In this work, we study the effect of a high-precision semianalytical mass function on the merger rate of primordial black holes (PBHs) in dark matter halos. For this purpose, we first explain a theoretical framework for dark matter halo models and introduce relevant quantities such as the halo density profile, the concentration parameter, and a high-precision semianalytical function, namely Del Popolo (DP) mass function. In the following, we calculate the merger rate of PBHs in the framework of ellipsoidal-collapse dark matter halo models while considering the DP mass function, and compare it with our previous study for the Sheth-Tormen (ST) mass function. The results show that by taking the mass of PBHs as $M_{\mathrm{PBH}}=30M_{\odot }$, the DP mass function can potentially amplify the merger rate of PBHs. Moreover, we calculate the merger rate of PBHs for the DP mass function as a function of their mass and fraction and compare it with the black hole mergers recorded by the Laser Interferometer Gravitational-Wave Observatory (LIGO)-Virgo detectors during the latest observing run. Our findings show that the merger rate of PBHs will fall within the LIGO-Virgo band if $f_{\mathrm{PBH}}\gtrsim \mathcal{O}({10}^{-1})$. This implies that the DP mass function can be used to strengthen constraints on the fraction of PBHs.

This paper proposes a new approach to separate the $\mu$ spectral distortions of the cosmic microwave background from foregrounds with poorly defined spectral shapes. The idea is based on finding the optimal response to the observed signal. This response is weakly sensitive to foregrounds with parameters that are within some certain limits of their possible variations and, at the same time, very sensitive to the amplitude of $\mu$ distortion. The algorithm described in this paper is stable, easy to implement, and simultaneously minimizes the response to foregrounds and photon noise.

The Alpha Magnetic Spectrometer (AMS-02) has provided unprecedented precision measurements of the electron and positron cosmic-ray fluxes and the positron fraction spectrum. At the higher energies, sources as energetic local pulsars, may contribute to both cosmic-ray species. The discreteness of the source population, can result in features both on the positron fraction measurement and in the respective electron and positron spectra. For the latter, those would coincide in energy and would contrast predictions of smooth spectra as from particle dark matter. In this work, using a library of pulsar population models for the local part of the Milky Way, we perform a power-spectrum analysis on the cosmic-ray positron fraction. We also develop a technique to cross-correlate the electron and positron fluxes. We show that both such analyses, can be used to search statistically for the presence of spectral wiggles in the cosmic-ray data. For a significant fraction of our pulsar simulations, those techniques are already sensitive enough to give a signal for the presence of those features above the regular noise, with forthcoming observations making them even more sensitive. Finally, by cross-correlating the AMS-02 electron and positron spectra, we find an intriguing first hint for a positive correlation between them, of the kind expected by a population of local pulsars.

Dark matter (DM) detectors employing a spherical proportional counter (SPC) have demonstrated a single-electron detection threshold and are projected to have small background rates. We explore the sensitivity to DM-electron scattering with SPC detectors in the context of darksphere, a proposal for a 300 cm diameter fully electroformed SPC. SPCs can run with different gases, so we investigate the sensitivity for five targets: helium, neon, xenon, methane, and isobutane. We use tools from quantum chemistry to model the atomic and molecular systems and calculate the expected DM induced event rates. We find that darksphere has the potential to improve current exclusion limits on DM masses above 4 MeV by up to 5 orders of magnitude. Neon is the best all-round gas target and provides good sensitivity to scenarios with both light and heavy mediators. Gas mixtures, where methane or isobutane is added to a noble gas, can extend the sensitivity at lower masses. Our study highlights the currently untapped potential of SPCs to search for DM-electron scattering in the MeV-to-GeV DM mass range.

We report on the search for dark matter weakly interacting massive particles (WIMPs) in the mass range below $10\mathrm{GeV}/{\mathrm{c}}^2$, from the analysis of the entire dataset acquired with a low-radioactivity argon target by the DarkSide-50 experiment at Laboratori Nazionali del Gran Sasso. The new analysis benefits from more accurate calibration of the detector response, improved background model, and better determination of systematic uncertainties, allowing us to accurately model the background rate and spectra down to $0.06{\mathrm{keV}}_{er}$. A 90% C.L. exclusion limit for the spin-independent cross section of $3\mathrm{GeV}/{\mathrm{c}}^2$ mass WIMP on nucleons is set at $6\times {10}^{-43}{\mathrm{cm}}^2$, about a factor 10 better than the previous DarkSide-50 limit. This analysis extends the exclusion region for spin-independent dark matter interactions below the current experimental constraints in the [1.2, 3.6] $\mathrm{GeV}/{\mathrm{c}}^2$ WIMP mass range.

The precisions of existing gravitational calibrators for gravitational wave observatories are limited by their dependence on the relative position between the calibrators and the observatory’s test masses. Here we present a novel geometry consisting of four quadrupole rotors placed at the vertices of a rectangle centered on the test mass. The phases and rotation directions are selected to produce a pseudoplane-wave sinusoidal gravitational acceleration with amplitude of $\sim 100\mathrm{fm}/{\mathrm{s}}^2$. We show that this acceleration only has minimal dependence on the test mass position relative to the rotor array and can yield 0.15% acceleration amplitude uncertainty while tolerating a 1-cm test mass position uncertainty. The acceleration can be directed precisely along the optical axis of the interferometer arm and applies no torque on the test mass. In addition, the small size of the rotors has significant engineering and safety benefits.

This paper presents a search for generic short-duration gravitational-wave (GW) transients (or GW bursts) in the data from the third observing run of Advanced LIGO and Advanced Virgo. We use a coherent WaveBurst (cWB) pipeline enhanced with a decision-tree classification algorithm for more efficient separation of GW signals from noise transients. The machine-learning (ML) algorithm is trained on a representative set of noise events and a set of simulated stochastic signals that are not correlated with any known signal model. This training procedure preserves the model-independent nature of the search. We demonstrate that the ML-enhanced cWB pipeline can detect GW signals at a larger distance than previous model-independent searches. The sensitivity improvements are achieved across the broad spectrum of simulated signals, with the goal of testing the robustness of this model-agnostic search. At a false-alarm rate of one event per century, the detectable signal amplitudes are reduced up to almost an order of magnitude, most notably for the single-cycle signal morphologies. This ML-enhanced pipeline also improves the detection efficiency of compact binary mergers in a wide range of masses, from stellar mass to intermediate-mass black holes, both with circular and elliptical orbits. After excluding previously detected compact binaries, no new gravitational-wave signals are observed for the twofold Hanford-Livingston and the threefold Hanford-Livingston-Virgo detector networks. With the improved sensitivity of the all-sky search, we obtain the most stringent constraints on the isotropic emission of gravitational-wave energy from short-duration burst sources.

The exact elementary excitations in a typical $U(1)$ symmetry broken quantum integrable system, that is the twisted $J_1-J_2$ spin chain with nearest-neighbor, next nearest neighbor, and chiral three spin interactions, are studied. The main technique is that we quantify the energy spectrum of the system by the zero roots of the transfer matrix instead of the traditional Bethe roots. From the numerical calculation and singularity analysis, we obtain the patterns of zero roots. Based on them, we analytically obtain the ground state energy and the elementary excitations in the thermodynamic limit. We find that the system also exhibits the nearly degenerate states in the regime of $\eta \in \mathbb{R}$, where the nearest-neighbor couplings among the $z$ direction are ferromagnetic. More careful study shows that the competing of interactions can induce the gapless low-lying excitations and quantum phase transition in the antiferromagnetic regime with $\eta \in \mathbb{R}+i\pi$.

In this work, we consider the implications of current $b\to s{\ell }^{+}{\ell }^{-}$ ($\ell =e$, $\mu$) measurements on several $B\to K^{*}{\tau }^{+}{\tau }^{-}$ observables under the assumption that the possible new physics can have both universal as well as nonuniversal couplings to leptons. For new physics solutions which provide a good fit to all $b\to s{\ell }^{+}{\ell }^{-}$ data, we intend to identify observables with large deviations from the Standard Model (SM) predictions as well as to discriminate between various new physics solutions. For this we consider the $B\to K^{*}{\tau }^{+}{\tau }^{-}$ branching fraction, the $K^{*}$ longitudinal fraction $f_L$, the tau forward-backward asymmetry $A_{\mathrm{FB}}$ and the optimized observables in the $P_i^{(\prime )}$ basis. Further, we construct the $\tau -\mu$ lepton-flavor differences ($Q^{\tau \mu }$) between these tau observables and their muonic counterparts in $B\to K^{*}{\mu }^{+}{\mu }^{-}$ decay. Moreover, we also consider lepton-flavor ratios ($R^{\tau \mu }$) of all of these observables. We find that the current data allows for deviations ranging from 25% up to an order of magnitude from the SM value in a number of observables. For e.g., the magnitudes of $Q_{P_3}^{\tau \mu }$ and $Q_{P_8^{\prime }}^{\tau \mu }$ observables can be enhanced up to an order of magnitude, a twofold enhancement in $Q_{A_{\mathrm{FB}}}^{\tau \mu }$ is possible along with $\sim 50\%$ enhancement in $R_{K^{*}}^{\tau \mu }$ and $\sim 25\%$ in $R_{A_{\mathrm{FB}}}^{\tau \mu }$. Moreover, the branching ratio of $B\to K^{*}{\tau }^{+}{\tau }^{-}$ can be suppressed up to 25%. A precise measurement of these observables can also discriminate between a number of new physics solutions.

Heavy neutral leptons (HNLs) with masses $\mathcal{O}(0.1–1\mathrm{GeV}/c^2)$ are promising candidates for the simultaneous explanation of the smallness of the observed neutrino masses as well as the matter-antimatter asymmetry in the observable Universe. These particles can be produced in the decay of hadrons typically produced in a neutrino beamline used for oscillation experiments, and have sufficient lifetime to propagate to a near detector, where they decay to observable particles. For the approximation of a single new mass eigenstate mixing with the Standard Model via the lepton mixing matrix, a simulation framework based on the genie event generator has been developed. This module is designed to facilitate searches for HNL through a unified, minimal interface employing a detailed treatment of the kinematics and dynamics of massive unstable neutrinos, with a transparently organized suite of physics effects tracking the HNL from its production to its decay. These mechanisms are expounded on in the current work, underlining the rich landscape for novel, nontrivial physics that has already been identified in previous literature. This framework is an ongoing effort to provide a consistent and comprehensive description of heavy neutrinos from particle decays. We highlight use cases and future applications of interest to the accelerator neutrino community.

The forward-backward asymmetry ($A_{FB}$) in the Drell-Yan process $pp/p\overline{p}\to Z{\gamma }^{*}\to {\ell }^{+}{\ell }^{-}$ is sensitive to the proton structure information. Such information has been factorized into well-defined proton structure parameters which can be regarded as experimental observables. In this paper, we extract the structure parameters from the $A_{FB}$ distributions reported by the CMS Collaboration in $pp$ collisions at $\sqrt{s}=8\mathrm{TeV}$, and by the D0 Collaboration in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$. It is the first time that the unique parton information in the $A_{FB}$ spectrum can be decoupled from the electroweak calculation and measured as standalone observables, which can be used as new data constraints in the global quantum chromodynamics analysis of the parton distribution functions. Although the parton information in the $pp$ and $p\overline{p}$ collisions are different, and the precisions are statistically limited, the results from both the hadron colliders indicate that the down quark contribution might be higher in the data than their theoretical predictions.

We investigate the mechanical structure of a spin-1 particle. Introducing three different frameworks, i.e., the three-dimensional (3D) Breit frame, the two-dimensional (2D) Breit frame, and the 2D infinite momentum frame (equivalently the two-dimensional Drell-Yan frame), we scrutinize the 2D and 3D energy-momentum tensor (EMT) distributions in these frames. We first derive the EMT distributions in the 2D Breit frame by performing the Abel transformation. The mass distribution in the 2D Breit frame contains an additional monopole contribution induced geometrically. The pressure distribution in the 2D Breit frame also gets an induced monopole structure. When the Lorentz boost is carried out, the mass distribution in the 2D infinite-momentum frame acquires the induced dipole term. Similarly, we also have the induced dipole contributions to the pressure and shear-force densities. We visualize the 2D mass distributions when the spin-1 particle is polarized along the $x$- and $z$-axes. We observe that the 2D mass distribution in the infinite momentum frame exhibit clearly the induced dipole structure when the spin-1 particle is polarized along the $x$-axis. We also discuss the strong force fields inside a polarized spin-1 particle.

I present a general method for determining the massive cusp anomalous dimension in QCD to a very high degree of accuracy using its asymptotic behavior at small and large quark velocities. I show that the method works exceedingly well at two and three loops where exact results are already known. I then present a calculation of the massive cusp anomalous dimension using its asymptotics at four loops, and I provide a detailed study of the results for different values of the number of flavors and for separate color structures. The method can be further extended and applied to higher numbers of loops.

Heavy quarkonium production in ultraperipheral nuclear collisions (UPC) is described within the QCD dipole formalism. Realistic quarkonium wave functions in the $Q\overline{Q}$ rest frame are calculated by solving the Schrödinger equation with a subsequent Lorentz boost to high energy. We rely on several realistic $Q\overline{Q}$ potentials, which allow us to describe well the quarkonium masses and decay widths, as well as data on diffractive electroproduction of quarkonia on protons. Nuclear effects are calculated with the phenomenological dipole cross sections fitted to deep-inelastic scattering (DIS) data. The higher twist quark shadowing related to the lowest $Q\overline{Q}$ Fock component of the photon, as well as the leading twist gluon shadowing, related to higher components containing gluons, are included. The results for coherent and incoherent photoproduction of charmonia and bottomonia in UPC of heavy nuclei are in good accord with available data from the LHC. They can also be verified in future experiments at electron-ion colliders.

We show how background field inhomogeneities modify the nonperturbative structure of the effective action. The simple Borel poles of the Euler-Heisenberg effective action become branch points, and new branch points also appear, indicating new nonperturbative effects. This information is resurgently encoded in the perturbative weak field expansion and becomes physically significant for strongly inhomogeneous fields. We also show that resurgent extrapolation methods permit the decoding of a surprising amount of nonperturbative information from a relatively modest amount of perturbative input, enabling accurate analytic continuations from weak field to strong field, and of a spatially dependent magnetic background to a time dependent electric background. These extrapolations are far superior to standard Wentzel-Kramers-Brillouin approximation and locally constant-field approximations.

While numerous numerical relativity simulations adopt a $1+\log$ slicing condition, shock-avoiding slicing conditions form a viable and sometimes advantageous alternative. Despite both conditions satisfying similar equations, recent numerical experiments point to a qualitative difference in the behavior of the lapse in the vicinity of the black-hole puncture: for $1+\log$ slicing, the lapse appears to decay approximately exponentially, while for shock-avoiding slices it performs approximately harmonic oscillation. Motivated by this observation, we consider dynamical coordinate transformations of the Schwarzschild spacetime to describe small perturbations of static trumpet geometries analytically. We find that the character of the resulting equations depends on the (unperturbed) mean curvature at the black-hole puncture: for $1+\log$ slicing it is positive, predicting exponential decay in the lapse, while for shock-avoiding slices it vanishes, leading to harmonic oscillation. In addition to identifying the value of the mean curvature as the origin of these qualitative differences, our analysis provides insight into the dynamical behavior of black-hole punctures for different slicing conditions.

Gravitational waves travel through the distributions of matter and dark energy during propagation. For this reason, gravitational waves emitted from binary compact objects serve as a useful tool especially to probe the nature of dark energy. The geometrical optics approximation is a conventional way of investigating wave propagation. However, the approximation becomes less accurate as the wavelength approaches the curvature radius of the background, which can occur in generic situations. In this paper, we suggest a formulation for higher-order corrections of the geometrical optics expansion, applied to Horndeski theory which accommodates many dark energy models. At the level of the background, assuming that the derivative of the scalar field is nonvanishing and timelike, we choose the time slices to coincide with the contours of the scalar field. This choice of the background time slices is advantageous as the sound cones of both scalar and tensor gravitational waves are upright with respect to the background time slices whenever the scalar field behaves as a perfect fluid. We then analyze the equations of motion for scalar and tensor components of gravitational waves at the leading and next-to-leading order in the geometrical optics expansion, deriving the evolution equations for their amplitudes under certain conditions. In particular, for generalized Brans-Dicke theories, we find a simple description of equations for gravitational waves in terms of an effective metric.

Analyses of the full shape of the Baryon Oscillation Spectroscopic Survey (BOSS) DR12 power spectrum using the one-loop prediction from the effective field theory of large-scale structures (EFTBOSS) have led to new constraints on extensions to the $\mathrm{\Lambda }$ cold dark matter model, such as early dark energy (EDE), which has been suggested as a resolution to the “Hubble tension.” In this paper, we reassess the constraining power of the EFTBOSS on EDE in light of a correction to the normalization of BOSS window functions. Overall we find that constraints from EFTBOSS on EDE are weakened and represent a small change compared to constraints from Planck and the conventional baryon acoustic $\mathrm{oscillation}/f{\sigma }_8$ measurements. The combination of Planck data with EFTBOSS provides a bound on the maximal fractional contribution of EDE $f_{\mathrm{EDE}}<0.083$ at 95% C.L. (compared to $<0.054$ with the incorrect normalization and $<0.088$ without full-shape data) and the Hubble tension is reduced to $2.1\sigma$. However, the more extreme model favored by an analysis with just data from the Atacama Cosmology Telescope is disfavored by the EFTBOSS data. We also show that the updated $\mathrm{Pantheon}+\text{type}$ Ia supernova (SN1a) analysis can slightly increase the constraints on EDE. Yet, the inclusion of the SN1a magnitude calibration by SH0ES strongly increases the preference for EDE to above $5\sigma$, yielding $f_{\mathrm{EDE}}\sim {0.12}_{-0.02}^{+0.03}$ around the redshift $z_c={4365}_{-1100}^{+3000}$. Our results demonstrate that EFTBOSS data (alone or combined with Planck data) do not exclude the EDE resolution of the Hubble tension.

We explore the possibility of explaining the $W$ boson mass with an extra gauge boson mixing with the $Z$ boson at tree level. Extra boson mixing with the $Z$ boson will change the expression of the $Z$ boson mass, thus altering the $W$ boson mass. We explore two models in this work. We find that in the derivative portal dark matter model there are parameter spaces which can give the observed $W$ boson mass, as well as the observed dark matter, relic density. These parameters’ spaces can also fulfill the constraints from the electroweak oblique parameters and dark matter indirect detection. In the U(1) extension model, the kinetic mixing between extra boson and $B$ boson can also give the observed $W$ boson mass. However, to fulfill the electroweak oblique parameters’ fit, the kinetic mixing in the U(1) model can only contribute about 27 MeV extra mass to the Standard Model $W$ boson mass. Both models indicate the extra vector boson with the best fit mass around 120 GeV.

Single-photon atom gradiometry is a powerful experimental technique that can be employed to search for the oscillation of atomic transition energies induced by ultralight scalar dark matter (ULDM). In the sub-Hz regime, the background is expected to be dominated by gravity gradient noise (GGN), which arises as a result of mass fluctuations around the experiment. In this work, we model the GGN as surface Rayleigh waves, and we construct a likelihood-based analysis that consistently folds GGN into the sensitivity estimates of vertical atom gradiometers in the frequency window between ${10}^{-3}\mathrm{Hz}$ and 1 Hz. We show that in certain geological settings GGN can be significantly mitigated when operating a multigradiometer configuration, which consists of three or more atom interferometers in the same baseline. Multigradiometer experiments, such as future versions of AION and MAGIS-100, have the potential to probe regions of scalar ULDM parameter space in the sub-Hz regime that have not been excluded by existing experiments.