The next generation of long-baseline neutrino experiments will be capable of precise measurements of neutrino oscillation parameters, precise neutrino-nucleus scattering, and unprecedented sensitivity to physics beyond the Standard Model. Reduced uncertainties in neutrino fluxes are necessary to achieve high precision and sensitivity in these future neutrino measurements. New measurements of hadron-nucleus interaction cross sections are needed to reduce uncertainties of neutrino fluxes. We report measurements of the differential cross section as a function of scattering angle for proton-carbon interactions with a single charged particle in the final state at beam momenta of 20, 30, and $120\mathrm{GeV}/c$. These measurements are the result of a beam test for EMPHATIC, a hadron-scattering and hadron-production experiment. The total, elastic and inelastic cross sections are also extracted from the data and compared to previous measurements. These results can be used in current and future long-baseline neutrino experiments and demonstrate the feasibility of future measurements by an upgraded EMPHATIC spectrometer.

We present for the first time classical multiparticle solutions in anti–de Sitter space (AdS) involving scalars, gluons, and gravitons. They are recursively defined through multiparticle currents which reduce to Berends-Giele currents in the flat space limit. This construction exposes a compact definition of tree-level boundary correlators using a general prescription that removes unphysical boundary contributions. Similarly to the flat space perturbiner, a convenient gauge choice leads to a scalar basis for all degrees of freedom, while the tensor structure is exclusively captured by field theory vertices. This provides a fully automated way to compute AdS boundary correlators to any multiplicity and cosmological wave function coefficients after Wick rotating to de Sitter space.

We present a realization of fracton-elasticity duality purely formulated in terms of ordinary gauge fields, encompassing standard elasticity and incommensurate crystals. Our construction comprises a description of all types of two-dimensional defects, body forces, and impurities. The original form of the duality in terms of tensor gauge fields is recovered after partial gauge fixing. We identify the coupling of the defects to the dual gauge fields, and from gauge invariance we derive continuity equations for the defect currents and the expected mobility restrictions of elasticity defects.

We show that the crossing symmetric dispersion relation (CSDR) for 2-2 scattering leads to a fascinating connection with knot polynomials and $q$-deformed algebras. In particular, the dispersive kernel can be identified naturally in terms of the generating function for the Alexander polynomials corresponding to the torus knot $(2,2n+1)$ arising in knot theory. Certain linear combinations of the low energy expansion coefficients of the amplitude can be bounded in terms of knot invariants. Pion S-matrix bootstrap data respect the analytic bounds so obtained. We correlate the $q$-deformed harmonic oscillator with the CSDR-knot picture. In particular, the scattering amplitude can be thought of as a $q$-averaged thermal two-point function involving the $q$-deformed harmonic oscillator. The low temperature expansion coefficients are precisely the $q$-averaged Alexander knot polynomials.

Quantum field effects on a classical background spacetime may be obtained from the semiclassical equations of general relativity with the expectation value of the stress-energy tensor of the quantum field as a source. This expectation value can be calculated from Hadamard’s elementary two-point function, which in practice is given in terms of sums of products of field modes evaluated at two spacetime points. We derive expressions for the two-point function for a massless scalar field in the Unruh state on a Kerr black hole spacetime. Our main result in this paper is a novel expression valid when the two points lie inside the black hole; we also (re)derive, using a new method, the known expression valid when the two points lie outside the black hole. We achieve these expressions by finding relationships between Unruh modes, defined in terms of the retarded Kruskal coordinate, and Eddington modes, defined in terms of the Eddington coordinates. While our starting expression for the two-point function is written in terms of the Unruh modes, we give our final expression in terms of the Eddington modes, which have the computational advantage that they decompose into factors that obey ordinary differential equations. In an appendix we also derive expressions for the bare mode contributions to the flux components of the stress-energy tensor for a minimally coupled massless scalar field inside the black hole. Our results thus lay the groundwork for future calculations of quantum effects inside a Kerr black hole.

Using the Cornwall-Jackiw-Tomboulis effective action $\mathrm{\Gamma }(S)$ for composite operators ($S$ is the full fermion propagator), the phase structure of the massless ($2+1$)-dimensional Thirring model with four-component spinors is investigated in the Hartree-Fock (HF) approximation. In this case both $\mathrm{\Gamma }(S)$ and its stationary (or HF) equation for the full fermion propagator $S$ are calculated in the first order of the bare coupling constant $G$. We have shown that there exists a well-defined dependence of $G\equiv G(\mathrm{\Lambda })$ on the cutoff parameter $\mathrm{\Lambda }$ under which the HF equation is renormalized. In general, it has two sets, (i) and (ii), of solutions for the fermion propagator corresponding to dynamical appearance of different mass terms in the model. In the case of set (i) the mass terms are Hermitian, but the solutions from the set (ii) correspond to a dynamical generation of the non-Hermitian mass terms, i.e., to a spontaneous non-Hermiticity of the Thirring model. Despite this, the mass spectrum of the quasiparticle excitations of all non-Hermitian ground states is real. In addition, among these non-Hermitian phases there are both $\mathcal{P}\mathcal{T}$ symmetrical and nonsymmetrical phases. Moreover, in contrast with previous investigations of this effect in other models, we have observed the spontaneous non-Hermiticity phenomenon also in the massive ($2+1$)-dimensional Thirring model.

Gauge symmetries in teleparallel gravity, together with the identities among the dynamical equations they provide, are analyzed in relation to the way they condition the coupling between matter and gravity. Particularly, the coupling of fermionic matter seems to be excluded in a wide range of teleparallel theories.

The necessary and sufficient conditions for a perfect energy tensor to describe the energy evolutions of a monoatomic relativistic Synge gas are obtained. Then, a Rainich-like theory for the Einstein-Synge solutions can be constructed. Equations of state approximating that of a Synge gas at low or at high temperatures, or in the entire domain of applicability, are analyzed from a hydrodynamic point of view.

We consider the search for gamma rays produced by the annihilation or decay of low-mass dark matter which couples to quarks. In this scenario, most of the photons are produced from the decays of ${\pi }^0$ or $\eta$ mesons. These decays produce distinctly different photon signatures due to the difference in meson mass. We assess the ability of the future MeV-range observatories to constrain the hadronic final states produced by dark matter annihilation or decay from the shape of the resulting photon spectrum. We then comment on how this information can be used to determine properties of the dark matter coupling to the quark current, based on the approximate symmetries of low-energy QCD.

Ultralight primordial black holes (PBHs) in the mass range of ${10}^{16}–{10}^{22}\mathrm{g}$ are allowed by current observations to constitute a significant fraction, if not all, of the dark matter in the Universe. In this work, we present limits on ultralight, nonrotating PBHs which arise from the nondetection of the Hawking radiation signals from such objects in the keV-MeV energy band. Namely, we consider observations from the current-generation missions XMM-Newton and INTEGRAL/SPI and discuss the observational perspectives of the future missions Athena, eXTP, and THESEUS for PBH searches. Based on 3.4 Msec total exposure time XMM-Newton observations of Draco dwarf spheroidal galaxy, we conclude that PBH with masses $\lesssim {10}^{16}\mathrm{g}$ cannot make all dark matter at 95% confidence level. Our ON-OFF-type analysis of $>100\mathrm{Msec}$ of INTEGRAL/SPI data on the Milky Way halo puts significantly stronger constraints. Only $\lesssim 10\%$ dark matter can be presented by PBHs with masses $\lesssim 3\times {10}^{16}\mathrm{g}$ while the majority of dark matter cannot be represented by PBHs lighter than $7\times {10}^{16}\mathrm{g}$ at 95% confidence level. We discuss the strong impact of systematic uncertainty related to the variations of instrumental and astrophysical INTEGRAL/SPI background on the derived results and estimate its level. We also show that future large-field-of-view missions such as THESEUS /X-GIS will be able to improve the constraints by a factor of 10–100 depending on the level of control under the systematics of these instruments.

In the Large High Altitude Air Shower Observatory (LHAASO), the square kilometer array, with 5249 electromagnetic particle detectors (EDs) and 1188 muon detectors, is deployed to explore the gamma-ray sources above 30 TeV with unprecedented sensitivity and to measure primary cosmic rays in the energy range from 10 TeV to 100 PeV. The energetic particles produced by extensive air showers can serve as a continuously available source for calibration of the numerous EDs over a large area. In this study, the detector untriggered probability is first proposed to estimate the particle density at different distances from the shower core and distinguish the characteristic single-particle signal detected by each ED. This method uses science data directly, and does not require prior knowledge of the cosmic-ray elemental composition or hadronic interaction model. Experimental results show that this self-calibration can be used to determine the number of particles detected by each ED with an accuracy better than 2% within a time scale of hours, which is adequate to meet the physics requirements of the LHAASO experiment. With this high efficiency and accuracy, this calibration also provides an ideal method to monitor the detector performance throughout an expected lifetime of $>10\mathrm{years}$.

The photon is the paradigm for a massless particle, and current experimental tests set severe upper bounds on its mass. Probing such a small mass, or equivalently large Compton wavelength, is challenging at laboratory scales, but planetary or astrophysical phenomena may potentially reach much better sensitivities. In this work, we consider the effect of a finite photon mass on Schumann resonances in the Earth-ionosphere cavity, since the transverse magnetic modes circulating Earth have eigenfrequencies of order $\mathcal{O}(10\mathrm{Hz})$ that could be sensitive to $m_{\gamma }\approx {10}^{-14}{\mathrm{eV}/\mathrm{c}}^2$. In particular, we update the limit from Kroll [Phys. Rev. Lett. 27, 340 (1971)], $m_{\gamma }\le 2.4\times {10}^{-13}{\mathrm{eV}/\mathrm{c}}^2$, by considering realistic conductivity profiles for the atmosphere. We find the conservative upper bound $m_{\gamma }\le 2.5\times {10}^{-14}{\mathrm{eV}/\mathrm{c}}^2$, a factor 9.6 more strict than Kroll’s earlier projection.

In this work, we explore the mixing between neutron ($n$) and elementary neutral particle ($\eta$), which violates both the baryon number ($\mathcal{B}$) and the lepton number ($\mathcal{L}$) by one unit but conserves their difference $(\mathcal{B}-\mathcal{L})$. Such mixing may give rise to nontrivial effects that are different from the Standard Model predictions. We organize our discussions based on two scenarios, roughly depending on whether an interference between oscillation and decay occurs, or whether the new-physics effects associated with the $n\text{−}\eta$ mixing contribute to the absorptive mixing amplitude. If an oscillation process is not accompanied by an interference between oscillation and decay, or no interactions contribute to the absorptive mixing amplitude, such a process can be classified as pure oscillation (e.g., neutrino oscillation). Otherwise, it can be classified as impure oscillation (e.g., meson-antimeson oscillation). In the scenario of pure oscillation, $CP$-violation arising from the Majorana phase can manifest itself through the $n-\overline{n}$ oscillation process and may lead to observable effects. In the scenario of impure oscillation, we analyze the testable implications on the masses and lifetimes of the mass eigenstates formed as a result of the $n-\overline{n}$ oscillation mediated by $\eta$. In this scenario, we also suggest a unified interpretation of the neutron lifetime anomaly and the $n-\overline{n}$ oscillation measurements based on the $n-\eta$ mixing. In both scenarios, we present the lower bounds imposed by the experimental searches for $n-\overline{n}$ oscillations on the masses of the color multiplet bosons and point out that they could be within the reach of a direct detection at the LHC or future high-energy experiments. Furthermore, we discuss about the observability of the geometric phase associated with the $n-\eta$ mixing. The measurement of such a geometric phase may provide another opportunity for the study of new-physics effects.

In this work we study the production of two Higgs bosons at the two planned electron positron colliders with energies at the TeV domain, CLIC and ILC, within the context of effective field theories (EFTs) to describe beyond the Standard Model Higgs physics. We focus first on the case of the Higgs effective field theory (HEFT) and next we compare with the case of the Standard Model effective field theory (SMEFT). The predictions for double Higgs production in both EFTs are first presented for the most relevant subprocess participating in the total process of our interest, $e^{+}{e}^{-}\to HH\nu \overline{\nu }$, which is the scattering of two gauge bosons, $WW\to HH$, also called $WW$ fusion. The predictions for the cross section $\sigma (W_X{W}_Y\to HH)$ as a function of the subprocess energy are analyzed in full detail for the two EFTs, for all the polarization channels with longitudinal and transverse modes $XY=LL,TT,LT,TL$, and for the most relevant effective operators in both cases. We will demonstrate that in the HEFT case, the total cross section can be fully understood in terms of the $LL$ contribution and this in turn is dominated at these TeV energies mainly by two HEFT coefficients. By doing the matching between the two EFTs at the level of the scattering amplitude for the subprocess, we will be able to find the correspondence of the leading coefficients in the HEFT and the SMEFT. In the final part of this work we will then explore the sensitivity to these two most relevant HEFT coefficients, at CLIC (3 TeV, $5{\mathrm{ab}}^{-1}$) and ILC (1 TeV, $8{\mathrm{ab}}^{-1}$). We will then conclude on the accessible region of these two parameters by studying the predicted rates at these two $e^{+}{e}^{-}$ colliders for the final state $b\overline{b}b\overline{b}\nu \overline{\nu }$ leading to characteristic signals with four bottom jets and missing energy.

We reassess nonstandard triple gauge couplings in the light of the recent $(g-2{)}_{\mu }$ measurement at FNAL, the new lattice theory result of $(g-2{)}_{\mu }$, and the updated measurements of several $B$-decay modes. In the framework of SMEFT, three bosonic dimension-6 operators are invoked to parametrize physics beyond the Standard Model, and their contributions to such low-energy observables are computed. Constraints on the corresponding Wilson coefficients are then derived from fits to the current experimental bounds on the observables and compared with the most stringent ones available from the 13 TeV LHC data in the $W^{+}{W}^{-}$ and $W^{\pm }Z$ production channels.

We present the vector, scalar, and tensor renormalization constants (RCs) using overlap fermions with either regularization independent momentum subtraction ($\mathrm{RI}/\mathrm{MOM}$) or symmetric momentum subtraction ($\mathrm{RI}/\mathrm{SMOM}$) as the intermediate scheme on the lattice with lattice spacings $a$ from 0.04 fm to 0.12 fm. Our gauge field configurations from the MILC and RBC/UKQCD collaborations include sea quarks using either the domain wall or the HISQ action, respectively. The results show that $\mathrm{RI}/\mathrm{MOM}$ and $\mathrm{RI}/\mathrm{SMOM}$ can provide consistent renormalization constants to the $\overline{\mathrm{MS}}$ scheme, after proper $a^2{p}^2$ extrapolations. But at $p\sim 2\mathrm{GeV}$, both $\mathrm{RI}/\mathrm{MOM}$ and $\mathrm{RI}/\mathrm{SMOM}$ suffer from nonperturbative effects which cannot be removed by the perturbative matching. The comparison between the results with different sea actions also suggests that the renormalization constant is discernibly sensitive to the lattice spacing but not to the bare gauge coupling in the gauge action.

The analytic structure of the two flavorful QCD lattice Landau gauge quark propagator is investigated with Padé approximants applied to its vector and scalar form factors. No poles at complex momentum are observed for the propagator. Moreover, there is clear evidence of a pole at real on-axis negative Euclidean momentum, i.e., for a Minkowski type of momentum. This pole occurs at Euclidean momenta $p\sim -300\mathrm{MeV}$ and it reproduces typical quark mass values used in phenomenological effective quark models. The Padé approximant analysis also gives hints on the presence of a branch cut. Our results also show a clear correlation between the position of this pole, understood as an effective quark mass, and the pion mass that is compatible with partial conservation of the axial current. Slightly differences between the poles for the two quark form factors are observed which can be viewed either as a limitation of the method or as a suggestion that the quark propagator has no spectral representation.

We investigate the effects of including strong $CP$ violating effects through axion fields in the microscopic equation of state of massive hybrid neutron stars. We assume that their cores contain deconfined quark matter and include the effects of axions via an effective ‘t Hooft determinant interaction. The hadronic crusts are described using different approaches in order to make our results more general. We find that the presence of axions stabilizes massive hybrid neutron stars against gravitational collapse by weakening the deconfinement phase transition and bringing it to lower densities. This enables to reproduce hybrid neutron stars in agreement with modern astrophysical constraints.

The present work investigates the entanglement entropies of the Hawking radiations, Page times, and scrambling times for the eternal planar black holes in the holographic axion gravity. The solutions correspond to a new class of charged black holes, because the boundary diffeomorphism is broken due to the graviton mass induced by the axion fields in the bulk. The information theoretical aspects of these black hole solutions are determined upon applying the island rule for the entanglement entropy. Like nonextremal charged black holes, the radiation entropy grows linearly in the no-island configurations, while it is saturated at late times by asymptotic values set by the Bekenstein-Hawking entropy in the island configurations, with the boundary being located slightly outside the outer horizon. In particular, for the extremal black planes of holographic axion gravity, we find that (a) the entanglement entropy of the Hawking radiation is ill-defined at the early times when the island is absent, (b) it tends to a distinctive constant at the late times, and (c) the late-time location of the island is indeed universal. Moreover, we investigate how the Page time is affected by the holographic massive gravity deformation. For neutral solutions at the small deformation parameter, and for charged solutions with almost-extremal deformation parameter, we find that the Page transition happens at earlier times.

The quantum complexity of conformal field theory (CFT) states can be computed holographically from the dual gravitational solutions. In this paper, we have studied the late-time growth of holographic complexity of a charged black hole in five-dimensional anti–de Sitter spacetime in the presence of quartic derivative interaction terms using the $complexity=action$ conjecture. These interaction terms in the gravitational action can lead to the violation of Lloyd’s bound. The dual CFT is known to admit a hydrodynamic description where the KSS bound is also violated due to higher derivative terms in the bulk action. The origin of terms which violate both bounds are the same for the gravitational action of consideration. It is fascinating that the wormhole and the boundary fluid show similar features in the presence of higher derivative terms. We have also discussed the late-time complexity growth rate of the Jackiw-Teitelboim (JT) model with higher derivative corrections.