In this study, we investigate the masses and decay constants of the light mesons with $J^P=3^{-}$ (${\rho }_3$, ${\omega }_3$, $K_3$, ${\varphi }_3$) within the QCD sum rules method by taking into account $SU(3)$ violation effects. We state that our predictions on masses of the considered mesons are in good agreement with experimental data within the precision of the model.

A search is performed for delayed and nonpointing photons originating from the displaced decay of a neutral long-lived particle (LLP). The analysis uses the full run 2 dataset of proton-proton collisions delivered by the LHC at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$ between 2015 and 2018 and recorded by the ATLAS detector, corresponding to an integrated luminosity of $139{\mathrm{fb}}^{-1}$. The capabilities of the ATLAS electromagnetic calorimeter are exploited to precisely measure the arrival times and trajectories of photons. The results are interpreted in a scenario where the LLPs are pair produced in exotic decays of the 125 GeV Higgs boson, and each LLP subsequently decays into a photon and a particle that escapes direct detection, giving rise to missing transverse momentum. No significant excess is observed above the expectation due to Standard Model background processes. The results are used to set upper limits on the branching ratio of the exotic decay of the Higgs boson. A model-independent limit is also set on the production of photons with large values of displacement and time delay.

Because of coherent superradiant amplification, massive bosonic fields can trigger an instability in spinning black holes, tapping their energy and angular momentum and forming macroscopic Bose-Einstein condensates around them. This phenomenon produces gaps in the mass-spin distribution of astrophysical black holes, a continuous gravitational-wave signal emitted by the condensate, and several environmental effects relevant for gravitational-wave astronomy and radio images of black holes. While the spectrum of superradiantly unstable mode is known in great detail for massive scalar (spin-0) and vector (spin-1) perturbations, so far only approximated results were derived for the case of massive tensor (spin-2) fields, due to the nonseparability of the field equations. Here, solving a system of ten elliptic partial differential equations, we close this program and compute the spectrum of the most unstable modes of a massive spin-2 field for generic black-hole spin and boson mass, beyond the hydrogenic approximation and including the unique dipole mode that dominates the instability in the spin-2 case. We find that the instability timescale for this mode is orders of magnitude shorter than for any other superradiant mode, yielding much stronger constraints on massive spin-2 fields. These results pave the way for phenomenological studies aimed at constraining beyond Standard Model scenarios, ultralight dark matter candidates, and extensions to general relativity using gravitational-wave and electromagnetic observations, and have implications for the phase diagram of vacuum solutions of higher-dimensional gravity.

We test the eigenstate thermalization hypothesis (ETH) for $2+1$ dimensional SU(2) lattice gauge theory. By considering the theory on a chain of plaquettes and truncating basis states for link variables at $j=1/2$, we can map it onto a quantum spin chain with local interactions and numerically exactly diagonalize the Hamiltonian for reasonably large lattice sizes. We find energy level repulsion in momentum sectors with no remaining discrete symmetry. We study two local observables made up of Wilson loops and calculate their matrix elements in the energy eigenbasis, which are shown consistent with the ETH.

The study of the Cabibbo-favored semileptonic decay ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{\mu }^{+}{\nu }_{\mu }$ is reported using $4.5{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ annihilation data collected at center-of-mass energies ranging from 4.600 to 4.699 GeV. The branching fraction of the decay is measured to be $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{\mu }^{+}{\nu }_{\mu })=(3.48\pm 0.14_{\mathrm{stat}}\pm 0.10_{\mathrm{syst}})\%$, 3 times more precise than the prior world average result. Tests of lepton flavor universality using ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{\ell }^{+}{\nu }_{\ell }$ ($\ell =e$, $\mu$) decays are reported for the first time, based on measurements of the differential decay rates and the forward-backward asymmetries in separate four-momentum transfer regions. The results are compatible with Standard Model predictions. Furthermore, we improve the determination of the form-factor parameters in ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{\ell }^{+}{\nu }_{\ell }$ decays, which provide stringent tests and calibration for lattice quantum chromodynamics calculations.

We compute the radius of convergence of the linearized relativistic hydrodynamic expansion around a nontrivially rotating strongly coupled $\mathcal{N}=4$ super-Yang-Mills plasma. Our results show that the validity of hydrodynamics is sustained and can even get enhanced for conformal field theory (CFT) in a rotating state. Analytic equations for the hydrodynamic dispersion relations and transport coefficients of the rotating plasma as a function of their values in a plasma at rest are given.

We construct a deformation of any ($0+1$)-dimensional theory of $N$ bosons with $SO(N)$ symmetry which is driven by a function of conserved quantities that resembles the root-$T\overline{T}$ operator of (2D) quantum field theories. In the special case of $N=2$ bosons and a harmonic oscillator potential, the solution to the flow equation is the ModMax oscillator of 2209.06296. We argue that the deforming operator is related, in a particular special regime, to the dimensional reduction of the 2D root-$T\overline{T}$ operator on a spatial circle. It follows that the ModMax oscillator is a dimensional reduction of the 4D ModMax theory to quantum mechanics, justifying the name. We then show how to construct a manifestly supersymmetric extension of this root-$T\overline{T}$-like operator for any ($0+1$)-dimensional theory with $SO(N)$ symmetry and $\mathcal{N}=2$ supersymmetry by defining a flow equation directly in superspace.

Pole skipping has been discussed in black-hole backgrounds, but we point out that pole skipping exists even in a non-black-hole background, the anti–de Sitter soliton. For black holes, the pole-skipping points are typically located at imaginary Matsubara frequencies $\omega =-(2\pi T)ni$ with an integer $n$. The anti–de Sitter soliton is obtained by the double Wick rotation from a black hole. As a result, the pole-skipping points are located at $q_z=-(2\pi n)/l$, where $l$ is the $S^1$ periodicity and $q_z$ is the $S^1$ momentum. The “chaotic” and the “hydrodynamic” pole-skipping points lie in the physical region. We also propose a method to identify all pole-skipping points instead of the conventional method.

Inspired by the second law of thermodynamics, we study the change in subsystem entropy generated by dynamical unitary evolution of a product state in a bipartite system. Working at leading order in perturbative interactions, we prove that the quantum $n$-Tsallis entropy of a subsystem never decreases, $\mathrm{\Delta }{S}_n\ge 0$, provided that subsystem is initialized as a statistical mixture of states of equal probability. This is true for any choice of interactions and any initialization of the complementary subsystem. When this condition on the initial state is violated, it is always possible to explicitly construct a “Maxwell’s demon” process that decreases the subsystem entropy, $\mathrm{\Delta }{S}_n<0$. Remarkably, for the case of particle scattering, the circuit diagrams corresponding to $n$-Tsallis entropy are the same as the on shell diagrams that have appeared in the modern scattering amplitudes program, and $\mathrm{\Delta }{S}_n\ge 0$ is intimately related to the nonnegativity of cross sections.

We study the mechanism of chiral symmetry breaking for fermionic systems in a gravitational background with curvature and torsion. The analysis is based on a scale-dependent effective potential derived from a bosonized version of the Nambu-Jona-Lasino model in a Riemann-Cartan background. We have investigated the fate of chiral symmetry in two different regimes. First, to gain some intuition on the combined effect of curvature and torsion, we investigate the regime of weak curvature and torsion. However, this regime does not access the deep infrared limit, which is essential to answer questions related to the mechanism of gravitational catalysis in fermionic systems. Second, we look at the regime of vanishing curvature and homogeneous torsion. In this case, although we cannot probe the combined effects of curvature and torsion, we can access the deep infrared contributions of the background torsion to the mechanism of chiral symmetry breaking. Our main finding is that, in the scenario where only torsion is present, there is no indication of a mechanism of gravitational catalysis.

Gravitational waves might help resolve the tension between early and late Universe measurements of the Hubble constant, and this possibility can be enhanced with a gravitational wave detector in the decihertz band as we will demonstrate in this study. Such a detector is particularly suitable for the multiband observation of stellar-mass black hole binaries between space and ground, which would significantly improve the source localization accuracy thanks to a long baseline for timing triangulation, hence promoting the “dark siren” cosmology. Proposed decihertz concepts include Decihertz Interferometer Gravitational Wave Observatory (DECIGO)/B-DECIGO, TianGO, and others. We consider here the prospects of multiband observation of dark siren binaries with a variety of network configurations. We find that a multiband observation can uniquely identify a black hole binary to a single galaxy to a cosmological distance, and thus a dark siren behaves as if it had an electromagnetic counterpart. Considering only fully localized dark sirens, we use a Fisher matrix approach to estimate the error in the Hubble constant and matter density parameter. We find that a decihertz detector substantially improves our ability to measure cosmological parameters because it enables host galaxies to be identified out to a larger distance without the systematics from statistical techniques based on comparing the population distribution.

We present a complete algebraic classification for the curvature tensor in Weyl-Cartan geometry, by applying methods of eigenvalues and principal null directions on its irreducible decomposition under the group of global Lorentz transformations, thus providing a full invariant characterization of all the possible algebraic types of the torsion and nonmetricity field strength tensors in Weyl-Cartan spacetimes. As an application, we show that in the framework of metric-affine gravity the field-strength tensors of a dynamical torsion field cannot be doubly aligned with the principal null directions of the Riemannian Weyl tensor in scalar-flat, slowly rotating, stationary and axisymmetric space-times.

We derive the time dilation formula for charged quantum clocks in electromagnetic fields. As a concrete example of noninertial motion, we consider a cyclotron motion in a uniform magnetic field. Applying the time dilation formula to coherent state of the charged quantum clock, we evaluate the time dilation quantum mechanically.

Very light pseudoscalar fields, often referred to as axions, are compelling dark matter candidates and can potentially be detected through their coupling to the electromagnetic field. Recently a novel detection technique using the cosmic microwave background (CMB) was proposed, which relies on the fact that the axion field oscillates at a frequency equal to its mass in appropriate units, leading to a time-dependent birefringence. For appropriate oscillation periods this allows the axion field at the telescope to be detected via the induced sinusoidal oscillation of the CMB linear polarization. We search for this effect in two years of POLARBEAR data. We do not detect a signal, and place a median 95% upper limit of 0.65° on the sinusoid amplitude for oscillation frequencies between $0.02{\mathrm{days}}^{-1}$ and $0.45{\mathrm{days}}^{-1}$, which corresponds to axion masses between $9.6\times {10}^{-22}\mathrm{eV}$ and $2.2\times {10}^{-20}\mathrm{eV}$. Under the assumptions that (1) the axion constitutes all the dark matter and (2) the axion field amplitude is a Rayleigh-distributed stochastic variable, this translates to a limit on the axion-photon coupling $g_{\varphi \gamma }<2.4\times {10}^{-11}{\mathrm{GeV}}^{-1}\times (m_{\varphi }/{10}^{-21}\mathrm{eV})$.

We investigate the effects of a nonstandard interaction (NSI) extension of the standard model of particle physics on solar neutrino flavor oscillations. This NSI model introduces a $U_{Z^{\prime }}(1)$ gauge symmetry through a $Z^{\prime }$ boson that mixes with the photon, creating a neutral current between active neutrinos and matter fields via a unique coupling to up and down quarks. The interaction is defined by a single parameter, ${\zeta }_o$, which is related to the $Z^{\prime }$ boson’s mass $m_{Z^{\prime }}$ and coupling constant $g_{Z^{\prime }}$. Notably, this model relaxes the bounds on coherent elastic neutrino-nucleus scattering experiments and fits the experimental values of the anomalous magnetic dipole moment of the muon. In this study, we use solar neutrino measurements and an up-to-date standard solar model to evaluate the neutrino flavor oscillations and assess the constraints on ${\zeta }_o$. Our study indicates that the NSI model aligns with the current solar neutrino data when ${\zeta }_o$ is between $-0.7$ and 0.002. These models have ${\chi }_{\nu }^2$ values equal to or better than the standard neutrino flavor oscillation model, which stands at a ${\chi }_{\nu }^2$ of 3.12. The best NSI model comes with a ${\zeta }_o$ value of $-0.2$ and a ${\chi }_{\nu }^2$ of 2.96. Including extra data from the Darwin experiment in our analysis refines the range of ${\zeta }_o$ values from $-0.7$ to 0.002, down to $-0.5$ to $-0.002$. These results hint at the possible existence of novel interactions, given that NSI models achieve a comparable or superior fit to the solar neutrino data when contrasted with the prevailing standard model of neutrino flavor oscillation.

We explore the implications of third family ($t-b-\tau$) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$ model. The deviation from exact Yukawa unification is quantified through the relation $y_t:y_b:y_{\tau }=(1+C):(1-C):(1+3C)$, with $C$ being a real parameter ($|C|\le 0.2$). We allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including the lightest supersymmetric particle (LSP) DM (whose stability is guaranteed by a $Z_2$ gauge symmetry). We highlight solutions that include a next to LSP (NLSP) gluino with mass $\sim 1.3–2.5\mathrm{TeV}$, which should be accessible at LHC Run 3. There also exist NSLP stop solutions with masses heavier than about 1.8 TeV, which are consistent with the LSP neutralino dark matter relic density through stop-neutralino coannihilation. We identify A-resonance solutions, which arise when the $CP$-odd Higgs boson is in resonance with a pair of LSP neutralinos ($m_A=2m_{{\tilde{\chi }}_1^0}$) with DM mass $\sim 0.8–2\mathrm{TeV}$, as well as bino-chargino, bino-slepton and bino-stau coannihilation scenarios. Finally, we also identify Wino-like ($\sim 99\%$) and Higgsino-like ($\sim 99\%$) solutions whose masses are heavier than about 1.5 and 1 TeV, respectively. These solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments.

One of the sensitive probes of physics beyond the standard model is the test of the unitarity of the Cabbibo-Kobyashi-Maskawa matrix. Current analysis of the first row is based on $|V_{ud}|$ from fifteen superallowed $0^{+}\to 0^{+}$ nuclear $\beta$ decays and $|V_{us}|$ from the kaon semileptonic decay, $K\to \pi \ell {\nu }_{\ell }$. Modeling the nuclear effects in the $0^{+}\to 0^{+}$ decays is a major source of uncertainty, which would be absent in neutron decays. To make neutron decay competitive requires improving the measurement of neutron lifetime and the axial charge, as well as the calculation of the radiative corrections (RC) to the decay. The largest uncertainty in these RCs comes from the nonperturbative part of the $\gamma W$-box diagram, and lattice QCD provides a first principle method for its evaluation. Our calculations, using lattice configurations generated with highly improved staggered quarks by the MILC Collaboration, show that the analogous calculations for the pion and kaon decays are robust and give ${\square }_{\gamma W}^{VA}{|}_{\pi }=2.810(26)\times {10}^{-3}$ and ${\square }_{\gamma W}^{VA}{|}_{K^{0,SU(3)}}=2.389(17)\times {10}^{-3}$ in agreement with the previous analysis carried out by Feng et al. using a different discretization of the fermion action.

The Feynman-Hellmann approach to computing matrix elements in lattice QCD by first adding a perturbing operator to the action is described using the transition matrix and the Dyson expansion formalism. This perturbs the energies in the two-point baryon correlation function, from which the matrix element can be obtained. In particular at leading order in the perturbation we need to diagonalize a matrix of near-degenerate energies. While the method is general for all hadrons, we apply it here to a study of a sigma to nucleon baryon transition vector matrix element.

In a previous paper [1], it was pointed out that the wave functions of all particles are not pure waves, besides the main partial waves, they all contain other partial waves. It is very interesting to know what role these different partial waves play in particle transitions. Therefore, by using the Bethe-Salpeter equation method, we study the radiative electromagnetic decays $\psi \to \gamma {\chi }_{cJ}$ and $\mathrm{\Upsilon }\to \gamma {\chi }_{bJ}$ ($J=0$, 1, 2). We find that for the $S$ and $P$ wave dominated states, like the $\psi (2S)$, $\mathrm{\Upsilon }(2S)$, ${\chi }_{cJ}(1P)$, and ${\chi }_{bJ}(1P)$ etc., the dominant $S$ and $P$ waves provide main and nonrelativistic contrition to the decays; other partial waves mainly contribute to the relativistic correction. For the states like the $\psi (1D)$, $\mathrm{\Upsilon }(2D)$, ${\chi }_{c2}(1F)$, and ${\chi }_{b2}(1F)$ etc., they are the $S-P-D$ mixing state dominated by $D$ wave or the $P-D-F$ mixing state dominated by $F$ wave. Large decay widths are found in the transitions $\psi (2D)\to {\chi }_{c2}(1F)$, $\mathrm{\Upsilon }(1D)\to {\chi }_{bJ}(1P)$, and $\mathrm{\Upsilon }(2D)\to {\chi }_{bJ}(2P)$ etc., which may be helpful to study the missing states ${\chi }_{c2}(1F)$, $\mathrm{\Upsilon }(1D)$, and $\mathrm{\Upsilon }(2D)$.