While the ground-state tensor ($J^{PC}=2^{++}$) mesons $a_2(1320)$, $K_2^{*}(1430)$, $f_2(1270)$, and $f_2^{\prime }(1525)$ are well known experimentally and form an almost ideal nonet of quark-antiquark states, their chiral partners, the ground-states axial-tensor ($J^{PC}=2^{--}$) mesons are poorly settled: only the kaonic member $K_2(1820)$ of the nonet has been experimentally found, whereas the isovector state ${\rho }_2$ and two isoscalar states ${\omega }_2$ and ${\varphi }_2$ are still missing. Here, we study masses, strong, and radiative decays of tensor and axial-tensor mesons within a chiral model that links them: the established tensor mesons are used to test the model and to determine its parameters, and subsequently various predictions for their chiral partners, the axial-tensor mesons, are obtained. The results are compared to current lattice QCD outcomes as well as to other theoretical approaches and show that the ground-state axial-tensor mesons are expected to be quite broad, the vector-pseudoscalar mode being the most prominent decay mode followed by the tensor-pseudoscalar one. Nonetheless, their experimental finding seems to be possible in ongoing and/or future experiments.

B. Nachman et al. [Phys. Rev. Lett. 126, 062001 (2021)] recently introduced an algorithm (QPS) for simulating parton showers with intermediate flavor states using polynomial resources on a digital quantum computer. We make use of a new quantum hardware capability called dynamical quantum computing to improve the scaling of this algorithm, which significantly improves the method precision. In particular, we modify the quantum parton shower circuit to incorporate midcircuit qubit measurements, resets, and quantum operations conditioned on classical information. This reduces the computational depth from $\mathcal{O}(N^5{\log }_2(N{)}^2)$ to $\mathcal{O}(N^3{\log }_2(N{)}^2)$ and the qubit requirements from $\mathcal{O}(N{\log }_2(N))$ to $\mathcal{O}(N)$. Using “matrix product state” state vector simulators, we demonstrate that the improved algorithm yields expected results for 2, 3, 4, and 5-steps of the algorithm. We compare absolute costs with the original QPS algorithm, and show that dynamical quantum computing can significantly reduce costs in the class of digital quantum algorithms representing quantum walks (which includes the QPS). Python code that implements QPS, both with and without dynamic gates, is publicly available on Github.

A fraction of the dark matter may consist of a particle species that interacts much more strongly with the Standard Model than a typical weakly interacting massive particle (WIMP) of similar mass. Such a strongly interacting dark matter component could have avoided detection in searches for WIMP-like dark matter through its interactions with the material in the atmosphere and the Earth that slow it down significantly before reaching detectors underground. These same interactions can also enhance the density of a strongly interacting dark matter species near the Earth’s surface to well above the local galactic dark matter density. In this work, we propose two new methods of detecting strongly interacting dark matter based on accelerating the enhanced population expected in the Earth through scattering. The first approach is to use underground nuclear accelerator beams to upscatter the ambient dark matter population into a WIMP-style detector located downstream. In the second technique, dark matter is upscattered with an intense thermal source and detected with a low-threshold dark matter detector. We also discuss potential candidates for strongly interacting dark matter, and we show that the scenario can be naturally realized with a hidden fermion coupled to a sub-GeV dark photon.

We explore the parameter space of the type-II two-Higgs-doublet model with softly broken $Z_2$ symmetry, allowing for $CP$ violation in the scalar potential. Imposing theory-motivated and experimentally-driven constraints, we show that as the $CP$-violating phases are increased, only small regions of parameter space survive, including regions slightly away from the alignment limit. Electroweak oblique parameters and electric dipole moments emerge as most restrictive constraints. We show that imposing these constraints (as well as theoretical bounds such as perturbativity) the masses of the charged and heavy neutral Higgs, unlike in the $CP$ conserving case, are bound from above and below. In particular, the heavy neutral Higgs masses are almost degenerate. In this parameter space region we highlight the relevant decay signals of the heavy neutral Higgs, involving both $Zh$ and $WW/ZZ$, indicative of $CP$ violation in the model.

We present the first calculation of the jet transport coefficient $\widehat{q}$ in quenched and ($2+1$)-flavor QCD on a 4D Euclidean lattice. The lightlike propagation of an energetic parton is factorized from the mean square gain in momentum transverse to the direction of propagation, which is expressed in terms of the thermal field-strength field-strength correlator. The leading-twist term in its operator product expansion is calculated on the lattice. Continuum extrapolated quenched results, and full QCD estimates based on unrenormalized lattice data, over multiple lattice sizes, are compared with (non)perturbative calculations and phenomenological extractions of $\widehat{q}$. The lattice data for $\widehat{q}$ show a temperature dependence similar to the entropy density. Within uncertainties, these are consistent with phenomenological extractions, contrary to calculations using perturbation theory.

Taylor expansion of the thermodynamic potential in powers of the (baryo)chemical potential ${\mu }_B$ is a well-known method to bypass the sign problem of lattice QCD. Due to the difficulty in calculating the higher order Taylor coefficients, various alternative expansion schemes as well as resummation techniques have been suggested to extend the Taylor series to larger values of ${\mu }_B$. Recently, a way to resum the contribution of the first $N$ charge density correlation functions $D_1,\dots ,D_N$ to the Taylor series to all orders in ${\mu }_B$ was proposed in [Phys. Rev. Lett. 128, 022001 (2022)]. The resummation takes the form of an exponential factor. Since the correlation functions are calculated stochastically, the exponential factor contains a bias which can be significant for large $N$ and ${\mu }_B$. In this paper, we present a new method to calculate the QCD equation of state based on the well-known cumulant expansion from statistics. By truncating the expansion at a maximum order $M$, we end up with only finite products of the correlation functions which can be evaluated in an unbiased manner. Although our formalism is also applicable for ${\mu }_B\ne 0$, here we present it for the simpler case of a finite isospin chemical potential ${\mu }_I$ for which there is no sign problem. We present and compare results for the pressure and the isospin density obtained using Taylor expansion, exponential resummation and cumulant expansion, and provide evidence that the absence of bias in the latter actually improves the convergence.

The $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ processes are ideal platforms to search for higher $\omega$ states. Focusing on the observations of two enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ at BESIII, we analyze how the $\omega (4S)$ and $\omega (3D)$ states play the role in the $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ processes. The present study is supported by theoretical $\omega$ mesonic spectroscopy. For reproducing the data of the cross sections of $e^{+}{e}^{-}\to \omega \eta$ and $\omega {\pi }^0{\pi }^0$, the intermediate $\omega (4S)$ and $\omega (3D)$ should be introduced, which indicates that the enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $\omega {\pi }^0{\pi }^0$ contain the $\omega (4S)$ and $\omega (3D)$ signals. Nonetheless, in the process $e^{+}{e}^{-}\to \omega \eta$, the $\omega (4S)$ plays a dominant role, while the $\omega (4S)$ and $\omega (3D)$ have similar sizable contributions in the process of $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$, which leads to a difference in the line shape of enhancement structure in the cross sections under the interference effect. Thus, we find a solution to alleviate the puzzling difference of resonance parameter of two reported enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ at BESIII. The present study provides valuable information to construct $\omega$ meson family, which can be accessible at future experiment like BESIII.

In this article, we investigate the $\cos 2{\varphi }_t$ azimuthal asymmetry in $ep\to eJ/\psi$ jet $X$, where the $J/\psi$-jet pair is almost back to back in the transverse plane, within the framework of the generalized parton model. We use nonrelativistic QCD (NRQCD) to calculate the $J/\psi$ production amplitude and incorporate both color singlet and color octet contributions to the asymmetry. We estimate the asymmetry using different parametrizations of the gluon transverse-momentum-dependent parton distributions in the kinematics that can be accessed at the future electron-ion collider (EIC) and also investigate the impact of transverse-momentum-dependent evolution on the asymmetry. We present the contributions coming from different states to the asymmetry in NRQCD.

The Bose-Marletto-Vedral experiment is a proposal for testing the quantum nature of gravity with entanglement due to Newtonian gravity. This proposal has stimulated controversy on how the entanglement due to Newtonian gravity is related to the essence of quantum gravity and the existence of gravitons. Motivated by this, we analyze the entanglement generation between two charged particles coupled to a photon field. We assume that each particle is in a superposition of two trajectories and that the photon field is initially in a coherent state. Based on covariant quantum electrodynamics, the formula for the entanglement negativity of the charged particles is derived for the first time. Adopting simple analytic trajectories of the particles, we demonstrate the entanglement between them. It is observed that the entanglement is suppressed by the decoherence due to the vacuum fluctuations of the photon field. We also find that the effect of quantum superposition of bremsstrahlung appears in the entanglement negativity formula. The similar structures between the gravity theory and electromagnetic theory suggests that a similar feature may be observed in the entanglement generation by quantum gravitational radiation.

We study the Lyapunov exponent ${\lambda }_L$ in quantum field theories with spacetime-independent disorder interactions. Generically ${\lambda }_L$ can only be computed at isolated points in parameter space, and little is known about the way in which chaos grows as we deform the theory away from weak coupling. In this paper, we describe families of theories in which the disorder coupling is an exactly marginal deformation, allowing us to follow ${\lambda }_L$ from weak to strong coupling. We find surprising behaviors in some cases, including a discontinuous transition into chaos. We also derive self-consistency equations for the two- and four-point functions for products of $N$ nontrivial conformal field theories deformed by disorder at leading order in $1/N$.

We define “third-derivative” general relativity by promoting the integration measure in Einstein-Hilbert action to be an arbitrary 4-form field strength. We project out its local fluctuations by coupling it to another 4-form field strength. This ensures that the gravitational sector contains only the usual massless helicity-2 propagating modes. Adding the charges to these 4-forms allows for discrete variations of the coupling parameters of conventional general relativity: $G_N,\mathrm{\Lambda },H_0$, and even $⟨\mathsf{Higgs}⟩$ are all variables which can change by jumps. Hence, de Sitter spacetime is unstable to membrane nucleation. Using this instability, we explain how the cosmological constant problem can be solved. The scenario utilizes the idea behind the irrational axion, but instead of an axion it requires one more 4-form field strength and corresponding charged membranes. When the membrane charges satisfy the constraint $\frac{2{\kappa }_{\mathsf{eff}}^2{\kappa }^2|{\mathcal{Q}}_i|}{3{\mathcal{T}}_i^2}<1$, the theory which ensues exponentially favors a huge hierarchy $\mathrm{\Lambda }/M_{\mathrm{Pl}}^4\ll 1$ instead of $\mathrm{\Lambda }/M_{\mathrm{Pl}}^4\simeq 1$. The discharges produce the distribution of the values of $\mathrm{\Lambda }$ described by the saddle point approximation of the Euclidean path integral.

We analytically investigate a new family of horizonless compact objects in vector-tensor theories of gravity, called ultracompact vector stars. They are sourced by a vector condensate, induced by a nonminimal coupling with gravity. They can be as compact as black holes, thanks to their internal anisotropic stress. In the spherically symmetric case their interior resembles an isothermal sphere, with a singularity that can be resolved by tuning the available integration constants. The star interior smoothly matches to an exterior Schwarzschild geometry, with no need of extra energy momentum tensor at the star surface. We analyze the behavior of geodesics within the star interior, where stable circular orbits are allowed, as well as trajectories crossing in both ways the star surface. We analytically study stationary deformations of the vector field and of the geometry, which break spherical symmetry, and whose features depend on the vector-tensor theory we consider. We introduce and determine the vector magnetic susceptibility as a probe of the star properties, and we analyze how the rate of rotation of the star is affected by the vector charges.

We derive analytic covariance matrices for the $N$-point correlation functions (NPCFs) of galaxies in the Gaussian limit. Our results are given for arbitrary $N$ and projected onto the isotropic basis functions given by spherical harmonics and Wigner $3j$ symbols. A numerical implementation of the 4PCF covariance is compared to the sample covariance obtained from a set of lognormal simulations, Quijote dark matter halo catalogues, and MultiDark-Patchy galaxy mocks, with the latter including realistic survey geometry. The analytic formalism gives reasonable predictions for the covariances estimated from mock simulations with a periodic-box geometry. Furthermore, fitting for an effective volume and number density by maximizing a likelihood based on Kullback-Leibler divergence is shown to partially compensate for the effects of a nonuniform window function. Our result is recently shown to facilitate NPCF analysis on a realistic survey data.

We present a directed search for continuous gravitational wave (CW) signals emitted by spinning neutron stars located in the inner parsecs of the Galactic Center (GC). Compelling evidence for the presence of a numerous population of neutron stars has been reported in the literature, turning this region into a very interesting place to look for CWs. In this search, data from the full O3 LIGO-Virgo run in the detector frequency band $[10,2000]\mathrm{Hz}$ have been used. No significant detection was found and 95% confidence level upper limits on the signal strain amplitude were computed, over the full search band, with the deepest limit of about $7.6\times {10}^{-26}$ at $\simeq 142\mathrm{Hz}$. These results are significantly more constraining than those reported in previous searches. We use these limits to put constraints on the fiducial neutron star ellipticity and r-mode amplitude. These limits can be also translated into constraints in the black hole mass–boson mass plane for a hypothetical population of boson clouds around spinning black holes located in the GC.

We have gone through a detailed calculation of the two-point correlation function of vector currents at finite density and magnetic field by employing the real time formalism of finite temperature field theory and Schwinger’s proper-time formalism. With respect to the direction of the external magnetic field, the parallel and perpendicular components of electric conductivity for the degenerate relativistic fermionic matter are obtained from the zero-momentum limit of the current-current correlator, using the Kubo formula. Our quantum-field theoretical expressions and numerical estimations are compared with those obtained from the relaxation-time approximation methods of kinetic theory and its Landau quantized extension, which can be called classical and quantum results, respectively. All the results are merged in the classical domain i.e., the high-density and low-density magnetic field region, but in the remaining (quantum) domain, quantum results carry a quantized information like the Shubnikov-de Haas oscillation along the density and magnetic field axes. We have obtained a completely new quantum-field theoretical expression for perpendicular conductivity of degenerate relativistic fermionic matter. Interestingly, our quantum field theoretical calculation provides a new mathematical form of the cyclotron frequency with respect to its classical definition, which might require more future research to interpret the phenomena.

We provide a modification to the quantum phase estimation algorithm (QPEA) [Abrams and Lloyd, Phys. Rev. Lett. 83, 5162 (1999); Cleve et al., Proc. R. Soc. A 454, 339 (1998); Nielsen and Chuang, Quantum computation and quantum information, 2002.] inspired by classical windowing methods for spectral density estimation. From this modification we obtain an upper bound in the cost that implies a cubic improvement with respect to the algorithm’s error rate. Numerical evaluation of the costs also demonstrates an improvement. Moreover, with similar techniques, we detail an iterative projective measurement method for ground state preparation that gives an exponential improvement over previous bounds using QPEA. Numerical tests that confirm the expected scaling behavior are also obtained. For these numerical tests we have used a lattice Thirring model as testing ground. Using well-known perturbation theory results, we also show how to more appropriately estimate the cost scaling with respect to state error instead of evolution operator error.

The thermal response of the hot QCD matter has been studied in the presence of a time-varying magnetic field. The impact of the magnetic field, its time dependence, and the collision aspects of the medium on thermal transport have been studied within the relativistic kinetic theory. The decay time of the magnetic field in the medium seems to have a strong dependence on thermal conductivity. The applicability of the Wiedemann-Franz law for the QCD medium has been investigated in the presence of time-varying external electromagnetic fields. The phenomenological significance of thermal transport in heavy-ion collision experiments has also been investigated by relating the thermal conductivity to the elliptic flow through the Knudsen number. The investigations are extended to study the thermoelectric behavior of hot QCD medium and its dependence on the magnetic field. The time dependent magnetic field is observed to significantly influence the thermoelectric behavior of the medium.

We investigate a consistent scenario of time-varying neutrino masses, and discuss its impact on cosmology, beta decay, and neutrino oscillation experiments. Such time-varying masses are assumed to be generated by the coupling between a sterile neutrino and an ultralight scalar field, which in turn affects the light neutrinos by mixing. We demonstrate how various cosmological bounds, such as those coming from big bang nucleosynthesis, the cosmic microwave background, as well as large scale structures, can be evaded in this model. This scenario can be further constrained using multiple terrestrial experiments. In particular, for beta-decay experiments like KATRIN, nontrivial distortions to the electron spectrum can be induced, even when time-variation is fast and it gets averaged. Furthermore, the presence of time-varying masses of sterile neutrinos will alter the interpretation of light sterile neutrino parameter space in the context of the reactor and gallium anomalies. In addition, we also study the impact of such time-varying neutrino masses on results from the BEST collaboration, which have recently strengthened the gallium anomaly. If confirmed, we find that the time-varying neutrino mass hypothesis could give a better fit to the recent BEST data.

The modeling of neutrino-nucleus interactions constitutes a challenging source of systematic uncertainty for the extraction of precise values of neutrino oscillation parameters in long-baseline accelerator neutrino experiments. To improve such modeling and minimize the corresponding uncertainties, a new generation of detectors is being developed, which aim to measure the complete final state of particles resulting from neutrino interactions. In order to fully benefit from the improved detector capabilities, precise simulations of the nuclear effects on the final-state nucleons are needed. This article presents the study of the in-medium propagation of knocked-out protons, i.e., final-state interactions (FSI), comparing the NuWro and INCL cascade models. The INCL model is used here for the first time to predict exclusive final states in measured neutrino interaction cross sections. This study of INCL in the framework of neutrino interactions features various novelties, including the production of nuclear clusters (e.g., deuterons, $\alpha$ particles) in the final state. The paper includes a complete characterization of the final state after FSI, comparisons to available measurements of single transverse variables, and an assessment of the observability of nuclear clusters.