Self-polarizing weak decays of $\mathrm{\Lambda }$-hyperons provide unique insight into the role of entanglement in the fragmentation of QCD strings through measurements of the spin correlations of $\mathrm{\Lambda }\overline{\mathrm{\Lambda }}$ pairs produced in collider experiments. The simplest quantum field theory representing the underlying parton dynamics is the four-flavor massive Schwinger model plus an effective spin-flip term, where the flavors are mapped to light (up or down) and heavy (strange) quarks and their spins. This construction provides a novel way to explore hyperon spin correlations in $1+1$ dimensions. We investigate the evolution of these correlations for different string configurations that are sensitive to the rich structure of the model Hamiltonian.

We calculate target-material responses for dark matter–electron scattering at the ab initio all-electron level using atom-centered Gaussian basis sets. The all-electron effects enhance the material response at high momentum transfers from dark matter to electrons, $q\gtrsim \mathcal{O}(10\alpha m_e)$, compared to calculations using conventional plane wave methods, including those used in qedark; this enhances the expected event rates at energy transfers $E\gtrsim 10\mathrm{eV}$, especially when scattering through heavy mediators. We carefully test a range of systematic uncertainties in the theory calculation, including those arising from the choice of basis set, exchange-correlation functional, number of unit cells in the Bloch sum, $\mathbf{k}$-mesh, and neglect of scatters with very high momentum transfers. We provide state-of-the-art crystal form factors, focusing on silicon and germanium. Our code and results are made publicly available as a new tool, called quantum chemistry dark (“qcdark”).

Precision measurements of neutrino-electron scattering may provide a viable way to test the nonminimal form of the charged and neutral current weak interactions within a hypothetical near-detector setup for the Deep Underground Neutrino Experiment (DUNE). Although low-statistics, these processes are clean and provide information complementing the results derived from oscillation studies. They could shed light on the scale of neutrino mass generation in low-scale seesaw schemes.

An excess in the branching fraction for $B^{+}\to K^{+}\nu \nu$ recently measured at Belle II may be a hint of new physics. We perform thorough likelihood analyses for different new physics scenarios such as $B\to KX$ with a new invisible particle $X$, or $B\to K\chi \chi$ through a scalar, vector, or tensor current with $\chi$ being a new invisible particle or a neutrino. We find that vector-current three-body decay with $m_X\simeq 0.6$ GeV—which may be dark matter—is most favored, while two-body decay with $m_X\simeq 2\mathrm{GeV}$ is also competitive. The best-fit branching fractions for the scalar and tensor cases are a few times larger than for the two-body and vector cases. Past BABAR measurements provide further discrimination, although the best-fit parameters stay similar.

We discuss a possibility whether a model of grand gauge-Higgs unification incorporating family unification in higher dimensions can be constructed. We first extend a five-dimensional $SU(6)$ grand gauge-Higgs unification model to a five-dimensional $SU(7)$ grand gauge-Higgs unification model compactified on an orbifold $S^1/Z_2$ to obtain three generations of quarks and leptons after symmetry breaking of the larger family unified gauge group. A prescription of constructing a six-dimensional $SU(N)$ grand gauge-Higgs unification model including a five-dimensional $SU(7)$ grand gauge-Higgs unification after compactifying the sixth dimension on an orbifold $S^1/Z_2$ is given. We find a six-dimensional $SU(14)$ grand gauge-Higgs unification model with a set of representations containing three generations of quarks and leptons.

At fine lattice spacings, Markov chain Monte Carlo simulations of QCD and other gauge theories with or without fermions are plagued by slow modes that give rise to large autocorrelation times. This can lead to simulation runs that are effectively stuck in one topological sector, a problem known as topological freezing. Here, we demonstrate that for a relevant set of parameters, metadynamics can be used to unfreeze four-dimensional SU(3) gauge theory. However, compared to local update algorithms and the Hybrid Monte Carlo algorithm, the computational overhead is significant in pure gauge theory, and the required reweighting procedure may considerably reduce the effective sample size. To deal with the latter problem, we propose modifications to the metadynamics bias potential and the combination of metadynamics with parallel tempering. We test the new algorithm in four-dimensional SU(3) gauge theory and find that it can achieve topological unfreezing without compromising the effective sample size, thereby reducing the autocorrelation times of topological observables by at least 2 orders of magnitude compared to conventional update algorithms. Additionally, we observe significantly improved scaling of autocorrelation times with the lattice spacing in two-dimensional U(1) gauge theory.

A recent report of $e^{+}{e}^{-}\to D\overline{D}$ events by the BESIII collaboration suggests the presence of a structure $R$ at 3900 MeV. We argue that this structure, called $G(3900)$ in the past, is not in fact due to a new $c\overline{c}$ resonance but rather naturally emerges due to a combination of interference between nearby resonances and the opening of the $D^{*}\overline{D}$ channel. We further find that the appearance of this structure does not require suppression because of a radial node in the $\psi (4040)$ wave function, although a node improves fit quality. The measured $e^{+}{e}^{-}$ coupling of $\psi (4040)$ is found to be substantially smaller than previously estimated. In addition, we report new corrections to the measured cross section $\sigma (e^{+}{e}^{-}\to D\overline{D})$ at energies near $\psi (3770)$.

The $\mathrm{\Xi }N$ interaction plays an important role in understanding the long-anticipated $H$ dibaryon. Recent lattice QCD calculations verified the attractive nature of the $\mathrm{\Xi }N$ interaction. On the other hand, whether it is strong enough to generate a bound state remains inconclusive. In this work, assuming it can generate a weakly bound state, we study the yields of the $\mathrm{\Xi }N$ dibaryon for different binding energies in $pp$ collisions at 7 TeV using the coalescence model and the transport model PACIAE. The yields are estimated first numerically and then analytically, adopting a Yukawa-type wave function. In particular, we find that in the weak binding limit, there exists a universal relation between the yield and the binding energy, valid for $pp$ collisions.

We present an algorithm for massive parton evolution which is based on the differentially accurate simulation of soft-gluon radiation by means of a nontrivial azimuthal angle dependence of the splitting functions. The kinematics mapping is chosen such as to reflect the symmetry of the final state in soft-gluon radiation and collinear splitting processes. We compute the counterterms needed for a fully differential next-to-leading order matching and discuss the analytic structure of the parton shower in the next-to-leading logarithmic limit. We implement the new algorithm in the numerical code Alaric and present a first comparison to experimental data.

The $\mathrm{\Upsilon }(10753)$ state has been recently observed by the Belle and Belle II collaborations with enough global significance to motivate an assessment of the high-energy spectrum usually predicted by any reasonable naïve quark model. In the framework of a constituent quark model which satisfactorily describes a wide range of properties of conventional hadrons containing heavy quarks, the quark-antiquark and meson-meson degrees of freedom have been incorporated with the goal of elucidating the influence of open-bottom meson-meson thresholds into the $\mathrm{\Upsilon }$ states whose masses are within the energy range of the $\mathrm{\Upsilon }(10753)$’s mass. It is well known that such effects could be relevant enough as to dynamically generate new states and thus provide a plausible explanation of the nature of the $\mathrm{\Upsilon }(10753)$ state. In particular, we have performed a coupled-channels calculation in which the bare states $\mathrm{\Upsilon }(4S)$, $\mathrm{\Upsilon }(3D)$, $\mathrm{\Upsilon }(5S)$, and $\mathrm{\Upsilon }(4D)$ are considered together with the threshold channels $B\overline{B}$, $B{\overline{B}}^{*}$, $B^{*}{\overline{B}}^{*}$, $B_s{\overline{B}}_s$, $B_s{\overline{B}}_s^{*}$, and $B_s^{*}{\overline{B}}_s^{*}$. Among the results we have described, the following are of particular interest: (i) a richer complex spectrum is gained when thresholds are present and bare bound states are sufficiently nonrelativistic; (ii) those poles obtained in the complex energy plane do not have to appear as simple peaks in the relevant cross sections; and (iii) the $\mathrm{\Upsilon }(10753)$ candidate is interpreted as a dressed hadronic resonance whose structure is an equally mixture of a conventional $b\overline{b}$ state and $B^{*}{\overline{B}}^{*}$ molecule.

The $J/\psi \to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$ decay has been observed with a statistical significance in excess of five standard deviations. The analysis is based on an event sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of $33.6{\mathrm{fb}}^{-1}$. Normalizing to the $J/\psi \to {\mu }^{+}{\mu }^{-}$ decay mode leads to a branching fraction of $[{10.1}_{-2.7}^{+3.3}(\mathrm{stat})\pm 0.4(\mathrm{syst})]\times {10}^{-7}$, a value that is consistent with the standard model prediction.

We compute the F- and D-term potential energy for the dilaton, complex structure, and Kähler moduli of realistic vacua of heterotic M-theory compactified on Calabi-Yau threefolds where, for simplicity, we choose $h^{1,1}=h^{2,1}=1$. However, the formalism is immediately applicable to the “universal” moduli of Calabi-Yau threefolds with $h^{1,1}=h^{1,2}>1$ as well. The F-term potential is computed using the nonperturbative complex structure, gaugino condensate and “world sheet instanton” superpotentials in theories in which the hidden sector contains an anomalous $U(1)$ structure group. The Green-Schwarz anomaly cancellation induces inhomogeneous “axion” transformations for the imaginary components of the dilaton and Kähler modulus—which then produce a D-term potential. $V_D$ is a function of the real components of the dilaton and Kähler modulus ($s$ and $t$) that is minimized and precisely vanishes along a unique line in the $s\text{−}t$ plane. Excitations transverse to this line have a mass $m_{\mathrm{anom}}$ which is an explicit function of $t$. The F-term potential energy is then evaluated along the $V_D=0$ line. For values of $t$ small enough that $m_{\mathrm{anom}}\gtrsim M_U$—where $M_U$ is the compactification scale—we plot $V_F$ for a realistic choice of coefficients as a function of the Pfaffian parameter $p$. We find values of $p$ for which $V_F$ has a global minimum at negative or zero vacuum density or a metastable minimum with positive vacuum density. In all three cases, the $s$, $t$, and associated “axion” moduli are completely stabilized. Finally, we show that, for any of these vacua, the large $t$ behavior of the potential energy satisfies the “large scalar field” Swampland conjecture.

We show that for a particular model, the quantum mechanical bootstrap is capable of finding exact results. We consider a solvable system with Hamiltonian $H=SZ(1-Z)S$, where $Z$ and $S$ satisfy canonical commutation relations. While this model may appear unusual, using an appropriate coordinate transformation, the Schrödinger equation can be cast into a standard form with a Pöschl-Teller-type potential. Since the system is defined on an interval, it is well-known that $S$ is not self-adjoint. Nevertheless, the bootstrap method can still be implemented, producing an infinite set of positivity constraints. Using a certain operator ordering, the energy eigenvalues are only constrained into bands. With an alternative ordering, however, we find that a finite number of constraints is sufficient to fix the low-lying energy levels exactly.

It is shown that the foundational axioms of modified Newtonian dynamics (MOND) alone predict a strong correlation between a bulk measure of the baryonic surface density ${\mathrm{\Sigma }}_B$ and the corresponding dynamical one ${\mathrm{\Sigma }}_D$ of an isolated, self-gravitating object, such as a galaxy. The correlation is encapsulated by its high- and low-${\mathrm{\Sigma }}_B$ behaviors. For ${\mathrm{\Sigma }}_B\gg {\mathrm{\Sigma }}_M\equiv a_0/2\pi G$ (${\mathrm{\Sigma }}_M$ being the critical MOND surface density) one has ${\mathrm{\Sigma }}_D\approx {\mathrm{\Sigma }}_B$. More specifically, their difference—which would be interpreted as the contribution of dark matter—is ${\mathrm{\Sigma }}_p={\mathrm{\Sigma }}_D-{\mathrm{\Sigma }}_B\sim {\mathrm{\Sigma }}_M\ll {\mathrm{\Sigma }}_B$. In the deep-MOND limit, ${\mathrm{\Sigma }}_B\ll {\mathrm{\Sigma }}_M$, one has ${\mathrm{\Sigma }}_D\sim ({\mathrm{\Sigma }}_M{\mathrm{\Sigma }}_B{)}^{1/2}$. This is a primary prediction of MOND, shared by all theories that embody its basic tenets. Sharper correlations, even strict algebraic relations, ${\mathrm{\Sigma }}_D({\mathrm{\Sigma }}_B)$, are predicted in specific MOND theories, for specific classes of mass distribution—e.g., pure disks or spherical systems—and for specific definitions of the surface densities. I proceed to discuss such tighter correlations for the central surface densities of axisymmetric galactic systems, ${\mathrm{\Sigma }}_B^0$ and ${\mathrm{\Sigma }}_D^0$. Past work has demonstrated such relations for pure disks in the aquadratic Lagrangian and quasilinear MOND theories. Here I consider them in broader classes of MOND theories. For most observed systems, ${\mathrm{\Sigma }}_D^0$ cannot be determined directly at present, but, in many cases, a good proxy for it is the acceleration integral $\mathcal{G}\equiv {\int }_0^{\infty }{g}_{r}d\ln r$, where $g_r$ is the radial acceleration along the reflection-symmetry plane of a system, such as a disk galaxy. $\mathcal{G}$ can be determined directly from the rotation curve. I discuss the extent to which $\mathcal{G}$ is a good proxy for ${\mathrm{\Sigma }}_D^0$ and how the relation between them depends on system geometry, from pure disks, through disk-plus-bulge ones, to quasispherical systems.

The superradiant stability of asymptotically flat $D$-dimensional nonextremal Reissner-Nordström black holes under charged massive scalar perturbation is analytically studied. In previous works, it was proved that there are no black hole bombs for five- and six-dimensional nonextremal Reissner-Nordström black holes against charged massive scalar perturbation. In this work, we extend the previous discussions to the $D$-dimensional case ($D\ge 7$) and find that the same conclusion holds in arbitrary higher dimensional case.

Accelerated expansion of the Universe prompted searches of modified gravity theory beyond general relativity, instead of adding a mysterious dark energy component with exotic physical properties. One such alternative gravity approach is metric-affine Palatini $f(\widehat{R})$ theory. By now routine gravitational wave detections have opened a promising avenue of searching for modified gravity effects. Future expected cases of strong lensing of gravitational waves will enhance this opportunity further. In this paper, we present a systematic study of the propagation and gravitational lensing of gravitational waves in Palatini $f(\widehat{R})$ gravity and compare it with general relativity. Using the Wentzel- Kramers-Brillouin approximation we explore the geometric-optical limit of lensing and derive the corrections to the measured luminosity distance of the gravitational source. In addition, we study the lensing by the singular isothermal sphere lens model and show that Palatini $f(\widehat{R})$ modifies the lensing potential and hence the deflection angle. Then we show that the lens model and chosen theory of gravity influence the rotation of the gravitational wave polarization plane through the deflection angle. To be more specific we discuss the $f(\widehat{R})=\widehat{R}+\alpha {\widehat{R}}^2$ gravity theory and find that the modifications compared to general relativity are negligible if the upper bound of $\alpha \sim {10}^9{\mathrm{m}}^2$ suggested in the literature is adopted. However, this bound is not firmly established and can be updated in the future. Therefore, the results we obtained could be valuable for further metric-affine gravity vs general relativity tests involving lensing of gravitational waves and comparison of luminosity distances measured from electromagnetic and gravitational wave sources.

The signal strength of primordial gravitational waves experiencing an epoch of early scalar domination, due to an oscillating scalar field, is reduced with respect to radiation domination. In this paper, we demonstrate that the specific pattern of this reduction is sensitive to the coupling between the dominant field and gravity. When this coupling is zero, the impact of early-matter domination on gravitational waves is solely attributed to the alteration of the Hubble parameter and the scale factor. In the presence of nonzero couplings, on the other hand, the evolution of primordial gravitational waves is directly affected as well, resulting in a distinct steplike feature in the power spectrum of the gravitational wave as a function of frequency. This feature serves as a smoking gun signature of this model. Although the aforementioned results are obtained numerically, we also provide an analytical expression of the power spectrum to illustrate its dependence on the model parameters and initial conditions. Furthermore, we provide analytical relations that specify the frequency interval in which the step occurs. We compare the analytical estimates with numerical analysis and show they match well.

We demonstrate the effectiveness of one of the many multitracer analyses enabled by optimal transport (OT) reconstruction. Leveraging a semidiscrete OT algorithm, we determine the displacements between initial and observed positions of biased tracers and the remaining matter field. With only redshift-space distorted final positions of biased tracers and a simple premise for the remaining mass distribution as input, OT solves the displacement field. This extracted field, assuming asymptotically uniform density and a gradient flow displacement, enables reconstruction of the initial overdensity fluctuation field. We show that the divergence of the OT displacement field is a good proxy of the linear density field, even though the method never assumes the linear theory growth. Additionally, this divergence field can be combined with the reconstructed protohalos to provide a higher signal-to-noise measurement of the baryon acoustic oscillations standard ruler than was possible with either measurement individually.

Accurate modeling of the multimessenger signatures connected to binary neutron star mergers requires proper knowledge on the final remnant’s fate and the conditions under which black holes (BHs) can form in such mergers. In this article, we use a suite of 84 numerical-relativity simulations in 28 different physical setups to explore the impact of the individual stars’ spin on the merger outcome and on the early postmerger dynamics. We find that for setups close to the prompt-collapse threshold, the stars’ intrinsic spin significantly changes the lifespan of the remnant before collapse and that the mass of the debris disk surrounding the BH is also altered. To enable a better understanding of BH formation, we check if there is at least a theoretical chance of observing densities that are above the maximum density allowed in a stable isolated neutron star, and we investigate the importance of different pressure contributions on the evolution of the postmerger remnant and BH formation.

Cosmological and astrophysical observations suggest that both energy densities of baryon and dark matter take the same order values in the present Universe. We propose a scenario to give an answer for this problem in a scotogenic model and its extension. The model naturally provides dark matter candidates as its crucial ingredients to explain the small neutrino mass. If a neutral component of an inert doublet scalar plays a role of dark matter and leptogenesis occurs at TeV scales, both dark matter abundance and baryon number asymmetry could be explained with a same mother particle. Coincidence between the order of their energy densities might be understood through such a background.