The RES-NOVA project is an experimental initiative aimed at detecting neutrinos from the next galactic supernova using ${\mathrm{PbWO}}_4$ cryogenic detectors, operated at low temperatures in a low-background environment. By utilizing archaeological lead (Pb) as the target material, RES-NOVA leverages its high radiopurity, large nuclear mass, and the natural abundance of ${}^{207}\mathrm{Pb}$, making it well-suited for exploring both spin-independent and spin-dependent dark matter (DM) interactions via nuclear scattering. This work presents a background model developed for the RES-NOVA technology demonstrator and evaluates its implications for dark matter detection. Detailed calculations of nuclear matrix elements, combined with the unique properties of archaeological Pb, demonstrate RES-NOVA’s potential as a complementary tool to existing direct detection experiments for studying dark matter interactions. The experiment will conduct DM searches over a broad mass range spanning 4 orders of magnitude, from sub-$\mathrm{GeV}/c^2$ to $\mathrm{TeV}/c^2$. In the most optimistic scenario of 1 y of data taking, RES-NOVA is expected to probe DM-nucleon cross sections down to $1\times {10}^{-43}{\mathrm{cm}}^2$ and $2\times {10}^{-46}{\mathrm{cm}}^2$ for candidates with masses of $2\mathrm{GeV}/c^2$ and $20\mathrm{GeV}/c^2$, respectively.

In this paper, we present a new approximation for efficiently and effectively including heavy-lepton neutrino pair-production processes in neutrino transport simulations of core-collapse supernovae. In the neutrino-driven explosion mechanism, the electron neutrinos and antineutrinos are the main players in transporting the energy of the cooling PNS to the matter behind the shock. While heavy-lepton neutrinos, ${\nu }_x$, play a smaller role in the heating of the gain region, they dominate the cooling of the proto-neutron star (PNS) and therefore still play a crucial role in the explosion mechanism. In this study, we explore the impacts of modifications in the transport and formalisms of pair (${\nu }_x{\overline{\nu }}_x$) emission and absorption processes. We quantify the impact in terms of the emergent neutrino signal and the nature of the PNS convection and early cooling. For this, we perform a set of simulations, spherically symmetric and axisymmetric, of a $20M_{\odot }$ progenitor using two different state-of-the-art equations of state (EOS). First and foremost, we show that our new efficient approximation for neutrino pair production matches the results of a full treatment very well. Furthermore, for this progenitor, we show that the impact of the modifications is dependent on the EOS used, as the EOS drives the PNS evolution. The variations we explore, including variations due to the nucleon-nucleon bremsstrahlung formalism, have a comparatively smaller impact than the EOS has as a whole.

Due to interactions with dark matter, neutrinos can acquire refractive masses which explain the data from oscillation experiments. We study the effects of relic neutrinos with refractive masses on structure formation in the Universe. In the model with a light fermionic mediator, above the resonance energy, $E_R$, associated with the mass of the mediator, refractive masses have all the properties identical to the usual vacuum masses. Below the resonance, refractive masses decrease with neutrino energy, however, they cannot be used in the same way as usual masses. We study the dispersion relations and group velocities of such neutrinos and their dependence on redshift. We show that in the epoch of structure formation, relic neutrinos were ultrarelativistic and essentially massless particles for $E_R=(10-{10}^5)\mathrm{eV}$. This allows us to reconcile the values of masses extracted from oscillation experiments with the stringent bounds on sum of neutrino masses from cosmological surveys.

Studies of nonlinear quantum vacuum signals often model the driving laser fields as paraxial beams. This in particular holds for analytic approaches. While this allows for reliable predictions in most situations, there are also notable exceptions. A prominent example is the overestimation of the polarization-flipped signal photon yield in the collision of two equally focused, parallel polarized laser beams by a factor of about 6. In the present work, we identify the origin of this deficiency and devise a strategy to obtain accurate closed-form expressions also in cases challenging the conventional (leading order) paraxial beam model. We demonstrate the potential of our approach on the example of two linearly polarized laser pulses colliding at a generic collision angle.

We study the discovery potential for a light Higgs boson via $gg\to H_{\mathrm{SM}\text{−}\mathrm{like}}\to hh\to b\overline{b}\gamma \gamma$ process at the Large Hadron Collider (LHC). Focusing on the 2-Higgs Doublet Model Type-I, which can accommodate light neutral Higgs states, of $\mathcal{O}(100)\mathrm{GeV}$ or less in mass, while agreeing with theoretical and up-to-date experimental constraints, we explore the feasibility of a light $CP$-even Higgs state $h$ via the largely unexplored final state $b\overline{b}\gamma \gamma$ at Run-3 of the LHC. We further propose a few benchmark points for future searches.

We examine the minimal $\mathrm{U}(1{)}_{L_{\mu }-L_{\tau }}$ gauge model in light of the latest neutrino data, including neutrino oscillations, cosmological observations, direct mass measurements, and neutrinoless double-beta decay. Using the most conservative oscillation data, we find that normal ordering is excluded at approximately the 90% confidence level (CL). Incorporating cosmological constraints from cosmic microwave background observations strengthens this exclusion to about 95% CL, while further including baryon acoustic oscillation data increases it to nearly 99% CL. The inverted ordering is even more strongly disfavored. Our analysis is performed within a frequentist framework, minimizing sensitivity to prior assumptions inherent in Bayesian approaches. These results impose strong constraints on the viability of the minimal $\mathrm{U}(1{)}_{L_{\mu }-L_{\tau }}$ gauge model.

We look into the $D_s^{+}\to {\rho }^{+}\varphi$ and $D_s^{+}\to {\rho }^{+}\omega$ weak decays recently measured by the BESIII collaboration, which proceed very differently in a first step of the weak decay. While the first reaction proceeds directly via external emission, the second one does not go via external nor internal emission, what prompted the experimental team to claim that it proceeds via $W$-annihilation. We show in this work that the unexpectedly large rate of the $D_s^{+}\to {\rho }^{+}\omega$ has a different explanation since is it naturally obtained once final state interaction of the ${\rho }^{+}\varphi ,{\rho }^{+}\omega$ and $K^{*+}{\overline{K}}^{*0}$ channels is taken into consideration. The interaction of these channels produces the $a_0(1710)$ resonance, predicted long ago as a molecular state of these coupled channels, and only recently observed, and it is the presence of this resonance what makes the effect of the final state interaction very important in the weak decays and provides a natural explanation of the experimental decay rates at a quantitative level. We also take into account the $D_s^{+}\to {\rho }^{+}\omega$ decay in $P$- and $D$-waves empirically, and show that a good reproduction of the experimental results is obtained in this case.

We calculate the cross sections for the processes $e^{+}{e}^{-}\to J/\psi \eta$ and $e^{+}{e}^{-}\to J/\psi {\eta }^{\prime }$ at various c.m. energies $\sqrt{s}$. We first predict these cross sections by combining nonrelativistic QCD with light cone factorization. The predicted cross sections are on the order of several femtobarns for $e^{+}{e}^{-}\to J/\psi {\eta }^{\prime }$ and less than 1 fb for $e^{+}{e}^{-}\to J/\psi \eta$, which are significantly smaller than the experimental measurements. It is anticipated that the cross sections are dominated by resonant contributions when $\sqrt{s}$ is close to the resonance mass. In this study, we employ the vector meson dominance model to predict these resonant contributions. The effective coupling constants between the photon and the resonance, as well as between the resonance and $J/\psi \eta$ are extracted from the data either provided by the latest Particle Data Group (PDG) or predicted by theoretical calculations. Taking the predictions from the factorization calculation as the continuum contribution, we predict the cross section of $e^{+}{e}^{-}\to J/\psi \eta$ through a coherent sum of contributions from various resonances and the continuum. The relative phase angles between these contributions are determined through a least-${\chi }^2$ fit to the experimental data. We then compare our theoretical predictions with the experimental data. Additionally, we find our theoretical prediction for the cross section of $e^{+}{e}^{-}\to J/\psi \eta$ is significantly larger than those for $e^{+}{e}^{-}\to J/\psi {\eta }^{\prime }$ measured by the BESIII Collaboration.

The relation between parton and hadron multiplicity distributions is discussed. To obtain parton multiplicity distribution, we propose decomposition of the multiplicity distributions of final-state hadrons. Such a procedure offers hope for experimental testing of physical probes of quantum complexity.

We present the implementation of a new interface in vbfnlo 3.0 supporting all diboson and triboson processes with fully leptonic final states, enabling next-to-leading order $(\mathrm{NLO})+\mathrm{parton}$ shower (PS) matched calculations. To demonstrate its capabilities, we study parton shower effects in the triboson production process $pp\to e^{+}{\nu }_e{\mu }^{-}{\overline{\nu }}_{\mu }\gamma +X$ using herwig 7.3 with NLO QCD amplitudes from vbfnlo 3.0. We estimate uncertainties from scale variations and analyze the impact of generation-level cuts on parton shower events. This study showcases the new interface’s potential and provides insights into the interplay between fixed-order calculations and parton shower effects in multiboson production processes, crucial for precision measurements and beyond the Standard Model searches at the LHC and future colliders.

We investigate the properties of QCD axion at low temperature and moderate density in the Nambu-Jona-Lasinio model with instanton induced interactions by simultaneously considering the scalar and pseudoscalar condensates in both quark-antiquark and diquark channels. We derive the analytical dispersion relations of quarks with four-type condensates at nonzero theta angle $\theta =a/f_a$. The axion mass, quartic self-coupling, and the axion potential are calculated in both the chiral symmetry breaking and two-flavor color superconducting phases. Using the commonly adopted model parameters, we find that, due to the emergence of color superconductivity, the chiral phase transition not only does not lead to a significant decrease in axion mass and self-coupling but rather results in an obvious enhancement of them. As a $\theta$ function, the axion potential exhibits an approximate period of $\pi$, which is quite different from the case without considering the color superconductivity. The surface tension of axion domain wall is also calculated in the presence of color superconductivity.

We construct relativized mock meson states for heavy quarkonium, where the Dirac spinors import kinetic relativistic correction and the dynamic wave functions are the same as those solved from the Schrödinger equation. We find that the relativistic correction imported by Dirac spinors is crucial to study the two-photon transition form factors. Using relativized mock meson states, we give credible predictions for the two-photon transition form factors and decay widths of ${\eta }_{c,b}(n{{}^{1}S}_0)$ and ${\chi }_{c,b}(n{{}^{3}P}_0)$ ($n=1$, 2, 3).

The challenges in neutrino-nucleus cross section modeling and its impact on neutrino oscillation experiments are widely recognized. However, a comprehensive and theoretically robust estimation of cross section uncertainties has been lacking, and few studies have quantitatively examined their impact on oscillation measurements. In this work, we evaluate the effect of cross section uncertainties on oscillation parameters using setups inspired by NOvA and DUNE. To characterize these uncertainties, we adopt multiple neutrino-nucleus event generators and simulate a realistic experimental procedure that incorporates near-detector data and near-to-far-detector extrapolation. Our results confirm that cross section uncertainties cannot significantly bias oscillation results in current statistics-dominated experiments like NOvA. However, they could lead to substantial bias for future systematics-dominated experiments like DUNE, even when near-detector data are employed to mitigate uncertainties. These findings underscore the need for further studies on the quantitative impacts of cross section modeling, improved strategies to utilize near-detector data and the PRISM concept, and more robust cross section models to optimize the success of future experiments.

In neutrino experiments sensitive to multiple flavors, the analyzers may be presented with a choice of treating the uncertainties on the respective cross sections in a correlated or an uncorrelated manner. This study focuses on the charged current deep inelastic scattering (CC DIS) channel in experiments sensitive to both muon and tau neutrinos. We evaluate the ratio of the leading-order ${\nu }_{\tau }$ and ${\nu }_{\mu }$ cross sections and derive its uncertainty from the underlying parton distribution functions (PDFs). We find that, for neutrino energies above 8 GeV, the PDF-driven uncertainty on the cross section ratio is less than 1.5%, with a larger (up to 9%) variation seen in antineutrinos at the lowest DIS energies. These results suggest that for atmospheric tau neutrino appearance analyses, the uncertainties in ${\nu }_{\tau }$ and ${\nu }_{\mu }$ DIS cross sections should be coupled, while separate treatment for the two flavors may be warranted in long-baseline experiments with an antineutrino beam. We further explore the role of the invariant hadronic mass threshold defining the onset of the DIS regime. We argue that its impact may be incorporated only if it is applied to both DIS and resonance cross sections, and if the correlations with other DIS and resonance cross section parameters are taken into account.

We present a measurement of the ratio of partial branching fractions of the semileptonic inclusive decays, $\overline{B}\to X_u\ell \overline{\nu }$ to $\overline{B}\to X_c\ell \overline{\nu }$, where $\ell =(e,\mu )$, using the full Belle sample of $772\times {10}^{6}B\overline{B}$ pairs collected at the $\mathrm{\Upsilon }(4S)$ resonance. The identification of inclusive $\overline{B}\to X_u\ell \overline{\nu }$ decays is difficult due to the abundance of Cabibbo–Kobayashi–Maskawa-favored $\overline{B}\to X_c\ell \overline{\nu }$ events, which share a similar event topology. To minimize dependence on the modeling of these channels, a data-driven description of $\overline{B}\to X_c\ell \overline{\nu }$ is employed. The ratio is measured via a two-dimensional fit to the squared four-momentum transfer to the lepton pair, and the charged lepton energy in the $B$ meson rest frame, where the latter must be larger than 1 GeV, covering approximately 86% and 78% of the $\overline{B}\to X_u\ell \overline{\nu }$ and $\overline{B}\to X_c\ell \overline{\nu }$ phase space, respectively. We find $\mathrm{\Delta }\mathcal{B}(\overline{B}\to X_u\ell \overline{\nu })/\mathrm{\Delta }\mathcal{B}(\overline{B}\to X_c\ell \overline{\nu })=(1.99\pm 0.17_{\mathrm{stat}}\pm 0.16_{\mathrm{syst}})\times {10}^{-2}$, where the uncertainties are statistical and systematic, respectively. We extract $|V_{ub}|/|V_{cb}|$ using two theoretical calculations for the partial decay rate of $\overline{B}\to X_u\ell \overline{\nu }$, finding $(|V_{ub}|/|V_{cb}|{)}^{\mathrm{BLNP}}=(9.81\pm 0.42_{\mathrm{stat}}\pm 0.38_{\mathrm{syst}}\pm 0.51_{\mathrm{\Delta }\mathrm{\Gamma }(\overline{B}\to X_u\ell \overline{\nu })}\pm 0.20_{\mathrm{\Delta }\mathrm{\Gamma }(\overline{B}\to X_c\ell \overline{\nu })})\times {10}^{-2}$ and $(|V_{ub}|/|V_{cb}|{)}^{\mathrm{GGOU}}=(10.06\pm 0.43_{\mathrm{stat}}\pm 0.39_{\mathrm{syst}}\pm 0.23_{\mathrm{\Delta }\mathrm{\Gamma }(\overline{B}\to X_u\ell \overline{\nu })}\pm 0.20_{\mathrm{\Delta }\mathrm{\Gamma }(\overline{B}\to X_c\ell \overline{\nu })})\times {10}^{-2}$, where the third and fourth uncertainties are from the partial decay rates of $\overline{B}\to X_u\ell \overline{\nu }$ and $\overline{B}\to X_c\ell \overline{\nu }$, respectively. In addition, we report the partial branching fractions separately for charged and neutral $B$ meson decays, and for electron and muon decay channels. We place a limit on isospin breaking in $\overline{B}\to X_u\ell \overline{\nu }$ decays, and find no indication of lepton flavor universality violation in either the charmed or charmless mode. Furthermore, we unfold the $\overline{B}\to X_u\ell \overline{\nu }$ and $\overline{B}\to X_c\ell \overline{\nu }$ yields and report the differential ratio in lepton energy and four-momentum transfer squared.

We present a novel family of analytical and numerical classical solitonic solutions to the nonlinear equations governing the dynamics of the bosonic part of a supermembrane (M2-brane) mass operator formulated on a flat spacetime toroidally compactified with worldvolume fluxes. The dynamics of membrane excitations is associated with sectors of the supermembrane theory that exhibit a discrete spectrum at the supersymmetric level, which is an expected property of any well-defined sector of the M-theory. Contrary to expectations, the presence of worldvolume fluxes facilitates the acquisition of novel solutions while preserving the theory’s nonlinear character even in the absence of bosonic scalar potential. The theory remains nonlinear due to the coupling of the scalars with the fluxes and with a symplectic gauge field that arises in the theory. It is noteworthy that the theory also permits the existence of quasiharmonic solutions to the nonlinear equations. We then focus on the M2 brane theory realization of $Q$-ball-like solitons. In order to ascertain the behavior of these solutions, we examine the existence of M2-brane solitonic nondispersive solutions, their composition rules, their dynamics, and the existence of localized solutions along the worldvolume. We also establish a relation between the worldvolume fluxes and the nontopological $Q$-ball charges.

We calculate the effects of quantum fluctuations of a scalar field in the “ballpoint pen” cosmic string geometry. Using the approach to renormalization established previously for the energy density in two space dimensions, we extend those calculations to $3+1$ dimensions, nonzero scalar mass, and the full stress-energy tensor, including its contribution to the null energy condition for radial geodesics. The calculation demonstrates in detail the process of renormalization in curved spacetime, including the effects of the conformal anomaly. This model provides one of the few examples where quantum effects in curved spacetime can be explicitly calculated.

We compute the renormalized charge current for a massless, minimally coupled, charged quantum scalar field on a charged Reissner-Nordström black hole space-time, using the method of pragmatic mode-sum renormalization. Since the field exhibits superradiance, we consider the past Unruh, Boulware and Candelas-Chrzanowski-Howard states and study how the renormalized current in these states depends on the charges of the black hole and scalar field. We also study the backreaction of the charge current on the electromagnetic field.

In order to empirically test the quantum nature of gravity, it is essential to explore the construction of classical gravity theories that are as consistent with experiments as possible. In particular, the classical gravity field must receive input regarding matter distribution. Previously, such input has been constructed by taking expectation values of the matter density operator on the quantum state, or by using the outcomes of all measurements being performed on the quantum system—or by using information obtained by auxiliary observers (like those that lead to the continuous spontaneous localization and Diosi-Penrose collapses) that continuously monitor the quantum dynamics. We propose a framework that unifies these models, and argue that the Causal Conditional Formulation of Schrödinger-Newton (CCSN) theory, which takes classical inputs only from experimental and environmental channels—without auxiliary observers—is a minimum model within this framework. Since CCSN can be viewed as a quantum feedback control scheme, it can be made explicitly causal and free from pathologies that previously plagued Schrödinger-Newton theories. Since classical information from measurement results are used to generate classical gravity, CCSN can mimic quantum gravity better than one would naively expect for a classical theory—making it more subtle to perform tests of the quantum nature of gravity. We predict experimental signatures of CCSN in two concrete scenarios: (i) a single test mass continuously monitored by light, and (ii) two objects interacting via mutual gravity, each monitored separately. In case (i), we show that the mass-concentration effect of self classical gravity still makes CCSN much easier to test than testing the establishment of mutual entanglement, yet the signatures are more subtle than previously thought for classical gravity theories. Using time-delayed measurements and nonstationary measurements, which delay or suspend the flow of classical information into classical gravity, one can make CCSN more detectable. In case (ii), we show that mutual gravity generated by CCSN can lead to correlations that largely mimic signatures of quantum entanglement in steady-state measurements. Rigorous protocols that rule out local operation and classical communication channels, which are experimentally more challenging than simply testing steady-state entanglement, must be applied in order to completely rule out CCSN.

We study second-order electromagnetic perturbations in the Schwarzschild background and derive the effective source terms for the Regge-Wheeler equation, which are quadratic in first-order gravitational and electromagnetic perturbations. In addition to the induced mixed quadratic modes, we find that linear gravitational modes are also excited, with amplitudes dependent on the electromagnetic potential. A toy model involving a Dirac delta function potential demonstrates mixing of linear gravitational and electromagnetic perturbations with frequencies ${\omega }^{(1)}$ and ${\mathrm{\Omega }}^{(1)}$, resulting in the second-order quasinormal mode (QNM) mixing in the electromagnetic field at ${\mathrm{\Omega }}^{(2)}={\mathrm{\Omega }}^{(1)}+{\omega }^{(1)}$. This complements prior work in Aly et al. [Companion paper, Phys. Rev. D 111, 104082 (2025).] on the second-order gravitational perturbation mixing and highlights potential applications in multimessenger astrophysics for systems observed by LIGO-Virgo-KAGRA and upcoming LISA. We also study first-order perturbations due to a point charge and show it could be reduced to a one-dimensional path integral. Within the toy model, we investigate the first-order electromagnetic perturbation due to a radially free-falling single charge $q$ and radial dipole moment $p=q\eta$, employing semianalytical and numerical methods. For the dipole case, we show that the QNM perturbation is excited with a nearly constant amplitude. Future work will focus on incorporating mixing in more realistic potentials and exploring a numerical approach in the context of rotating spacetimes.