ and $L_e-L_{\tau }$ for DUNE while competitive constraints can be achieved with the existing data from the MiniBooNE’s beam dump run.

We present a numerical study of the spectrum of an asymptotically nonfree SU(2) gauge theory with $N_f=24$ massive fermion flavors. For such a large number of flavors, asymptotic freedom is lost and the massless theory is governed by a Gaussian fixed point at long distances. If fermions are massive they decouple at low energy scales and the theory is confining. We present a scaling law for the masses of the hadrons, glueballs and string tension as functions of fermion mass. The hadrons become effectively heavy quark systems, with masses approximately twice the fermion mass, whereas the energy scale of the confinement, probed by e.g., the string tension, is much smaller and vanishes asymptotically as $m_{\text{fermion}}^{2.18}$. Our results from lattice simulations are compatible with this behavior.

Two hadrons with exotic quark content $Z_b^{+}\simeq \overline{b}b\overline{d}u$ were discovered by Belle. We present a lattice study of the $\overline{b}b\overline{d}u$ systems with various quantum numbers using static bottom quarks. Only one set of quantum numbers that couples to $Z_b$ and $\mathrm{\Upsilon }\pi$ was explored on the lattice before; these studies found an attractive potential between $B$ and ${\overline{B}}^{*}$ resulting in a bound state below the threshold. The present study considers the other three sets of quantum numbers. Eigenenergies of the $\overline{b}b\overline{d}u$ system are extracted as a function of separation between $b$ and $\overline{b}$. The resulting eigenenergies do not show any sizable deviation from noninteracting energies of the systems $\overline{b}b+\overline{d}u$ and $\overline{b}u+\overline{d}b$, so no significant attraction or repulsion is found. A slight exception is a small attraction between $B$ and ${\overline{B}}^{*}$ at small distance for the quantum number that couples to $Z_b$ and ${\eta }_b\rho$.

We perform a unitary coupled channel study of the interaction of the $D^{*+}{D}^0,D^{*0}{D}^{+}$ channels and find a state barely bound, very close to isospin $I=0$. We take the experimental mass as input and obtain the width of the state and the $D^0{D}^0{\pi }^{+}$ mass distribution. When the mass of the $T_{cc}$ state quoted in the experimental paper from raw data is used, the width obtained is of the order of the 80 keV, small compared to the value given in that work. Yet, when the mass obtained in an analysis of the data considering the experimental resolution is taken, the width obtained is about 43 keV and both the width and the $D^0{D}^0{\pi }^{+}$ mass distribution are in remarkable agreement with the results obtained in that latter analysis.

We extract the excitation energy scales of the hadron spectra in a less model-dependent method using the Schottky anomaly. The Schottky anomaly is a thermodynamical phenomenon that the specific heat of a system consisting of a finite number of energy levels has a peak at finite temperature due to the energy gaps. Using the masses of all hadrons that are experimentally established, we obtain the excitation energy scales of the hadron spectra and investigate their flavor dependence.

A search for Majoron-emitting modes of the neutrinoless double beta decay of ${}^{136}\mathrm{Xe}$ is performed with the full EXO-200 dataset. This dataset consists of a total ${}^{136}\mathrm{Xe}$ exposure of $234.1\mathrm{kg}·\mathrm{yr}$, and includes data with detector upgrades that have improved the energy threshold relative to previous searches. A lower limit of ${\mathrm{T}}_{1/2}^{{}^{136}\mathrm{Xe}}>4.3\times {10}^{24}\mathrm{yr}$ at 90% C.L. on the half-life of the spectral index $n=1$ Majoron decay was obtained, a factor of 3.6 more stringent than the previous limit from EXO-200 and a factor of 1.6 more stringent than the previous best limit from KamLAND-Zen. This limit corresponds to a constraint on the Majoron-neutrino coupling constant of $|⟨g_{ee}^M⟩|<(0.4–0.9)\times {10}^{-5}$. The lower threshold and the additional data taken resulted in a factor 8.4 improvement for the $n=7$ mode compared to the previous EXO-200 search. This search provides the most stringent limits to date on the Majoron-emitting decays of ${}^{136}\mathrm{Xe}$ with spectral indices $n=1$, 2, 3, and 7.

The RENO experiment reports measured flux and energy spectrum of reactor electron antineutrinos ${\overline{\nu }}_e$ from the six reactors at Hanbit Nuclear Power Plant. The measurements use 966 094 $116111{\overline{\nu }}_e$ candidate events with a background fraction of 2.39% (5.13%), acquired in the near (far) detector, from August 2011 to March 2020. The inverse beta decay (IBD) yield is measured as $(5.852\pm 0.094)\times {10}^{-43}{\mathrm{cm}}^2/\mathrm{fission}$, corresponding to $0.941\pm 0.015$ of the prediction by the Huber and Mueller (HM) model. A reactor ${\overline{\nu }}_e$ spectrum is obtained by unfolding a measured IBD prompt spectrum. The obtained neutrino spectrum shows a clear excess around 6 MeV relative to the HM prediction. The obtained reactor ${\overline{\nu }}_e$ spectrum will be useful for understanding unknown neutrino properties and reactor models. The observed discrepancies suggest the next round of precision measurements and modification of the current reactor ${\overline{\nu }}_e$ models.

We quantify the quantum correlations between two accelerated detectors coupled to a scalar field in a cavity. It has been realized that an accelerated detector will experience a thermal bath, which is termed the Unruh effect. We examine the similarities and differences for quantum correlations regarding either temperature or acceleration. As the accelerations (respective temperatures) of the detectors increase, the entanglement decreases to zero at some instant but the mutual information (respective discord) can be amplified. As the accelerations increase but are in opposite directions, the quantum correlations decay. Importantly, we also reveal that larger quantum correlations can appear in certain nonequilibrium scenarios in which either the acceleration difference or the coupling difference becomes significant.

The excitation factors of black hole quasinormal modes quantify the ease of excitation of the quasinormal modes and are independent of the source of perturbation. We compute the excitation factors of Kerr black holes up to the 20th overtone and find that the fourth, fifth, and sixth overtones have the first three highest excitation factors for intermediate and high spin parameters. This provides an independent confirmation of the importance of overtones that has been confirmed by the fitting data analysis of numerical relativity waveforms beginning around the strain peak amplitude.

We present phenompnr, a frequency-domain phenomenological model of the gravitational-wave signal from binary-black-hole mergers that is tuned to numerical relativity (NR) simulations of precessing binaries. In many current waveform models, e.g., the “phenom” and “eobnr” families that have been used extensively to analyse LIGO-Virgo GW observations, analytic approximations are used to add precession effects to models of nonprecessing (aligned-spin) binaries, and it is only the aligned-spin models that are fully tuned to NR results. In phenompnr we incorporate precessing-binary numerical relativity results in two ways: (i) we produce the first numerical relativity-tuned model of the signal-based precession dynamics through merger and ringdown, and (ii) we extend a previous aligned-spin model, phenomd, to include the effects of misaligned spins on the signal in the coprecessing frame. The numerical relativity calibration has been performed on 40 simulations of binaries with mass ratios between $1:1$ and $1:8$, where the larger black hole has a dimensionless spin magnitude of 0.4 or 0.8, and we choose five angles of spin misalignment with the orbital angular momentum. phenompnr has a typical mismatch accuracy within 0.1% up to mass ratio $1:4$ and within 1% up to mass ratio $1:8$.