We study weak radiative $|\mathrm{\Delta }c|=|\mathrm{\Delta }u|=1$ decays of the charmed antitriplet (${\mathrm{\Lambda }}_c$, ${\mathrm{\Xi }}_c^{+}$, ${\mathrm{\Xi }}_c^0$) and sextet (${\mathrm{\Sigma }}_c^{++}$, ${\mathrm{\Sigma }}_c^{+}$, ${\mathrm{\Sigma }}_c^0$, ${\mathrm{\Xi }}_c^{\prime +}$, ${\mathrm{\Xi }}_c^{\prime 0}$, ${\mathrm{\Omega }}_c$) baryons in the standard model (SM) and beyond. We work out $SU(2)$- and $SU(3{)}_F$-symmetry relations. We propose to study self-analyzing decay chains such as ${\mathrm{\Xi }}_c^{+}\to {\mathrm{\Sigma }}^{+}(\to p{\pi }^0)\gamma$ and ${\mathrm{\Xi }}_c^0\to \mathrm{\Lambda }(\to p{\pi }^{-})\gamma$, which enable new physics sensitive polarization studies. SM contributions can be controlled by a corresponding analysis of the Cabibbo-favored decays ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}(\to p{\pi }^0)\gamma$ and ${\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^0(\to \mathrm{\Lambda }{\pi }^0)\gamma$. Further tests of the SM are available with initially polarized baryons including ${\mathrm{\Lambda }}_c\to p\gamma$ together with ${\mathrm{\Lambda }}_c\to {\mathrm{\Sigma }}^{+}\gamma$ decays, or ${\mathrm{\Omega }}_c\to {\mathrm{\Xi }}^0\gamma$ together with ${\mathrm{\Omega }}_c\to (\mathrm{\Lambda },{\mathrm{\Sigma }}^0)\gamma$. In addition, $CP$-violating new physics contributions to dipole operators can enhance $CP$ asymmetries up to a few percent.

We write down an $\mathcal{N}=1$ supersymmetric extension for non-Abelian gauge theories in ($1+3$) dimensions with a Lorentz- and $CPT$-violating term of the Carroll-Field-Jackiw type. By including effects of the background (supersymmetric) fermion bilinears that accompany Lorentz-symmetry violation in a Carroll-Field-Jackiw scenario, we investigate both the gauge boson and gaugino dispersion relations in order to compute their respective masses in terms of the background structures. Such results open up a potential path towards a possible mechanism for gaugino-gauge boson conversion, an analog of the Primakoff effect, induced here not by an external magnetic field, but instead by the (Majorana) fermionic sector of the supersymmetry multiplet in the backstage of the Lorentz-symmetry violation.

Dark sector particles at the GeV scale carrying baryon number provide an attractive framework for understanding the origin of dark matter and the matter-antimatter asymmetry of the universe. We demonstrate that dark decays of hadronic states containing strange quarks—hyperons—offer excellent prospects for discovering such dark baryons. Building up on novel calculations of the matrix elements relevant for hyperon dark decays, and in view of various collider, flavor, and astrophysical constraints, we determine the expected rates at hyperon factories like BESIII and LHCb. We also highlight the interesting theoretical connections of hyperon dark decays to the neutron lifetime anomaly and mesogenesis.

String scenarios typically not only predict axionlike particles (ALPs) but also significant amounts of ALP dark radiation originating from the decay of the inflaton or a more general modulus. In this paper, we study the decay of such nonthermally produced relativistic (but massive) ALPs to photons. If the ALPs are sufficiently highly energetic, contribute to $\mathrm{\Delta }{N}_{\mathrm{eff}}\gtrsim \mathcal{O}(0.001)$, and have a mass $m_a\gtrsim \mathrm{MeV}$ we find that, using observations of x-, and $\gamma$-rays, the CMB and BBN, very small values of the ALP-photon coupling, can be probed, corresponding to an origin of this coupling at the string (or even Planck) scale.

We consider two Higgs doublet models (THDMs) with both the Higgs potential and Yukawa interactions being aligned, which we call “double-aligned THDMs.” In this scenario, coupling constants of the discovered Higgs boson to the Standard Model (SM) particles are identical to those of the SM Higgs boson, and flavor changing neutral currents via neutral Higgs bosons do not appear at tree level. We investigate current constraints and future prospects of the model by using measurements from flavor experiments and data of multilepton final states at LHC. Especially, we focus on the electroweak pair production of the additional Higgs bosons with their masses below $2m_t$. We find that the most of the parameter space are already excluded by the current LHC data when the leptonic decays of the additional Higgs bosons are dominant, which can be interpreted to the scenario in the Type-X THDM as a special case. We also clarify the parameter region where the high-luminosity LHC can explore, and demonstrate the reconstruction of the masses of additional Higgs bosons from the $b\overline{b}{\tau }^{+}{\tau }^{-}$ final states in a few benchmark points.

We describe the simulation of dihedral gauge theories on digital quantum computers. The non-Abelian discrete gauge group $D_N$—the dihedral group—serves as an approximation to $U(1)\times {\mathbb{Z}}_2$ lattice gauge theory. In order to carry out such a lattice simulation, we detail the construction of efficient quantum circuits to realize basic primitives including the non-Abelian Fourier transform over $D_N$, the trace operation, and the group multiplication and inversion operations. For each case the required quantum resources scale linearly or as low-degree polynomials in $n=\log N$. We experimentally benchmark our gates on the Rigetti Aspen-9 quantum processor for the case of $D_4$. The estimated fidelity of all $D_4$ gates was found to exceed 80%.

The elastic production of top quark pairs in $pp$ collisions at low and high luminosity regimes is investigated in detail. We extend the study performed in [V. P. Gonçalves et al., Phys. Rev. D 102, 074014 (2020).] which has demonstrated that the sum of two semiexclusive $t\overline{t}$ production modes, namely in photon-Pomeron ($\gamma \mathbb{P}$) and Pomeron-Pomeron ($\mathbb{P}\mathbb{P}$) interactions, can be experimentally measured when the $t\overline{t}$ system decays semileptonically, $t\overline{t}\to jjbl{\nu }_l\overline{b}$, both forward protons are tagged and a low amount of pile-up is present. In this study we focus on separating individual channels and a special attention is paid to the situation at high-luminosity LHC environment. We observe that the separation of the $\mathbb{P}\mathbb{P}$ and $\gamma \gamma$ events is a challenging task, especially at high amounts of pile-up even with an optimistic 10 ps resolution of timing detectors. In contrast, the $\gamma \mathbb{P}$ signal is relatively well separable from all backgrounds at low levels of pile-up, allowing us to discover the elastic $t\overline{t}$ production and probe, for the first time, the production of a top quark pair in the $\gamma \mathbb{P}$ interactions. The diffractive photoproduction of such a complex system as the $t\overline{t}$ pair hence can be used not only to study diffractive properties of the scattering amplitude but also to search for new physics beyond the Standard Model, and consequently to be a solid part of the physics program of forward proton detectors at LHC.

The measurement of the branching fraction of a heavy quarkonium decaying into light hadronic final state at $e^{+}{e}^{-}$ colliders is revisited. In $e^{+}{e}^{-}$ annihilation experiments, background contributions from the continuum amplitude and its interference with the resonance amplitude are irreducible. These effects become more and more significant as the precision of experimental measurements improves. While the former can be easily subtracted with data taken off the resonance peak, the latter depends on the relative size and phase between the resonance and continuum amplitudes. Two ratios are defined to estimate the size of these effects, $r_R^f$ for the ratio of the contribution of the interference term to the resonance term and $r_c^f$ for that to the continuum term. We find that $r_R^f$ could be as large as a few percent for narrow resonances, and both $r_R^f$ and $r_c^f$ could be large for broad resonances. This indicates that the interference effect is crucial for the measurements of the branching fractions aiming at the percent level or better precision and needs to be measured or estimated properly.

In a gauge theory, the gauge invariant Hilbert space is unchanged by the coupling to arbitrary local operators. In the presence of Wilson loops, though, the physical Hilbert space must be enlarged by adding test electric charges along the loop. I discuss how at nonzero temperature Polyakov loops are naturally related to the propagator of a test charge. ’t Hooft loops represent the propagation of a test magnetic charge, and so do not alter the physical Hilbert space.

We check formally that the Hubeny-Rangamani-Takayanagi prescription for holographic entanglement entropy—when applied to a static black brane spacetime and to a wide class of subregions that do not lie on a constant time slice—gives rise to volume-law entropy in the limit of large subregion. By volume-law entropy, we mean that the entanglement entropy scales with the volume of the projection of the boundary subregion onto a static time slice with respect to the boundary thermal state (with the same coefficient as in the volume law on the static time slice). Our result applies to subregions that have reflection symmetry as well as strips, and we also present field-theoretic arguments in support of our holographic findings.

The emergence of nontrivial symmetries for black holes minisuperspaces has been recently pointed out. These Noether symmetries possess non-null charges and hence map physical solutions to different ones. The symmetry group is isomorphic to the finite-dimensional Poincaré group $\mathrm{ISO}(2,1)$, whose irreducible representations are well known. This structure is used to build a consistent quantum theory of black hole minisuperspace. This has, among other consequences, the striking consequence of implying a continuous spectrum for the mass operator. Following loop quantum cosmology, we obtain a regularization scheme compatible with the symmetry structure. It is possible to study the evolution of coherent states following the classical trajectories in the low curvature regime. We show that this produces an effective metric where the singularity is replaced by a Killing horizon merging two asymptotically flat regions. The quantum correction comes from a fundamental discreteness of spacetime, and the uncertainty on the energy of the system. Remarkably, the effective evolution of semiclassical states is described by an effective Hamiltonian, related to the original one through a canonical transformation.

This article aims to study nonlocal Lagrangians with an infinite number of degrees of freedom. We obtain an extension of Noether’s theorem and Noether’s identities for such Lagrangians. We then set up a Hamiltonian formalism for them. In addition, we show that $n$-order local Lagrangians can be treated as a particular case, and the standard results can be recovered. Finally, this formalism is applied to the case of $p$-adic open string field.

We construct a family of multidyonically charged and rotating supersymmetric ${\mathrm{AdS}}_2\times \mathrm{\Sigma }$ solutions of $D=4$, $\mathcal{N}=4$ gauged supergravity, where $\mathrm{\Sigma }$ is a sphere with two conical singularities known as a spindle. We argue that these arise as near horizon limits of extremal dyonically charged rotating and accelerating supersymmetric black holes in ${\mathrm{AdS}}_4$ that we conjecture to exist. We demonstrate this in the nonrotating limit, constructing the accelerating black hole solutions and showing that the nonspinning spindle solutions arise as the near horizon limit of the supersymmetric and extremal subclass of these black holes. From the near horizon solutions we compute the Bekenstein-Hawking entropy of the black holes as a function of the conserved charges, and show that this may equivalently be obtained by extremizing a simple entropy function. For appropriately quantized magnetic fluxes, the solutions uplift on $S^7$, or its $\mathcal{N}=4$ orbifolds $S^7/\mathrm{\Gamma }$, to smooth supersymmetric solutions to $D=11$ supergravity, where the entropy is expected to count microstates of the theory on $N$ M2-branes wrapped on a spinning spindle, in the large $N$ limit.

The NANOGrav, Parkes, European, and International Pulsar Timing Array (PTA) Collaborations have reported evidence for a common-spectrum process that can potentially correspond to a stochastic gravitational wave background (SGWB) in the 1–100 nHz frequency range. We consider the scenario in which this signal is produced by magnetohydrodynamic (MHD) turbulence in the early Universe, induced by a nonhelical primordial magnetic field at the energy scale corresponding to the quark confinement phase transition. We perform MHD simulations to study the dynamical evolution of the magnetic field and compute the resulting SGWB. We show that the SGWB output from the simulations can be very well approximated by assuming that the magnetic anisotropic stress is constant in time, over a time interval related to the eddy turnover time. The analytical spectrum that we derive under this assumption features a change of slope at a frequency corresponding to the GW source duration that we confirm with the numerical simulations. We compare the SGWB signal with the PTA data to constrain the temperature scale at which the SGWB is sourced, as well as the amplitude and characteristic scale of the initial magnetic field. We find that the generation temperature is constrained to be in the 1–200 MeV range, the magnetic field amplitude must be $>1\%$ of the radiation energy density at that time, and the magnetic field characteristic scale is constrained to be $>10\%$ of the horizon scale. We show that the turbulent decay of this magnetic field will lead to a field at recombination that can help to alleviate the Hubble tension and can be tested by measurements in the voids of the Large Scale Structure with gamma-ray telescopes like the Cherenkov Telescope Array.

Rank-2 tensor fields of large-scale structure, e.g., a tensor field inferred from shapes of galaxies, open up a window to directly access 2-scalar, 2-vector, and 2-tensor modes, where the scalar fields can be measured independently from the standard density field that is traced by distribution of galaxies. Here we develop an estimator of the multipole moments of coordinate-independent power spectra for the three-dimensional tensor field, taking into account the projection of the tensor field onto plane perpendicular to the line-of-sight direction. To do this, we find that a convenient representation of the power spectrum multipoles can be obtained by the use of the associated Legendre polynomials in the form which allows for the fast Fourier transform estimations under the local plane-parallel (LPP) approximation. The formulation also allows us to obtain the Hankel transforms to connect the two-point statistics in Fourier and configuration space, which are needed to derive theoretical templates of the power spectrum including convolution of a survey window. To validate our estimators, we use the simulation data of the projected tidal field assuming a survey window that mimics the BOSS-like survey footprint. We show that the LPP estimators fairly well recover the multipole moments that are inferred from the global plane-parallel approximation. We find that the survey window causes a more significant change in the multipole moments of projected tensor power spectrum at $k\lesssim 0.1h{\mathrm{Mpc}}^{-1}$ from the input power spectrum, than in the density power spectrum. Nevertheless, our method to compute the theory template including the survey window effects successfully reproduces the window-convolved multipole moments measured from the simulations. The analysis method presented here paves the way for a cosmological analysis using three-dimensional tensor-type tracers of large-scale structure for current and future surveys.

In light of recent results from low-threshold dark matter detectors, we revisit the possibility of a common dark matter origin for multiple excesses across numerous direct detection experiments, with a focus on the excess rates in semiconductor detectors. We explore the interpretation of the low-threshold calorimetric excess rates above 40 eV in the silicon SuperCDMS Cryogenic Phonon Detector and above 100 eV in the germanium EDELWEISS Surface detector as arising from a common but unknown origin, and demonstrate a compatible fit for the observed energy spectra in both experiments, which follow a power law of index $\alpha =3.43_{-0.06}^{+0.11}$. Despite the intriguing scaling of the normalization of these two excess rates with approximately the square of the mass number $A^2$, we argue that the possibility of common origin by dark matter scattering via nuclear recoils is strongly disfavored, even allowing for exotic condensed matter effects in an as-yet unmeasured kinematic regime, due to the unphysically large dark matter velocity required to give comparable rates in the different energy ranges of the silicon and germanium excesses. We also investigate the possibility of inelastic nuclear scattering by cosmic ray neutrons, solar neutrinos, and photons as the origin, and quantitatively disfavor all three based on known fluxes of particles.

We present the first conservative finite volume numerical scheme for the causal, stable relativistic Navier-Stokes equations developed by Bemfica, Disconzi, Noronha, and Kovtun (BDNK). BDNK theory has arisen very recently as a promising means of incorporating entropy-generating effects (viscosity, heat conduction) into relativistic fluid models, appearing as a possible alternative to the so-called Müller-Israel-Stewart (MIS) theory successfully used to model quark-gluon plasma. The major difference between the two lies in the structure of the system of partial differential equations (PDEs): BDNK theory only has a set of conservation laws, whereas MIS also includes a set of evolution equations for its dissipative degrees of freedom. The simpler structure of the BDNK PDEs in this respect allows for rigorous proofs of stability, causality, and hyperbolicity in full generality which have as yet been impossible for MIS. To capitalize on these advantages, we present the first fully conservative multidimensional fluid solver for the BDNK equations suitable for physical applications. The scheme includes a flux-conservative discretization, nonoscillatory reconstruction, and a central-upwind numerical flux and is designed to smoothly transition to a high-resolution shock-capturing perfect fluid solver in the inviscid limit. We assess the robustness of our new method in a series of flat-spacetime tests for a conformal fluid and provide a detailed comparison with previous approaches of Pandya and Pretorius [Phys. Rev. D 104, 023015 (2021)].

We review the status of the 2-Higgs doublet model (2HDM) type-II, in the light of the current experimental results and various theoretical consistency conditions. Compared to the existing literature, in this paper, we apply for the first time a new method that can improve the standard procedure for setting bounds on the 2HDM parameter space, as no experimental evidence has been found so far. Our new numerical framework, called Magellan, and statistical techniques can be applied to any beyond the Standard Model (BSM) scenario. Here, we take as testing ground the 2HDM, particularly as it is physically interesting and moreover characterized by a far from trivial multidimensional parameter space where the effectiveness of the new methods can be proved. Magellan uses a Markov chain Monte Carlo technique for scanning the parameter space and leverages the use of data processing and visualisation methods, allowing the user to perform inference on the model in a complete and efficient way. The novelty of the proposed method is that the parameter space of any BSM theory can be projected onto any bidimensional plane while still retaining all underlying attributes of those points, so that it is possible to investigate the associations between the properties of the various lower dimensional subspaces of the complete parameter space. The Magellan’s website interactive dashboards can be accessed via a public link. Through this website, the user can explore the full parameter space and exploit the phenomenological features of a BSM model with ease.

We present a detailed study, at the fast detector simulation level, of top-pair photoproduction in semileptonic mode at the Large Hadron-electron Collider (LHeC) and Future Circular Collider (FCC-he). We work in full tree-level QED, not relying on the equivalent photon approximation, taking into account the complete photoproduction kinematics. This allows us to define three photoproduction regions based on the angular acceptance range of the electron tagger. Those regions provide different degrees of sensitivity to top quark effective couplings. We focus on the $t\overline{t}\gamma$ dipole couplings and the left-handed vector $tbW$ coupling for which we determine limits at both energies and in different photoproduction regions. We find that the LHeC and FCC-he will yield tight direct bounds on top dipole moments, greatly improving on current direct limits from hadron colliders, and direct limits on the $tbW$ coupling as restrictive as those expected from the HL-LHC. We also consider indirect limits from $b\to s\gamma$ branching ratio and $CP$ asymmetry, that are well known to be very sensitive probes of top electromagnetic dipole moments.

Searches for $\mathrm{\Delta }L=2$ decays are crucial to disentangle the Dirac vs Majorana nature of neutrinos. While neutrinoless nuclear double beta decays are the most promising tool to look for dielectron signals of $\mathrm{\Delta }L=2$, searches of dilepton channels with other flavors are far less limited by statistics. We revisit the calculation of $\mathrm{\Delta }L=2$ decays of hyperons $B_i^{-}\to B_f^{+}{\ell }^{-}{{\ell }^{\prime }}^{-}$. We compute the rates of these decays by including the hyperon form factors, which yields finite results in the one-loop model mechanism involving Majorana neutrinos (long-range contributions). In addition, we study the short-range contributions to these kinds of processes in two appealing scenarios. First, we consider the effects of heavy Majorana neutrinos in low-scale seesaw models that involve a minimal parametrization with only two heavy Majorana states. Second, we study an alternative model where $\mathrm{\Delta }L=2$ decays are induced by a scalar boson coupled to dileptons to provide additional predictions.