What are the symmetries of a dataset? Whereas the symmetries of an individual data element can be characterized by its invariance under various transformations, the symmetries of an ensemble of data elements are ambiguous due to Jacobian factors introduced while changing coordinates. In this paper, we provide a rigorous statistical definition of the symmetries of a dataset, which involves inertial reference densities, in analogy to inertial frames in classical mechanics. We then propose SymmetryGAN as a novel and powerful approach to automatically discover symmetries using a deep learning method based on generative adversarial networks (GANs). When applied to Gaussian examples, SymmetryGAN shows excellent empirical performance, in agreement with expectations from the analytic loss landscape. SymmetryGAN is then applied to simulated dijet events from the Large Hadron Collider (LHC) to demonstrate the potential utility of this method in high energy collider physics applications. Going beyond symmetry discovery, we consider procedures to infer the underlying symmetry group from empirical data.

We consider the minimal extended seesaw model that can accommodate an eV scale sterile neutrino. The scenario also includes three heavy right-handed neutrinos in addition to the light-sterile neutrino. In this model, the active-sterile mixing acts as nonunitary parameters. If the values of these mixing angles are of $\mathcal{O}(0.1)$, the model introduces deviation of the Pontecorvo-Maki-Nakagawa-Sakata matrix from unitarity to this order. We find that the oscillation data from various experiments impose an upper bound on the lightest heavy neutrino mass scale as $\sim {10}^{11}\mathrm{GeV}$ in the context of this model. We study vanilla leptogenesis in this scheme, where the decay of the heavy right-handed neutrinos in the early Universe can give rise to the observed baryon asymmetry. Here, even though the eV scale sterile neutrino does not participate directly in leptogenesis, its effect is manifested through the nonunitary effects. We find that the parameter space that can give rise to successful leptogenesis is constrained by the bounds on the active-sterile mixing as obtained from the global analysis.

Supersymmetric models with radiatively driven naturalness enjoy low electroweak fine tuning whilst respecting LHC search limits on gluinos and top squarks and allowing for $m_h\simeq 125\mathrm{GeV}$. While the heavier Higgs bosons $H$ and $A$ may have TeV-scale masses, the supersymmetry (SUSY)-conserving $\mu$ parameter must lie in the few hundred GeV range. Thus, in natural SUSY models there should occur large heavy Higgs boson branching fractions to electroweakinos, with Higgs boson decays to Higgsino plus gaugino dominating when they are kinematically accessible. These SUSY decays can open up new avenues for discovery. We investigate the prospects of discovering heavy neutral Higgs bosons $H$ and $A$ decaying into light plus heavy chargino pairs which can yield a four isolated lepton plus missing transverse energy signature at the LHC and at a future 100 TeV $pp$ collider. We find that the discovery of heavy Higgs decay to electroweakinos via its $4\ell$ decay mode is very difficult at HL-LHC. For FCC-$hh$ or SPPC, we study the $H,A\to \mathrm{SUSY}$ reaction along with dominant physics backgrounds from the Standard Model and devise suitable selection requirements to extract a clean signal for FCC-$hh$ or SPPC with $\sqrt{s}=100\mathrm{TeV}$, assuming an integrated luminosity of $15{\mathrm{ab}}^{-1}$. We find that while a conventional cut-and-count analysis yields a signal statistical significance greater than $5\sigma$ for $m_{A,H}\sim 1.1\mathrm{TeV}-1.65\mathrm{TeV}$, a boosted decision-tree analysis allows for heavy Higgs signal discovery at FCC-$hh$ or SPPC for $m_{A,H}\sim 1\mathrm{TeV}-2\mathrm{TeV}$.

The electromagnetic Dalitz decays $J/\psi \to {\eta }^{(\prime )}{e}^{+}{e}^{-}$ with large recoil momentum are studied in the framework of perturbative QCD. Meanwhile, the soft contributions from the small recoil momentum region are described by the overlap of soft wave functions, and the resonance contributions are estimated by the vector meson dominance model. Based on this dynamical picture, the transition form factors $f_{\psi {\eta }^{(\prime )}}(q^2)$ in full kinematic region are calculated for the first time, and we find that the transition form factors are insensitive to the shapes of ${\eta }^{(\prime )}$ distribution amplitudes. Our prediction of the normalized transition form factor $F_{\psi \eta }(q^2)\equiv f_{\psi \eta }(q^2)/f_{\psi \eta }(0)$ agrees well with its experimental data. In addition, we also find that the branching ratios $\mathcal{B}(J/\psi \to {\eta }^{(\prime )}{e}^{+}{e}^{-})$ are dominated by the contributions of perturbative QCD, and the resonance contributions are negligibly small as well as the soft contributions due to the suppression of the kinematic factor. With all these contributions, our results of the branching ratios $\mathcal{B}(J/\psi \to {\eta }^{(\prime )}{e}^{+}{e}^{-})$ and the ratio $R_{J/\psi }^e=\mathcal{B}(J/\psi \to \eta e^{+}{e}^{-})/\mathcal{B}(J/\psi \to {\eta }^{\prime }{e}^{+}{e}^{-})$ are in good agreement with their experimental data. Using the obtained $F_{\psi {\eta }^{(\prime )}}(q^2)$, we give the predictions of the branching ratios $\mathcal{B}(J/\psi \to {\eta }^{(\prime )}{\mu }^{+}{\mu }^{-})$ and their ratio $R_{J/\psi }^{\mu }$.

We provide a comprehensive overview of transversely polarized $\mathrm{\Lambda }$ production at the future Electron-Ion Collider (EIC). In particular, we study both spontaneous transverse $\mathrm{\Lambda }$ polarization as well as the transverse spin transfer within the transverse momentum dependent (TMD) factorization region. To describe spontaneous $\mathrm{\Lambda }$ polarization, we consider the contribution from the TMD polarizing fragmentation function (TMD PFF). Similarly, we study the contribution of the transverse spin transfer originating from the transversity TMD fragmentation function (TMD FF). We provide projections for the statistical uncertainties in the corresponding spin observables at the future EIC. Using these statistical uncertainties, we characterize the role that the future EIC will play in constraining these distributions. We perform an impact study in the semi-inclusive deep inelastic scattering process for spontaneous $\mathrm{\Lambda }$ polarization with a proton beam. We find that the projected experimental data leads to a significant decrease in the uncertainties for the $u$ and sea TMD PFFs. Furthermore, to access the impact of the EIC on the transversity TMD FF, we perform the first extraction of the transversity TMD FF from the recent COMPASS data. We compare the statistical uncertainties of the future EIC with the theoretical uncertainties from our extraction and find that the EIC could have a significant role in constraining this distribution. Finally, we also provide projections for both spontaneous $\mathrm{\Lambda }$ polarization as well as the transverse spin transfer inside the jets in back-to-back electron-jet production at the EIC.

The susperscaling model SuSAv2, already available for charged-current neutrino-nucleus cross sections in the quasielastic region, is extended to the full inelastic regime. In the model the resonance production and deep inelastic reactions are described through the extension to the neutrino sector of the SuSAv2 inelastic model developed for ($e$, $e^{\prime }$) reactions, which combines phenomenological structure functions with a nuclear scaling function. This work also compares two different descriptions of the $\mathrm{\Delta }$ resonance region, one based on a global scaling function for the full inelastic spectrum and the other on a semiphenomenological $\mathrm{\Delta }$ scaling function extracted from ($e$, $e^{\prime }$) data for this specific region and updated with respect to previous work. The results of the model are tested against ($e$, $e^{\prime }$) data on ${}^{12}\mathrm{C}$, ${}^{16}\mathrm{O}$, ${}^{40}\mathrm{Ca}$, and ${}^{40}\mathrm{Ar}$ and applied to the study of the charged current inclusive neutrino cross-section on ${}^{12}\mathrm{C}$ and ${}^{40}\mathrm{Ar}$ measured by the T2K, MicroBooNE, ArgoNEUT, and MINERvA experiments, thus covering several kinematical regions.

We explicitly carry out the symplectic quantization of a family of multifield generalized Proca (GP) electrodynamics theories. In the process, we provide an independent derivation of the so-called secondary constraint enforcing relations—consistency conditions that significantly restrict the allowed interactions in multifield settings already at the classical level. Additionally, we unveil the existence of quantum consistency conditions, which apply in both single- and multifield GP scenarios. Our newly found conditions imply that not all classically well-defined (multi-)GP theories are amenable to quantization. The extension of our results to the most general multi-GP class is conceptually straightforward, albeit algebraically cumbersome.

Fully nonlinear numerical evolutions of the Einstein-(multi)-Klein-Gordon equations are performed to study head-on collisions of $\ell$-boson stars. Despite being spherically symmetric, $\ell$-boson stars have a (hidden) frame of reference, used in defining their individual multipolar fields. To assess the impact of their relative orientation, we perform simulations with different angles between the axes of the two colliding stars. Additionally, two scenarios are considered for the colliding stars: that they are composites of either the same or different scalar fields. Despite some model-specific behaviors, the simulations generically indicate that (1) the collision of two sufficiently (and equally) massive stars leads to black hole formation; (2) below a certain mass threshold the end result of the evolution is a bound state of the composite scalar fields, that neither disperses nor collapses into a black hole within the simulation time; (3) this end product (generically) deviates from spherical symmetry and the equipartition of the number of bosonic particles between the different scalar fields composing the initial boson stars is lost, albeit not dramatically. This last observation indicates, albeit without being conclusive, that the end result of these collisions belongs to the previously reported larger family of equilibrium multifield boson stars, generically nonspherical, and of which $\ell$-boson stars are a symmetry enhanced point. We also extract and discuss the waveforms from the collisions studied.

The sensitivity of gravitational wave searches is reduced by the presence of non-Gaussian noise in the detector data. These non-Gaussianities often match well with the template waveforms used in matched filter searches, and require signal-consistency tests to distinguish them from astrophysical signals. However, empirically tuning these tests for maximum efficacy is time consuming and limits the complexity of these tests. In this work we demonstrate a framework to use machine-learning techniques to automatically tune signal-consistency tests. We implement a new ${\chi }^2$ signal-consistency test targeting the large population of noise found in searches for intermediate mass black hole binaries, training the new test using the framework set out in this paper. We find that this method effectively trains a complex model to downweight the noise, while leaving the signal population relatively unaffected. This improves the sensitivity of the search by $\sim 11\%$ for signals with masses $>300M_{\odot }$. In the future this framework could be used to implement new tests in any of the commonly used matched-filter search algorithms, further improving the sensitivity of our searches.

Superradiance is a process by which massive bosonic particles can extract energy from spinning black holes, leading to the build up of a condensate if the particle has a Compton wavelength comparable to the black hole’s Schwarzschild radius. One interesting possibility is that superradiance may occur for photons in a diffuse plasma, where they gain a small effective mass. Studies of the spin-0 case have indicated that such a build up is suppressed by a spatially varying effective mass, supposed to mimic the photons’ interaction with a physically realistic plasma density profile. We carry out relativistic simulations of a massive Proca field evolving on a Kerr background, with modifications to account for the spatially varying effective mass. This allows us to treat the spin-1 case directly relevant to photons, and to study the effect of thinner disk profiles in the plasma. We find similar qualitative results to the scalar case, and so support the conclusions of that work: either a constant asymptotic mass or a shell-like plasma structure is required for superradiant growth to occur. We study thin disks and find a leakage of the bosonic condensate that suppresses its growth, concluding that thick disks are more likely to support the instability.

In this paper we shall consider an axionic Chern-Simons-corrected $f(R)$ gravity theoretical framework, and we shall study the chirality of the generated primordial gravitational waves. Particularly, we shall consider two main axion models, the canonical misalignment axion model and the kinetic axion model, both of which provide an interesting particle phenomenology, in the presence of $R^2$ terms in the inflationary Lagrangian. The axion does not affect significantly the background evolution during the inflationary era, which is solely controlled by $R^2$ gravity. However, due to the presence of the Chern-Simons term, the tensor perturbations are directly affected, and our aim is to reveal the extent of the effects of the Chern-Simons term on the gravitational wave modes, for both the axion models. We aim to produce analytical descriptions of the primordial tensor mode behavior, and thus we solve analytically the evolution equations of the tensor modes, for a nearly de Sitter primordial evolution controlled by the $R^2$ gravity. We focus the analytical study on superhorizon and subhorizon modes. For the misalignment model, we were able to produce analytic solutions for both the subhorizon and superhorizon modes, in which case we find the behavior of the circular polarization function. Our results indicate that the produced tensor spectrum is strongly chiral. For the kinetic axion model though, analytic solutions are obtained only for the superhorizon modes. In order to have a grasp of the behavior of the chirality of the tensor modes, we studied the chirality of the superhorizon modes, however, a more complete study is needed, which is impossible to do analytically though.

Thermodynamics of black holes in anti–de Sitter (AdS) spacetimes typically contain critical points in the phase diagram, some of which correspond to the first order transition ending in a second order one. Following the recent proposal in [Phys. Rev. D 105, 104003 (2022)] on using Duan’s $\varphi$-mapping theory, we classify the critical points of six dimensional charged Gauss-Bonnet black holes in AdS spacetime. We find that the higher derivative curvature terms in the form of Gauss-Bonnet gravity do not change the topological class of critical points in charged black holes in AdS, unlike the case of Born-Infeld corrections noted earlier. The connection between the topological nature of critical points and existence of first order phase transitions breaks down in a certain parameter regime. A resolution is proposed by treating the novel and conventional critical points as phase creation and phase annihilation points, respectively. Examples are provided to support the proposal.

The study of the generation of metric perturbation in the laboratory presents an opportunity to observe and understand more easily the mechanisms at work in gravitation. The present study will focus on the metric perturbation generated by a light pulse, as it could be generated by a current ultrahigh power laser. Although of very small magnitude, the potential thus generated has advantages over that generated by mass acceleration, such as the absence of noise due to nonuniform acceleration or the ability to scale up the experiment. It is indeed easier to scale up an electromagnetic oscillation compared to a mechanical oscillator, which must either be made with a large accelerated mass or a lot of small masses, all in sync, which acceleration must furthermore be quadripolar. Generation of metric deformation by laser could therefore prove useful in the long-term establishment of a laboratory experiment for the generation and detection of gravitational waves.

We derive new constraints on combination of dark matter-electron cross section (${\sigma }_{\chi e}$) and dark matter-neutrino cross section (${\sigma }_{\chi \nu }$) utilizing the gain in kinetic energy of the dark matter (DM) particles due to scattering with the cosmic ray electrons and the diffuse supernova neutrino background (DSNB). Since the flux of the DSNB neutrinos is comparable to the cosmic ray (CR) electron flux in the energy range $\sim 1\mathrm{MeV}–50\mathrm{MeV}$, scattering with the DSNB neutrinos can also boost low-mass DM significantly in addition to the boost due to interaction with the CR electrons. We use the XENON1T as well as the Super-Kamiokande data to derive bounds on ${\sigma }_{\chi e}$ and ${\sigma }_{\chi \nu }$. While our bounds for ${\sigma }_{\chi e}$ are comparable with those in the literature, we show that the Super-Kamiokande experiment provides the strongest constraint on ${\sigma }_{\chi \nu }$ for DM masses below a few MeV.

It is known that the large-scale structure mapped by a galaxy redshift survey is subject to distortions by galaxies’ peculiar velocities. Besides the signatures generated in common $N$-point statistics, such as the anisotropy in the galaxy two-point correlation function, the peculiar velocities also induce distinct features in large-scale structures morphological properties, which are fully described by four Minkowski functionals (MFs), i.e., the volume, surface area, integrated mean curvature, and Euler characteristic (or genus). In this work, by using large suite of $N$-body simulations, we present and analyze these important features in the MFs of large-scale structure on both (quasi)linear and nonlinear scales, with a focus on the latter. We also find the MFs can give competitive constraints on cosmological parameters compared to the power spectrum, probably due to the nonlinear information contained. For a galaxy number density similar to the DESI BGS galaxies, the constraint on ${\sigma }_8$ from the MFs with one smoothing scale can be better by $\sim 50\%$ than from the power spectrum. These findings are important for the cosmological applications of MFs of large-scale structure, and probably open up a new avenue for studying the peculiar velocity field itself.

We propose a simple method to identify a continuous Lie algebra symmetry in a dataset through regression by an artificial neural network. Our proposal takes advantage of the $\mathcal{O}({\epsilon }^2)$ scaling of the output variable under infinitesimal symmetry transformations on the input variables. As symmetry transformations are generated post-training, the methodology does not rely on sampling of the full representation space or binning of the dataset, and the possibility of false identification is minimized. We demonstrate our method in the SU(3)-symmetric (non-) linear $\mathrm{\Sigma }$ model.

In light of the increasing hints of new physics at the muon $g-2$ and neutrino oscillation experiments, we consider the recently observed tension in the long-baseline neutrino oscillation experiments as a potential indication of Lorentz invariance violation. For this purpose, the latest data from T2K and $\mathrm{NO}\nu \mathrm{A}$ is analyzed in the presence of nonminimal Lorentz invariance violation. Indeed, we find that isotropic violation in dimensions $D=4$, 5, and 6 can alleviate the tension in neutrino oscillation data by about $0.4–2.4\sigma$ confidence level significance, with the isotropic coefficient ${\gamma }_{\tau \tau }^{(5)}=3.58\times {10}^{-32}{\mathrm{GeV}}^{-1}$ yielding the best fit. At the same time, the anomalous muon $g-2$ result can be reproduced with an additional nonisotropic violation of $d^{zt}=-1.7\times {10}^{-25}$. The analysis highlights the possibility of simultaneous relaxation of experimental tensions with Lorentz invariance violation of a mixed nature.

Experimental measurements point at the Standard Model (SM) as the theory of electroweak symmetry breaking, but as we close in on our characterization the question arises of what limits in theory space lead to the SM. The class of theories with this property cannot be ruled out, only constrained to an ever smaller neighborhood of the SM. In contrast, which class of theories does not possess this limit and can therefore potentially be ruled out experimentally? In this work we study both classes and find evidence to support the Standard Model effective field theory being the single road to the Standard Model, theories that fall outside this class keeping a “minimum distance” from the SM characterized by a cutoff of at most $4\pi v/g_{\mathrm{SM}}$.

We present a study of Higgs boson production in vector boson fusion and in association with a vector boson and its decay to two vector bosons, with a focus on the treatment of virtual loops and virtual photons. Our analysis is performed with the JHU generator framework. Comparisons are made to several other frameworks, and the results are expressed in terms of an effective field theory. New features of this study include a proposal on how to handle singularities involving Higgs boson decays to light fermions via photons, calculation of the partial Higgs boson width in the presence of anomalous couplings to photons, a comparison of the next-to-leading-order electroweak corrections to effects from effective couplings, and phenomenological observations regarding the special role of intermediate photons in analysis of LHC data in the effective field theory framework. Some of these features are illustrated with projections for experimental measurements with the full LHC and HL-LHC datasets.