The bubble wall velocity in the first-order phase transition plays an important role in determining both the amplitude and the pivot frequency of stochastic gravitational wave background. In the framework of the minimal left-right symmetric model, we study the wall velocity when the first-order phase transition can occur. The wall velocity can be determined by matching the distribution functions in the free particle approximation and the local thermal equilibrium approximation. It is found that the wall velocity can be determined in the range $0.2<v_w<0.5$ for the parameter space with the first-order phase transition. It is also found that for the case when the wall velocity is close to the speed of sound, the peak amplitude of gravitational wave spectrum can be larger than that in the runaway case. Moreover, It is also found that there exists an approximate power law between the wall velocity and pressure difference between broken and symmetry phases, and the power index is equal to 0.41 or so.

In a broad class of theories, the accumulation of ultralight dark matter (ULDM) with particles of mass ${10}^{-22}\mathrm{eV}<m_{\varphi }<1\mathrm{eV}$ leads to the formation of long-lived bound states known as boson stars. When the ULDM exhibits self-interactions, prodigious bursts of energy carried by relativistic bosons are released from collapsing boson stars in bosenova explosions. We extensively explore the potential reach of terrestrial and space-based experiments for detecting transient signatures of emitted relativistic bursts of scalar particles, including ULDM coupled to photons, electrons, and gluons, capturing a wide range of motivated theories. For the scenario of relaxion ULDM, we demonstrate that upcoming experiments and technology such as nuclear clocks as well as space-based interferometers will be able to sensitively probe orders of magnitude in the ULDM coupling-mass parameter space, challenging to study otherwise, by detecting signatures of transient bosenova events. Detection of a bosenova event may also give information about microphysics properties of $\varphi$ that would otherwise be difficult with typical direct detection methods. Our analysis can be readily extended to different scenarios of relativistic scalar particle emission.

We analyze the capability of the DarkQuest proton beam-dump experiment at Fermilab to discover new light resonances decaying into photons. As an example model, we focus on muon-philic scalar particles that decay to photons. This is one of the few minimal models that can address the $(g-2{)}_{\mu }$ anomaly at low mass. These scalars can be copiously produced by meson decays and muon bremsstrahlung. We point out that thanks to DarkQuest’s compact geometry, muons can propagate through the dump and efficiently produce dark scalars near the end of the dump. This mechanism enables DarkQuest to be sensitive to both long-lived and prompt scalars. At the same time, diphoton signatures are generically not background free, and we discuss in detail the different sources of background and strategies to mitigate them. We find that the backgrounds can be sufficiently reduced for DarkQuest to test currently viable $(g-2{)}_{\mu }$ parameter space.

Binder-cumulant analysis of the critical point in the heavy-quark region of QCD is performed by Monte-Carlo simulations with the hopping-parameter expansion at $N_t=6$. We extend our previous analysis at $N_t=4$ to finer lattices and perform high-precision analyses on large spatial volumes up to the aspect ratio $LT=N_s/N_t=18$. Higher order terms in the hopping-parameter expansion are incorporated effectively up to 14th order. The numerical results show that the violation of the finite-size scaling becomes more prominent on the finer lattice at a given aspect ratio.

We present the first nonperturbative large $N$ calculation of the $\mathcal{N}=1$ supersymmetric $\mathrm{SU}(N)$ Yang-Mills gluino condensate obtained by means of numerical simulations of the lattice-discretized theory, exploiting large-$N$ twisted volume reduction. We present two different determinations based, respectively, on the Banks-Casher formula and on the Gell-Mann–Oakes–Renner relation, both giving perfectly consistent results. By expressing the lattice results in the Novikov-Shifman-Vainshtein-Zakharov (NSVZ) scheme, we are able for the first time to compare numerical and analytic computations. Our most accurate determination of the renormalization group invariant (RGI) gluino condensate gives ${\mathrm{\Sigma }}_{\mathrm{RGI}}/{\mathrm{\Lambda }}_{\mathrm{NSVZ}}^3=[1.18(08{)}_{\mathrm{stat}}(12{)}_{\mathrm{syst}}{]}^3=1.64(33{)}_{\mathrm{stat}}(50{)}_{\mathrm{syst}}=1.64(60)$, in agreement with the $N$ dependence and the value predicted by the weak coupling instanton-based approach ${\mathrm{\Sigma }}_{\mathrm{RGI}}/{\mathrm{\Lambda }}_{\mathrm{NSVZ}}^3=1$.

We study the renormalization of four-quark operators in one-loop perturbation theory. We employ a coordinate-space gauge-invariant renormalization scheme (GIRS), which can be advantageous compared to other schemes, especially in nonperturbative lattice investigations. From our perturbative calculations, we extract the conversion factors between GIRS and the modified minimal subtraction scheme ($\overline{\mathrm{MS}}$) at the next-to-leading order. As a by-product, we also obtain the relevant anomalous dimensions in the GIRS scheme. A formidable issue in the study of the four-quark operators is that operators with different Dirac matrices mix among themselves upon renormalization. We focus on both parity-conserving and parity-violating four-quark operators, which change flavor numbers by two units ($\mathrm{\Delta }F=2$). The extraction of the conversion factors entails the calculation of two-point Green’s functions involving products of two four-quark operators, as well as three-point Green’s functions with one four-quark and two bilinear operators. The significance of our results lies in their potential to refine our understanding of QCD phenomena, offering insights into the precision of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and shedding light on the nonperturbative treatment of complex mixing patterns associated with four-quark operators.

In this work we continue our efforts to study the existence of a phase with an inhomogeneous, i.e., spatially varying, chiral condensate in QCD. To this end we employ a previously established method of stability analysis of the two-particle irreducible effective action in a truncation that corresponds to a rainbow-ladder approximation of the quark-gluon interaction of QCD. If the analysis is restricted to homogeneous phases, the phase diagram features a first-order chiral transition in the lower-temperature regime. Performing the stability analysis along the lower-chemical-potential border of the corresponding spinodal region, we find that below a certain temperature the homogeneous chirally symmetric solution is unstable against inhomogeneous condensation. We argue that this instability may persist to chemical potentials above the homogeneous first-order phase boundary, in which case it signals the existence of an inhomogeneous ground state. Our methodology is also applicable for more sophisticated truncations of the QCD effective action.

In this work, we investigate the hidden charm decays properties of $Y(4626)$, where $Y(4626)$ is assigned as a $S-$wave $D_s^{*+}{D}_{s1}(2536{)}^{-}$ molecular state with $J^{PC}=1^{--}$. The partial widths of the processes $Y(4626)\to J/\psi \eta$, $J/\psi {\eta }^{\prime }$, ${\eta }_c\varphi$, and ${\chi }_{cJ}\varphi ,(J=\{0,1,2\})$ are estimated by employing the effective Lagrangian approach. The present estimations indicate that the partial widths of the $J/\psi \eta$ and $J/\psi {\eta }^{\prime }$ channels are of the order of 1 MeV, while the one of ${\chi }_{c1}\varphi$ is of the order of 0.1 MeV. Thus, we propose to further examine the molecular interpretation of $Y(4626)$ by searching it in the cross sections for the $e^{+}{e}^{-}\to J/\psi {\eta }^{(\prime )}$ processes, which should be accessible by the BES III and Belle II.

The MUonE experiment is designed to extract the hadronic contribution to the electromagnetic coupling in the spacelike region $\mathrm{\Delta }{\alpha }_{\mathrm{had}}(t)$ from elastic $e\mu$ scattering. The leading-order hadronic vacuum polarization contribution to the muon $g-2$, $a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$, can then be obtained from a weighted integral over $\mathrm{\Delta }{\alpha }_{\mathrm{had}}(t)$. This, however, requires knowledge of $\mathrm{\Delta }{\alpha }_{\mathrm{had}}(t)$ in the whole domain of integration, which cannot be achieved by experiment. In this work, we propose to use Padé and D-Log Padé approximants as a systematic and model-independent method to fit and reliably extrapolate the future MUonE experimental data, extracting $a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$ with a conservative but competitive uncertainty, using no or very limited external information. The method relies on fundamental analytic properties of the two-point correlator underlying $a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$ and provides lower and upper bounds for the result for $a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$. We demonstrate the reliability of the method using toy datasets generated from a model for $\mathrm{\Delta }{\alpha }_{\mathrm{had}}(t)$ reflecting the expected statistics of the MUonE experiment.

We revisit the neutron lifetime puzzle, a discrepancy between beam and bottle measurements of the weak neutron decay. Since both types of measurements are realized at different times after the nuclear production of free neutrons, we argue that the existence of excited states could be responsible for the different lifetimes. We elaborate on the required properties of such states and under what circumstances it is possible that these states have not been experimentally identified yet.

Four-dimensional all-loop amplitudes in quantum electrodynamics and gravity exhibit universal IR singularities with a factorization structure. This structure is governed by tree amplitudes and a universal IR-divergent factor representing the exchange of soft particles between external lines. This Letter offers a precise dual interpretation of these universal IR-divergent factors within celestial holography. Considering the tree amplitude as the foundation of the celestial conformal field theory (CCFT), these universal factors correspond to marginal deformations with a double-current construction in the CCFT. Remarkably, a novel geometric representation of these deformations through topological gauging provides an exact description of transitions within bulk vacuum moduli spaces which extends the celestial holography beyond the perturbative level. Our findings establish a concrete dictionary for celestial holography and offer a holographic lens to understand loop corrections in scattering amplitudes.

Recent work has shown that the quasinormal mode spectrum of black holes is unstable under small perturbations (of order $\epsilon$) of the radial potential, while the early time-domain ringdown waveform is only marginally affected. In this paper we provide further insight into the apparent tension between the frequency-domain and the time-domain descriptions by analyzing the scattering properties of the problem. In the frequency domain, we study analytically the solutions corresponding to the perturbed potential. We show that there are two qualitatively different classes of instabilities, and that both Schwarzschild and Kerr black holes are affected by what we call a “type II” instability, i.e., an exponential migration of the mode frequencies away from their unperturbed value as the perturbing “bump” moves away from the peak of the unperturbed potential. In the time domain, we elucidate the effect of the spectral instability in terms of the causal structure of the Green’s function. By using an equivalent scattering problem, we confirm analytically (and show numerically) that the deviation from the unperturbed waveform in the early ringdown stage is proportional to $\epsilon$ when $\epsilon \lesssim {10}^{-2}$.

Recently, several new experimental results of the test of lepton flavor universality (LFU) in $B\to D^{(*)}$ semileptonic decays were announced: the first result of $R_D$ from the LHCb run 1 data, the first results of $R_D$ and $R_{D^{*}}$ from the LHCb run 2 data, and the first result of $R_{D^{*}}$ from the Belle II collaboration. Including these new data, a global analysis still prefers the violation of the LFU between the tau and light leptons. A new world average of the data from the BABAR, LHCb, Belle, and Belle II collaborations is $R_D=0.342\pm 0.026$ and $R_{D^{*}}=0.287\pm 0.012$. Including this new data, we update a circumstance of the $b\to c\tau \overline{\nu }$ measurements and their implications for new physics (NP). Incorporating recent developments for the $B\to D^{(*)}$ form factors in the Standard Model, we observe a $4.4\sigma$ deviation from the Standard Model prediction. Our updates also include model-independent NP formulas for the related observables and the global fittings of parameters for leptoquark scenarios as well as single NP operator scenarios. Furthermore, we show future potential to indirectly distinguish different NP scenarios with the use of the precise measurements of the polarization observables in $B\to D^{(*)}\tau \overline{\nu }$ at the Belle II and the high-$p_{\mathrm{T}}$ flavored-tail searches at the LHC. We also discuss an impact on the LFU violation in $\mathrm{\Upsilon }\to l^{+}{l}^{-}$.

We analyze the gauge fixing precision dependence of some nonlocal quark-bilinear lattice operators interesting in computing parton physics for several measurements, using five lattice spacings ranging from 0.032 to 0.121 fm. Our results show that gauge-dependent nonlocal measurements are significantly more sensitive to the precision of gauge fixing than anticipated. The impact of imprecise gauge fixing is significant for fine lattices and long distances. For instance, even with the typically defined precision of Landau gauge fixing of ${10}^{-8}$, the deviation caused by imprecise gauge fixing can reach 12%, when calculating the trace of Wilson lines at 1.2 fm with a lattice spacing of approximately 0.03 fm. Similar behavior has been observed in $\xi$ gauge and Coulomb gauge as well. For both quasi-parton-distribution functions (quasi-PDFs) and quasi-transverse-momentum-dependent PDFs operators renormalized using the regularization independent momentum subtraction (RI/MOM) scheme, convergence for different lattice spacings at long distance is only observed when the precision of Landau gauge fixing is sufficiently high. To describe these findings quantitatively, we propose an empirical formula to estimate the required precision.

A distinct feature of Hermitian quantum chaotic dynamics is the exponential increase of certain out-of-time-order correlation (OTOC) functions around the Ehrenfest time with a rate given by a Lyapunov exponent. Physically, the OTOCs describe the growth of quantum uncertainty that crucially depends on the nature of the quantum motion. Here, we employ the OTOC in order to provide a precise definition of dissipative quantum chaos. For this purpose, we compute analytically the Lyapunov exponent for the vectorized formulation of the large-$q$ limit of a $q$-body Sachdev-Ye-Kitaev model coupled to a Markovian bath. These analytic results are confirmed by an explicit numerical calculation of the Lyapunov exponent for several values of $q\ge 4$ based on the solutions of the Schwinger-Dyson and Bethe-Salpeter equations. We show that the Lyapunov exponent decreases monotonically as the coupling to the bath increases and eventually becomes negative at a critical value of the coupling signaling a transition to a dynamics which is no longer quantum chaotic. Therefore, a positive Lyapunov exponent is a defining feature of dissipative many-body quantum chaos. The observation of the breaking of the exponential growth for sufficiently strong coupling suggests that dissipative quantum chaos may require in certain cases a sufficiently weak coupling to the environment.

We demonstrate that strings near the horizon of a Schwarzschild black hole, when viewed by a stationary observer at infinity, probe a string Carroll geometry, where the effective light speed is given by the distance from the horizon. We expand the Polyakov action in powers of this light speed to find a theory of Carrollian strings. We show that the string shrinks to a point to leading order near the horizon, which follows a null geodesic in a two-dimensional Rindler space. At the next-to-leading order the string oscillates in the embedding fields associated with the near-horizon two-sphere.

In the framework of the analog Hawking radiation for dielectric media, we analyze a toy model and also the 2D reduction of the Hopfield model for a specific monotone and realistic profile for the refractive index. We are able to provide exact solutions, which do not require any weak dispersion approximation. The theory of Fuchsian ordinary differential equations is the basic tool for recovering exact solutions, which are rigorously identified and involve the so-called generalized hypergeometric functions ${}_4{F}_3({\alpha }_1,{\alpha }_2,{\alpha }_3,{\alpha }_4;{\beta }_1,{\beta }_2,{\beta }_3;z)$. A complete set of connection formulas are available, both for the subcritical case and for the transcritical one, and also the Stokes phenomenon occurring in the problem is fully discussed. From the physical point of view, we focus on the problem of thermality. Under suitable conditions, the Hawking temperature is deduced, and we show that it is in full agreement with the expression deduced in other frameworks under various approximations.

Using the Ehlers transformation, we derive an exact solution for a doubly rotating black ring in five-dimensional vacuum Einstein theory. It is well known that the vacuum Einstein theory with three commuting Killing vector fields can be reduced to a nonlinear sigma model with $SL(3,\mathbb{R})$ target space symmetry. As shown previously by Giusto and Saxena, the $SO(2,1)$ subgroup in the $SL(3,\mathbb{R})$ can generate a rotating solution from a static solution while preserving asymptotic flatness. This so-called Ehlers transformation actually transforms the five-dimensional Schwarzschild black hole into the five-dimensional Myers-Perry black hole. However, unlike the case with the black hole, applying this method directly to the static black ring or the Emparan-Reall black ring, does not yield a regular rotating black ring due to the emergence of a Dirac-Misner string singularity. To solve this undesirable issue, we use a singular vacuum solution of a rotating black ring/lens that already possesses a Dirac-Misner string singularity as the seed solution for the Ehlers transformation. The resulting solution is regular, indicating the absence of curvature singularities, conical singularities, orbifold singularities, Dirac-Misner string singularities, and closed timelike curves both on and outside the horizon. We show that this solution obtained by the Ehlers transformation coincides precisely with the Pomeransky-Sen’kov solution. We expect that applying this method to other theories may lead to the finding of new exact solutions, such as solutions for black lenses and capped black holes, as well as black ring configurations.