The use of experimental data to constrain the values of the Wilson coefficients of an effective field theory involves minimizing a ${\chi }^2$ function that may contain local minima. Classical optimization algorithms can become trapped in these minima, preventing the determination of the global minimum. The quantum annealing framework has the potential to overcome this limitation and reliably find the global minimum of nonconvex functions. We present QFitter, a quantum annealing method to perform effective field theory fits. Using a state-of-the-art quantum annealer, we show with concrete examples that QFitter can be used to fit sets of at least eight coefficients, including their quadratic contributions. An arbitrary number of observables can be included without changing the required number of qubits. We provide an example in which ${\chi }^2$ is nonconvex and show that QFitter can find the global minimum more accurately than its classical alternatives.

The traditional Markov chain Monte Carlo (MCMC) suffers from the problem of critical slowing down. Generative machine learning methods, such as normalizing flows, offer a promising method to speed up MCMC simulations, especially in critical regions of lattice field theory. However, training these models for different parameter values in the critical region is inefficient. In this paper, we address this issue by interpolating or extrapolating the flow model to any parameter value in the critical region. We demonstrate the effectiveness of the proposed method for MCMC sampling in critical regions.

We report the first measurement of ${\pi }^0$ production in neutral current (NC) interactions on argon with average neutrino energy of $\lesssim 1\mathrm{GeV}$. We use data from the MicroBooNE detector’s 85 metric tons active volume liquid argon time projection chamber situated in Fermilab’s Booster Neutrino Beam and exposed to $5.89\times {10}^{20}$ protons on target for this measurement. Measurements of NC ${\pi }^0$ events are reported for two exclusive event topologies without charged pions. Those include a topology with two photons from the decay of the ${\pi }^0$ and one proton and a topology with two photons and zero protons. Flux-averaged cross sections for each exclusive topology and for their semi-inclusive combination are extracted (efficiency correcting for two-plus proton final states), and the results are compared to predictions from the genie, neut, and nuwro neutrino event generators. We measure cross sections of $1.243\pm 0.185(\mathrm{syst})\pm 0.076(\mathrm{stat})$, $0.444\pm 0.098\pm 0.047$, and $0.624\pm 0.131\pm 0.075[{10}^{-38}{\mathrm{cm}}^2/\mathrm{Ar}]$ for the semi-inclusive NC${\pi }^0$, exclusive NC${\pi }^0+1p$, and exclusive NC${\pi }^0+0p$ processes, respectively.

We compute the disruption of mutual information between the hemispherical subsystems on the left and right conformal field theories of a thermofield double state described by a Kerr geometry in ${\mathrm{AdS}}_4$ due to shock waves along the equatorial plane. The shock waves and the subsystems considered respect the axisymmetry of the geometry. At late times, the disruption of the mutual information is given by the lengthening of the Hubeny-Rangamani-Takayanagi surface connecting the two subsystems; we compute the minimum value of the Lyapunov index-${\lambda }_L^{(\min )}$ at late times and find that it is bounded by $\kappa =\frac{2\pi T_H}{(1-\mu \mathcal{L})}$, where $\mu$ is the horizon velocity, and $\mathcal{L}$ is the angular momentum per unit energy of the shock wave. At very late times, we find the scrambling time for such a system is governed by $\kappa$ with $\kappa t_{*}=\log \mathcal{S}$ for large black holes with a large entropy $\mathcal{S}$. We also find a term that increases the scrambling time by $\log (1-\mu \mathcal{L}{)}^{-1}$ but which does not scale with the entropy of the Kerr geometry.

We consider mechanical systems on $T^{*}M$ with possibly irregular and reducible first class constraints linear in the momenta, which thus correspond to singular foliations on $M$. According to a recent result, the latter ones have a Lie-infinity algebroid $(\mathcal{M},Q)$ covering them, where we restrict to the case of Lie-2 algebroids. We propose to consider $T^{*}\mathcal{M}$ as a potential Batalin-Fradkin-Vilkovisky (BFV) extended phase space of the constrained system, such that the canonical lift of the nilpotent vector field $Q$ yields automatically a solution to the BFV master equation. We show that in this case, the BFV extension of the Hamiltonian, providing a second corner stone of the BFV formalism, may be obstructed. We identify the corresponding complex governing this second extension problem explicitly (the first extension problem was circumvented by means of the lift of the Lie-2 algebroid structure). We repeatedly come back to the example of angular momenta on $T^{*}{\mathbb{R}}^3$: in this procedure, the standard free Hamiltonian does not have a BFV extension—while it does so on $T^{*}({\mathbb{R}}^3\backslash \{0\})$, with a relatively involved ghost contribution singular at the origin.

Gravitational wave observations from merging compact objects are becoming commonplace, and as detectors improve and gravitational wave sources become more varied, it is increasingly important to have dense and expansive template banks of predicted gravitational waveforms. Since numerical relativity is the only way to fully solve the nonlinear merger regime of general relativity for comparably massed systems, numerical relativity simulations are critical for gravitational wave detection and analysis. These simulations are computationally expensive, with each simulation placing one point within the high dimensional parameter space of binary black hole coalescences. This makes it important to have a method of placing new simulations in ways that use our computational resources optimally while ensuring sufficient coverage of the parameter space. Accomplishing this requires predicting the impact of a new set of parameters before performing the simulation. To this effect, this paper introduces a neural network to predict the mismatch between the gravitational waves of two binary systems. Using this network, we then show how we can propose new numerical relativity simulations that will provide the most benefit. We also use the network to identify gaps in existing public catalogs and identify degeneracies in the binary black hole parameter space.

We develop the reduced phase space quantization of causal diamonds in pure ($2+1$)-dimensional gravity with a nonpositive cosmological constant. The system is defined as the domain of dependence of a topological disc with fixed boundary metric. By solving the initial value constraints in a constant-mean-curvature time gauge and removing all the spatial gauge redundancy, we find that the phase space is the cotangent bundle of ${\text{Diff}}^{+}(S^1)/\mathrm{PSL}(2,\mathbb{R})$. To quantize this phase space we apply Isham’s group-theoretic quantization scheme, with respect to a ${\mathrm{BMS}}_3$ group, and find that the quantum theory can be realized by wave functions on some coadjoint orbit of the Virasoro group, with labels in irreducible unitary representations of the corresponding little group. We find that the twist of the diamond boundary loop is quantized in integer or half-integer multiples of the ratio of the Planck length to the boundary length.

The spatial covariant gravities provide a natural way to including odd-order spatial derivative terms into the gravitational action, which breaks the parity symmetry at gravitational sector. A lot of parity-violating scalar-tensor theories can be mapped to the spatial covariant framework by imposing the unitary gauge. This provides us with a general framework for exploring the parity-violating effects in primordial gravitational waves (PGWs). The main purpose of this paper is to investigate the polarization of PGWs in the spatial covariant gravities and their possible observational effects. To this end, we first construct the approximate analytical solution to the mode function of the PGWs during the slow-roll inflation by using the uniform asymptotic approximation. With the approximate solution, we calculate explicitly the power spectrum and the corresponding circular polarization of the PGWs analytically. It is shown that the new contributions to power spectrum from spatial covariant gravities contain two parts, one from the parity-preserving terms and the other from the parity-violating terms. While the parity-preserving terms can only affect the overall amplitudes of PGWs, the parity-violating terms induce nonzero circular polarization of PGWs, i.e., the left-hand and right-hand polarization modes of GWs have different amplitudes. The observational implications of this nonzero circular polarization is also briefly discussed.

Blip glitches, a type of short-duration noise transient in the LIGO-Virgo data, are a nuisance for the binary black hole (BBH) searches. They affect the BBH search sensitivity significantly because their time-domain morphologies are very similar, and that creates difficulty in vetoing them. In this work, we construct a deep-learning neural network to efficiently distinguish BBH signals from blip glitches. We introduce sine-Gaussian projection (SGP) maps, which are projections of gravitational wave (GW) frequency-domain data snippets on a basis of sine-Gaussians defined by the quality factor and central frequency. We feed the SGP maps to our deep-learning neural network, which classifies the BBH signals and blips. Whereas only simulated BBH signals are used for training, both simulated and real BBH signals are used for testing. For glitches only blips from real LIGO data are used for both testing and training. We show that our network significantly improves the identification of the BBH signals in comparison to the results obtained using traditional-${\chi }^2$ and sine-Gaussian ${\chi }^2$. For example, our network improves the sensitivity by 75% at a false-positive probability of ${10}^{-2}$ for BBHs with total mass in the range $[80,140]M_{\odot }$ and SNR in the range [3, 8]. When tested on real GW events, it correctly identifies 95% of the events in GWTC-3. The computation time for classification is a few minutes for thousands of SGP maps on a single core. With further optimization in the next version of our algorithm, we expect a further reduction in the computational cost. Our proposed method can potentially improve the veto process in the LIGO-Virgo GW data analysis and conceivably support identifying GW signals in low-latency pipelines.

The fluctuations in the dark matter-baryon relative velocity field are imprinted as acoustic oscillations in the 21-cm power spectrum during cosmic dawn (CD). These velocity acoustic oscillations (VAOs) keep the imprints of the comoving sound horizon scale. In a previous work by Muñoz, it has been demonstrated that these VAOs can be treated as standard rulers to measure the cosmic expansion rate at high redshifts by considering a variety of Lyman-Werner feedback strengths and foreground contamination scenarios. Here we extend that analysis by using a modified version of the public code 21cmfast. We use this code to simulate the VAOs in 21-cm power spectrum and forecast the potential to constrain $H(z)$ with the HERA radio telescope, taking into account the effects of Lyman-$\alpha$ heating, Lyman-Werner feedback and foregrounds, the dependence on various astrophysical parameters, and the degeneracy with cosmological parameters. We find that $H(z)$ can be measured with HERA at $\sim 0.3–6\%$ relative accuracy in the range $11<z<20$, under different astrophysical and foreground scenarios, with uncertainties in the Planck cosmological parameters setting a $\sim 0.08–0.2\%$ relative-error floor in the measurement. This accuracy is on par with most low-redshift measurements and can be helpful in testing various cosmological scenarios motivated by the ongoing “Hubble tension.”

Extreme conditions present in the interiors of the core-collapse supernovae make neutrino-neutrino interactions not only feasible but dominant in specific regions, leading to the nonlinear evolution of the neutrino flavor. Results obtained when such collective neutrino oscillations are treated in the mean-field approximation deviate from the results using the many-body picture because of the ignored quantum correlations. We present the first three-flavor many-body calculations of the collective neutrino oscillations. The entanglement is quantified in terms of the entanglement entropy and the components of the polarization vector. We propose a qualitative measure of entanglement in terms of flavor-lepton number conserved quantities. We find that in the cases considered in the present work, the entanglement can be underestimated in the two-flavor approximation. The dependence of the entanglement on mass ordering is also investigated. We also explore the mixing of mass eigenstates in different mass orderings.

Neutrino oscillation experiments have measured precisely at few percent levels the mass-squared differences ($\mathrm{\Delta }{m}_{21}^2$, $\mathrm{\Delta }{m}_{31}^2$) of three neutrino mass eigenstates, and the three leptonic mixing angles (${\theta }_{12}$, ${\theta }_{13}$, ${\theta }_{23}$) by utilizing both neutrino and antineutrino oscillations. The possible $CPT$ violation may manifest itself in the difference of neutrino and antineutrino oscillation parameters, making these experiments promising tools for testing $CPT$ invariance at unprecedented precision. We investigate empirically the sensitivity of the $CPT$ test via the difference in mass-squared splittings ($\mathrm{\Delta }{m}_{31}^2-\mathrm{\Delta }{\overline{m}}_{31}^2$) and in leptonic mixing angles (${\sin }^2{\theta }_{23}-{\sin }^2{\overline{\theta }}_{23}$) with the synergy of T2K-II, $\mathrm{NO}\nu \mathrm{A}$ extension, and JUNO experiments. If the $CPT$ symmetry is found to be conserved, the joint analysis of the three experiments will be able to establish limits of $|\mathrm{\Delta }{m}_{31}^2-\mathrm{\Delta }{\overline{m}}_{31}^2|<5.3\times {10}^{-3}{\mathrm{eV}}^2$ and $|{\sin }^2{\theta }_{23}-{\sin }^2{\overline{\theta }}_{23}|<0.10$ at $3\sigma$ confidence level (CL) on the possible $CPT$ violation, extending substantially the current bound of these parameters. We find that with ($\mathrm{\Delta }{m}_{31}^2-\mathrm{\Delta }{\overline{m}}_{31}^2$), the dependence of the statistical significance on the relevant parameters to exclude the $CPT$ conservation is marginal, and that, if the difference in the best-fit values of $\mathrm{\Delta }{m}_{31}^2$ and $\mathrm{\Delta }{\overline{m}}_{31}^2$ measured by $\mathrm{MINOS}(+)$ and $\mathrm{NO}\nu \mathrm{A}$ persists as the true, the combined analysis will rule out the $CPT$ conservation at $4\sigma$ CL. With the (${\sin }^2{\theta }_{23}-{\sin }^2{\overline{\theta }}_{23}$), the statistical significance to exclude $CPT$ invariance depends strongly on the true value of ${\theta }_{23}({\overline{\theta }}_{23})$ mixing angle. In the case of maximal mixing of ${\theta }_{23}$, as indicated by the current T2K and $\mathrm{NO}\nu \mathrm{A}$ measurements, the $CPT$ conservation will be excluded at $3\sigma$ CL or higher if the difference in the best-fit values of ${\theta }_{23}$ and ${\overline{\theta }}_{23}$ remains as the true.

For a cold dark matter (DM) originating from the coannihilation processes, there will be excited state(s) in the dark sector that may decay or annihilate away shortly after their freeze-out. In this paper, we investigate the impact of the decay of these excited states on the effective number of neutrino species, $N_{\mathrm{eff}}$, which is an important cosmological parameter and will be tested by the future CMB-S4 project. We work in the framework of pseudo-Dirac DM mode via the Higgs portal. The relic density and the direct detection signal of the DM are calculated, which gives the available parameter space. Impacts of the excited state (the heavy component of the pseudo-Dirac fermion) on the decoupling of active neutrinos are investigated by solving Boltzmann equations of photon and neutrinos with a collision term induced by the decay of the excited state. The numerical result shows that the maximum value of $|\mathrm{\Delta }{N}_{\mathrm{eff}}|$ can reach the order $\mathcal{O}(0.1)$ with suitable mass and lifetime of the excited DM state, which may be probed by future CMB-S4 and SPT/SO projects.

Recently, it has been found that introducing a triplet Higgs to the standard model could provide a feasible leptogenesis to generate the baryon asymmetry of our Universe, providing that the inflation is driven by the mixing state of the triplet Higgs and standard model Higgs. In this work, we survey the viable parameter space satisfying the vacuum stability and perturbativity in this model. We find that the introduction of the triplet Higgs would also ameliorate the problem of the Higgs vacuum instability. We present two representative parameter regions where the origin of neutrino masses, baryon asymmetry of the Universe, and inflation can be explained while keeping consistent with the condition of vacuum stability and perturbativity.

The continued nonobservation of events emanating from dark matter annihilations in various direct and indirect detection experiments calls into question the mechanism for determining the relic density of a weakly interacting massive particle. However, if the relic density is determined primarily by a semiannihilation process, as opposed to the usual annihilation, this tension can be ameliorated. Here, we investigate a $Z_3$ symmetric effective field theory incorporating a fermionic dark matter that semiannihilates to right-handed neutrinos. The dynamics of the right-handed neutrinos and the impact of its late decays are also scrutinized while obtaining the correct dark matter relic. Finally, indirect detection bounds on the semiannihilation cross sections are drawn from the gamma-ray observations in the direction of dwarf spheroidal galaxies (Fermi-LAT), and including the projections obtained for the H.E.S.S. and the CTA detectors.

The oscillating light axion field is known as wave dark matter. We propose an LC (inductor-capacitor)-resonance enhanced detection of the narrow band electric signals induced by the axion dark matter using a solenoid magnet facility. We provide full 3D electromagnetic simulation results for the signal electric field. The electric signal is enhanced by the high $Q$-factor of a resonant LC circuit and then amplified and detected by the state-of-the-art cryogenic electrical transport measurement technique. The cryogenic amplifier noise is the dominant noise source in the proposed detection system. We estimate that the detection system can have a promising sensitivity to axion dark matter with mass below ${10}^{-6}\mathrm{eV}$. The projected sensitivities improve with the size of the magnetic field, and the electric signal measurement can be potentially sensitive to the quantum chromodynamics (QCD) axion with $g_{a\gamma }\sim {10}^{-16}{\mathrm{GeV}}^{-1}$ around $m_a\sim {10}^{-8}\mathrm{eV}$, with a multimeter scale magnetized region. This limit is around five orders of magnitude below the current constraint from the cosmic rays.

We use HPQCD’s recent lattice QCD determination of $B\to K$ scalar, vector and tensor form factors to determine Standard Model differential branching fractions for $B\to K{\ell }^{+}{\ell }^{-}$, $B\to K{\ell }_1^{+}{\ell }_2^{-}$ and $B\to K\nu \overline{\nu }$. These form factors are calculated across the full $q^2$ range of the decay and have smaller uncertainties than previous work, particularly at low $q^2$. For $B\to K{\ell }^{+}{\ell }^{-}$ we find the Standard Model branching fraction in the $q^2$ region below the squared $J/\psi$ mass to exceed the LHCb results, with tensions as high as $4.7\sigma$ for $B^{+}\to K^{+}{\mu }^{+}{\mu }^{-}$. For the high $q^2$ region we see $3\sigma$ tensions. The tensions are much reduced by applying shifts to Wilson coefficients $C_9$ and $C_{10}$ in the effective weak Hamiltonian, moving them away from their Standard Model values consistent with those indicated by other $B$ phenomenology. We also update results for lepton-flavor ratios $R_e^{\mu }$ and $R_{\mu }^{\tau }$ and the “flat term,” $F_H^{\ell }$ in the differential branching fraction for $\ell \in \{e,\mu ,\tau \}$. Our results for the form-factor dependent contributions needed for searches for lepton-flavor violating decays $B\to K{\ell }_1^{-}{\ell }_2^{+}$ achieve uncertainties of 7%. We also compute the branching fraction $\mathcal{B}(B\to K\nu \overline{\nu })$ with an uncertainty below 10%, for comparison with future experimental results.

We present the result of lattice QCD calculation of the scalar, vector and tensor form factors for the $B\to K{\ell }^{+}{\ell }^{-}$ decay, across the full physical range of momentum transfer. We use the highly improved staggered quark (HISQ) formalism for all valence quarks on eight ensembles of gluon-field configurations generated by the MILC collaboration. These include four flavors of HISQ quarks in the sea, with three ensembles having the light $u/d$ quarks at physical masses. In the first fully relativistic calculation of these form factors, we use the heavy-HISQ method. This allows us to determine the form factors as a function of heavy-quark mass from the $c$ to the $b$, and so we also obtain new results for the $D\to K$ tensor form factor. The advantage of the relativistic formalism is that we can match the lattice weak currents to their continuum counterparts much more accurately than in previous calculations; our scalar and vector currents are renormalized fully nonperturbatively and we use a well-matched intermediate momentum-subtraction scheme for our tensor current. Our scalar and vector $B\to K$ form factors have uncertainties of less than 4% across the entire physical $q^2$ range and the uncertainty in our tensor form factor is less than 7%. Our heavy-HISQ method allows us to map out the dependence on heavy-quark mass of the form factors and we can also see the impact of changing spectator quark mass by comparing to earlier HPQCD results for the same quark weak transition but for heavier mesons.

We construct a factorization theorem that allows one to systematically include QCD corrections to the contribution of the electromagnetic dipole operator in the effective weak Hamiltonian to the ${\overline{B}}_s\to {\mu }^{+}{\mu }^{-}$ decay amplitude. We first rederive the known result for the leading-order QED box diagram, which features a double-logarithmic enhancement associated with the different rapidities of the light quark in the ${\overline{B}}_s$ meson and the energetic muons in the final state. We provide a detailed analysis of the cancellation of the related endpoint divergences appearing in individual momentum regions, and show how the rapidity logarithms can be isolated by suitable subtractions applied to the corresponding bare factorization theorem. This allows us to include in a straightforward manner the QCD corrections arising from the renormalization-group running of the hard matching coefficient of the electromagnetic dipole operator in soft-collinear effective theory, the hard-collinear scattering kernel, and the $B_s$-meson distribution amplitude. Focusing on the contribution from the double endpoint logarithms, we derive a compact formula that resums the leading-logarithmic QCD corrections.

Using $(771.6\pm 10.6)\times {10}^{6}B\overline{B}$ meson pairs recorded by the Belle experiment at the KEKB $e^{+}{e}^{-}$ collider, we report the branching fractions $\mathcal{B}({\overline{B}}^0\to D^{*+}{\pi }^{-})=(2.62\pm 0.02\pm 0.09)\times {10}^{-3}$ and $\mathcal{B}({\overline{B}}^0\to D^{*+}{K}^{-})=(2.22\pm 0.06\pm 0.08)\times {10}^{-4}$; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented, ${\mathcal{R}}_{K/\pi }=\mathcal{B}(\overline{B}\to D^{*+}{K}^{-})/\mathcal{B}(\overline{B}\to D^{*+}{\pi }^{-})=(8.41\pm 0.24\pm 0.13)\times {10}^{-2}$, where systematic uncertainties due to the $D^{*+}$ meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for $\overline{B}\to D^{*+}{h}^{-}$ and $\overline{B}\to D^{*+}{\ell }^{-}\nu$ decays at squared momentum transfer values equivalent to the mass of the $h=\pi$ or $K$ hadron. The parameters $|a_1(h)|$ are measured to be $|a_1(\pi )|=0.884\pm 0.004\pm 0.003\pm 0.016$ and $|a_1(K)|=0.913\pm 0.019\pm 0.008\pm 0.013$, where the last uncertainties account for all external inputs. These values are approximately 15% lower than those expected from theoretical predictions. Subsequently, flavor $SU(3)$ symmetry is tested by measuring the ratios for pions and kaons, $|a_1(K){|}^2/|a_1(\pi ){|}^2=1.066\pm 0.042\pm 0.018\pm 0.023$, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for $SU(3)$ symmetry breaking effects is found at the 5% precision level.