We report a precise measurement of the ratio of branching fractions $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_S^0{\pi }^0)/\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})$ using $980{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ data from the Belle experiment. We obtain a value of $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_S^0{\pi }^0)/\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})=0.339\pm 0.002\pm 0.009$, where the first and second uncertainties are statistical and systematic, respectively. This Belle result is consistent with the previous measurement from the CLEO experiment but has a fivefold improvement in precision. By combining our result with the world average $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})$, we obtain the absolute branching fraction $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_S^0{\pi }^0)=(2.12\pm 0.01\pm 0.05\pm 0.10)\%$, where the uncertainties are statistical, systematic, and the uncertainty in the absolute branching fraction scale $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})$, respectively. This measurement can shed light on hadronic decay mechanisms in charmed baryon decays.

Using a sample of $(10087\pm 44)\times {10}^{6}J/\psi$ events collected with the BESIII detector at the BEPCII collider, the first evidence for the doubly Okubo-Zweig-Iizuka (OZI)-suppressed decay ${\eta }_c\to \omega \varphi$ is reported with a significance of $4.0\sigma$. The branching fraction of ${\eta }_c\to \omega \varphi$ is measured to be $\mathcal{B}({\eta }_c\to \omega \varphi )=(3.86\pm 0.92\pm 0.62)\times {10}^{-5}$, where the first uncertainty is statistical and the second is systematic. This result provides valuable insights into the underlying mechanisms of charmonium decays, particularly for processes such as ${\eta }_c\to VV$ (where $V$ represents a vector meson).

This paper presents the multiplicity of neutral and charged hadrons produced in $90\mathrm{GeV}/c$ proton-carbon interactions from a dataset taken by the NA61/SHINE experiment in 2017. Particle identification via $\mathrm{d}E/\mathrm{d}x$ was performed for the charged hadrons ${\pi }^{\pm }$, $K^{\pm }$, and $p/\overline{p}$; the neutral hadrons $K_S^0$, $\mathrm{\Lambda }$, and $\overline{\mathrm{\Lambda }}$ were identified via an invariant mass analysis of their decays to charged hadrons. Double-differential multiplicity results as a function of laboratory momentum and polar angle are presented for each particle species; these results provide vital constraints on the predicted neutrino beam flux for current and future long-baseline neutrino oscillation experiments.

The “sterile neutrino” hypothesis, which predicts a fourth neutrino flavor that does not interact through the weak nuclear force, has drawn considerable attention as it presents a potential dark matter candidate. We present an updated analysis of the 1981 Institut Laue-Langevin (ILL) reactor antineutrino experiment to reevaluate its impact on the sterile neutrino hypothesis. Existing global analyses exclude the ILL experiment, use a ${\chi }^2$ formulation that severely overestimates systematic error, or perform underpowered magnitude-only analyses. The most comprehensive existing analysis centered on the ILL experiment, by Cogswell et al., rectifies these issues and accounts for an 18% upward correction to the expected neutrino flux. Cogswell et al. identify a $2.9–3.6\sigma$ discrepancy (depending on flux estimate) resolved by the introduction of a sterile neutrino. We expand on this study while correcting an error described in the Erratum, providing a replication of the results of the original ILL study prior to conducting a spectral analysis. Using the Daya Bay flux (Huber-Mueller flux with ${}^{235}\mathrm{U}$ reduced by 7.8%), our most preferred values of $\mathrm{\Delta }{m}^2$ and ${\sin }^{2}2\theta$ are $2.35{\mathrm{eV}}^2$ and 0.245, respectively, at a $\mathrm{\Delta }{\chi }^2$ value of $-4.38$ ($2.09\sigma$). We conclude that the evidence for a sterile neutrino produced by ILL is substantially weaker than posited by Cogswell et al. This result partially reconciles the gap between the reactor anomaly and the absence of sterile neutrino detection in recent experiments such as PROSPECT and STEREO.

A measurement of the $WZ\gamma$ triboson production cross section is presented. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$ recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$. The analysis focuses on the final state with three charged leptons, ${\ell }^{\pm }\nu {\ell }^{+}{\ell }^{-}$, where $\ell =e$ or $\mu$, accompanied by an additional photon. The observed (expected) significance of the $WZ\gamma$ signal is 5.4 (3.8) standard deviations. The cross section is measured in a fiducial region, where events with an ℓ originating from a tau lepton decay are excluded, to be $5.48\pm 1.11\mathrm{fb}$, which is compatible with the prediction of $3.69\pm 0.24\mathrm{fb}$ at next-to-leading order in quantum chromodynamics. Exclusion limits are set on anomalous quartic gauge couplings and on the production cross sections of massive axionlike particles.

In general relativity, gravitational memory describes the lasting change in the separation and relative velocity of freely falling detectors after the passage of gravitational waves (GWs). In this paper, we elucidate the relation between Bondi-Metzner-Sachs transformations at future null infinity and the description of gravitational memory in local synchronous coordinates, commonly used in GW detectors like LISA. We show that gravitational memory corresponds to large residual diffeomorphisms in this gauge, such as volume-preserving spatial rescalings. We reproduce the associated soft theorems for scattering amplitudes. Finally, we derive novel soft theorems for equal-time (in-in) correlation functions, which are recognized as the flat space analogues of inflationary consistency relations with a soft tensor mode. These relations provide a pathway toward uncovering deeper connections between gravitational memory and cosmological correlators.

Here we investigate a general class of massless local theories of spin 2 and spin 3, both invariant under generalized transverse diffeomorphisms (TDiff). We identify the ghost-free region in their parameter space and show the relationship of those models with the “doublet” action stemming from the tensionless limit of the open bosonic string field theory (for symmetric tensors). The connection is implemented via a nonlocal field redefinition which introduces a Stueckelberg-like field of rank 0 (rank 1) for the spin-2 (spin-3) case. An apparent mismatch between most TDiff models and the “doublet” action has led us to prove a nontrivial equivalence among TDiff models, thereby restoring consistency. Any point in the parameter subspace of ghost-free TDiff models is equivalent to any other one within that subspace. In particular, they are all physically equivalent to their simplest versions known as Maxwell-like models. So, the physical TDiff models seem to differ from each other by a Becchi-Rouet-Stora-Tyutin cohomologically trivial term.

Gravitational memory, which describes the permanent shift in the strain after the passage of gravitational waves, is directly related to Weinberg’s soft graviton theorems and the Bondi-Metzner-Sachs (BMS) symmetry group of asymptotically flat space-times. In this work, we provide an equivalent description of the phenomenon in local coordinates around gravitational wave detectors, such as transverse-traceless (TT) gauge. We show that gravitational memory is encoded in large residual diffeomorphisms in this gauge, which include time-dependent anisotropic spatial rescalings, and prove their equivalence to BMS transformations when translated to TT gauge. We then derive the associated Ward identities and associated soft theorems, for both scattering amplitudes and equal-time (in-in) correlation functions, and explicitly check their validity for planar gravitational waves. The in-in identities are recognized as the flat-space analog of the well-known inflationary consistency relations.

This paper presents an improvement to the four-dimensional spinfoam model with cosmological constant ($\mathrm{\Lambda }$-SF model) in loop quantum gravity. The original $\mathrm{\Lambda }$-SF model, defined via $\mathrm{SL}(2,\mathbb{C})$ Chern-Simons theory on graph-complement 3-manifolds, produces finite amplitudes and reproduces curved 4-simplex geometries in the semiclassical limit. However, extending the model to general simplicial complexes necessitated ad hoc, nonuniversal phase factors in face amplitudes, complicating systematic constructions. We resolve this issue by redefining the vertex amplitude using a novel set of phase space coordinates that eliminate the extraneous phase factor, yielding a universally defined face amplitude. Key results include: (1) The vertex amplitude is rigorously shown to be well defined for Chern-Simons levels $k\in 8\mathbb{N}$, compatible with semiclassical analysis ($k\to \infty$). (2) The symplectic structure of the Chern-Simons phase space is modified to accommodate $\mathrm{SL}(2,\mathbb{C})$ holonomies, relaxing quantization constraints to $\mathrm{Sp}(2r,\mathbb{Z}/4)$. (3) Edge amplitudes are simplified using constraints aligned with colored tensor models, enabling systematic gluing of 4-simplices into complexes dual to colored graphs. (4) Stationary phase analysis confirms consistency of critical points with prior work, recovering Regge geometries with curvature determined by $\mathrm{\Lambda }$. These advancements streamline the spinfoam amplitude definition, facilitating future studies of colored group field theories and continuum limits of quantum gravity. The results establish a robust framework for 4D quantum gravity with nonzero $\mathrm{\Lambda }$, free of previous ambiguities in face amplitudes.

Consideration is being given to upgrading the SuperKEKB electron-positron collider with the introduction of electron-beam polarization. This would enable a unique precision electroweak physics program that opens new ways to search for physics beyond the Standard Model. The upgrade would enable Belle II to make a number of high precision measurements, one of which is the left-right cross-section asymmetry in the $e^{+}{e}^{-}\to e^{+}{e}^{-}$ Bhabha scattering process. The expected level of precision in such a measurement will require the theoretical values of the asymmetry to be calculated at least to the next-to-leading order (NLO) level, and the implementation of simulation event generators with a similar level of precision. In this study, we compare the calculations of the ReneSANCe Monte Carlo generator with those of an independent NLO calculation to determine the level of agreement in this process. An average difference of 0.3% between the calculations is found. Using the published Belle II efficiency for selecting Bhabha events and assuming a $40{\mathrm{ab}}^{-1}$ dataset having 70% polarization, the projected uncertainty on the weak mixing angle, ${\sin }^2{\theta }_W$, is calculated using ReneSANCe to be $\pm 0.00032$ or better. Combining this with left-right asymmetry measurements from muons and taus under the assumption of lepton universality yields a projected overall uncertainty of $\pm 0.00019$ on ${\sin }^2{\theta }_W$ with SuperKEKB upgraded to have polarized electron beams.

We investigate the massless scalar perturbations of the Plebański-Demiański black hole considering the general case that admits all nonzero parameters. This case, which is the most generic black hole spacetime in general relativity, is characterized by mass, spin, acceleration, electric and magnetic charges, Newman-Unti-Tamburino parameter, and cosmological constant. Employing conformal transformations, we can separate the massless scalar field equation and reduce the effective potential in the radial perturbation equation into the Pöschl-Teller potential in the near-Nariai limit in which the event and cosmo-acceleration horizons are close. This allows us to obtain an exact analytical solution of the quasinormal frequency, implying that the decay rate of the field is quantized depending only on the surface gravity of the black hole.

The direct detection of gravitational waves by LIGO has confirmed Einstein’s general relativity (GR) and sparked rapid growth in gravitational wave (GW) astronomy. However, subtle post-Newtonian (PN) deviations observed during the analysis of high signal-to-noise ratio events from the observational runs suggest that standard waveform templates, which assume strict adherence to GR, might overlook signals from alternative theories of gravity. Incorporating these exotic signals into traditional search algorithms is computationally infeasible due to the vast template space required. This paper introduces a proof-of-principle deep learning framework for detecting exotic GW signals, leveraging neural networks trained on GR-based templates. Through their generalization ability, neural networks learn intricate features from the data, enabling the detection of signals that deviate from GR. We present the first study evaluating the capability of deep learning to detect beyond-GR signals, including a variety of PN orders. Our model achieves rapid and accurate identification of exotic GW signals across different luminosity distances, with performance comparable to GR-based detections. In particular, applying the model to the GW150914 event demonstrates excellent performance, highlighting the potential of AI-driven methods for detecting previously overlooked signals beyond GR. This work paves the way for new discoveries in gravitational wave astronomy, enabling the detection of signals that might escape traditional search pipelines.

We introduce an extension of the evolution mapping framework to cosmological models that include massive neutrinos. The original evolution mapping framework exploits a degeneracy in the linear matter power spectrum when expressed in Mpc units, which compresses its dependence on cosmological parameters into those that affect its shape and a single extra parameter ${\sigma }_{12}$, defined as the rms linear variance in spheres of radius 12 Mpc. We show that by promoting the scalar amplitude of fluctuations, $A_{\mathrm{s}}$, to a shape parameter, we can additionally describe the suppression due to massive neutrinos at any redshift to sub-0.01% accuracy across a wide range of masses and for different numbers of mass eigenstates. This methodology has been integrated into the public comet package, enhancing its ability to emulate predictions of state-of-the-art perturbative models for galaxy clustering, such as the effective field theory (EFT) model. Additionally, the updated software now accommodates a broader cosmological parameter space for the emulator, enables the simultaneous generation of multiple predictions to reduce computation time, and incorporates analytic marginalization over nuisance parameters to expedite posterior estimation. Finally, we explore the impact of different infrared resummation techniques on galaxy power spectrum multipoles, demonstrating that any discrepancies can be mitigated by EFT counterterms without impacting the cosmological parameters.

We perform a detailed investigation of interacting phantom cosmology, by applying the powerful method of dynamical system analysis. We consider two well-studied interaction forms, namely one global and one local one, while the novel ingredient of our work is the examination of new potentials for the phantom field. Our analysis shows the existence of saddle matter-dominated points, stable dark-energy dominated points, and scaling accelerating solutions, that can attract the Universe at late times. As we show, some of the stable accelerating scaling attractors, in which dark matter and dark energy can coexist, alleviating the cosmic coincidence problem, are totally new, even for the previously studied interaction rates, and arise purely from the novel potential forms.

The recent evidence of nanohertz (nHz) gravitational wave (GW) background by pulsar timing array (PTA) collaborations has sparked considerable interest in understanding its astrophysical origins, particularly regarding supermassive black hole binaries (SMBHBs). In this work, we focus on individual SMBHBs that will be hopefully detected in upcoming PTA observations. The effect of nHz GWs on the pulse arriving times is in general decomposed as a pulsar term and an Earth term, where the pulsar term encodes the pulsar-Earth distance as a phase shift relative to the Earth term, but is usually treated as an extra noise source since the pulsar distance is in general not well measured with uncertainty larger than the wavelength of nHz GWs. We propose that the pulsar distance could be constrained by combining the phase information of multiple SMBHBs that are individually resolved. Using Markov chain Monte Carlo simulations, we demonstrate that the pulsar distances can be measured to better than 0.4 pc (1 pc) for pulsars at $D\sim 1\mathrm{kpc}$ ($\sim 2.2\mathrm{kpc}$) with 30 years of observations by a 20-pulsar PTA with a noise level of ${\sigma }_{\mathrm{n}}=20\mathrm{ns}$ in the square kilometre array era.

Parameter estimation of gravitational wave data is often computationally expensive, requiring simplifying assumptions such as circularization of binary orbits. Although, if included, the subdominant effects like orbital eccentricity may provide crucial insights into the formation channels of compact binary mergers. To address these challenges, we present a pipeline strategy leveraging minimally modeled waveform reconstruction to identify the presence of eccentricity in real time. Using injections ($40M_{\odot }$ binary black hole signals), we demonstrate that ignoring eccentricity (with values larger than $\sim 0.15$ estimated at 20 Hz ($e_{20}$)) leads to significant biases in parameter recovery, including chirp mass estimates falling outside the 90% credible interval. Waveform reconstruction shows that inconsistencies increase with eccentricity, and this behavior is consistent for different mass ratios. Our method enables low-latency inferences of binary properties supporting targeted follow-up analyses and can be applied to identify any physical effect of measurable strength.

At present, there is no consensus on whether the spectral break in the cosmic-ray flux of all elements around 4 PeV is a general characteristic of the Milky Way or is determined by a combination of factors that significantly affect the energy position of the knee. We argue that considering the anisotropic propagation of cosmic rays within a realistically modeled Galactic magnetic field enables an accurate description of the spectral break without invoking a source-related cutoff energy and naturally predicts a spatial dependence of this phenomenon. To demonstrate this, we constructed a 3D diffusion propagation model with a diffusion tensor within a two-component magnetic field and determined both the local cosmic-ray spectrum and the spectra for specific regions of the Milky Way. We found that the spectral break is well reproduced by the energy dependence of the diffusion tensor components and appears at different energies in various regions of the Galaxy due to the inclusion of the turbulent component of the magnetic field. Furthermore, the spectral slope is determined by the degree of anisotropy in cosmic-ray diffusion. The model is based on the calculation of the diffusion tensor components using the trajectory method and on the direct solution of the stationary diffusion equation with a fully anisotropic diffusion tensor that includes all nine components in the global Galactic coordinate system, accounting for off-diagonal terms arising from the projection of locally field-aligned diffusion. We calculated the integral flux of diffuse gamma rays in the inner and outer regions of the Galaxy based on the cosmic-ray proton and nuclei spectra obtained within our model, which features a spatially dependent position of the knee. The resulting spectral shape of the diffuse gamma-ray flux is consistent with experimental data from LHAASO and Fermi-LAT.

We study the four-body heavy baryon decay, including two leptons in the final state, of the form $B_A\to B_{B}P{\ell }_{\alpha }{\ell }_{\beta }$, which can be either a lepton number conserving (LNC) or a lepton number violating (LNV) process (where $B$, $P$, and $\ell$ are baryons, pseudoscalar mesons, and leptons, respectively), including all kinematic allowed lepton pair possibilities. We work beyond the simplified assumption of a single heavy Majorana neutrino mixing with the active sector, considering potential interference effects when including two nearly degenerate heavy Majorana neutrinos. Particularly, we provide a first estimate of the decay channels involving different flavors for the external leptons (e.g., muon-tau) and elaborate on the interference pattern due to leptons exchange. We show that the results for the two heavy almost degenerate neutrinos can be recast into a single Majorana neutrino and exhibit the features for both the LNC and LNV scenarios. We determine the potential exclusion region for the mass and heavy-light mixing parameters, of the neutrinos driving the decay, including finite size detector effects, and compare them with those from direct searches and $\tau$ and meson decays. We also obtain the branching ratio as a function of the heavy neutrino mass for the current upper limit of the heavy-light mixings.

Cosmic strings are powerful witnesses to cosmic events including any period of early matter domination. If such a period of matter domination was catalyzed by metastable, long-lived particles, then there will be complementary signals to ascertain the nature of the dark sector in experiments detecting primordial features in the gravitational wave (GW) power spectrum and laboratory searches for long-lived particles. We give explicit examples of global and local $U(1)$ gauge extended dark sectors to demonstrate such a complementarity as the union of the two experiments reveals more information about the dark sector than either experiment. Demanding that Higgs-portal long-lived scalar be looked for, in various experiments such as DUNE, FASER, FASER-II, MATHUSLA, and SHiP, we identify the parameter space that leads to complementary observables for GW detectors such as the Laser Interferometer Space Antenna and Einstein Telescope.

Addressing the fermion flavor structures using modular invariance is a challenging task in the framework of quark-lepton unification. Building on recent applications of modular symmetry in nonsupersymmetric models, we propose the first renormalizable $SU(5)$ grand unified theory incorporating level 3 nonholomorphic modular symmetry, ${\mathrm{\Gamma }}_3\simeq A_4$. This framework constrains Yukawa couplings to polyharmonic Maaß forms, significantly reducing the number of free parameters while enhancing the predictive power of the models. We present a comprehensive analysis of fermion masses and mixing while tackling key grand unified theory (GUT) queries such as gauge coupling unification and proton decay. Beyond the minimal $SU(5)$ framework, the Higgs sector incorporates the $45_H$ dimensional Higgs field crucial in differentiating the masses of down quarks and charged leptons, and the fermion sector is extended with three right-handed neutrinos enabling neutrino masses via the type-I seesaw mechanism. We analyze two benchmark models with distinct modular weight and $A_4$ charge assignments. The predicted effective Majorana mass $m_{\beta \beta }$ values align with current neutrinoless double-beta decay experiments, and the effective neutrino mass $m_{\beta }$ is within the reach of future beta decay searches. The predicted sum of neutrino masses, $\sum m_i$, satisfies the upper bound set by recent cosmological observations. The gauge coupling unification is achieved through a light scalar triplet ${\varphi }_3\sim (3,3,-1/3)$ and a scalar octet ${\varphi }_5\sim (8,2,1/2)$ belonging to the $45_H$ Higgs, while proton decay constraints require that the contribution of the $45_H$ Higgs to the up-quark mass matrix remains highly suppressed.