Not all experiments publish their results with a description of the correlations between the data points. This makes it difficult to do hypothesis tests or model fits with that data, since just assuming no correlation can lead to an overestimation or underestimation of the resulting uncertainties. This work presents robust test statistics that can be used with datasets with missing correlation information. They are exact in the case of no correlation and either guaranteed to be conservative—i.e., the uncertainty is never underestimated—in the presence of correlations, or they are also exact in the degenerate case of perfect correlation between the data points.

We investigate the contributions of the hadronic structure of the neutron to radiative $O(\alpha E_e/m_N)$ corrections [or the inner $O(\alpha E_e/m_N)$ RC] to the neutron beta decay, where $\alpha$, $E_e$, and $m_N$ are the fine-structure constant, the electron energy, and the nucleon mass, respectively. We perform the calculation within the effective quantum field theory of strong low-energy pion-nucleon interactions described by the linear $\sigma$ model with chiral $SU(2)\times SU(2)$ symmetry and electroweak hadron-hadron, hadron-lepton, and lepton-lepton interactions for the electron-lepton family with $SU(2{)}_L\times U(1{)}_Y$ symmetry of the standard electroweak theory [Ivanov et al., Phys. Rev. D 99, 093006 (2019)]. We show that after renormalization, carried out in accordance with Sirlin’s prescription [Sirlin, Phys. Rev. 164, 1767 (1967)], the inner $O(\alpha E_e/m_N)$ RC are of the order of a few parts of ${10}^{-5}–{10}^{-4}$. This agrees well with the results obtained in [Ivanov et al., Phys. Rev. D 99, 093006 (2019)].

This paper reports the first T2K measurement of the transverse kinematic imbalance in the single-${\pi }^{+}$ production channel of neutrino interactions. We measure the differential cross sections in the muon-neutrino charged-current interaction on hydrocarbon with a single ${\pi }^{+}$ and at least one proton in the final state, at the ND280 off axis near detector of the T2K experiment. The extracted cross sections are compared to the predictions from different neutrino-nucleus interaction event generators. Overall, the results show a preference for models that have a more realistic treatment of nuclear medium effects including the initial nuclear state and final-state interactions.

In this work we consider ${\mathrm{AdS}}_3$ gravitational theory with certain mixed boundary conditions at infinity. Using the Chern-Simons formalism of ${\mathrm{AdS}}_3$ gravity, we find that these mixed boundary conditions lead to nontrivial boundary terms, which, in turn, produce exactly the spectrum of the $T\overline{T}/J\overline{T}$-deformed conformal field theories (CFTs). We then follow the procedure for constructing asymptotic boundary dynamics of ${\mathrm{AdS}}_3$ to derive the constrained $T\overline{T}$-deformed Wess-Zumino-Witten (WZW) model from Chern-Simons gravity. The resulting theory turns out to be the $T\overline{T}$-deformed Alekseev-Shatashvili action after disentangling the constraints. Furthermore, by adding a $U(1)$ gauge field associated to the current $J$, we obtain one type of the $J\overline{T}$-deformed WZW model, and show that its action can also be constructed from the gravity side. These results provide a check on the correspondence between the $T\overline{T}/J\overline{T}$-deformed CFTs and the deformations of boundary conditions of ${\mathrm{AdS}}_3$, the latter of which may be regarded as coordinate transformations.

Quantum error correcting codes with finite-dimensional Hilbert spaces have yielded new insights on bulk reconstruction in AdS/CFT. In this paper, we give an explicit construction of a quantum error correcting code where the code and physical Hilbert spaces are infinite-dimensional. We define a von Neumann algebra of type ${\mathrm{II}}_1$ acting on the code Hilbert space and show how it is mapped to a von Neumann algebra of type ${\mathrm{II}}_1$ acting on the physical Hilbert space. This toy model demonstrates the equivalence of entanglement wedge reconstruction and the exact equality of bulk and boundary relative entropies in infinite-dimensional Hilbert spaces.

Binary black hole (BH) may form near a supermassive black hole. The background BH will affect the gravitational wave (GW) generated by the binary black hole. It is well known that the Penrose process may provide extra energy due to the ergosphere. In the present paper, we investigate the energy amplification of the gravitational wave by a Kerr black hole background. In particular and different from the earlier studies, we compare the energies of the waves in the cases with and without a nearby Kerr BH. We find that only when the binary black hole is moving relative to the Kerr background can the GW energy be amplified. Otherwise, the energy will be suppressed by the background Kerr black hole. This finding is consistent with the inequality found by Wald for Penrose process. Taking into account realistic astrophysical scenarios, we find that the Kerr black hole background can amplify the GW energy by at most 5 times.

We apply the diabatic approach, specially suited for a QCD based study of conventional (quark-antiquark) and unconventional ($\mathrm{quark}\text{−}\mathrm{antiquark}+\mathrm{meson}\text{−}\mathrm{meson}$) meson states, to the description of hidden-bottom mesons. A spectral analysis of the $I=0$, $J^{++}$ and $1^{--}$ resonances with masses up to about 10.8 GeV is carried out. Masses and widths of all the experimentally known resonances, including conventional and unconventional states, can be well reproduced. In particular, we predict a significant $B{\overline{B}}^{*}$ component in $\mathrm{\Upsilon }(10580)$. We also predict the existence of a not yet discovered unconventional $1^{++}$ narrow state, with a significant $B_s{\overline{B}}_s^{*}$ content making it to decay into $\mathrm{\Upsilon }(1S)\varphi$, whose experimental discovery would provide definite support to our theoretical analysis.

We report results from a study of the spin and parity of ${\mathrm{\Xi }}_c(2970{)}^{+}$ using a $980{\mathrm{fb}}^{-1}$ data sample collected by the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The decay angle distributions in the chain ${\mathrm{\Xi }}_c(2970{)}^{+}\to {\mathrm{\Xi }}_c(2645{)}^0{\pi }^{+}\to {\mathrm{\Xi }}_c^{+}{\pi }^{-}{\pi }^{+}$ are analyzed to determine the spin of this charmed-strange baryon. The angular distributions strongly favor the ${\mathrm{\Xi }}_c(2970{)}^{+}$ spin $J=1/2$ over $3/2$ or $5/2$, under an assumption that the lowest partial wave dominates in the decay. We also measure the ratio of ${\mathrm{\Xi }}_c(2970{)}^{+}$ decay branching fractions $R=\mathcal{B}[{\mathrm{\Xi }}_c(2970{)}^{+}\to {\mathrm{\Xi }}_c(2645{)}^0{\pi }^{+}]/\mathcal{B}[{\mathrm{\Xi }}_c(2970{)}^{+}\to {\mathrm{\Xi }}_c^{\prime 0}{\pi }^{+}]=1.67\pm 0.29{(\mathrm{stat})}_{-0.09}^{+0.15}(\mathrm{syst})\pm 0.25(\mathrm{IS})$, where the last uncertainty is due to possible isospin-symmetry-breaking effects. This $R$ value favors the spin-parity $J^P=1/2^{+}$ with the spin of the light-quark degrees of freedom $s_l=0$. This is the first determination of the spin and parity of a charmed-strange baryon.

We consider a theory of scalar QED on a spatially compact $1+1$-dimensional spacetime. By considering a constant electric field pointing down the compact dimension, we compute the quantum effective action by integrating out the scalar degrees of freedom in the Euclidean sector. Working in the saddle-point approximation, we uncover two novel branches/physical regimes upon analytically continuing back to real time and discover a new result, hitherto unreported in previous literature. Implications of our results are discussed.

Spherically symmetric spacetimes admit the so-called Kodama vector, which provides a locally conserved current and a preferred time even for dynamical spacetime without any time translation symmetry. A charge associated with this conserved current leads to a quasilocal mass which agrees with the Misner-Sharp mass. In three dimensions, spherically symmetric spacetimes correspond to axisymmetric ones, while axisymmetry allows spacetimes to be rotating with angular momentum. We extend the notion of the Kodama vector to axisymmetric rotating spacetimes in three dimensions. We also define a quasilocal mass taking into account angular momentum in three-dimensional axisymmetric spacetimes.

The no-hair conjecture in general relativity (GR) states that the properties of an astrophysical Kerr black hole (BH) are completely described by its mass and spin. As a consequence, the complex quasinormal-mode (QNM) frequencies of a binary–black-hole (BBH) ringdown can be uniquely determined by the mass and spin of the remnant object. Conversely, measurement of the QNM frequencies could be an independent test of the no-hair conjecture. This paper extends to spinning BHs earlier work that proposed to test the no-hair conjecture by measuring the complex QNM frequencies of a BBH ringdown using parameterized inspiral-merger-ringdown waveforms in the effective-one-body formalism, thereby taking full advantage of the entire signal power and removing dependency on the predicted or estimated start time of the ringdown. Our method was used to analyze the properties of the merger remnants for BBHs observed by LIGO-Virgo in the first half of their third observing (O3a) run. After testing our method with GR and non-GR synthetic-signal injections in Gaussian noise, we analyze, for the first time, two BBHs from the first (O1) and second (O2) LIGO-Virgo observing runs and two additional BBHs from the O3a run. We then provide joint constraints with published results from the O3a run. In the most agnostic and conservative scenario, where we combine the information from different events using a hierarchical approach, we obtain, at 90% credibility, that the fractional deviations in the frequency (damping time) of the dominant QNM are $\delta f_{220}={0.03}_{-0.09}^{+0.10}$ ($\delta {\tau }_{220}={0.10}_{-0.39}^{+0.44}$), respectively, an improvement of a factor of $\sim 4$ ($\sim 2$) over the results obtained with our model in the LIGO-Virgo publication. The single-event most-stringent constraint to date continues to be GW150914, for which we obtain $\delta f_{220}={0.05}_{-0.07}^{+0.11}$ and $\delta {\tau }_{220}={0.07}_{-0.23}^{+0.26}$.

We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction program. This allows us to easily obtain a qualitative feel of how much the $\mathrm{\Lambda }\mathrm{CDM}$ model differs from other $f(R)$ theories of gravity at the level of linear perturbation theory for theories that share the same background dynamics. This is achieved by using the standard model independent cosmographic parameters to develop a new dynamical system formulation of $f(R)$ gravity which is free from the limitation of having to first specify the functional form of $f(R)$. By considering a set of representative trajectories, which are indistinguishable from $\mathrm{\Lambda }\mathrm{CDM}$, we use purely qualitative arguments to determine the extent to which these models deviate from the standard model by including an analysis of the linear growth rate of density fluctuations and also whether or not they suffer from the Dolgov-Kawasaki instability. We find that if one demands that a late time $f(R)$ cosmology is observationally close to the $\mathrm{\Lambda }\mathrm{CDM}$ model, there is a higher risk that it suffers from a Dolgov-Kawasaki instability. Conversely, the more one tries to construct a physically viable late time $f(R)$ cosmology, the more likely it is observationally different from the $\mathrm{\Lambda }\mathrm{CDM}$ model.

We investigate the possibility that radio-bright active galactic nuclei (AGN) are responsible for the TeV–PeV neutrinos detected by IceCube. We use an unbinned maximum-likelihood-ratio method, 10 yr of IceCube muon-track data, and 3388 radio-bright AGN selected from the Radio Fundamental Catalog. None of the AGN in the catalog have a large global significance. The two most significant sources have global significance of $\simeq 1.5\sigma$ and $0.8\sigma$, though $4.1\sigma$ and $3.8\sigma$ local significance. Our stacking analyses show no significant correlation between the whole catalog and IceCube neutrinos. We infer from the null search that this catalog can account for at most 30% (95% C.L.) of the diffuse astrophysical neutrino flux measured by IceCube. Moreover, our results disagree with recent work that claimed a $4.1\sigma$ detection of neutrinos from the sources in this catalog, and we discuss the reasons of the difference.

In this article we perform a combined analysis of low energy precision constraints and LHC searches for leptoquarks which couple to first generation fermions. Considering all ten leptoquark representations, five scalar and five vector ones, we study at the precision frontier the constraints from $K\to \pi \nu \nu$, $K\to \pi e^{+}{e}^{-}$, $K^0-{\overline{K}}^0$ and $D^0-{\overline{D}}^0$ mixing, as well as from experiments searching for parity violation (atomic parity violation experiments and Qweak). We include LHC searches for $s$-channel single resonant production, pair production and Drell-Yan-like signatures of leptoquarks. Interestingly, we find that the recent nonresonant dilepton analysis of ATLAS provides stronger bounds than the resonant searches recasted so far to constrain $t$-channel production of leptoquarks. Taking into account all these bounds, we observe that none of the leptoquark representations can address the so-called “Cabibbo-angle anomaly” via a direct contribution to superallowed beta decays.

We propose a soft-breaking mechanism for dark matter (DM) shift symmetry in a class of composite dark matter models, where both DM and the Higgs boson arise as pseudo Nambu-Goldstone bosons from novel strong dynamics. Our mechanism is utilized to suppress the nonderivative portal coupling between the Higgs boson and DM particle, which can evade the stringent bound of current DM direct detection experiments. Otherwise, this nonderivative portal coupling would naturally be at the same order of the Higgs quartic, rendering this class of models under severe crisis. For realizing the soft-breaking mechanism, we introduce vectorlike top partners dubbed “softons” to restore the shift symmetry of DM in the top Yukawa sector, which, however, is only broken by the softon masses. The portal coupling automatically vanishes as the shift-symmetry-breaking softon masses approach zero. Specifically, we present a proof-of-concept model of soft breaking based on the coset $O(6)/O(5)$ and the simplest fermion embedding, and study its DM phenomenology, where we show a large amount of novel parameter space is opened up by using the soft-breaking mechanism.

Motivated by the measurements of the branching fractions of the quasi-two-body decays $B^0\to K^{*0}(f_0(980)\to ){\pi }^{+}{\pi }^{-}$ and $B^0\to {\rho }^0(f_0(980)\to ){\pi }^{+}{\pi }^{-}$, we study the charmless $B\to V(f_0(980)\to ){\pi }^{+}{\pi }^{-}$ decays in the perturbative QCD approach. Supposing that $f_0(980)$ is a two-quark state and mixture of $n\overline{n}=(u\overline{u}+d\overline{d})/\sqrt{2}$ and $s\overline{s}$ with the mixing angle $\theta$, we calculate the branching fractions of these decays with the new introduced $s$-wave ${\pi }^{+}{\pi }^{-}$-pair wave function. When the mixing angle $\theta$ lies in the range $[135°,155°]$, the calculated branching fractions of the $B^0\to K^{*0}{f}_0(980)\to K^{*0}{\pi }^{+}{\pi }^{-}$ and $B^0\to {\rho }^0{f}_0(980)\to {\rho }^0{\pi }^{+}{\pi }^{-}$ decays are in agreement with the experimental data. The branching fractions of other decays could be measured in the current LHCb and Belle II experiments. Considering the isospin symmetry, we also estimate the branching fractions of the quasi-two-body decays $B\to V{f}_0(980)\to V{\pi }^0{\pi }^0$, which are half of the corresponding decays $B\to V{f}_0(980)\to V{\pi }^{+}{\pi }^{-}$. Moreover, the direct $CP$ asymmetries of these decays are also calculated, and some of them can be tested in the current experiments.

The T2K experiment reports updated measurements of neutrino and antineutrino oscillations using both appearance and disappearance channels. This result comes from an exposure of $14.9(16.4)\times 10^{20}$ protons on target in neutrino (antineutrino) mode. Significant improvements have been made to the neutrino interaction model and far detector reconstruction. An extensive set of simulated data studies have also been performed to quantify the effect interaction model uncertainties have on the T2K oscillation parameter sensitivity. T2K performs multiple oscillation analyses that present both frequentist and Bayesian intervals for the Pontecorvo-Maki-Nakagawa-Sakata parameters. For fits including a constraint on ${\sin }^2{\theta }_{13}$ from reactor data and assuming normal mass ordering T2K measures ${\sin }^2{\theta }_{23}={0.53}_{-0.04}^{+0.03}$ and $\mathrm{\Delta }{m}_{32}^2=(2.45\pm 0.07)\times {10}^{-3}{\mathrm{eV}}^2{\mathrm{c}}^{-4}$. The Bayesian analyses show a weak preference for normal mass ordering (89% posterior probability) and the upper ${\sin }^2{\theta }_{23}$ octant (80% posterior probability), with a uniform prior probability assumed in both cases. The T2K data exclude CP conservation in neutrino oscillations at the $2\sigma$ level.

We define and study the $T\overline{T}$ deformation of a random matrix model: showing a consistent definition requires the inclusion of both the perturbative and the nonperturbative solutions to the flow equation. The deformed model is well defined for arbitrary values of the coupling, exhibiting a phase transition for the critical value in which the spectrum complexifies. The transition is between a single- and a double-cut phase, typically third order and in the same universality class as the Gross-Witten transition in lattice gauge theory. The $T\overline{T}$ deformation of a double scaled model is more subtle and complicated, and we are not able to give a compelling definition, although we discuss obstacles and possible alternatives. Quantitative comparisons with finite cutoff Jackiw-Teitelboim gravity are presented.

We revisit the question of predicting both Hodge numbers $h^{1,1}$ and $h^{2,1}$ of complete intersection Calabi-Yau (CICY) 3-folds using machine learning (ML), considering both the old and new datasets built respectively by Candelas-Dale-Lutken–Schimmrigk/Green-Hübsch-Lutken and by Anderson-Gao-Gray-Lee. In real-world applications, implementing a ML system rarely reduces to feed the brute data to the algorithm. Instead, the typical workflow starts with an exploratory data analysis (EDA) which aims at understanding better the input data and finding an optimal representation. It is followed by the design of a validation procedure and a baseline model. Finally, several ML models are compared and combined, often involving neural networks with a topology more complicated than the sequential models typically used in physics. By following this procedure, we improve the accuracy of ML computations for Hodge numbers with respect to the existing literature. First, we obtain 97% (resp. 99%) accuracy for $h^{1,1}$ using a neural network inspired by the inception model for the old dataset, using only 30% (resp. 70%) of the data for training. For the new one, a simple linear regression leads to almost 100% accuracy with 30% of the data for training. The computation of $h^{2,1}$ is less successful as we manage to reach only 50% accuracy for both datasets, but this is still better than the 16% obtained with a simple neural network (SVM with Gaussian kernel and feature engineering and sequential convolutional network reach at best 36%). This serves as a proof of concept that neural networks can be valuable to study the properties of geometries appearing in string theory.

At one loop, quantum kinks are described by a sum of quantum harmonic oscillator Hamiltonians, and the ground state is just the product of the oscillator ground states. Two-loop kink masses are only known in integrable and supersymmetric cases and two-loop states have never been found. We find the two-loop kink mass and explicitly construct the two-loop kink ground state in a scalar field theory with an arbitrary nonderivative potential. We use a coherent state operator that maps the vacuum sector to the kink sector, allowing all states to be treated with a single Hamiltonian that needs to be renormalized only once, eliminating the need for regulator matching conditions. Our calculation is greatly simplified by a recently introduced alternative to collective coordinates, in which the kink momentum is fixed perturbatively.