We present for the first time an analysis of high-frequency gravitational wave emission from proto-neutron star (PNS) in core collapse supernovae (CCSNe) that combines spatial decomposition and modal decomposition to both source and characterize the emission using three-dimensional CCSN simulations. Our analysis is based on three-dimensional CCSN simulations initiated from a solar-metallicity $15\text{−}{M}_{\odot }$ progenitor and a zero-metallicity $25\text{−}{M}_{\odot }$ progenitor. We decompose the gravitational wave strains into five spatial regions, and find that strains are initially largest in the PNS surface layers from accretion and later largest from the Ledoux convective and convective overshoot regions deep within the PNS. We compute the fractional gravitational wave luminosity as a function of enclosed radius and observe that the majority of the luminosity moves from the PNS surface at $\sim 100$ ms after bounce to deep within the PNS at later times. Using a self-consistent perturbative analysis, we investigate the evolution of the quadrupolar, nonradial, quasinormal oscillation modes of the PNS. We find that the frequency of the evolving high-frequency component of the gravitational wave signal is well matched to the eigenfrequency evolution of the ${{}^{2}g}_2$ mode initially, then the ${{}^{2}g}_1$ mode, and finally the ${}^{2}f$ mode, as labeled by the Generalized Cowling Nomenclature. We show that the ${}^{2}g$ modes emit most of their power in gravitational waves initially from the PNS surface region, but within a few 100 ms after bounce, it is the convective overshoot region of the PNS, just above the region of sustained Ledoux convection, that emits the most gravitational wave power for the ${{}^{2}g}_1$ mode. Eventually, the ${}^{2}f$ mode is the dominant mode producing gravitational waves, and these waves are emitted primarily from the convective overshoot region. Thus, with three interconnected analyses, we show that, while the gravitational wave emission is global, stemming from multiple regions in and around the PNS, it nonetheless remains possible to source the dominant contributions to it. We find that the source of the high-frequency gravitational wave emission from the PNS in CCSNe is more complex than assessed by other methods, as well as time dependent, first emitted mainly by ${}^{2}g$ modes driven by accretion onto the PNS and later emitted by the ${}^{2}f$ mode driven by sustained Ledoux convection.

We report the identification of two statistically significant quasiperiodic oscillations in the weekly binned $\gamma$-ray light curve of the flat-spectrum radio quasar PKS 0805-07, observed by Fermi-LAT over the period MJD 59047.5-59740.5. By applying a suite of complementary time-series analysis techniques, we identify periodic signatures at $\sim 255$ and $\sim 112\mathrm{days}$. These techniques include the Lomb-Scargle periodogram, weighted wavelet Z-transform, REDFIT, date-compensated discrete Fourier transform , phase dispersion minimization, and the string-length method. The reliability of these signals is supported by high local significance ($\ge 99\%$) in all methods and reinforced through phase-folding. Model selection using the Akaike information criterion and Bayesian information criterion strongly supports a two-component periodic model. The detection of dual quasiperiodic oscillations is rare among blazars and suggests complex variability mechanisms. Although a binary supermassive black hole scenario could be considered given the source’s high redshift ($z=1.837$), the short periodicities are difficult to reconcile with orbital motion unless invoking extreme parameters. Double-sine model fitting reveals that the oscillatory components have comparable amplitudes but are out of phase, suggesting a potential beating phenomenon due to interference. This amplitude-modulated variability is consistent with a geometric origin, most plausibly jet precession driven by Lense-Thirring torques, superimposed with a secondary process such as polar jet oscillation. Doppler factor modulation arising from these effects can account for the observed flux variations without requiring an unrealistically compact binary.

Ultraheavy dark matter candidates evade traditional direct detection experiments due to their low particle flux. We explore the potential of large underwater acoustic arrays, originally developed for ultrahigh energy neutrino detection, to detect ultraheavy dark matter interactions. These particles deposit energy via nuclear scattering while traversing seawater, generating thermoacoustic waves detectable by hydrophones. We present the first robust first-principles calculation of dark matter-induced acoustic waves, establishing a theoretical framework for signal modeling and sensitivity estimates. Our framework incorporates frequency-dependent attenuation effects, including viscous and chemical relaxation, not considered in previous calculations. A sensitivity analysis for a hypothetical $100{\mathrm{km}}^3$ hydrophone array in the Mediterranean Sea demonstrates that such an array could extend sensitivity to the previously unexplored mass range of $0.1-10\mathrm{\mu }\mathrm{g}$ ($\sim {10}^{20}–{10}^{23}\mathrm{GeV}$), with sensitivity to both spin-independent and spin-dependent interactions. Our results establish acoustic detection as a complementary dark matter search method, enabling searches in existing hydrophone data and informing future detector designs.

We obtain stringent bounds on neutrino quantum decoherence from the analysis of SN1987A data. We show that for the decoherence model considered here, which allows for neutrino loss along the trajectory, the bounds are many orders of magnitude stronger than the ones that can be obtained from the analysis of data from reactor neutrino oscillation experiments or neutrino telescopes.

Violent astrophysical events, including core-collapse supernovae and binary neutron star mergers, can result in rotating neutron stars with diverse degrees of differential rotation. Oscillation modes of these neutron stars could be excited and emit strong gravitational waves. Detecting these modes may provide information about neutron stars, including their structures and dynamics. Hence, dynamical simulations were employed to construct relations for quantifying the oscillation mode frequency in previous studies. Specifically, linear relations for the frequencies of fundamental $l=0$ quasiradial mode $f_F$ and fundamental $l=2$ quadrupolar mode $f_{{}^{2}f}$ were constructed by simulations with the Cowling approximation. Nevertheless, these relations can overestimate $f_F$ and underestimate $f_{{}^{2}f}$ up to $\sim 30\%$. Furthermore, it has yet to be fully studied how the degree of differential rotation affects $f_F$ and $f_{{}^{2}f}$. Here, for the first time, we consider both various degrees of differential rotation $\tilde{A}$ and dynamical spacetime to construct linear relations for quantifying $f_F$ and $f_{{}^{2}f}$. Through 2D axisymmetric simulations, we first show that both $f_F$ and $f_{{}^{2}f}$ scale almost linearly with the stellar compactness $M/R$ for different values of $\tilde{A}$. We also observe the quasilinear relations for both $f_F$ and $f_{{}^{2}f}$ with the kinetic-to-binding energy ratio $T/|W|$ for different $\tilde{A}$ values. Finally, we constructed linear fits that can quantify $f_F$ and $f_{{}^{2}f}$ by $T/|W|$. Consequently, this work updated the relations for the fundamental modes of rotating neutron stars with differential rotations in dynamical spacetime.

We consider a theory of fermions interacting with a (in general, non-Abelian) gauge field. The theory is assumed to be essentially inhomogeneous, which might be provided by nontrivial background fields interacting with both fermions and gauge bosons. For this theory, a version of Wigner-Weyl calculus is developed, in which the Wigner transformation of the fermion Green function belongs to a matrix representation of the gauge group. We demonstrate the power of the proposed formalism through the representation of responses of vector and axial currents to the gauge field strength through the topological invariants composed of the Wigner transformed two-point Green functions. This way, a new family of nondissipative transport phenomena is introduced. In particular, we discuss the non-Abelian versions of the chiral separation effect and of the quantum Hall effect.

In this paper, we investigate the helicity form factors (HFFs) of the $B_{(s)}$-meson decay into a scalar meson with a mass larger than 1 GeV, i.e., $B\to a_0(1450)$, $B_{(s)}\to K_0^{*}(1430)$, and $B_s\to f_0(1500)$ by using the light-cone sum rules approach. We take the standard currents for correlation functions. To enhance the precision of our calculations, we incorporate the next-to-leading order (NLO) corrections and retain the scalar meson twist-3 light-cone distribution amplitudes. Furthermore, we extend the HFFs to the entire physical $q^2$ region employing a simplified $z$-series expansion. At the point of $q^2=1{\mathrm{GeV}}^2$, all NLO contributions to the HFFs are negative, with the maximum contribution around 25%. Then, as applications of these HFFs, we analyze the differential decay widths, branching ratios, and lepton polarization asymmetries for the semileptonic $B_{(s)}\to S\ell {\overline{\nu }}_{\ell }$, FCNC $B_{(s)}\to S\ell \overline{\ell }$ and rare $B_{(s)}\to S\nu \overline{\nu }$ decays. Our results are consistent with existing studies within uncertainties. The current data still suffer from large uncertainties and need to be measured more precisely, which can lead to a better understanding of the fundamental properties of light scalar mesons.

For the first time, we comprehensively examine the potential of a neutral-current interaction of reactor neutrino with ${}^{13}\mathrm{C}$ emitting a 3.685 MeV photon to identify the origin of the 5 MeV bump in reactor antineutrino spectra observed through the inverse beta decay process. This anomaly may be due to new physics, reactor antineutrino flux inaccuracies, or inverse beta decay systematics. The 3.685 MeV photon released during the deexcitation of ${}^{13}{\mathrm{C}}^{*}$ to its ground state is observable in liquid scintillator detectors. Remarkably, we confirm the powerfulness of our proposal by completely ruling out a new physics scenario explaining the bump from the existing NEOS data. We also explore the potential of current and forthcoming experiments, including solar neutrino studies at JUNO, pion and muon decay-at-rest experiments at OscSNS, and isotope decay-at-rest studies at Yemilab, to measure the cross section precisely enough to distinguish the expected bump and the theoretical flux models via our channel. Additionally, we propose a novel method to track the time evolution of reactor isotopes by analyzing the ${}^{13}\mathrm{C}$ signal, which yields critical insights into the contributions of ${}^{235}\mathrm{U}$ and ${}^{239}\mathrm{Pu}$ to the bump, acting as a robust tool.

The conservation of lepton flavor is a prediction of the Standard Model and is still an excellent approximate symmetry despite our observation of neutrino oscillations. Lepton flavor violation by one or two units has been discussed for decades, with several dedicated experiments exploring the vast model landscape but no discoveries so far. Here, we explore operators and processes that violate at least one lepton flavor by three units and identify testable signatures. In the Standard Model effective field theory, such operators already arise at mass dimension 7 and can be tested through their contributions to Michel parameters in leptonic decays. True neutrinoless charged-lepton flavor violation arises at mass dimension 10 and can realistically only be seen in the tau decay channels $\tau \to eee\overline{\mu }\overline{\mu }$ or $\tau \to \mu \mu \mu \overline{e}\overline{e}$, for example in Belle II. Testable rates for these tau decays require light new particles and subsequently predict an avalanche of remarkably clean but so-far unconstrained collider signatures.

While gluon fusion dominates Higgs pair production at the LHC, vector boson fusion (VBF) offers a unique window into beyond the Standard Model (BSM) physics through its distinctive kinematic features and direct sensitivity to Higgs-vector boson interactions. We perform a comprehensive analysis of double Higgs production via VBF in the Standard Model effective field theory (SMEFT), systematically investigating how dimension-6 and dimension-8 bosonic operators—particularly those involving field derivatives—can enhance the production rate. We identify the most relevant Wilson coefficients (WCs) affecting the trilinear Higgs coupling ($hhh$) and Higgs-vector boson interactions ($hVV$, $hhVV$). Using constraints from global fits and interpolating fit results for unconstrained WCs with naive dimensional analysis, we assess their effects on the $VV\to hh$ ($V=W,Z$) scattering amplitudes and cross sections. Our analysis includes a study of EFT convergence and validity in models with scalar extensions of the SM. Numerical simulations for the planned High-Luminosity LHC experiment (HL-LHC) in general reveal only a modest and challenging to detect enhancement of the VBF di-Higgs production rate over the SM prediction. However, we show that in optimistic scenarios, such a process could be observed at the HL-LHC. In certain cases, when the enhancement is dominated by the dimension-6 or dimension-8 operators containing field derivatives (and thus leading to stronger energy-dependent effects), this channel becomes competitive with di-Higgs production via gluon fusion. This work highlights the role of VBF di-Higgs production as a complementary channel for probing anomalous Higgs couplings and their impact on BSM physics.

The kinetically mixed dark photon is a simple, testable dark matter candidate with strong theoretical motivation. Detecting the feeble electric field dark photon dark matter produces requires extremely sensitive detectors. Bulk acoustic resonators (BARs), with their exceptionally high-quality phonon modes, are highly sensitive detectors, and have previously leveraged this sensitivity to search for gravitational waves in the MHz to GHz frequency range. The BAR phonons are typically read out by detecting the electric field generated by the BAR materials’ piezoelectricity. Here we show that this piezoelectricity also rewards such detectors sensitivity to dark photon dark matter, as the dark electric field can resonantly excite BAR phonons. A single 10 g piezoelectric BAR in a large, cold, environment can be orders of magnitude more sensitive to the kinetic mixing parameter than any current experiment, with only a month-long exposure and thermally limited backgrounds.

The current Large Hadron Collider (LHC) data show no clear indication of new physics and only incremental improvements are anticipated at the energy frontier in the near future. However, while the focus of the LHC has been on constraining TeV scale physics, new particles could still be hiding below the electroweak scale. In order to obtain sensitivity to a new light boson with couplings to SM fermions, a potentially promising decay channel, for resonances with mass $\gtrsim \mathcal{O}(10)\mathrm{GeV}$, would be the decay to $b\overline{b}$ pairs. The measurement of such signatures is challenging due to the trigger requirements at the LHC. In this work, we explore the LHC sensitivity to a light pseudoscalar, or axionlike particle (ALP), in the $b\overline{b}$ final state with an associated photon, using jet substructure techniques, in the mass range between 10 and 100 GeV. We obtain projected exclusions on the ALP-fermion coupling in a region of phase space which has not so far been probed by direct searches. We further discuss the impact that lower trigger thresholds may have on the LHC reach.

In this paper, we present an analysis of coincident particle production in ultraperipheral heavy ion collisions. In particular, we present the first detailed and differential predictions for coincident ${\rho }^0$ meson production in association with muon pair production, motivated by the recent ATLAS measurement of this process. These are found to describe the data very well, including the dependence of the coincidence fraction on the zero degree calorimeter selection and/or other kinematic constraints on the muons. Differential predictions at the level of various kinematic variables are presented, and the calculation is made publicly available in the superchic MC generator. We also present general results for coincident two-photon-initiated production focusing on muon and electron pair production; while the former is rather suppressed, the latter will be ubiquitous at threshold. The impact of coincident production on exclusivity vetoes in ultraperipheral measurements is in addition discussed.

We investigate the role of the QCD scale anomaly in the gravitational form factors of the nucleon—particularly the $D(t)$ form factor—as well as the associated stress distribution and internal forces, using a Skyrme model based on the scale-invariant chiral perturbation theory. A distinctive feature of this model is the inclusion of both the pion and the scalar meson, which respectively capture the effects of the current quark mass and gluonic quantum contributions to the scale anomaly. By varying the mass of the scalar meson, we evaluate the sensitivity of the gluonic scale anomaly to the nucleon properties. We find that the gluonic scale anomaly plays a crucial role in satisfying the stability conditions of the nucleon and provides an internal confining force. Moreover, we also evaluate the momentum-transfer dependence of $D(t)$, which closely reproduces the lattice QCD results. With an appropriate choice of the anomalous dimension associated with the quark mass, its forward-limit value (i.e., the $D$-term) also matches the lattice data well.

We study the full infrared dynamics of $2+1$ flavor quantum chromodynamics (QCD) with the functional renormalization group approach. We resolve self-consistently the glue dynamics as well as the dynamics of chiral symmetry breaking. The computation hosts no phenomenological parameter or external input. The only ultraviolet input parameters are the physical ones in QCD: the light and strange quark masses. They are adjusted to the physical ratios of the pion and kaon masses, divided by the pion decay constant. The results for other observables of current first-principles computations are in quantitative agreement with the physical ones. This work completes the series of papers, initiated and furthered in [SciPost Phys. 14, 069 (2023); SciPost Phys. 17, 148 (2024)], on dynamical chiral symmetry breaking and the emergence of mesonic bound states within the functional renormalization group. As a first application we discuss the formation of light mesonic bound states. Among other applications such as the phase structure of QCD, the current work paves the way for studying QCD parton distribution functions within the functional renormalization group approach to first-principles QCD.

Consistent chiral limit has been investigated in the curvature mass parametrized quark-meson (QM) model with the quark one-loop vacuum term (QMVT) employing the infrared regularized chiral perturbation theory predicted scaling of the pion, kaon decay constants $f_{\pi }$, $f_K$ and $M_{\eta }^2=m_{\eta }^2+m_{{\eta }^{\prime }}^2$ when the $\pi$ and $K$ meson masses are reduced as one moves away from the physical point in the Columbia plot. Comparing the QMVT model Columbia plots with the corresponding Columbia plots computed in the very recent work of Tiwari [Phys. Rev. D 111, 114014 (2025)], using the on-shell renormalized QM (RQM) model and the earlier work of Resch et al. [Phys. Rev. D 99, 076005 (2019)] using functional renormalization group techniques in the extended mean field approximation of the QM (e-MFA:QM-FRG) model, it has been estimated how the first, second, and crossover chiral transition regions in the $m_{\pi }-m_K$($m_{ud}-m_s$) and the $\mu -m_K$($\mu -m_s$) planes get modified by different methods of implementing the quark one-loop vacuum fluctuations in the QM model. Since both the e-MFA:QM-FRG and the QMVT model use curvature meson masses to fix the parameters and the dimensional regularization of vacuum divergences are incorporated equivalently, the differences in their results can be attributed to different methods of approaching the chiral limit. The first order regions in the QMVT model while being much smaller than those in the RQM model have similar features but moderately smaller area than those in the e-MFA:QM-FRG study. In going to the chiral limit, the vacuum mass $m_{\sigma }=530\mathrm{MeV}$ that is taken at the physical point does not change in the QMVT model whereas it decreases significantly in the e-MFA:QM-FRG study. Being different from the pole mass $m_{\sigma }=530\mathrm{MeV}$, the RQM model vacuum curvature mass $m_{\sigma ,c}$ increases toward the chiral limit from its minimum value at the physical point.

We systematically investigate the $CP$-averaged branching ratios and $CP$ violations ($CPV\mathrm{s}$) for the two-body hadronic decays ${\mathrm{\Lambda }}_b\to ph$, where $h$ runs through the mesons ${\pi }^{-}$, ${\rho }^{-}$, $a_1^{-}(1260)$, $K^{-}$, $K^{*-}$, $K_1^{-}(1270)$, and $K_1^{-}(1400)$, in the perturbative QCD approach to order ${\alpha }_s^2$ in the strong coupling. Various topological amplitudes are obtained by incorporating subleading-twist hadron distribution amplitudes, which exhibit reasonable hierarchical patterns, sizable strong phases, and non-negligible higher-power corrections. The predicted direct $CPV\mathrm{s}$ in ${\mathrm{\Lambda }}_b\to p{\pi }^{-},p{K}^{-}$, different from those in similar $B$ meson decays, are as small as the current data. The low $CPV$ in ${\mathrm{\Lambda }}_b\to p{\pi }^{-}$ results from the cancelation between the $S$- and $P$-wave $CPV\mathrm{s}$, while the one in ${\mathrm{\Lambda }}_b\to p{K}^{-}$ is determined by the tiny $S$-wave $CPV$. However, individual partial-wave $CPV\mathrm{s}$ can exceed 10%, consistent with direct $CPV\mathrm{s}$ in $B$ meson decays. The $CPV\mathrm{s}$ in the ${\mathrm{\Lambda }}_b\to p{K}_1^{-}(1270),p{K}_1^{-}(1400)$ channels are relatively larger. In particular, $CPV\mathrm{s}$ above 20% appear in the up-down asymmetries associated with the final-state angular distributions of ${\mathrm{\Lambda }}_b\to p{K}_1^{-}(1270),p{K}_1^{-}(1400)$, followed by the secondary $K_1\to K\pi \pi$ decays. These observables offer promising prospects for firmly establishing baryon $CPV\mathrm{s}$. The decay asymmetry parameters of ${\mathrm{\Lambda }}_b\to ph$ are also predicted for future experimental confrontations.

The ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{D}_s^{-}{K}^{+}{K}^{-}$ decay is observed for the first time using the data sample from proton-proton collisions recorded at a center-of-mass energy of 13 TeV with the LHCb detector, corresponding to an integrated luminosity of $6{\mathrm{fb}}^{-1}$. The ratio of branching fraction to that of ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{D}_s^{-}$ decays is measured as $0.0141\pm 0.0019\pm 0.0012$, where the first uncertainty is statistical and the second systematic. A search for hidden-charm pentaquarks with strangeness is performed in the ${\mathrm{\Lambda }}_c^{+}{D}_s^{-}$ system. No evidence is found, and upper limits on the production ratio of $P_{c\overline{c}s}(4338{)}^0$ and $P_{c\overline{c}s}(4459{)}^0$ pentaquarks relative to the ${\mathrm{\Lambda }}_c^{+}{D}_s^{-}$ final state are set at the 95% confidence level as 0.12 and 0.20, respectively.

A sample of $pp$ collision data, corresponding to an integrated luminosity of $5.4{\mathrm{fb}}^{-1}$ and collected by the LHCb experiment during LHC Run 2, is used to measure the ratio of the lifetime of the ${\mathrm{\Xi }}_b^0$ baryon to that of the ${\mathrm{\Lambda }}_b^0$ baryon, $r_{\tau }\equiv {\tau }_{{\mathrm{\Xi }}_b^0}/{\tau }_{{\mathrm{\Lambda }}_b^0}$. The value $r_{\tau }^{\mathrm{Run}2}=1.004\pm 0.009\pm 0.006$ is obtained, where the first uncertainty is statistical and the second systematic. This value is averaged with the corresponding value from Run 1 to obtain $r_{\tau }=1.004\pm 0.008\pm 0.005$. Multiplying by the known value of the ${\mathrm{\Lambda }}_b^0$ lifetime yields ${\tau }_{{\mathrm{\Xi }}_b^0}=1.475\pm 0.012\pm 0.008\pm 0.009\mathrm{ps}$, where the last uncertainty is due to the limited knowledge of the ${\mathrm{\Lambda }}_b^0$ lifetime. This measurement improves the precision of the current world average of the ${\mathrm{\Xi }}_b^0$ lifetime by about a factor of two, and is in good agreement with the most recent theoretical predictions.