We search for the rare decay $B^{+}\to K^{+}\nu \overline{\nu }$ in a $362{\mathrm{fb}}^{-1}$ sample of electron-positron collisions at the $\mathrm{\Upsilon }(4S)$ resonance collected with the Belle II detector at the SuperKEKB collider. We use the inclusive properties of the accompanying $B$ meson in $\mathrm{\Upsilon }(4S)\to B\overline{B}$ events to suppress background from other decays of the signal $B$ candidate and light-quark pair production. We validate the measurement with an auxiliary analysis based on a conventional hadronic reconstruction of the accompanying $B$ meson. For background suppression, we exploit distinct signal features using machine learning methods tuned with simulated data. The signal-reconstruction efficiency and background suppression are validated through various control channels. The branching fraction is extracted in a maximum likelihood fit. Our inclusive and hadronic analyses yield consistent results for the $B^{+}\to K^{+}\nu \overline{\nu }$ branching fraction of $[2.7\pm 0.5(\mathrm{stat})\pm 0.5(\mathrm{syst})]\times {10}^{-5}$ and $[{1.1}_{-0.8}^{+0.9}(\mathrm{stat}{)}_{-0.5}^{+0.8}(\mathrm{syst})]\times {10}^{-5}$, respectively. Combining the results, we determine the branching fraction of the decay $B^{+}\to K^{+}\nu \overline{\nu }$ to be $[2.3\pm 0.5(\mathrm{stat}{)}_{-0.4}^{+0.5}(\mathrm{syst})]\times {10}^{-5}$, providing the first evidence for this decay at 3.5 standard deviations. The combined result is 2.7 standard deviations above the standard model expectation.

The cross section of the process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about $62{\mathrm{pb}}^{-1}$. In the dominant $\rho$-resonance region, a systematic uncertainty of 0.7% has been reached. At energies around $\varphi$-resonance the ${\pi }^{+}{\pi }^{-}$ production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the ${\pi }^{+}{\pi }^{-}$ production has also been measured. It shows a strong deviation from the theoretical prediction based on the conventional scalar quantum electrodynamics framework, and it is in good agreement with the generalized vector-meson-dominance and dispersive-based predictions. The impact of the presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed.

Differential cross sections are measured for the standard model Higgs boson produced in association with vector bosons ($W$, $Z$) and decaying to a pair of $b$ quarks. Measurements are performed within the framework of the simplified template cross sections. The analysis relies on the leptonic decays of the $W$ and $Z$ bosons, resulting in final states with 0, 1, or 2 electrons or muons. The Higgs boson candidates are either reconstructed from pairs of resolved $b$-tagged jets, or from single large-radius jets containing the particles arising from two $b$ quarks. Proton-proton collision data at $\sqrt{s}=13\mathrm{TeV}$, collected by the CMS experiment in 2016–2018 and corresponding to a total integrated luminosity of $138{\mathrm{fb}}^{-1}$, are analyzed. The inclusive signal strength, defined as the product of the observed production cross section and branching fraction relative to the standard model expectation, combining all analysis categories, is found to be $\mu =1.15_{-0.20}^{+0.22}$. This corresponds to an observed (expected) significance of 6.3 (5.6) standard deviations.

We investigate gravitational-wave backgrounds (GWBs) of primordial origin that would manifest only at ultrahigh frequencies, from kilohertz to 100 gigahertz, and leave no signal at LIGO, the Einstein Telescope, the Cosmic Explorer, LISA, or pulsar-timing arrays. We focus on GWBs produced by cosmic strings and make predictions for the GW spectra scanning over high-energy scale (beyond ${10}^{10}\mathrm{GeV}$) particle physics parameters. Signals from local string networks can easily be as large as the big bang nucleosynthesis/cosmic microwave background bounds, with a characteristic strain as high as ${10}^{-26}$ in the 10 kHz band, offering prospects to probe grand unification physics in the ${10}^{14}–{10}^{17}\mathrm{GeV}$ energy range. In comparison, GWB from axionic strings is suppressed (with maximal characteristic strain $\sim {10}^{-31}$) due to the early matter era induced by the associated heavy axions. We estimate the needed reach of hypothetical futuristic GW detectors to probe such GWB and, therefore, the corresponding high-energy physics processes. Beyond the information of the symmetry-breaking scale, the high-frequency spectrum encodes the microscopic structure of the strings through the position of the UV cutoffs associated with cusps and kinks, as well as potential information about friction forces on the string. The IR slope, on the other hand, reflects the physics responsible for the decay of the string network. We discuss possible strategies for reconstructing the scalar potential, particularly the scalar self-coupling, from the measurement of the UV cutoff of the GW spectrum.

Quasiperiodic eruptions (QPEs) are intense, repeating, soft x-ray bursts with recurrence times of about a few to ten hours from nearby galactic nuclei. The origin of QPEs is still unclear. In this work, we investigate the extreme mass ratio inspiral (EMRI) + accretion disk model, where the disk is formed from a previous tidal disruption event (TDE). In this $\mathrm{EMRI}+\mathrm{TDE}$ disk model, the QPEs are the result of collisions between a TDE disk and a stellar mass object (a stellar mass black hole or a main sequence star) orbiting around a supermassive black hole (SMBH) in galactic nuclei. If this interpretation is correct, QPEs will be invaluable in probing the orbits of stellar mass objects in the vicinity of SMBHs and further inferring the formation of EMRIs, which are one of the primary targets of spaceborne gravitational wave missions. Taking GSN 069 as an example, we find the EMRI that is of low eccentricity ($e<0.1$ at the $3\text{−}\sigma$ confidence level) and a semimajor axis about $O({10}^2)$ gravitational radii of the central SMBH, which is consistent with the prediction of the wet EMRI formation channel while incompatible with alternatives.

Extracting the non-Gaussian information of the cosmic large-scale structure (LSS) is vital in unlocking the full potential of the rich datasets from the upcoming stage-IV galaxy surveys. Galaxy skew spectra serve as efficient beyond-two-point statistics, encapsulating essential bispectrum information with computational efficiency akin to power spectrum analysis. This paper presents the first cosmological constraints from analyzing the full set of redshift-space galaxy skew spectra of the data from the SDSS-III BOSS, accessing cosmological information down to nonlinear scales. Employing the simbig forward modeling framework and simulation-based inference via normalizing flows, we analyze the CMASS-SGC subsample, which constitute approximately 10% of the full BOSS data. Analyzing the scales up to $k_{\max }=0.5h^{-1}\mathrm{Mpc}$, we find that the skew spectra improve the constraints on ${\mathrm{\Omega }}_{\mathrm{m}},{\mathrm{\Omega }}_{\mathrm{b}},h$, and $n_s$ by 34%, 35%, 18%, 10%, respectively, compared to constraints from previous simbig power spectrum multipoles analysis, yielding ${\mathrm{\Omega }}_{\mathrm{m}}=0.288_{-0.034}^{+0.024}$, ${\mathrm{\Omega }}_{\mathrm{b}}=0.043_{-0.007}^{+0.005}$, $h=0.759_{-0.050}^{+0.104}$, $n_{\mathrm{s}}=0.918_{-0.090}^{+0.041}$ (at 68% confidence limit). On the other hand, the constraints on ${\sigma }_8$ are weaker than from the power spectrum. Including the big bang nucleosynthesis (BBN) prior on baryon density reduces the uncertainty on the Hubble parameter further, achieving $h=0.750_{-0.032}^{+0.034}$, which is a 38% improvement over the constraint from the power spectrum with the same prior. Compared to the simbig bispectrum (monopole) analysis, skew spectra offer comparable constraints on larger scales ($k_{\max }<0.3h^{-1}\mathrm{Mpc}$) for most parameters except for ${\sigma }_8$.

We study the evolution of heavy stars ($M\ge 40M_{\odot }$) undergoing pair-instability in the presence of annihilating dark matter. Focusing on the scenario where the dark matter is in capture-annihilation equilibrium, we model the profile of energy injections in the local thermal equilibrium approximation. We find that significant changes to masses of astrophysical black holes formed by (pulsational) pair-instability supernovae can occur when the ambient dark matter density ${\rho }_{\mathrm{DM}}\gtrsim {10}^9\mathrm{GeV}{\mathrm{cm}}^{-3}$. There are two distinct outcomes, depending on the dark matter mass. For masses $m_{\mathrm{DM}}\gtrsim 1\mathrm{GeV}$ the DM is primarily confined to the core. The annihilation increases the lifetime of core helium burning, resulting in more oxygen being formed, fueling a more violent explosion during the pair-instability-induced contraction. This drives stronger pulsations, leading to lighter black holes being formed than predicted by the standard model. For masses $m_{\mathrm{DM}}\lesssim 0.5\mathrm{GeV}$ there is significant dark matter in the envelope, leading to a phase where the star is supported by the energy from the annihilation. This reduces the core temperature and density, allowing the star to evade the pair-instability allowing heavier black holes to be formed. We find a mass gap for all models studied.

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.