We investigate gravitational microlensing signals produced by a spatially extended object transiting in front of a finite-sized source star. The most interesting features arise for lens and source sizes comparable to the Einstein radius of the setup. Using this information, we obtain constraints from the Subaru-HSC survey of M31 on the dark matter populations of nfw subhalos and boson stars of asteroid to Earth masses. These lens profiles capture the qualitative behavior of a wide range of dark matter substructures. We find that dark matter fractions down to $5\times {10}^{-3}$ may be probed, and that deviations from constraints on pointlike lenses (e.g., primordial black holes and machos) become visible for lenses of radius $0.1{\mathrm{R}}_{\odot }$ and larger, with the upper bound on lens masses weakening with increasing lens size.

Gravitational waves may be one of the few direct observables produced by ultralight bosons, conjectured dark matter candidates that could be the key to several problems in particle theory, high-energy physics and cosmology. These axionlike particles could spontaneously form “clouds” around astrophysical black holes, leading to potent emission of continuous gravitational waves that could be detected by instruments on the ground and in space. Although this scenario has been thoroughly studied, it has not been yet appreciated that both types of detector may be used in tandem (a practice known as “multibanding”). In this paper, we show that future gravitational-wave detectors on the ground and in space will be able to work together to detect ultralight bosons with masses $25\lesssim \mu /({10}^{-15}\mathrm{eV})\lesssim 500$. In detecting binary-black-hole inspirals, the LISA space mission will provide crucial information enabling future ground-based detectors, like Cosmic Explorer or Einstein Telescope, to search for signals from boson clouds around the individual black holes in the observed binaries. We lay out the detection strategy and, focusing on scalar bosons, chart the suitable parameter space. We study the impact of ignorance about the system’s history, including cloud age and black hole spin. We also consider the tidal resonances that may destroy the boson cloud before its gravitational signal becomes detectable by a ground-based follow-up. Finally, we show how to take all of these factors into account, together with uncertainties in the LISA measurement, to obtain boson mass constraints from the ground-based observation facilitated by LISA.

We propose an extension to the Standard Model accommodating two families of Dirac neutral fermions and Majorana fermions under additional $U(1{)}_{e-\mu }\times Z_3\times Z_2$ symmetries where $U(1{)}_{e-\mu }$ is a flavor dependent gauge symmetry related to the first and second family of the lepton sector, which features a two-loop induced neutrino mass model. The two families are favored by minimally reproducing the current neutrino oscillation data and two mass difference squares and canceling the gauge anomalies at the same time. As a result, we have a prediction for neutrino masses. The lightest Dirac neutral fermion is a dark matter candidate with tree-level interaction restricted to electron, muon and neutrinos, which makes it difficult to detect in direct dark matter search as well as indirect search focusing on the $\tau$-channel, such as through $\gamma$-rays. It may however be probed by search for dark matter signatures in electron and positron cosmic rays, and allows interpretation of a structure appearing in the CALET $\mathrm{electron}+\mathrm{positron}$ spectrum around 350–400 GeV as its signature, with a boost factor $\sim 40$ Breit-Wigner enhancement of the annihilation cross section.

We present a mechanism for dark matter (DM) production involving a self-interacting sector that at early times is ultrarelativistic but far underpopulated relative to thermal equilibrium (such initial conditions often arise, e.g., from inflaton decay). Although elastic scatterings can establish kinetic equilibrium we show that for a broad variety of self-interactions full equilibrium is never established despite the DM yield significantly evolving due to $2\to k$ ($k>2$) processes (the DM carries no conserved quantum number nor asymmetry). During the active phase of the process, the DM to Standard Model temperature ratio falls rapidly, with DM kinetic energy being converted to DM mass, the inverse of the recently discussed “cannibal DM mechanism.” As this evolution is an approach from an out-of-equilibrium to equilibrium state, entropy is not conserved. Potential observables and applications include self-interacting DM signatures in galaxies and clusters, dark acoustic oscillations, the alteration of free-streaming constraints, and possible easing of ${\sigma }_8$ and Hubble tensions.

Meson-meson amplitudes are important on their own and also play key roles in analyses of heavy-meson and tau decays. In this work we propose a new phenomenological model suited to all $SU(3)$ mesonic two-body final-state interactions up to energies around 2 GeV. It is aimed at replacing those entering the old isobar model, produced in the 1960s, long before the development of QCD. The only similarity between our new proposal and amplitudes used in the isobar model concerns vector resonances in the elastic regime. In other situations, especially those involving scalar resonances and coupled channels, the isobar model is not compatible with post-QCD dynamics. In order to support these claims convincingly and to motivate our approach, we consider applications to the $\pi \pi$ amplitude and compare our version with the isobar model in several different instances. We also show that the new model provides a clear indication of the mechanism responsible for the sharp rise observed in the $\pi \pi$ phase around 1 GeV. The phenomenological amplitudes proposed here are suited to any number of resonances in a given channel and rely just on masses and coupling constants as free parameters. Concerning theory, they incorporate chiral symmetry at low energies, include coupled channels, and respect unitarity whenever appropriate.

We study a paradigmatic model in field theory where a global $U(1)$ and scale symmetries are jointly and spontaneously broken. At zero density the model has a noncompact flat direction, which at finite density needs to be slightly lifted. The resulting low-energy spectrum is composed by a standard gapless $U(1)$ Nambu-Goldstone mode and a light dilaton whose gap is determined by the chemical potential and corrected by the couplings. Even though $U(1)$ and scale symmetries commute, there is a mixing between the $U(1)$ Nambu-Goldstone and the dilaton that is crucial to recover the expected dynamics of a conformal fluid and leads to a phonon propagating at the speed of sound. The results rely solely on an accurate study of the Ward-Takahashi identities and are checked against standard fluctuation computations. We extend our results to a boosted superfluid, and comment the relevance of our findings to condensed matter applications.

By making use of an explicit representation for the imaginary part of the photon polarization tensor in terms of transitions between the Landau levels of light quarks, we study the angular dependence of direct photon emission from a strongly magnetized quark-gluon plasma. Because of the magnetic field, the leading order photon rate comes from the three processes of the zeroth order in the coupling constant ${\alpha }_s$: (i) the quark splitting ($q\to q+\gamma$), (ii) the antiquark splitting ($\overline{q}\to \overline{q}+\gamma$), and (iii) the quark-antiquark annihilation ($q+\overline{q}\to \gamma$). In a wide range of moderately high temperatures, $T\gtrsim m_{\pi }$, and strong magnetic fields, $|eB|\gtrsim m_{\pi }^2$, the direct photon production is dominated by the two splitting processes. We show that the Landau-level quantization of quark states plays an important role in the energy and angular dependence of the photon emission. Among other things, it leads to a nontrivial momentum dependence of the photon ellipticity coefficient $v_2$, which takes negative values at small transverse momenta and positive values at large transverse momenta. The crossover between the two regimes occurs around $k_T\simeq \sqrt{|eB|}$. In application to heavy-ion collisions, this suggests that a large value of $v_2$ for the direct photons could be explained in part by the magnetic field in the quark-gluon plasma.

We report on a theoretical study of the newly observed $\mathrm{\Omega }(2012)$ resonance in the nonleptonic weak decays of ${\mathrm{\Omega }}_c^0\to {\pi }^{+}\overline{K}{\mathrm{\Xi }}^{*}(1530)(\eta \mathrm{\Omega })\to {\pi }^{+}(\overline{K}\mathrm{\Xi }{)}^{-}$ and ${\pi }^{+}(\overline{K}\mathrm{\Xi }\pi {)}^{-}$ via final-state interactions of the $\overline{K}{\mathrm{\Xi }}^{*}(1530)$ and $\eta \mathrm{\Omega }$ pairs. The weak interaction part is assumed to be dominated by the charm quark decay process: $c(ss)\to (s+u+\overline{d})(ss)$, while the hadronization part takes place between the $sss$ cluster from the weak decay and a quark-antiquark pair with the quantum numbers $J^{PC}=0^{++}$ of the vacuum, producing a pair of $\overline{K}{\mathrm{\Xi }}^{*}(1530)$ and $\eta \mathrm{\Omega }$. Accordingly, the final $\overline{K}{\mathrm{\Xi }}^{*}(1530)$ and $\eta \mathrm{\Omega }$ states are in pure isospin $I=0$ combinations, and the ${\mathrm{\Omega }}_c^0\to {\pi }^{+}\overline{K}{\mathrm{\Xi }}^{*}(1530)(\eta \mathrm{\Omega })\to {\pi }^{+}(\overline{K}\mathrm{\Xi }{)}^{-}$ decay is an ideal process to study the $\mathrm{\Omega }(2012)$ resonance. With the final-state interaction described in the chiral unitary approach, up to an arbitrary normalization, the invariant mass distributions of the final states are calculated, assuming that the $\mathrm{\Omega }(2012)$ resonance with spin-parity $J^P=3/2^{-}$ is dynamically generated from the coupled channels interactions of the $\overline{K}{\mathrm{\Xi }}^{*}(1530)$ and $\eta \mathrm{\Omega }$ in $s$-wave and $\overline{K}\mathrm{\Xi }$ in $d$-wave. We also calculate the ratio $R_{\overline{K}\mathrm{\Xi }}^{\overline{K}\mathrm{\Xi }\pi }=\mathrm{Br}[{\mathrm{\Omega }}_c^0\to {\pi }^{+}\mathrm{\Omega }(2012{)}^{-}\to {\pi }^{+}(\overline{K}\mathrm{\Xi }\pi {)}^{-}]/\mathrm{Br}[{\mathrm{\Omega }}_c^0\to {\pi }^{+}\mathrm{\Omega }(2012{)}^{-}\to {\pi }^{+}(\overline{K}\mathrm{\Xi }{)}^{-}]$. The proposed mechanism can provide valuable information on the nature of the $\mathrm{\Omega }(2012)$ and can in principle be tested by future experiments, such as LHCb, Belle, BelleII, and the planed facilities, such as the super tau charm facility and electron ion collider at China.

The light singlinolike neutralino is expected to be a promising candidate for dark matter (DM) in the allowed parameter space of the next-to-minimal supersymmetric standard model. The DM annihilation process takes place via the light Higgs bosons which are natural in this model. Identifying the allowed region of parameter space including various constraints, the detection prospect of such light DM candidate and Higgs bosons are explored at the LHC with its high luminosity options. Light Higgs bosons and the DM candidate, the lightest singlinolike neutralino are indirectly produced at the LHC via the SM Higgs production and its subsequent decays. Jet substructure techniques are used to tag boosted Higgs. It is found that the favorable range of masses of Higgs bosons and neutralino, compatible with a low mass DM solution, can be discovered with a reasonable signal significance ($\sim 5\sigma$) at the LHC, with the center of mass energy $\sqrt{s}=14\mathrm{TeV}$ and integrated luminosity options $\mathcal{L}=300{\mathrm{fb}}^{-1}$ and $3000{\mathrm{fb}}^{-1}$.

Without any mechanism to protect its mass, the self-energy of the Higgs boson diverges quadratically, leading to the hierarchy or fine-tuning problem. One bottom-up solution is to postulate some yet-to-be-discovered symmetry which forces the sum of the quadratic divergences to be zero, or almost negligible; this is known as the Veltman condition. Even if one assumes the existence of some new physics at a high scale, the fine-tuning problem is not eradicated, although it is softer than what it would have been with a Planck scale momentum cutoff. We study such divergences in an effective theory framework and construct the Veltman condition with dimension-six operators. We show that there are two classes of diagrams, the one-loop and the two-loop ones, that contribute to quadratic divergences, but the contribution of the latter is suppressed by a loop factor of $1/16{\pi }^2$. There are only six dimension-six operators that contribute to the one-loop category, and the Wilson coefficients of these operators play an important role towards softening the fine-tuning problem. We find the parameter space for the Wilson coefficients that satisfies the extended Veltman condition, and also discuss why one need not bother about the $d>6$ operators. The parameter space is consistent with the theoretical and experimental bounds of the Wilson coefficients and should act as a guide to the model builders.

Partial top quark compositeness is a crucial aspect of theories with strong electroweak symmetry breaking. Together with the heavy top partners that lift the top quark mass to its observed value, these theories predict correlated modifications of the top quark’s electroweak couplings. Associated measurements therefore provide direct constraints on the ultraviolet structure of the underlying hypercolor dynamics. In this paper, we employ a minimal version of top compositeness to discuss how measurements related to the top’s electroweak gauge interactions can inform the potential composite nature of the TeV scale. In doing so, we identify the dominant factors that limit the beyond the Standard Model sensitivity. Extrapolating to a future 100 TeV hadron collider, we demonstrate that top quark measurements performed at highest precision can provide additional information to resonance search by performing a representative resonant top partner search that specifically targets the correlated resonant electroweak top partner signatures.

We investigate the possibility of neutrinoless double beta decay ($0\nu \beta \beta$) and leptogenesis within the alternative left-right model (ALRM). Unlike the usual left-right symmetric model, ALRM features a Majorana right-handed neutrino which does not carry any charge. Further, in this picture the down-type quark and the charged leptons receive mass through the additional left-handed scalar field, rather than the usual doublet. Together, these features conspire to generate significant contributions to the $0\nu \beta \beta$ through vector-scalar ($WH$) mediation. For moderate masses of the relevant charged Higgs boson ($M_{H_1^{\pm }}\sim 200\mathrm{GeV}$), the half-life of $T_{\frac{1}{2}}^{WH}$ is $\sim 3\times {10}^{26}\mathrm{yrs}$ for both the case of ${}^{76}\mathrm{Ge}$ and ${}^{136}\mathrm{Xe}$, well within the sensitivity expected by future experiments. Invoking the resonant leptogenesis, $CP$ violation arising from the right-handed neutrino decay could be the required order to generate the correct baryogenesis, $\epsilon \sim {10}^{-6}$, for small Dirac phases and without any fine tuning.

Many studies for nonequilibrium systems, e.g., the pre-equilibration puzzle in heavy-ion collisions, require solving the relativistic Boltzmann equation (BE) with the full collisional kernel to high precision. It is challenging to solve relativistic BE due to its high dimensional phase-space integrals and limited computing resources. We have developed a numerical framework for a full solution of the relativistic Boltzmann equations for the quark-gluon matter using the multiple graphics processing units (GPUs) on distributed clusters. Including all the $2\to 2$ scattering processes of 3-flavor quarks and gluons, we compute the time evolution of distribution functions in both coordinate and momentum spaces for the cases of pure gluons, quarks, and the mixture of quarks and gluons. By introducing a symmetrical sampling method on GPUs which ensures the particle number conservation, our framework is able to perform the space-time evolution of quark-gluon system toward thermal equilibrium with high performance. We also observe that the gluons naturally accumulate in the soft region at the early time, which may indicate the gluon condensation.

We study neutrino-induced charged-current (CC) ${\pi }^0$ production on carbon nuclei using events with fully imaged final-state proton-${\pi }^0$ systems. Novel use of final-state correlations based on transverse kinematic imbalance enables the first measurements of the struck nucleon’s Fermi motion, of the intranuclear momentum transfer (IMT) dynamics, and of the final-state hadronic momentum configuration in neutrino pion production. Event distributions are presented for (i) the momenta of neutrino-struck neutrons below the Fermi surface, (ii) the direction of missing transverse momentum characterizing the strength of IMT, and (iii) proton-pion momentum imbalance with respect to the lepton scattering plane. The observed Fermi motion and IMT strength are compared to the previous $\mathrm{MINER}\nu \mathrm{A}$ measurement of neutrino CC quasielastic-like production. The measured shapes and absolute rates of these distributions, as well as the cross section asymmetries, show tensions with predictions from current neutrino generator models.

Recently, the standard model predictions for the $B$-meson hadronic decays, ${\overline{B}}^0\to D^{(*)+}{K}^{-}$ and ${\overline{B}}_s^0\to D_s^{(*)+}{\pi }^{-}$, have been updated based on the QCD factorization approach. This improvement sheds light on a novel puzzle in the $B$-meson hadronic decays: there are mild but universal tensions between data and the predicted branching ratios. Assuming the higher-order QCD corrections are not huge enough to solve the tension, we examine several new physics interpretations of this puzzle. We find that the tension can be partially explained by a left-handed $W^{\prime }$ model, which can be compatible with other flavor observables and collider bounds.

We report the first measurement of the charm-mixing parameter $y_{CP}$ in $D^0$ decays to the $CP$-odd final state $K_S^0\omega$. The study uses the full Belle $e^{+}{e}^{-}$ annihilation data sample of $976{\mathrm{fb}}^{-1}$ taken at or near the $\mathrm{\Upsilon }(4S)$ centre-of-mass energy. We find $y_{CP}=(0.96\pm 0.91\pm {0.62}_{-0.00}^{+0.17})\%$, where the first uncertainty is statistical, the second is systematic due to event selection and background, and the last is due to possible presence of $CP$-even decays in the data sample.

We apply the classical double-copy procedure to a class of regular, nonsingular black hole solutions. We give several examples, paying particular attention to a string-theory-corrected black hole solution emerging from T-duality. Nonperturbative stringy corrections introduce an ultraviolet (UV) zero-point length cutoff which results in nonsingular black hole spacetimes. Apart from the UV regulator, the solution is equivalent to the Bardeen black hole spacetime. We extend this solution to include an asymptotic de Sitter background. All Yang-Mills field theory quantities associated with the double copy are well-behaved and finite for all values of parameters. We present a thorough analysis of the black hole horizon structure, additionally uncovering a simple yet new connection between horizons on the gravity side and electric fields on the gauge theory side of the double copy.

We propose a general argument to show that if a physical system can mediate locally the generation of entanglement between two quantum systems, then it itself must be nonclassical. Remarkably, we do not assume any classical or quantum formalism to describe the mediating physical system: our result follows from general information-theoretic principles, drawn from the recently proposed constructor theory of information. This argument provides a broader theoretical basis for recently proposed tests of nonclassicality in gravity, based on witnessing gravitationally induced entanglement in quantum probes, making them applicable in the context where quantum theory may not apply.

We assess the performance of a perturbation theory inspired method for inferring cosmological parameters from the joint measurements of galaxy-galaxy weak lensing ($\mathrm{\Delta }\mathrm{\Sigma }$) and the projected galaxy clustering ($w_p$). To do this, we use a wide variety of mock galaxy catalogs constructed based on a large set of $N$-body simulations that mimic the Subaru HSC-Y1 and SDSS galaxies and apply the method to the mock signals to address whether to recover the underlying true cosmological parameters in the mocks. We find that, as long as the appropriate scale cuts, 12 and $8h^{-1}\mathrm{Mpc}$ for $\mathrm{\Delta }\mathrm{\Sigma }$ and $w_p$, respectively, are adopted, a “minimal-bias” model using the linear bias parameter $b_1$ alone and the nonlinear matter power spectrum can recover the true cosmological parameters (here focused on ${\mathrm{\Omega }}_m$ and ${\sigma }_8$) to within the 68% credible interval, for all the mocks we study, including one in which an assembly bias effect is implemented. This is as expected if physical processes inherent in galaxy formation and evolution are confined to local, small scales below the scale cut and thus implies that real-space observables have an advantage in filtering out the impact of small-scale nonlinear effects in parameter estimation, compared to their Fourier-space counterparts. In addition, we find that a theoretical template including the higher-order bias contributions such as nonlinear bias parameter ($b_2$) does not improve the cosmological constraints, but rather leads to a larger parameter bias compared to the baseline $b_1$ method. Another nontrivial finding is that the cosmological parameters are not necessarily recovered, even when the model prediction is used as the input mock signals, as a consequence of marginalization or projection of asymmetric posterior distributions in a multidimensional parameter space, such as the case of the “banana-shaped” distribution in the $({\mathrm{\Omega }}_m,{\sigma }_8)$ plane. We also study the performance of alternative observables, $\mathrm{\Upsilon }$ or $Y$ statistic, where the same scale cut for both the weak lensing and the galaxy clustering can be employed thanks to their same sensitivity to the Fourier modes, but do not find a promising advantage of these statistics over the fiducial observables $\{\mathrm{\Delta }\mathrm{\Sigma },w_p\}$.

Many modern simulations of accretion disks use moment-based methods for radiation transport to determine the thermal evolution of the disk and the properties of the ejected matter. The popular M1 scheme that evolves the rank-0 and rank-1 moments requires an analytic approximation for the rank-2 and higher tensors. We present the open-source Monte Carlo steady-state general-relativistic neutrino transport code SedonuGR, which we use to assess fundamental analytic closure assumptions, quantify proposed closure errors, and test an extension of the maximum entropy Fermi-Dirac (MEFD) closure to the rank-3 moment. We demonstrate that the fundamental assumptions employed in all analytic closures are strongly violated. This violation is most evident at the interface between the equatorial disk and the evacuated polar regions. Finally, we calculate the neutrino momentum and energy deposition rate from neutrino pair annihilation, and demonstrate that a moment-based annihilation power calculation is accurate to at most $\sim 20\%$ if the rank-2 and higher moments are neglected. Out of a selection of eight closures in the literature, we demonstrate that different closures reproduce different aspects of the radiation field (pressure tensor, rank-3 tensor, pair annihilation rate), though the MEFD, Levermore, and Janka 2 closures are all reasonable. The extra information from the neutrino degeneracy used in the MEFD closure is unable to account for the diversity in the rank-2 and rank-3 moments.