We present a set of new generalized kinematic imbalance variables that can be measured in neutrino scattering. These variables extend previous measurements of kinematic imbalance on the transverse plane and are more sensitive to modeling of nuclear effects. We demonstrate the enhanced power of these variables using simulation and then use the MicroBooNE detector to measure them for the first time. We report flux-integrated single- and double-differential measurements of charged-current muon neutrino scattering on argon using a topology with one muon and one proton in the final state as a function of these novel kinematic imbalance variables. These measurements allow us to demonstrate that the treatment of charged current quasielastic interactions in genie version 2 is inadequate to describe data. Further, they reveal tensions with more modern generator predictions particularly in regions of phase space where final state interactions are important.

Causal set theory is an approach to quantum gravity in which spacetime is fundamentally discrete at the Planck scale and takes the form of an irregular Lorentzian lattice, or “causal set,” from which continuum spacetime emerges in a large-scale (low-energy) approximation. In this work, we present new developments in the framework of interacting quantum field theory on causal sets. We derive a diagrammatic expansion for in-in correlators in local scalar field theories with finite polynomial interactions. We outline how these same correlators can be computed using the double-path integral, which acts as a generating functional for the in-in correlators. We modify the in-in generating functional to obtain a generating functional for in-out correlators. We define a notion of scattering amplitudes on causal sets with noninteracting past and future regions and verify that they are given by $S$-matrix elements (matrix elements of the time-evolution operator). We describe how these formal developments can be implemented to compute early Universe observables under the assumption that spacetime is fundamentally discrete.

By leveraging the physics of the Higgs branch, we argue that the conformal central charges $a$ and $c$ of an arbitrary 4D $\mathcal{N}=2$ superconformal field theory (SCFT) are rational numbers. Our proof of the rationality of $c$ is conditioned on a well-supported conjecture about how the Higgs branch of an SCFT is encoded in its protected chiral algebra. To establish the rationality of $a$, we further rely on a widely believed technical assumption on the high-temperature limit of the superconformal index.

We compute all helicity amplitudes for the scattering of five partons in two-loop QCD in all the relevant flavor configurations, retaining all contributing color structures. We employ tensor projection to obtain helicity amplitudes in the ’t Hooft-Veltman scheme starting from a set of primitive amplitudes. Our analytic results are expressed in terms of massless pentagon functions, and are easy to evaluate numerically. These amplitudes provide important input to investigations of soft-collinear factorization and to studies of the high-energy limit.

We complete the computation of two-loop helicity amplitudes required to obtain next-to-next-to-leading order QCD corrections for three-jet production at hadron colliders, including all contributions beyond the leading-color approximation. The analytic expressions are reconstructed from finite-field samples obtained with the numerical unitarity method. We find that the reconstruction is significantly facilitated by exploiting the overlaps between rational coefficient functions of quark and gluon processes, and we display their compact generating sets. We implement our results in a public code, and demonstrate its suitability for phenomenological applications.

We compute the two-loop helicity amplitudes for the scattering of five gluons, including all contributions beyond the leading-color approximation. The analytic expressions are represented as linear combinations of transcendental functions with rational coefficients, which we reconstruct from finite-field samples obtained with the numerical unitarity method. Guided by the requirement of removing unphysical singularities, we find a remarkably compact generating set of rational coefficients, which we display entirely in the manuscript. We implement our results in a public code, which provides efficient and reliable numerical evaluations for phenomenological applications.

We discuss the long-distance physics of 2D adjoint QCD when it is viewed as an effective field theory and determine the $\beta$ functions for its two classically marginal four-Fermi operators. These four-fermion terms preserve the invertible symmetries of the kinetic terms, and they have important implications at long distances if they are generated at short distances. Our results are likely to be important for future numerical lattice Monte Carlo studies of 2D adjoint QCD.

In AdS/CFT, we introduce a robust method for computing $n$-point gluon Mellin amplitudes, applicable in various spacetime dimensions. Using the Mellin transform and a recursive algorithm, we efficiently calculate tree-level gluon amplitudes. Our approach simplifies the representation of higher-point amplitudes, eliminating the need for complicated integrations. Crucially, the resulting amplitudes closely mirror those in flat space, allowing a straightforward dictionary between the two settings circumventing explicit calculations.

We investigate the embedding formalism in conjunction with the Mellin transform to determine tree-level gluon amplitudes in $\mathrm{AdS}/\mathrm{CFT}$. Detailed computations of three to five-point correlators are conducted, ultimately distilling what were previously complex results for five-point correlators into a more succinct and comprehensible form. We then proceed to derive a recursion relation applicable to a specific class of $n$-point gluon amplitudes. This relation is instrumental in systematically constructing amplitudes for a range of topologies. We illustrate its efficacy by specifically computing six to eight-point functions. Despite the complexity encountered in the intermediate steps of the recursion, the higher-point correlator is succinctly expressed as a polynomial in boundary coordinates, upon which a specific differential operator acts. Remarkably, we observe that these amplitudes strikingly mirror their counterparts in flat space, traditionally computed using standard Feynman rules. This intriguing similarity has led us to propose a novel dictionary: comprehensive rules that bridge AdS Mellin amplitudes with flat-space gluon amplitudes.

We refine and extend a recent construction of sets of black hole microstates with semiclassical interiors that span a Hilbert space of dimension $e^S$, where $S$ is the black hole entropy. We elaborate on the definition and properties of microstates in statistical and black hole mechanics. The gravitational description of microstates employs matter shells in the interior of the black hole, and we argue that in the limit where the shells are very heavy, the construction acquires universal validity. To this end, we show it for very wide classes of black holes; we first extend the construction to rotating and charged black holes, including extremal and near-extremal solutions, with or without supersymmetry, and we sketch how the construction of microstates can be embedded in string theory. We then describe how the approach can include general quantum corrections, near or far from extremality. For supersymmetric black holes, the microstates we construct differ from other recent constructions in that the interior excitations are not confined within the near-extremal throat.

In this paper, we compute ${\alpha }_s$ corrections to the matching coefficients of the dimension-six operators in the heavy quark expansion of the inclusive semileptonic heavy hadron decay rate and leptonic invariant mass spectrum with a massless quark and both a massive or massless lepton in the final state, analytically. The obtained results can be applied to the inclusive semileptonic $B\to X_u\ell {\overline{\nu }}_{\ell }$ ($\ell =e$, $\mu$, $\tau$) and $D\to X\ell {\overline{\nu }}_{\ell }$ ($\ell =e$, $\mu$) decays. The main application of our results is the background subtraction of the $B\to X_u\ell {\overline{\nu }}_{\ell }$ decay in the measurement of the $B\to X_c\ell {\overline{\nu }}_{\ell }$ decay, which is important for the precise extraction of $V_{cb}$ and $R(D^{(*)})$. They also play a role in the computation of lifetimes of heavy hadrons.

The proposed Laser Interferometer Space Antenna (LISA) mission is tasked with the detection and characterization of gravitational waves from various sources in the Universe. This endeavor is challenged by transient displacement and acceleration noise artifacts, commonly called glitches. Uncalibrated glitches impact the interferometric measurements and decrease the signal quality of LISA’s time-delay interferometry (TDI) data used for astrophysical data analysis. The paper introduces a novel calibration pipeline that employs a neural network ensemble to detect, characterize, and mitigate transient glitches of diverse morphologies. A convolutional neural network is designed for anomaly detection, accurately identifying and temporally pinpointing anomalies within the TDI time series. Then, a hybrid neural network is developed to differentiate between gravitational wave bursts and glitches, while a long short-term memory (LSTM) network architecture is deployed for glitch estimation. The LSTM network acts as a TDI inverter by processing noisy TDI data to obtain the underlying glitch dynamics. Finally, the inferred noise transient is subtracted from the interferometric measurements, enhancing data integrity and reducing biases in the parameter estimation of astronomical targets. We propose a low-latency solution featuring generalized LSTM networks primed for rapid response data processing and alert service in high-demand scenarios like predicting binary black hole mergers. The research highlights the critical role of machine learning in advancing methodologies for data calibration and astrophysical analysis in LISA.

We present an update of our determination of the isovector charges $g_A^{u-d}$, $g_S^{u-d}$ and $g_T^{u-d}$, and the isovector twist-2 forward matrix elements $⟨x{⟩}_{u-d}$, $⟨x{⟩}_{\mathrm{\Delta }u-\mathrm{\Delta }d}$ and $⟨x{⟩}_{\delta u-\delta d}$ on the $N_{\mathrm{f}}=2+1$ gauge ensembles generated by the Coordinated Lattice Simulations (CLS) effort. We have significantly extended our coverage of the parameter space by adding ensembles at the physical pion mass and fine lattice spacing, at nearly physical pion masses and very fine lattice spacings, and at very large physical lattice volumes, enabling a well-controlled extrapolation to the physical point. Another major improvement is achieved owing to the extended range of source-sink separations, which allows us to perform two-state fits to summed correlator ratios, leading to a much higher level of control over excited-state effects. Systematic uncertainties from the chiral, continuum and infinite-volume extrapolations are incorporated via model averages based on the Akaike information criterion. Our final results at the physical point are $g_A^{u-d}=1.254(19{)}_{\mathrm{stat}}(15{)}_{\mathrm{sys}}[24{]}_{\text{total}}$, $g_S^{u-d}=1.203(77{)}_{\mathrm{stat}}(81{)}_{\mathrm{sys}}[112{]}_{\text{total}}$, $g_T^{u-d}=0.993(15{)}_{\mathrm{stat}}(05{)}_{\mathrm{sys}}[16{]}_{\text{total}}$, $⟨x{⟩}_{u-d}=0.153(15{)}_{\mathrm{stat}}(10{)}_{\mathrm{sys}}[17{]}_{\text{total}}$, $⟨x{⟩}_{\mathrm{\Delta }u-\mathrm{\Delta }d}=0.207(15{)}_{\mathrm{stat}}(06{)}_{\mathrm{sys}}[16{]}_{\text{total}}$, and $⟨x{⟩}_{\delta u-\delta d}=0.195(17{)}_{\mathrm{stat}}(15{)}_{\mathrm{sys}}[23{]}_{\text{total}}$. While our results for the isovector charges are in excellent agreement with the FLAG 21 averages, we note that our error for the tensor charge $g_T^{u-d}$ is considerably smaller.

We present the first analytic results of next-to-next-to-next-to-leading-order (${\mathrm{N}}^3\mathrm{LO}$) QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At next-to-next-to-leading order (NNLO), this dominant contribution accounts for 95% of the total correction. By utilizing the optical theorem, the ${\mathrm{N}}^3\mathrm{LO}$ corrections are related to the imaginary parts of the four-loop self-energy Feynman diagrams, which are calculated with differential equations. The results are expressed in terms of harmonic polylogarithms, enabling fast and accurate evaluation. The third-order QCD corrections decrease the leading-order decay width by 0.667%, and the scale uncertainty is reduced by half compared to the NNLO result. The most precise prediction for the top-quark width is now 1.321 GeV for $m_t=172.69\mathrm{GeV}$. Additionally, we obtain the third-order QCD corrections to the dilepton invariant mass spectrum and decay width in the semileptonic $b\to u$ transition. The perturbative series in the on-shell mass scheme exhibits poor convergence behavior. In the $\overline{\mathrm{MS}}$ mass scheme, the scale dependence is greatly improved. A more precise determination of the CKM matrix element $V_{ub}$ could be obtained with such higher-order corrections.

Laser Interferometer Space Antenna (LISA) will observe gravitational waves from galactic binaries (GBs) of white dwarfs or neutron stars. Some of these objects are among the most magnetic astrophysical objects in the Universe. Magnetism, by secularly disrupting the orbit, can eventually affect the gravitational waves emission and could then be potentially detected and characterized after several years of observations by LISA. Currently, the data processing pipeline of the LISA Data Challenge (LDC) for GBs does not consider either magnetism or eccentricity. Recently, it was shown [Bourgoin et al., [Phys. Rev. D 105, 124042 (2022)]] that magnetism induces a shift on the gravitational wave frequencies. Additionally, it was argued that, if the binary’s orbit is eccentric, the presence of magnetism could be detected by LISA. In this work, we explore the consequences of a future data analysis conducted on quasicircular and magnetic GB systems using the current LDC tools. We first show that a single eccentric GB can be interpreted as several GBs and this can eventually bias population studies deduced from LISA’s future catalog. Then, we confirm that for quasicircular orbits, the secular magnetic energy of the system can be inferred if the signal-to-noise ratio of the second harmonic is high enough to be detected by traditional quasimonochromatic source searching algorithms. LISA observations could therefore bring new insights on the nature and origin of magnetic fields in white dwarfs or neutron stars.

We calculate the form factors for the $B\to D^{*}\ell {\nu }_{\ell }$ decay in $2+1$ flavor lattice QCD. For all quark flavors, we employ the Möbius domain-wall action, which preserves chiral symmetry to a good precision. Our gauge ensembles are generated at three lattice cutoffs $a^{-1}\sim 2.5$, 3.6, and 4.5 GeV with pion masses as low as $M_{\pi }\sim 230\mathrm{MeV}$. The physical lattice size $L$ satisfies the condition $M_{\pi }L\ge 4$ to control finite volume effects (FVEs), while we simulate a smaller size at the smallest $M_{\pi }$ to directly examine FVEs. The bottom quark masses are chosen in a range from the physical charm quark mass to $0.7a^{-1}$ to control discretization effects. We extrapolate the form factors to the continuum limit and physical quark masses based on heavy meson chiral perturbation theory at next-to-leading order. Then the recoil parameter dependence is parametrized using a model independent form leading to our estimate of the decay rate ratio between the tau ($\ell =\tau$) and light lepton ($\ell =e$, $\mu$) channels $R(D^{*})=0.252(22)$ in the Standard Model. A simultaneous fit with recent data from the Belle experiment yields $|V_{cb}|=39.19(91)\times {10}^{-3}$, which is consistent with previous exclusive determinations, and shows good consistency in the kinematical distribution of the differential decay rate between the lattice and experimental data.

One of the main challenges in the numerical modeling of binary neutron-star mergers are long-term simulations of the postmerger remnant over timescales of the order of seconds. When this modeling includes all the aspects of the complex physics accompanying the remnant, the computational costs can easily become enormous. To address this challenge in part, we have developed a novel hybrid approach in which the solution from a general-relativistic magnetohydrodynamics (GRMHD) code solving the full set of the Einstein equations in Cartesian coordinates is coupled with another GRMHD code in which the Einstein equations are solved under the conformally flat condition (CFC). The latter approximation has a long history and has been shown to provide an accurate description of compact objects in nonvacuum spacetimes. An important aspect of the CFC approximation is that the elliptic equations need to be solved only for a fraction of the steps needed for the underlying hydrodynamical/magnetohydrodynamical evolution, thus allowing for a gain in computational efficiency that can be up to a factor of $\sim 6(230)$ in three-dimensional (two-dimensional) simulations. We present here the basic features of the new code, the strategies necessary to interface it when importing both two- and three-dimensional data, and a novel and robust approach to the recovery of the primitive variables. To validate our new framework, we have carried out a number of tests with various coordinates systems and different numbers of spatial dimensions, involving a variety of astrophysical scenarios, including the evolution of the postmerger remnant of a binary neutron-star merger over a timescale of one second. Overall, our results show that the new code, bhac+, is able to accurately reproduce the evolution of compact objects in nonvacuum spacetimes and that, when compared with the evolution in full general relativity, the CFC approximation reproduces accurately both the gravitational fields and the matter variables at a fraction of the computational costs. This opens the way for the systematic study of the secular matter and electromagnetic emission from binary-merger remnants.

In this work, we investigate spectral complexity and Krylov complexity in quantum billiard systems at finite temperature. We study both circle and stadium billiards as paradigmatic examples of integrable and nonintegrable quantum-mechanical systems, respectively. We show that the saturation value and timescale of spectral complexity may be used to probe the nonintegrability of the system since we find that when computed for the circle billiard, it saturates at a later timescale compared to the stadium billiards. This observation is verified for different temperatures. Furthermore, we study the Krylov complexity of the position operator and its associated Lanczos coefficients at finite temperature using the Wightman inner product. We find that the growth rate of the Lanczos coefficients saturates the conjectured universal bound at low temperatures. Additionally, we also find that even a subset of the Lanczos coefficients can potentially serve as an indicator of integrability, as they demonstrate erratic behavior specifically in the circle billiard case, in contrast to the stadium billiard. Finally, we also study Krylov entropy and verify its early-time logarithmic relation with Krylov complexity in both types of billiard systems.

The violation of the Bell inequality is one of the hallmarks of quantum mechanics and can be used to rule out local deterministic alternative descriptions. We utilize the data analysis published by the LHCb Collaboration on the helicity amplitudes for the decay $B^0\to J/\psi K^{*}(892{)}^0$ to compute the entanglement among the polarizations of the final vector mesons and the violation of the Bell inequality that it entails. We find that quantum entanglement can be detected with a significance well above $5\sigma$ (nominally $84\sigma$) and Bell inequality is violated with a significance well above $5\sigma$ (nominally $36\sigma$)—thereby firmly establishing these distinguishing feature of quantum mechanics at high energies in a collider setting and in the presence of strong and weak interactions. Entanglement is also present and the Bell inequality is violated in other decays of the $B$ mesons into vector mesons, but with lesser significance.

Line-intensity mapping (LIM) is quickly attracting attention as an alternative technique to probe large-scale structure and galaxy formation and evolution at high redshift. LIM one-point statistics are motivated because they provide access to the highly non-Gaussian information present in line-intensity maps and contribute to break degeneracies between cosmology and astrophysics. Now that promising surveys are underway, an accurate model for the LIM probability distribution function (PDF) is necessary to employ one-point statistics. We consider the impact of extended emission and limited experimental resolution in the LIM PDF for the first time. We find that these effects result in a lower and broader peak at low intensities and a lower tail towards high intensities. Focusing on the distribution of intensities in the observed map, we perform the first model validation of LIM one-point statistics with simulations and find good qualitative agreement. We also discuss the impact on the covariance, and demonstrate that if not accounted for, large biases in the astrophysical parameters can be expected in parameter inference. These effects are also relevant for any summary statistic estimated from the LIM PDF, and must be implemented to avoid biased results. The comparison with simulations shows, however, that there are still deviations, mostly related with the modeling of the clustering of emitters, which encourage further development of the modeling of LIM one-point statistics.