Neutrinos with energy of order 10 MeV, such as from pion decay-at-rest sources, are an invaluable tool for studying low-energy neutrino interactions with nuclei—previously enabling the first measurement of coherent elastic neutrino-nucleus scattering. Beyond elastic scattering, neutrinos and dark matter in this energy range also excite nuclei to its low-lying nuclear states, providing an additional physics channel. Here, we consider neutral-current inelastic neutrino-nucleus and dark matter (DM)-nucleus scattering off ${}^{40}\mathrm{Ar}$, ${}^{133}\mathrm{Cs}$, and ${}^{127}\mathrm{I}$ nuclei that are relevant to a number of low-threshold neutrino experiments at pion decay-at-rest facilities. We carry out large scale nuclear shell model calculations of the inelastic cross sections considering the full set of electroweak multipole operators. Our results demonstrate that Gamow-Teller transitions provide the dominant contribution to the cross section and that the long-wavelength limit provides a reasonable approximation to the total cross section for neutrino sources. We show that future experiments will be sensitive to this channel, and thus these results provide additional neutrino and DM scattering channels to explore at pion decay-at-rest facilities.

In this paper, we perform partial wave decomposition on coupled-channel scattering amplitudes, $J/\psi J/\psi \text{−}J/\psi \psi (2S)\text{−}J/\psi \psi (3770)$, to study the resonance appears in these processes. Effective Lagrangians are used to describe the interactions of four charmed vector mesons, and the scattering amplitudes are calculated up to the next-to-leading order. Partial wave projections are performed, and unitarization is implemented by Padé approximation. Then we fit the amplitudes to the $J/\psi J/\psi$ invariant mass spectra measured by LHCb and determine the unknown couplings. The pole parameters of the $X(6900)$ are extracted as $M={6861.0}_{-8.8}^{+6.3}\mathrm{MeV}$ and $\mathrm{\Gamma }={129.0}_{-3.4}^{+5.6}\mathrm{MeV}$. Our analysis implies that its quantum number prefers to be $0^{++}$. The pole counting rule and phase shifts show that it is a normal Breit-Wigner resonance and, hence, should be a compact tetraquark.

We analyze nonlocal rotating observables in holography corresponding to spinning bound states. To renormalize their energies and momenta we suggest and discuss different holographic renormalization schemes motivated by the static nonlocal observables. Namely the holographic renormalization and the rotating color singlet mass subtraction scheme. In the holographic renormalization we identify the infinite boundary terms and subtract them. In the mass subtraction scheme we evaluate the energy of a spinning trailing string corresponding to the color charged singlet which experiences dragging phenomena and we subtract it from the energy of the bound state to obtain the renormalized finite energy. Then we apply our generic framework to certain strongly coupled thermal theories with broken rotational symmetry. We find numerical solutions corresponding to spinning bound states with a fixed size while varying their angular frequency. By applying numerically the renormalization schemes, we find that there is a critical frequency where the bound state ceases to exist or dissociates. We also note that bound states require lower angular frequencies to dissociate when the theory has less symmetry.

Applying the inverse scattering method to static and biaxisymmetric Einstein equations, we construct a nonrotating black lens inside a bubble of nothing whose horizon is topologically lens space, $L(n,1)=S^3/{\mathbb{Z}}_n$. Using this solution, we discuss whether a static black lens can be in equilibrium by the force balance between the expansion and gravitational attraction.

The capture of compact objects by massive black holes in galaxies or dwarf galaxies will generate short gravitational wave signals, called extreme-mass-ratio bursts (EMRBs), before evolving into extreme-mass-ratio inspirals. Their detection will provide an investigation of the black hole properties and shed light on astronomy and astrophysics. In this work, we investigate the detection number of the TianQin observatory on EMRBs. Our result shows that TianQin can detect tens of EMRBs events during its mission lifetime. For those detected events, we use the Fisher information matrix to quantify these uncertainties in the inference of their parameters. We consider the possible network of $\mathrm{TianQin}+\mathrm{LISA}$, and study how a network can improve parameter estimation. The result shows that, for most sources, the compact object mass, the massive black hole mass, and the massive black hole spin can be determined with a precision of the order ${10}^{-1}$ and the sky localization can be determined with a precision of 10 square degree. We further explore the gravitational wave background generated by those unsolved EMRBs and conclude that it is about ${10}^6$ times weaker than TianQin’s sensitivity, and thus it can be ignored.

The detection of stochastic gravitational wave background (SGWB) is among the leading scientific goals of the space-borne gravitational wave observatory, which would have significant impact on astrophysics and fundamental physics. In this work, we developed a data analysis software, tqsgwb, which can extract isotropic SGWB using the Bayes analysis method based on the TianQin detector. We find that for the noise cross spectrum, there are imaginary components and they play an important role in breaking the degeneracy of the position noise in the common laser link. When the imaginary corrections are considered, the credible regions of the position noise parameters are reduced by two orders of magnitude. We demonstrate that the parameters of various signals and instrumental noise could be estimated directly in the absence of a Galactic confusion foreground through Markov chain Monte Carlo sampling. With only a three-month observation, we find that TianQin could be able to confidently detect SGWBs with energy density as low as ${\mathrm{\Omega }}_{\mathrm{PL}}=1.3\times {10}^{-12}$, ${\mathrm{\Omega }}_{\text{Flat}}=6.0\times {10}^{-12}$, and ${\mathrm{\Omega }}_{\mathrm{SP}}=9.0\times {10}^{-12}$, for power-law, flat, and single-peak models, respectively.

We study the process, within classical general relativity, in which an incident gravitational plane wave, of weak amplitude and long wavelength, scatters off a massive spinning compact object, such as a black hole or neutron star. The amplitude of the asymptotic scattered wave, considered here at linear order in Newton’s constant $G$ while at higher orders in the object’s multipole expansion, is a valuable characterization of the response of the object to external gravitational fields. This amplitude coincides with a classical ($\hslash \to 0$) limit of a quantum four-point (object and graviton in, object and graviton out) gravitational Compton amplitude, at the tree (linear-in-$G$) level. Such tree-level Compton amplitudes are key building blocks in generalized-unitary-based approaches to the post-Minkowskian dynamics of binaries of spinning compact objects. In this paper, we compute the classical amplitude using an effective worldline theory to describe the compact object, determined by an action functional for translational and rotational degrees of freedom, including couplings of spin-induced higher multipole moments to space-time curvature. We work here up to the levels of quadratic-in-spin quadrupole and cubic-in-spin octupole couplings, respectively involving Wilson coefficients $C_2$ and $C_3$. For the special case $C_2=C_3=1$ corresponding to a black hole, we find agreement through cubic-in-spin order between our classical amplitude and previous conjectures arising from considerations of quantum scattering amplitudes. We also present new results for general $C_2$ and $C_3$, anticipating instructive comparisons with results from effective quantum theories.

We apply the $1+1+2$ covariant semitetrad approach to describe a general static and spherically symmetric relativistic stellar object which contains two fluids with anisotropic pressure. The corresponding Tolman-Oppenheimer-Volkoff equations are then obtained in covariant form for the anisotropic case. These equations are used to obtain new exact solutions using direct resolution and reconstruction techniques. Finally, we show that three of the generating theorems known for the single-fluid case can also be used to obtain two-fluid solutions from single-fluid ones.

We extend the results obtained in previous works by Piattella and Park for gravitational lensing in the McVittie metric by including the effect of the transition from the matter-dominated epoch of the Universe to the $\mathrm{\Lambda }$-dominated era. We derive a formula that agrees with the previous results for the McVittie metric at lowest order and compare the lensing angle predictions obtained from the Schwarzschild approximation, the McVittie model, and higher order corrections to the McVittie model. In doing this, we test if, beyond the correction from the accelerated expansion of the Universe, there is a need for including the matter content of the Universe in modeling lens systems at the redshifts observed in lens systems. We investigate if there is a need for a modification of the lens equation from these corrections and, if so, to which order and whether it is measurable. We find that, while the effect is of the same order as the one calculated previously, there is no significant contribution to the bending angle, as the first order effect is already of order $\mathcal{O}({\theta }_O^4)$ in the observed angle.

One of the toughest challenges in modern cosmology is to probe the small scales $k\gtrsim 0.5{\mathrm{Mpc}}^{-1}$ in the matter power spectrum and clustering. We show that such small scales will be accessible via upcoming line-intensity mapping surveys, with carbon monoxide (CO) emission from star-forming galaxies at high redshifts as an example. While these galaxies cannot be individually detected and the two-point correlations of the intensity fluctuation maps is not accessible at these scales, the voxel intensity distribution (VID) of the highly non-Gaussian intensity maps is sensitive to the integrated emission from faint sources. As we describe, the main limitations are due to uncertainties related with the halo mass function and the CO emission model. We show that via the VID, high-redshift next-generation experiments can probe deviations from $\mathrm{\Lambda }\mathrm{CDM}$ of order unity, while stage-3 experiments will be able to probe deviations as small as $\lesssim 10\%$ at least up to $k\sim 10{\mathrm{Mpc}}^{-1}$.

Primordial black holes, if considered to constitute a significant fraction of cold dark matter, trace the inhomogeneous large-scale structure of the Universe. Consequently, the stochastic gravitational-wave background, originating from incoherent superposition of unresolved signals emitted by primordial black hole binaries, is expected to display anisotropies across the sky. In this work, we investigate the angular correlations of such anisotropies for the first time and demonstrate their difference from the analogous signal produced by astrophysical black hole binaries. We carefully evaluate the associated uncertainties due to shot-noise and cosmic variance, and demonstrate that the studied signal in the low-frequency regime can be differentiated from the signal of astrophysical origin. Our results are particularly promising in the stellar mass-range, where the identification of the merger origin has been particularly challenging.

Generalized parton distribution functions (GPDs) of spin-$3/2$ particles are defined for the first time in this paper. Eight unpolarized and eight polarized GPDs are found. In the forward limit of GPDs, the structure functions and parton distribution functions are obtained. Then, the sum rules that connect the GPDs with the electromagnetic and gravitational form factors are explicitly displayed. Finally, the relations between GPDs and the helicity amplitudes of the system are derived.

We show that graphene, in its simplest form and settings, is a practical tabletop realization of the analog of exotic quantum gravity scenarios, which are speculated to lead to certain generalized Heisenberg algebras. In particular, we identify three different energy regimes (the “layers”) where the physics is still of a pseudorelativistic (Dirac) type but more and more sensitive to the effects of the lattice. This plays here a role analog to that of a discrete space, where the Dirac quasiparticles live. This work improves and pushes further earlier results, where the physical meaning of the high energy momenta was clear, but the conjugate coordinates only had a purely abstract description. Here we find the physical meaning of the latter by identifying the mapping between the high energy coordinates and low energy ones, i.e., those measured in the lab. We then obtain two generalized Heisenberg algebras that were not noticed earlier. In these two cases, we have the striking result that the high energy coordinates just coincide with the standard ones, measured in the lab. A third generalized Heisenberg algebra is obtained, and it is an improvement of the results obtained earlier in two respects: we now have an expression of the generalized coordinates in terms of the standard phase-space variables, and we obtain higher order terms. All mentioned results clearly open the doors to tabletop experimental verifications of many generalized uncertainty principle–corrected predictions of the quantum gravity phenomenology.

We propose a vector dark matter model from a hidden $\mathrm{SU}(2{)}_{\mathrm{D}}$ gauge symmetry at TeV scale. A scalar septuplet is introduced to break the $\mathrm{SU}(2{)}_{\mathrm{D}}$ symmetry spontaneously. The septuplet also plays the role of a portal between the standard model and the dark sector. We find that there are two different vacuum configurations corresponding to the sign of the quartic coupling ${\lambda }_3$, which yield different mass spectra for the gauge bosons. For a ${\lambda }_3<0$, the masses of gauge bosons are splitting, while for a ${\lambda }_3\ge 0$, the masses are degenerate. We also study the RG evolutions of the couplings, and find that the perturbativity and vacuum stability can set a stringent bound on the parameter space. For the phenomenological aspect, we consider the experimental constraints including dark matter direct detection, indirect detection, relic density, and Higgs couplings measurements. We find that there are parameter space survivors from all the constraints, and they can be tested in future dark matter direct and indirect detection experiments.

We put forward a method to tune the polarization state of decaying heavy particles (top quarks and $W/Z$ bosons) in a preexisting Monte Carlo sample. With this technique, dubbed as “custom angle replacement,” the decay angular distributions are modified in such a way that the desired polarization state is reproduced, while the production kinematics are unchanged. A nontrivial test of this approach is presented for the top quark semileptonic decay $t\to Wb\to \ell \nu b$, with $\ell =e$, $\mu$, in which the decay distribution is four-dimensional and involves three different Lorentz frames. The proposed method can be used to obtain event samples with polarized heavy particles, as required by experimental measurements of polarization and spin correlations.

The $Z_2$-symmetric version of the Georgi-Machacek model does not possess a decoupling limit in which all the new particles can be made arbitrarily heavy, opening the possibility that the model can be entirely excluded if experiments reveal no deviations from the Standard Model. We explore this model, focusing on the part of parameter space in which the vacuum expectation value of the triplets, ${\nu }_{\chi }$, is small. In the small-${\nu }_{\chi }$ limit, the second custodial-singlet scalar field $S$ necessarily becomes very light and can contribute to the total width of the 125 GeV Higgs boson $h$ via $h\to SS$. We show that this process, together with LHC measurements of the $h\to \gamma \gamma$ rate, entirely excludes masses $m_S<m_h/2$ and thereby severely constrains the parameter space, setting an experimental lower bound ${\nu }_{\chi }\gtrsim 12.5\mathrm{GeV}$ on the vacuum expectation value of the triplets. This lower bound makes it impossible to avoid deviations from the Standard Model in the couplings of $h$ to fermion and vector boson pairs. We study the remaining parameter space after imposing constraints from direct searches for the additional Higgs bosons, and show that it is on the edge of being fully excluded at 95% confidence level by LHC measurements of the 125 GeV Higgs boson’s couplings. Measurements of these couplings at the future high-luminosity run of the LHC will have sufficient precision to entirely exclude the model at $5\sigma$ if no deviations from the Standard Model are observed.

Within the framework of large-momentum effective theory, the light-cone distribution amplitude (LCDA) of the $B$ meson in heavy-quark effective theory can be extracted from lattice calculations of the quasidistribution amplitude through the hard-collinear factorization formula. This quasiquantity can be renormalized in a regularization-independent momentum subtraction (RI/MOM) scheme. In this work, we derive the matching coefficient which connects the renormalized quasidistribution amplitude in the RI/MOM scheme and the standard LCDA in the $\overline{\mathrm{MS}}$ scheme at one-loop accuracy. Our numerical analysis verifies the feasibility of the RI/MOM scheme for renormalizing the $B$-meson quasidistribution amplitude. These results will be crucial for exploring the partonic structure of heavy-quark hadrons.

We consider timelike Liouville theory with FZZT-like boundary conditions. The bulk one-point and boundary two-point structure constants on a disk are derived using bootstrap techniques. We find that these structure constants are not the analytic continuations of their spacelike counterparts.

We conjecture a chaos energy bound, an upper bound on the energy dependence of the Lyapunov exponent for any classical/quantum Hamiltonian mechanics and field theories. The conjecture states that the Lyapunov exponent $\lambda (E)$ grows no faster than linearly in the total energy $E$ in the high energy limit. In other words, the exponent $c$ in $\lambda (E)\propto E^c(E\to \infty )$ satisfies $c\le 1$. This chaos energy bound stems from thermodynamic consistency of out-of-time-order correlators and applies to any classical/quantum system with finite $N/\mathrm{large}$ $N$ ($N$ is the number of degrees of freedom) under plausible physical conditions on the Hamiltonians. To the best of our knowledge the chaos energy bound is satisfied by any classically chaotic Hamiltonian system known, and is consistent with the cerebrated chaos bound by Maldacena, Shenker, and Stanford, which is for quantum cases at large $N$. We provide arguments supporting the conjecture for generic classically chaotic billiards and multiparticle systems. The existence of the chaos energy bound may put a fundamental constraint on physical systems and the Universe.

There is a property of a quantum state called “magic.” As shown by the Gottesman-Knill theorem, so-called stabilizer states, which are composed of only Clifford gates, can be efficiently computed on a classical computer, and thus quantum computation gives no advantage. Nonstabilizer states are called magic states, which are necessary to achieve the universal quantum computation. Magic (monotone) is the measure of the amount of nonstabilizer resource, and it measures how difficult it is for a classical computer to simulate the state. We study magic of states in the integrable and chaotic regimes of the higher-spin generalization of the Ising model through two quantities: “mana” and “robustness of magic” (RoM). We find that in the chaotic regime, mana increases monotonically in time in the early-time region, and at late times these quantities oscillate around some nonzero value that increases linearly with respect to the system size. Our result also suggests that under chaotic dynamics, any state evolves to a state whose mana almost saturates the optimal upper bound; i.e., the state becomes “maximally magical.” We find that RoM also shows similar behaviors. On the other hand, in the integrable regime, mana and RoM behave periodically in time in contrast to the chaotic case. In addition to mana and RoM, for the early-time behavior of magic, we study the stabilizer Rényi entropy, which can be numerically computed for larger systems than mana and RoM. In the anti-de Sitter/conformal field theory correspondence, classical spacetime emerges from the chaotic nature of the dual quantum system. Our results suggest that magic of quantum states is strongly involved in the emergence of spacetime geometry.