We systematically investigate the S-wave singly heavy tetraquark systems containing two or three strange quarks, $Qs\overline{s}\overline{s}$, $Qn\overline{s}\overline{s}$, and $Qs\overline{s}\overline{n}(Q=c,b,n=u,d)$, within the constituent quark potential model. We solve the four-body Schrödinger equation using the Gaussian expansion method and identify resonances via the complex scaling method. There are no bound states below the lowest two-meson thresholds. We obtain several compact resonances with $J^P=0^{+},2^{+}$ in $Qs\overline{s}\overline{s}$, and $J^P=2^{+}$ in $Qn\overline{s}\overline{s}$ and $Qs\overline{s}\overline{n}$. The pole positions are mainly distributed around 7.0–7.2 GeV (bottom) and 3.7–3.9 GeV (charm), with widths from a few to several tens of MeV. These resonances decay into $D_s{\eta }^{\prime },D_{(s)}^{*}\varphi ,{D_s}^{*}{K}^{*}$, and $D_s^{*}{\overline{K}}^{*}$ (and their bottom counterparts), providing targets for future experimental searches.

The study of nuclear modification factor is crucial in advancing our knowledge of the hot and dense nuclear matter created during high energy heavy-ion collision. In this direction, we have developed a theoretical model for the nuclear modification factor using the Boltzmann transport equation in relaxation time approximation with the $q$-Weibull distribution as the final state distribution and studied the experimental data of nuclear modification factor of charged hadrons as well as identified particles at various energies ranging from 7.7 GeV measured at RHIC up to the maximum value of 5.44 TeV studied in LHC. We observed a good agreement between the model and the experimental data as can be quantified using the ${\chi }^2/NDF$ values. We have also studied the mass dependence of different fit parameters that appears in the theoretical model and observe a linear mass dependence of some parameters.

We study the nonleptonic decays of ${\mathrm{\Omega }}_b\to {\mathrm{\Omega }}_{c}P(V)$ with eight pseudoscalar and vector mesons using the naive factorization approach. We analyze all relevant topologies (the tree-level, color-suppressed, and penguin topologies) of these decays and calculate the decay amplitude for each separately. We determine the decay rates and branching ratios and compare our results with those from other theoretical predictions. The results obtained may be useful for the analysis of the related data in both ongoing and future experiments.

Modern resonant sensing tools can achieve increasingly high quality factors, which correspond to extremely narrow linewidths. In such systems, time variation of the resonator’s natural frequency can potentially impact its ability to accumulate power and its resulting sensitivity. One such example is the Dark SRF experiment, which utilizes superconducting radio frequency (SRF) cavities with quality factors of $Q\sim {10}^{10}$. Microscopic deformations of the cavity lead to stochastic jittering of its resonant frequency with amplitude 20 times its linewidth. Naively, one may expect this to lead to a large suppression in accumulated power. In this work, we study in detail the effects of frequency instability on high-quality resonant systems, utilizing the Dark SRF experiment as a case study. We show that the timescale of jittering is crucial to determining its effect on power accumulation. Namely, when the resonant frequency varies sufficiently quickly, the system accumulates power as if there were no jittering at all. This implies that the sensitivity of a jittering resonator is comparable to that of a stable resonator. In the case of Dark SRF, we find that jittering only induces a $\sim 10\%$ loss in power. Our results allow the dark-photon exclusion bound from Dark SRF’s pathfinder run to be refined, leading to a constraint that is an order of magnitude stronger than previously reported (corresponding to a signal-to-noise ratio that is four orders of magnitude larger). This result represents the world-leading constraint on dark photons over a wide range of masses below $6\mathrm{\mu }\mathrm{eV}$ and translates to the best laboratory-based limits on the photon mass $m_{\gamma }<2.9\times {10}^{-48}\mathrm{g}$.

We propose and evaluate a source-equals-detector search for the deexcitation of the long-lived isomer ${}^{180\mathrm{m}}\mathrm{Ta}$ in natural tantalum (Ta), using a $\gamma$-ray transition-edge-sensor (TES) array. Two capabilities absent in conventional high-purity germanium (HPGe) searches are exploited: (i) near-unity containment of low-energy secondaries [internal-conversion (IC) electrons and characteristic x-rays] and of the nuclear recoil, enabling a calorimetric, event-by-event measurement of the total deposited energy in the absorber; and (ii) a delayed-coincidence tag using the subsequent ${}^{180}\mathrm{Ta}$ electron-capture (EC) decay to ${}^{180}\mathrm{Hf}$. We evaluate the $3\sigma$ discovery reach for IC and for dark-matter (DM)-induced deexcitation in two benchmark scenarios: a strongly interacting DM subcomponent and inelastic DM with off diagonal couplings. Using a background model based on intrinsic radioactivity in the Ta absorber and realistic detector performance, we show that arrays with $N_{\mathrm{TES}}=256$ and 1,000 pixels can reach the theoretically expected IC half-life within 2.6 yr and 0.66 yr, respectively. For an array with $N_{\mathrm{TES}}={10}^4$ and a five-year exposure, the projected sensitivity to DM-induced de-excitation surpasses limits inferred from HPGe nonobservations of ${}^{180\mathrm{m}}\mathrm{Ta}$ and probes regions of parameter space not covered by current direct-detection experiments.

A uniformly accelerated atom in an inertial vacuum generally thermalizes to a Gibbs state, which is known as the Unruh effect. In contrast, for a noninteracting many-body system coupled to a common massless scalar field, we find that thermalization proceeds in multiple stages: the system first attains a prethermal generalized Gibbs state, before eventual relaxation to the thermal Gibbs state. The prethermal state is protected by emergent conserved quantities; hence, the system behaves like a nearly integrable one, which shows a sharp distinction from the Unruh effect. We coin the term “Unruh prethermalization” to characterize this phenomenon. The measure of entanglement is a good estimation of the lifetime of the prethermal state and is consistent with previous studies. Finally, we show that in such a regime, the dynamics show a Dicke superradiance-type radiation burst before reaching the prethermal state. In contrast, only a monoexponential decay is observed for Unruh thermalization. In addition, to highlight the significance of our results, we compare them with existing experimental observations.

Cosmic strings are topological defects arising in a variety of cosmological scenarios, as the Universe undergoes symmetry-breaking phase transitions, whose discovery would offer valuable insight into the high-energy physics that shaped the early Universe. To interpret such a detection, robust theoretical models are essential. The velocity-dependent one-scale (VOS) model is particularly prominent: it self-consistently treats the network as a thermodynamic system, characterizing its key properties, and predicting its large-scale evolution. This has recently been extended to include superconducting cosmic strings, which carry additional degrees of freedom, giving rise to the charge-velocity dependent one-scale (CVOS) model. One limitation of the latter model is that it only included loss mechanisms for the charge and current. Here, we extend this model by phenomenologically including a possible energy source mechanism, specifically by allowing current-carrying strings interactions with an external magnetic field. We discuss how this coupling impacts the network’s evolution, present and classify the physically allowed scaling solutions for this extended CVOS model, and comment on the different impacts of the external magnetic field on the evolution of the network’s charge and current. Under our modeling assumptions, one of the ten physically plausible scaling solution enables the network to gain energy by this mechanism.

We investigate the impact of ultralight dark matter (ULDM) on the mergers of supermassive black holes (SMBH) and the resulting stochastic gravitational wave background. ULDM is based on exceptionally light particles and yields galactic halos with dense central solitons. This increases the drag experienced by binary SMBH, decreasing merger times and potentially suppressing gravitational radiation from the binary at low frequencies. We develop semianalytic models for the decay of SMBH binaries in ULDM halos and use current pulsar timing array (PTA) measurements to constrain the ULDM particle mass and its fractional contribution to the dark matter content of the universe. We find a median ULDM particle mass of $7\times {10}^{-22}\mathrm{eV}$ and show that scaling relations suggest that the drag remains effective at relatively low ULDM fractions, which are consistent with all other constraints on the model. Consequently, future pulsar timing measurements will be a sensitive probe of any ULDM contribution to the overall dark matter content of the Universe.

The violation of the null energy condition (NEC) is essential for constructing nonsingular cosmological scenarios, such as genesis cosmology, which avoids the initial singularity by initiating cosmic evolution from an asymptotically Minkowski state. To address theoretical concerns regarding the accumulation of negative energy, the smeared null energy condition (SNEC) has been proposed as a quantum-motivated, semilocal bound on NEC violation. In this work, we examine the implications of the SNEC conjecture for genesis models, typically constructed within generalized Galileon theories. Our results demonstrate that SNEC imposes nontrivial restrictions on the viability of genesis models, highlighting the SNEC conjecture as a powerful tool for constraining nonsingular cosmological scenarios.

Charting the phase diagram of quantum chromodynamics (QCD) at large density is a challenging task due to the complex action problem in lattice simulations. Through simulations at imaginary baryon chemical potential ${\mu }_B$ we observe that, if the strangeness neutrality condition is imposed, both the strangeness chemical potential ${\mu }_S/{\mu }_B$ and the strangeness susceptibility ${\chi }_2^S$ take on constant values at the chiral transition for varying ${\mu }_B$. We present new lattice data to extrapolate contours of constant ${\mu }_S/{\mu }_B$ or ${\chi }_2^S$ to finite baryon chemical potential. We argue that they are good proxies for the QCD crossover because, as we show, they are only mildly influenced by criticality and by finite volume effects. We obtain continuum limits for these proxies up to ${\mu }_B=400\mathrm{MeV}$, through a next-to-next-to-leading order (${\mathrm{N}}^2\mathrm{LO}$) Taylor expansion based on large-statistics data on ${16}^3\times 8$, ${20}^3\times 10$ and ${24}^3\times 12$ lattices with our 4HEX improved staggered action. We show that these are in excellent agreement with existing results for the chiral transition and, strikingly, also with analogous contours obtained with the hadron resonance gas (HRG) model. On the ${16}^3\times 8$ lattice, we carry out the expansion up to next-to-next-to-next-to-next-to-leading order (${\mathrm{N}}^4\mathrm{LO}$), and extend the extrapolation beyond ${\mu }_B=500\mathrm{MeV}$, again finding perfect agreement with the HRG model. This suggests that the crossover line constructed from this proxy starts deviating from the chemical freeze-out line near ${\mu }_B\approx 500\mathrm{MeV}$, as expected but not yet observed.

Black holes in general relativity exhibit a remarkable feature: their response to static scalar, electromagnetic, and gravitational perturbations—as quantified by the so-called tidal Love numbers—vanishes identically. We present the first exception to this rule: the Love numbers of a black hole perturbed by a fermionic field are nonzero. We derive a closed-form expression of these fermionic Love numbers for generic spin in the background of a Kerr black hole with arbitrary angular momentum. In contrast, we show that the fermionic dissipation numbers vanish for static perturbations, reflecting the absence of superradiance for fermions. These results highlight a fundamental distinction between bosonic and fermionic perturbations, which can be interpreted as a breaking of the hidden symmetries that underlie the vanishing of Love numbers in the bosonic sector.

Axions and axionlike particles have gained immense attention in searches for beyond Standard Model physics. Experiments searching for axions leverage their predicted couplings to Standard Model particles to look for observable signals. Though weak, these couplings allow axions to be produced abundantly in the interiors of stars such as the Sun. Once created, axions can escape the Sun and, while passing through the solar atmosphere, oscillate into photons in the magnetic field, producing x-rays. For the first time, to the best of our knowledge, we use data from the observation of soft x-rays from the quiet Sun during the 2019–2020 solar minimum by the Solar X-ray Monitor, on board India’s Chandrayaan-2 lunar exploration mission, to constrain the coupling of axions to photons ($g_{a\gamma \gamma }$). Using the latest models of the solar atmosphere to calculate the magnetic field and plasma frequency, we constrain $g_{a\gamma \gamma }\lesssim (0.50–2.26)\times {10}^{-10}{\mathrm{GeV}}^{-1}$ at 95% confidence level for axion masses $m_a\lesssim 5\times {10}^{-4}\mathrm{eV}$.

Near-extremal black membranes with topological (baryonic) $U(1{)}_B$ charge of M theory compactified on the coset space $M^{1,1,0}$ are stable. $M^{1,1,0}$ coset is a ${\mathbb{Z}}_2$-invariant truncation of a larger $Q^{1,1,1}$ coset, with diagonal $U(1{)}_B\equiv U(1{)}_{B,+}\subset U(1{)}_B^2$ symmetry of the latter. We show that the baryonic black membranes of M-theory $M^{1,1,0}$ compactifications are unstable to ${\mathbb{Z}}_2$-odd gravitational bulk gauge and scalar fluctuations, but only if this bulk scalar is identified with the holographically dual $2+1$-dimensional superconformal gauge theory operator of conformal dimension $\mathrm{\Delta }=1$. The instability is associated with the unstable charge transport of the off-diagonal $U(1{)}_{B,-}\subset U(1{)}_B^2$ symmetry.

We propose a unified framework within type IIA string theory, based on a globally consistent intersecting D6-brane model compactified on a $T^6/({\mathbb{Z}}_2\times {\mathbb{Z}}_2)$ orientifold. The model realizes the Minimal Supersymmetric Standard Model-like spectrum providing a framework for addressing four fundamental problems: $CP$ violation originates from both geometric phases in Yukawa couplings and nonperturbative phases induced by E2-instantons; the observed baryon asymmetry arises via instanton-mediated operators combined with moduli-driven leptogenesis; the electroweak hierarchy is stabilized through controlled supersymmetry breaking with a TeV-scale gravitino mass near a metastable vacuum; and a de Sitter uplift is achieved via anti-D6-branes in an STU moduli stabilization scheme. Crucially, the interplay of intersecting brane geometry, Euclidean D2-instantons, and flux-induced moduli potentials provides a coherent mechanism linking collider, flavor, and cosmological phenomena.

It was recently established that the paradigmatic Gross-Neveu model with $N$ copies of two-dimensional Dirac fermions features an $\mathrm{SO}(2N)$ symmetry if certain interactions are suppressed. This becomes evident when the theory is rewritten in terms of $2N$ copies of two-dimensional Majorana fermions. Mean-field theory for the $\mathrm{SO}(2N)$ model predicts, besides the chiral Ising transition at $g_{c1}$, a second critical point $g_{c2}$ where $\mathrm{SO}(2N)$ is broken down to $\mathrm{SO}(N)\times \mathrm{SO}(N)$. A subsequent Wilsonian renormalization group analysis directly in $d=3$ supports its existence in a generalized theory, where $N_f$ copies of the $4N$-component Majorana fermions are introduced. This allows us to track the evolution of a (i) quantum anomalous Hall Gross-Neveu-Ising, (ii) symmetric-tensor, and (iii) adjoint-nematic fixed point separately. However, it turns out that (ii) and (iii) lose their criticality when approaching $N_f=1$, suggesting that the transition is first order. In this work, we approach the problem from the lower-critical dimension of two. We construct a Fierz-complete renormalizable Lagrangian, compute the leading order $\beta$ functions, fermion anomalous dimension, as well as the order parameter anomalous dimensions, and resolve the three universality classes corresponding to (i)–(iii). Before becoming equal to the Gaussian fixed point at $N_f=1$, (ii) remains critical for all values of $N_f>N_{f,c}^{\mathrm{ST}}(N)\approx 0.56+1.48N+\mathcal{O}(\epsilon )$, which compares well with the estimate of previous studies. We further find that (iii) becomes equal to (i) when approaching $N_f=1$. An instability is, however, only present in the susceptibility corresponding to the Gross-Neveu-Ising order parameter.

This work examines an early dark energy (EDE) scenario in the context of $F(R)$ gravity. EDE is introduced to alleviate the Hubble tension by temporarily injecting approximately 10% of the energy fraction around the matter-radiation equality epoch ($z\approx {10}^3–{10}^4$). Building on several benchmark models, we focus on the potential-driven EDE scenario and investigate the conditions required within $F(R)$ gravity. We first introduce a dimensionless quantity to analytically visualize the evolution of the density ratio between EDE and other matter components. Considering several examples, we demonstrate that the desired EDE can indeed be realized in $F(R)$ gravity. However, stringent constraints arising from violations of the equivalence principle could exclude the allowed parameter space. Our result provides a generic constraint on the potential-driven EDE in $F(R)$ gravity at the background level. This work also concludes that nonperturbative effects or nontrivial mechanisms are indispensable for studying EDE in $F(R)$ gravity while maintaining compatibility with local tests of gravity.

We study an analog information paradox in acoustic black holes which emerge from the superfluid surrounding a Schwarzschild black hole. The resulting acoustic black hole contains both acoustic horizons and optical horizons, with analog Hawking radiation, i.e., phonons, emitted from the outer acoustic horizon. By using the island formula, we calculate the entanglement entropy of analog Hawking radiation of the acoustic black hole in both nonextremal and extremal cases. In the nonextremal case, the entanglement entropy of phonons follows the Page curve due to the emergence of islands, and it is approximately proportional to the area of the acoustic horizon at late times. In the extremal case, the entanglement entropy of phonons diverges, leading to an ill-defined Page time. Our study verifies the unitarity of the analog gravity system and provides further insight into the connection between the entanglement entropy and the causal structure of spacetime.

The covariant characterization of the existence of gravitational radiation traversing infinity $𝒥$ in the presence of a negative cosmological constant is presented. It is coherent and consistent with the previous characterizations put forward for the cases of non-negative cosmological constant, relying on the properties of the asymptotic super-Poynting vector, or in more transparent terms, based on the intrinsic properties of the flux of tidal energy at infinity. The proposed characterization is fully satisfactory. It can be covariantly typified in terms of boundary data at infinity, and it can also be categorized according to the geometric properties of the rescaled Weyl tensor at $𝒥$. The cases with no incoming radiation entering from (or no outgoing radiation escaping at) $𝒥$ can similarly be determined in terms of the boundary data or geometric properties of the rescaled Weyl tensor. In particular, we identify the most general boundary conditions that, in an initial-boundary value problem, ensure absence of gravitational radiation traversing $𝒥$, namely, (functional) proportionality between the Cotton-York tensor field and the holographic stress tensor field at $𝒥$. We also present novel conditions ensuring the absence of just incoming (outgoing) radiation at $𝒥$. These are given in a covariant way and also in terms of standard rescaled Weyl tensor scalars. The results are compatible with any matter content of the physical spacetime.

Recent advances in noncommutative geometry and string theory have stimulated increasing research on noncommutative gravity. The detection of gravitational waves (GW) opens a new window for testing this theory using observed data. In particular, the leading correction from noncommutative gravity to the GW of compact binary coalescences appears at the second post-Newtonian (2PN) order. This correction is proportional to the dimensionless parameter $\mathrm{\Lambda }\equiv |{\theta }^{0i}|/(l_P{t}_P)$, where ${\theta }^{0i}$ denotes the antisymmetric tensor characterizing noncommutative spacetime, and $l_P$, $t_P$ represent the Plank length and time, respectively. Previous study have used the phase deviation from general relativity at the 2PN order, as measured in GW150914, to constrain noncommutative gravity, resulting in an upper bound of $\sqrt{\mathrm{\Lambda }}\lesssim 3.5$. Another analysis, based on multiple events from the GWTC-1 catalog, has obtained consistent bounds. In this work, we construct the noncommutative gravity waveform in the parametrized post-Einsteinian framework. Based on the IMRPhenomXHM template, we incorporate both the dominant (2, 2) mode and several higher-order modes, including (2, 1), (3, 3), (3, 2), and (4, 4). We first reanalyze the GW150914 with a Bayesian parameter estimation and derive a 95th percentile upper bound on noncommutative gravity, obtaining $\sqrt{\mathrm{\Lambda }}<0.68$. We then analyze GW190814 and obtain an even tighter 95th percentile upper bound of $\sqrt{\mathrm{\Lambda }}<0.46$, which corresponds to a characteristic noncommutative gravity energy scale above $2.2E_P$ or a length scale below $0.46l_P$. This represent the strongest constraint on noncommutative gravity derived from real GW observations to date.

We revisit the near-horizon description of the Kerr space-time in the isolated horizon formalism using a nontwisting null geodesic congruence and eliminate the coordinate and geodesic pathologies that arise when the Carter constant of motion is globally fixed to a single constant. Adopting instead a previously proposed choice of the Carter constant which depends on the polar angle on the horizon, we obtain an analytic construction of the Newman–Penrose tetrad adapted to isolated horizons together with horizon-adapted coordinates in which its defining properties are manifest. We compute the associated curvature scalars and provide initial data on characteristics for the isolated horizon. In addition to an analytical solution, derived by leveraging extensive results on Kerr null geodesics, we develop two complementary series expansions and outline a practical numerical recipe to make the construction readily usable. Relative to earlier treatments, our formulation avoids caustic-induced breakdowns and incomplete coordinate coverage while yielding a detailed description of the Kerr black hole in the isolated horizon approach.