We study the decays ${\overline{B}}^0\to {\overline{K}}^{0}X$, $B^{-}\to K^{-}X$, ${\overline{B}}_s^0\to \eta ({\eta }^{\prime })X$, ${\overline{B}}^0\to {\overline{K}}^{*0}X$, $B^{-}\to K^{*-}X$, ${\overline{B}}_s^0\to \varphi X$, with $X\equiv X(3872)$, from the perspective of the $X(3872)$ being a molecular state made from the interaction of the $D^{*+}{D}^{-},D^{*0}{\overline{D}}^0$, and $\mathrm{c}.\mathrm{c}.$ components. We consider both the external and internal emission decay mechanisms and find an explanation for the ${\overline{K}}^{0}X$ and $K^{-}X$ production rates, based on the mass difference of the charged and neutral $D^{*}\overline{D}$ components. We also find that the internal and external emission mechanisms add constructively in the ${\overline{B}}^0\to {\overline{K}}^{0}X$, $B^{-}\to K^{-}X$ reactions, while they add destructively in the case of ${\overline{B}}^0\to {\overline{K}}^{*0}X$, $B^{-}\to K^{*-}X$ reactions. This feature explains the decay widths of the present measurements and allows us to make predictions for the unmeasured modes of ${\overline{B}}_s^0\to \eta ({\eta }^{\prime })X(3872)$ and $B^{-}\to K^{*-}X(3872)$. The future measurement of these decay modes will help us get a better perspective on the nature of the $X(3872)$ and the mechanisms present in production reactions of that state.

The scaling property of large-$p_{\perp }$ hadron suppression, $R_{\mathrm{AA}}(p_{\perp })$, measured in heavy ion collisions at the relativistic heavy ion collider and at the large hadron collider (LHC) leads to the determination of the average parton energy loss $⟨\epsilon ⟩$ in quark-gluon plasma produced in a variety of collision systems and centrality classes. Relating $⟨\epsilon ⟩$ to the particle multiplicity and collision geometry allows for probing the dependence of parton energy loss on the path length $L$. We find that $⟨\epsilon ⟩\propto L^{\beta }$ with $\beta ={1.02}_{-0.06}^{+0.09}$, which is consistent with the perturbative quantum chromodynamics expectation of parton energy loss in a longitudinally expanding quark-gluon plasma. We then demonstrate that the azimuthal anisotropy coefficient divided by the collision eccentricity, $v_2/\mathrm{e}$, follows the same scaling property as $R_{\mathrm{AA}}$. This scaling is observed in data, which are reproduced by the model at large $p_{\perp }$. Finally, a linear relationship between $v_2/\mathrm{e}$ and the logarithmic derivative of $R_{\mathrm{AA}}$ is found and confirmed in data, offering an additional way to probe the $L$ dependence of parton energy loss using coming measurements from LHC run 3.

In semiclassical gravity, the vacuum expectation value $⟨\widehat{N}⟩$ of the particle number operator for a quantum field gives rise to the perception of thermal radiation in the vicinity of a black hole. This Hawking effect has been examined only for observers asymptotically far from a Kerr black hole; here we generalize the analysis to various classes of freely falling observers both outside and inside the Kerr event horizon. Of note, we find that the effective temperature of the $⟨\widehat{N}⟩$ distribution remains regular for observers at the event horizon but becomes negative and divergent for observers reaching the (Cauchy) inner horizon. Furthermore, the perception of Hawking radiation varies greatly for different classes of observers, though the spectrum is generally a graybody that decreases in intensity with black hole spin and increases in temperature when looking toward the edges of the black hole shadow.

In this paper, we study the linearized gravity theory in the near horizon region of the Schwarzschild black hole in four dimensional spacetime. Under the Newman-Unti gauge, we derive the most general near horizon symmetry and solution space without any near horizon fall-off condition. There are four towers of surface charges that are generic functions on the horizon associated to the near horizon symmetry. With suitable near horizon fall-off conditions, we reveal a soft graviton theorem from the Ward identity of the near horizon supertranslation in both coordinates space and momentum space.

Black hole spectroscopy is a clean and powerful tool to test gravity in the strong-field regime and to probe the nature of compact objects. Next-generation ground-based detectors, such as the Einstein Telescope and Cosmic Explorer, will observe thousands of binary black hole mergers with large signal-to-noise ratios, allowing for accurate measurements of the remnant black hole quasinormal mode frequencies and damping times. In previous work we developed an observable-based parametrization of the quasinormal mode spectrum of spinning black holes beyond general relativity (parspec). In this paper we use this parametrization to ask the following question: can next-generation detectors detect or constrain deviations from the Kerr spectrum by stacking multiple observations of binary mergers from astrophysically motivated populations? We focus on two families of tests: (i) agnostic (null) tests, and (ii) theory-based tests, which make use of quasinormal frequency calculations in specific modified theories of gravity. We consider in particular two quadratic gravity theories (Einstein-scalar-Gauss-Bonnet and dynamical Chern-Simons gravity) and various effective field theory-based extensions of general relativity. We find that robust inference of hypothetical corrections to general relativity requires pushing the slow-rotation expansion to high orders. Even when high-order expansions are available, ringdown observations alone may not be sufficient to measure deviations from the Kerr spectrum for theories with dimensionful coupling constants. This is because the constraints are dominated by “light” black hole remnants, and only few of them have sufficiently high signal-to-noise ratio in the ringdown. Black hole spectroscopy with next-generation detectors may be able to set tight constraints on theories with dimensionless coupling, as long as we assume prior knowledge of the mass and spin of the remnant black hole.

We compute the gravitational wave (GW) spectrum sourced by the sound waves produced during a first-order phase transition in the radiation-dominated epoch. The correlator of the velocity field perturbations is evaluated in accordance with the sound shell model. In our derivation we include the effects of the expansion of the Universe, which are relevant in particular for sourcing processes whose time duration is comparable with the Hubble time. Our results show a causal growth of the GW spectrum at small frequencies, ${\mathrm{\Omega }}_{\mathrm{GW}}\sim k^3$, possibly followed by a linear regime ${\mathrm{\Omega }}_{\mathrm{GW}}\sim k$ at intermediate $k$, depending on the phase transition parameters. Around the peak, we find a steep growth that approaches the $\sim k^9$ scaling previously found within the sound shell model. The resulting bump around the peak of the GW spectrum may represent a distinctive feature of GWs produced from acoustic motion. Nothing similar has been observed for vortical (magneto)hydrodynamic turbulence. Nevertheless, we find that the $\sim k^9$ scaling is less extended than expected in the literature, and it does not necessarily appear. The dependence on the duration of the source, $\delta {\tau }_{\mathrm{fin}}$, is quadratic at small frequencies $k$, and proportional to ${\ln }^2(1+\delta {\tau }_{\mathrm{fin}}{\mathcal{H}}_{*})$ for an expanding universe. At frequencies around the peak, the growth is suppressed by a factor $\mathrm{\Upsilon }=1-1/(1+\delta {\tau }_{\mathrm{fin}}{\mathcal{H}}_{*})$ that becomes linear when the GW source is short. We discuss in which cases the dependence on the source duration is linear or quadratic for stationary processes. This affects the amplitude of the GW spectrum, both in the causality tail and at the peak, showing that the assumption of stationarity is a very relevant one, as far as the GW spectral shape is concerned. Finally, we present a general semianalytical template of the resulting GW spectrum, as a function of the parameters of the phase transition.

Observations of the millimeter sky contain valuable information on a number of signals, including the blackbody cosmic microwave background (CMB), Galactic emissions, and the Compton-$y$ distortion due to the thermal Sunyaev-Zel’dovich (tSZ) effect. Extracting new insight into cosmological and astrophysical questions often requires combining multiwavelength observations to spectrally isolate one component. In this work, we present a new arc-minute-resolution Compton-$y$ map, which traces out the line-of-sight-integrated electron pressure, as well as maps of the CMB in intensity and E-mode polarization, across a third of the sky (around $13,000{\mathrm{deg}}^2$). We produce these through a joint analysis of data from the Atacama Cosmology Telescope (ACT) data release 4 and 6 at frequencies of roughly 93, 148, and 225 GHz, together with data from the Planck satellite at frequencies between 30 and 545 GHz. We present detailed verification of an internal linear combination pipeline implemented in a needlet frame that allows us to efficiently suppress Galactic contamination and account for spatial variations in the ACT instrument noise. These maps provide a significant advance, in noise levels and resolution, over the existing Planck component-separated maps and will enable a host of science goals including studies of cluster and galaxy astrophysics, inferences of the cosmic velocity field, primordial non-Gaussianity searches, and gravitational lensing reconstruction of the CMB.

We present a significant extension of the quark-mass density-dependent model (QMDDM), initially revised in our prior study [Phys. Rev. D 107, 043025 (2023)], where thermodynamic inconsistencies were addressed. Our current work enriches the QMDDM by incorporating excluded volume effects, as a step toward a more realistic representation of the quark matter equation of state (EOS) at zero temperature. We introduce the concept of “available volume” in the Helmholtz free energy formulation, accounting for the space excluded by each quasiparticle due to its finite size or repulsive interactions. We present a methodology to modify the EOS for pointlike particles, allowing for a simple and direct incorporation of excluded volume effects. This is first addressed in a simple one-flavor model and then extended to a more realistic three-flavor system, incorporating both mass and volume dependencies on the baryon number density. We examine various Ansätze for the excluded volume, ultimately adopting one that aligns with the asymptotic freedom behavior of quantum chromodynamics. The EOS for electrically neutral systems in chemical equilibrium is computed, focusing on self-bound and hybrid matter scenarios. We show that the incorporation of excluded volume effects renders the EOS stiffer and that excluded volume effects are essential to align the mass-radius relation of self-bound and hybrid stars with modern astrophysical constraints.

In this paper, we put forward a connection between the self-interacting dark matter and the Dirac nature of neutrinos. Our exploration involves a $Z_4\otimes Z_4^{\prime }$ discrete symmetry, wherein the Dirac neutrino mass is produced through a type-I seesaw mechanism. This symmetry not only contributes to the generation of the Dirac neutrino mass but also facilitates the realization of self-interacting dark matter with a light mediator that can alleviate small-scale anomalies of the $\mathrm{\Lambda }\mathrm{CDM}$ while being consistent with the latter at large scales, as suggested by astrophysical observations. Thus the stability of the DM and Dirac nature of neutrinos are shown to stem from the same underlying symmetry. The model also features additional relativistic degrees of freedom $\mathrm{\Delta }{N}_{\mathrm{eff}}$ of either thermal or nonthermal origin, within the reach of cosmic microwave background (CMB) experiment providing a complementary probe in addition to the detection prospects of DM.

The effective field theory (EFT) framework is a precise approximation procedure when the inherent assumptions of a large-scale separation between the Standard Model (SM) and new interactions alongside perturbativity are realized. Constraints from available data might not automatically guarantee these circumstances when contrasted with UV scenarios that the EFT analysis wishes to inform. From an EFT perspective, achieving sufficient precision in navigating the alignment or decoupling limits beyond the SM scenarios can necessitate moving beyond the SM’s leading, dimension six EFT deformation. Using the example of Higgs boson mixing, we demonstrated the importance of higher-dimensional terms in the EFT expansion. We analyze the relevance of virtual EFT corrections and dimension eight contributions for well-determined electroweak precision observables. We find that when moving away from the decoupling limit, the relevance of additional terms in the EFT expansion quickly becomes relevant. This demonstrates the necessity to move beyond dimension six interactions for any scenario that contains Higgs boson mixing.

We present a recursive quantum mechanical model for the fragmentation of a string stretched between a quark and an antiquark with entangled spin states. The quarks are assumed to be produced in the $e^{+}{e}^{-}$ annihilation process via the exchange of a virtual photon and the correlations between their spin states are described by a joint spin-density matrix. The string fragmentation process is formulated at the amplitude level by using the splitting matrices of the recent $\mathrm{string}+{{}^{3}P}_0$ model of polarized quark fragmentation with pseudoscalar and vector meson emissions and accounts for the systematic propagation of the spin correlations in the fragmentation chain. The model is formulated as a recursive recipe suitable for a Monte Carlo implementation. It reproduces the expected angular correlation, due to the Collins effect, between back-to-back pseudoscalar and/or vector mesons. For the latter, this correlation also involves the momenta of the decay products. We use the model for studying the sign of the Collins asymmetry for back-to-back vector and pseudoscalar mesons.

In this work, the $\gamma \to 3\pi$ form factor is calculated within the Dyson-Schwinger equations framework using a contact interaction model within the so-called modified rainbow ladder truncation. The present calculation takes into account the pseudovector component in the pion Bethe-Salpeter amplitude (BSA) and $\pi -\pi$ scattering effects, producing a $\gamma \to 3\pi$ anomaly that is $1+6{\mathcal{R}}_{\pi }^2$ larger than the low energy prediction. Here ${\mathcal{R}}_{\pi }$ is the relative ratio of the pseudovector and pseudoscalar components in the pion BSA; with our parameters’ input, this correction raises the $\gamma \to 3\pi$ anomaly by around 10%. The main outcome of this work is the unveiling of the origin of such a correction, which could be a possible explanation of the discrepancy between the existing experimental data and the low energy prediction. Moreover, it is highlighted how the magnitude of the anomaly is affected in effective theories that require an irremovable ultraviolet cutoff. We find that for both the anomalous processes $\pi \to 2\gamma$ and $\gamma \to 3\pi$, the missing contribution to the anomaly can be compensated by the additional structures related with the quark anomalous magnetic moment.

We report measurements of radon progeny in liquid argon within the MicroBooNE time projection chamber (LArTPC). The presence of specific radon daughters in MicroBooNE’s 85 metric tons of active liquid argon bulk is probed with newly developed charge-based low-energy reconstruction tools and analysis techniques to detect correlated ${}^{214}\mathrm{Bi}\text{−}{}^{214}\mathrm{Po}$ radioactive decays. Special datasets taken during periods of active radon doping enable new demonstrations of the calorimetric capabilities of single-phase neutrino LArTPCs for $\beta$ and $\alpha$ particles with electron-equivalent energies ranging from 0.1 to 3.0 MeV. By applying ${}^{214}\mathrm{Bi}\text{−}{}^{214}\mathrm{Po}$ detection algorithms to data recorded over a 46-day period, no statistically significant presence of radioactive ${}^{214}\mathrm{Bi}$ is detected, and a limit on the activity is placed at $<0.35\mathrm{mBq}/\mathrm{kg}$ at the 95% confidence level. This bulk ${}^{214}\mathrm{Bi}$ radiopurity limit—the first ever reported for a liquid argon detector incorporating liquid-phase purification—is then further discussed in relation to the targeted upper limit of $1\mathrm{mBq}/\mathrm{kg}$ on bulk ${}^{222}\mathrm{Rn}$ activity for the DUNE neutrino detector.

In this article, we point out that to solve the null Raychaudhuri equation for higher-dimensional spacetime with an accelerating FRW solution in external directions and static compact internal directions, it is necessary to violate the strong-energy condition in higher dimensions. This constraint is well-known in obtaining accelerating cosmological solutions in string compactification, first described by Gibbons-Maldacena-Nunez. In deriving this constraint, we do not make any assumptions regarding the matter content.

We study the effects of conservation laws on wormholes that are made traversable by a double trace deformation. After coupling the two asymptotic boundaries of a maximally extended ($d+1$)-dimensional black brane geometry with $U(1)$ conserved current operators, we find that the quantum matter stress-energy tensor of the corresponding bulk gauge fields in the hydrodynamic limit violates the averaged null energy condition, rendering the wormhole traversable. Applying our results to axionic two-sided black hole solutions, we discuss how the wormhole opening depends on the charge diffusion constant, how this affects the amount of information that can be sent through the wormhole, and possible implications for many-body quantum teleportation protocols involving conserved current operators.

In the past decade, we have seen an unprecedented progress in our ability of testing general relativity in the strong field regime with black hole observations. Most studies have focused on the so-called tests of the Kerr hypothesis: they have tried to verify whether the spacetime geometry around black holes is described by the Kerr solution as expected in general relativity. One can follow either a theory-specific analysis or an agnostic approach. Each strategy has its advantages and disadvantages. In this work, we study the ability of agnostic x-ray tests of the Kerr hypothesis to discover new physics. We simulate x-ray observations of bright Galactic black holes of specific theories of gravity and we analyze the simulated data with a reflection model employing the correct theory of gravity and another reflection model for agnostic tests of the Kerr hypothesis. Our results suggest that agnostic x-ray tests are valid tools to discover new physics, but their constraining power may be lower than a theory-specific analysis.

We match scattering amplitudes in point particle effective field theory (EFT) and general relativity to extract low frequency dynamical tidal responses of rotating (Kerr) black holes to all orders in spin. In the conservative sector, we study local worldline couplings that correspond to the time-derivative expansion of the black hole tidal response function. These are dynamical (frequency-dependent) generalizations of the static Love numbers. We identify and extract couplings of three types of subleading local worldline operators: the curvature time derivative terms, the spin-curvature time derivative couplings, and quadrupole-octupole mixing operators that arise due to the violation of spherical symmetry. The first two subleading couplings are nonzero and exhibit a classical renormalization group running; we explicitly present their scheme-independent beta functions. The conservative mixing terms, however, vanish as a consequence of vanishing static Love numbers. In the nonconservative sector, we match the dissipation numbers at next-to-leading and next-to-next-to leading orders in frequency. In passing, we identify terms in the general relativity absorption probabilities that originate from tails and short-scale logarithmic corrections to the lowest order dissipation contributions.

General relativity’s prediction that all black holes are described by the Kerr metric, irrespective of their size, can now be empirically tested using electromagnetic observations of supermassive black holes and gravitational waves from mergers of stellar-mass black holes. In this work, we focus on the electromagnetic side of this test and quantify the constraining power of very-long-baseline-interferometry (VLBI) observations of emission generated by hot gas surrounding supermassive black holes. We demonstrate how to use lensing bands—annular regions on the observer’s screen surrounding the critical curve—to constrain the underlying spacetime geometry. Contingent upon a detection of a lensed VLBI feature, the resulting lensing-band framework allows us to exclude spacetimes for which said feature cannot arise from geodesics that traversed the equatorial plane more than once. Focusing on the first indirect image and tests of black-hole uniqueness, we employ a parametrized spacetime as a case study. We find that resolving geometric information that goes beyond the apparent size of the critical curve has the potential to lift degeneracies between different spacetime parameters. Our work thereby quantifies a conservative estimate of the constraining power of VLBI measurements and contributes to a larger effort to simultaneously constrain geometry and astrophysics.

We study the compact binary dynamics in the post-Newtonian approach implemented to the Einstein-Hilbert action adding the cosmological constant $\mathrm{\Lambda }$ at first post-Newtonian (1PN) order. We consider very small values of $\mathrm{\Lambda }$ finding that it plays the role of a PN factor to derive the Lagrangian of a compact two-body system at the center of mass frame at 1PN. Furthermore, the phase function $\varphi (t)$ is obtained from the balance equation, and the two polarizations $h_{+}$ and $h_{\times }$ are also calculated. We observe changes due to $\mathrm{\Lambda }$ only at very low frequencies, and we notice that it plays the role of “stretch” the spacetime such that both amplitudes become smaller. However, given its nearly negligible value, $\mathrm{\Lambda }$ has no relevance at higher frequencies whatsoever.

The Milky Way dwarf spheroidal satellite galaxies (dSphs) are particularly intriguing targets to search for gamma rays from weakly interacting massive particle dark matter (DM) annihilation or decay. They are nearby, DM-dominated, and lack significant emission from standard astrophysical processes. Previous studies using the Fermi-Large Area Telescope (LAT) of DM-induced emission from dSphs have provided the most robust and stringent constraints on the DM annihilation cross section and mass. We report here an analysis of the Milky Way dSphs using over 14 years of LAT data along with an updated census of dSphs and $J$-factor estimates. While no individual dSphs are significantly detected, we do find slight excesses with respect to background at the $\gtrsim 2\sigma$ local significance level in both tested annihilation channels ($b\overline{b}$, ${\tau }^{+}{\tau }^{-}$) for seven of the dSphs. We do not find a significant DM signal from the combined likelihood analysis of the dSphs ($s_{\text{global}}\sim 0.5\sigma$), yet a marginal local excess relative to background at a $2–3\sigma$ level is observed at a DM mass of $M_{\chi }=150–230\mathrm{GeV}$ ($M_{\chi }=30–50\mathrm{GeV}$) for DM annihilation into $b\overline{b}$ (${\tau }^{+}{\tau }^{-}$). Given the lack of a significant detection, we place updated constraints on the $b\overline{b}$ and ${\tau }^{+}{\tau }^{-}$ annihilation channels that are generally consistent with previous recent results. As in past studies, tension is found with some weakly interacting massive particle DM interpretations of the Galactic Center Excess, though the limits are consistent with other interpretations given the uncertainties of the Galactic DM density profile and Galactic Center Excess systematics. Based on conservative assumptions of improved sensitivity with increased Fermi-LAT exposure time and moderate increases in the sample of Milky Way dSphs, we project that the local $\sim 2\sigma$ signal, if real, could approach the $\sim 4\sigma$ local confidence level with additional $\sim 10\mathrm{years}$ of observation.