The spatial $z$ correlators of meson operators in $N_f=2+1+1$ lattice QCD with optimal domain-wall quarks at the physical point are studied for seven temperatures in the range of 190–1540 MeV. The meson operators include a complete set of Dirac bilinears (scalar, pseudoscalar, vector, axial vector, tensor vector, and axial-tensor vector), and each for six flavor combinations ($\overline{u}d$, $\overline{u}s$, $\overline{s}s$, $\overline{u}c$, $\overline{s}c$, and $\overline{c}c$). In a recent paper [Phys. Rev. D 107, 114501 (2023)], I focused on the meson correlators of $u$ and $d$ quarks, and discussed their implications for the effective restoration of $SU(2{)}_L\times SU(2{)}_R$ and $U(1{)}_A$ chiral symmetries, as well as the emergence of approximate $SU(2{)}_{CS}$ chiral spin symmetry. In this work, we extend our study to meson correlators of six flavor contents, and first observe the hierarchical restoration of chiral symmetries in QCD, from $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_A$ to $SU(3{)}_L\times SU(3{)}_R\times U(1{)}_A$, and to $SU(4{)}_L\times SU(4{)}_R\times U(1{)}_A$, as the temperature is increased from 190 to 1540 MeV. Moreover, we compare the temperature windows for the emergence of the approximate $SU(2{)}_{CS}$ symmetry in light and heavy vector mesons, and find that the temperature windows are dominated by the $(\overline{u}c,\overline{s}c,\overline{c}c)$ sectors.

We investigate the semileptonic decay of ${\mathrm{\Omega }}_b\to {\mathrm{\Omega }}_c\ell {\overline{\nu }}_{\ell }$ in three lepton channels. To this end, we use the QCD sum rule method in three point framework to calculate the form factors defining the matrix elements of these transitions. Having calculated the form factors as building blocks, we calculate the decay widths and branching fractions of the exclusive decays in all lepton channels and compare the results with other theoretical predictions. The obtained results for branching ratios and ratio of branching fractions at different leptonic channels may help experimental groups in their search for these weak decays. Comparison of the obtained results with possible future experimental data can be useful to check the order of consistency between the standard model theory predictions and data on the heavy baryon decays.

Azimuthal anisotropies of high-$p_T$ particles produced in heavy-ion collisions are understood as an effect of a geometrical selection bias. Particles oriented in the direction in which the QCD medium formed in these collisions is shorter suffer less energy loss, and thus, are over-represented in the final ensemble compared to those oriented in the direction in which the medium is longer. In this work we present the first semianalytical predictions, including propagation through a realistic, hydrodynamical background, of the elliptic azimuthal anisotropy for jets, obtaining a quantitative agreement with available experimental data as a function of the jet $p_T$, its cone size $R$, and the collisions centrality. Jets are multipartonic, extended objects and their energy loss is sensitive to substructure fluctuations. This sensitivity is determined by the physics of color coherence that relates to the ability of the medium to resolve those partonic fluctuations. Specifically, color dipoles with an angular separation smaller than a critical angle, ${\theta }_c$, are not resolved by the medium and they effectively act as a coherent source of energy loss. We find that elliptic jet azimuthal anisotropy has a specially strong dependence on coherence physics due to the marked length dependence of ${\theta }_c$. By combining our predictions for the collision systems and center-of-mass energies studied at RHIC and the LHC, covering a wide range of typical values of ${\theta }_c$, we show that the relative size of elliptic jet azimuthal anisotropies for jets with different cone sizes $R$ follows a universal trend that indicates a transition from a coherent regime of jet quenching to a decoherent regime. These results suggest a way forward to reveal the role played by the physics of jet color decoherence in probing deconfined QCD matter.

We investigate the interplay among the pion’s form factor, transverse momentum dependent distributions (TMDs), and parton distribution functions (PDFs) extending our light-front quark model (LFQM) computation based on the Bakamjian-Thomas construction for the two-point function [1,2] to the three-point and four-point functions. Ensuring the four-momentum conservation at the meson-quark vertex from the Bakamjian-Thomas construction, the meson mass is taken consistently as the corresponding invariant meson mass both in the matrix element and the Lorentz factor in our LFQM computation. We achieve the current-component independence in the physical observables such as the pion form factor and delve into the derivation of unpolarized TMDs and PDFs associated with the forward matrix element. We address the challenges posed by twist-4 TMDs and exhibit the fulfillment of the sum rule. Effectively, our LFQM successfully handles the light-front zero modes and offers insights for broader three-point and four-point functions and related observables.

Several continuum and lattice investigations of the QCD three-gluon vertex have recently exposed its key properties, some intimately connected with the low-momentum behavior of the two-point gluon Green’s function and especially relevant for the emergence of a mass scale in this latter, via the Schwinger mechanism. In the present study, we report on a lattice determination of the Landau-gauge, transversely projected three-gluon vertex, particularly scrutinizing an outstanding one of these properties, termed planar degeneracy, exploring its implications and capitalizing on it to gain further insight on the low-momentum running of both the three-gluon vertex and its associated strong coupling.

We investigate the medium modifications of the masses of pseudoscalar open charm ($D$ and $\overline{D}$) mesons and the charmonium state [$\psi (3770)$] in hot isospin asymmetric strange hadronic medium in the presence of an external magnetic field within a chiral effective model. The in-medium partial decay widths of $\psi (3770)$ to charged and neutral $D\overline{D}$ mesons are computed from the medium modifications of the masses of the initial and final state mesons. These are computed using two light quark pair creation models—(I) the ${}^3{P}_0$ model and (II) a field theoretical (FT) model of composite hadrons with quark (and antiquark) constituents. The production cross sections of $\psi (3770)$, arising from scattering of the $D$ and $\overline{D}$ mesons, are computed from the relativistic Breit-Wigner spectral function expressed in terms of the in-medium masses and the decay widths of the charmonium state. The effects of the magnetic field are considered due to the Dirac sea (DS) of the baryons, the mixing of the pseudoscalar ($S=0$) and vector ($S=1$) meson (PV mixing), the Landau level contributions for the charged hadrons. The anomalous magnetic moments (AMMs) of the baryons are also taken into account in the present study. For magnetized nuclear matter, at ${\rho }_B={\rho }_0$, the effect of Dirac sea leads to inverse magnetic catalysis (IMC), which is drop of the magnitude of the light quark condensates (proportional to the scalar fields) with increase in the magnetic field, contrary to the opposite effect of magnetic catalysis (MC) at ${\rho }_B=0$. The inclusion of hyperons to the nuclear medium is observed to lead to magnetic catalysis. There are observed to be significant effects from the DS and PV mixing on the properties of the charm mesons. The production cross sections of $\psi (3770)$ arising due to scattering of $D^{+}{D}^{-}(D^0{\overline{D}}^0)$ mesons in the hot magnetized strange hadronic matter are observed to have distinct peak positions, when the magnetic field is large. This is because the production cross sections have contributions from the transverse as well as longitudinal components of $\psi (3770)$, which have nondegenerate masses due to PV [$\psi (3770)-{\eta }_c^{\prime }$] mixing. These can have observable consequences on the dilepton spectra as well as on the production of the charm mesons in ultrarelativistic peripheral heavy ion collision experiments, where the produced magnetic field is huge.

The $B^0\to K_S^0{K}^{+}{K}^{-}$ decay amplitude is derived within a quasi-two-body QCD factorization framework in terms of kaon form factors and $B^0$ to two-kaon-transition functions. The final state kaon-kaon interactions in the $S$, $P$, and $D$ waves are taken into account. The unitarity constraints are satisfied for the two kaons in scalar states. It is shown that with few terms of the full decay amplitude one may reach a fair agreement with the total branching fraction and Dalitz-plot projections published in 2010 by the Belle Collaboration and in 2012 by the BABAR Collaboration. With 13 free parameters, our model fits the corresponding 422 data with a ${\chi }^2$ of 583.6 which leads to a ${\chi }^2$ per degree of freedom equal to 1.43. The dominant branching fraction arises from the $f_0(K^{+}{K}^{-})K_S^0$ mode with 83.0% of the total branching. The next important mode is dominated by $\varphi K_S^0$ plus small $\omega K_S^0$ and ${\rho }^0{K}_S^0$ modes with 18.3% of the total. Then follows the $a_0^{\pm }{K}^{\mp }$ mode with 6.2%. Adding the other smaller modes, the total percentage sum is 107.7% which indicates a small interference contribution. In most regions of the Dalitz plot, our model gives rather small $CP$ asymmetry, but in some parts its values can be large and positive or negative. Its predicted total value is equal to $-0.11\%$. The calculated time dependent $CP$-asymmetry parameters agree, within errors, with those obtained by the BABAR analysis. Our model amplitude can be the basis for a parametrization in experimental Dalitz plot analyses of LHCb and Belle II Collaborations.

A search for heavy neutral leptons (HNLs) decaying in the CMS muon system is presented. A data sample is used corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$, recorded at the CERN LHC in 2016–2018. Decay products of long-lived HNLs could interact with the shielding materials in the CMS muon system and create hadronic and electromagnetic showers detected in the muon chambers. This distinctive signature provides a unique handle to search for HNLs with masses below 4 GeV and proper decay lengths of the order of meters. The signature is sensitive to HNL couplings to all three generations of leptons. Candidate events are required to contain a prompt electron or muon originating from a vertex on the beam axis and a displaced shower in the muon chambers. No significant deviations from the standard model background expectation are observed. In the electron (muon) channel, the most stringent limits to date are set for HNLs in the mass range of 2.1–3.0 (1.9–3.3) GeV, reaching mixing matrix element squared values as low as $8.6(4.6)\times {10}^{-6}$.

The first observation of the decay ${\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-}$ and measurement of the branching ratio of ${\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-}$ to ${\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-}$ are presented. The $J/\psi$ and $\psi (2S)$ mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at $\sqrt{s}=13\mathrm{TeV}$ in 2016–2018, corresponding to an integrated luminosity of $140{\mathrm{fb}}^{-1}$. The branching fraction ratio is measured to be $\mathcal{B}({\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-})/\mathcal{B}({\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-})=0.84_{-0.19}^{+0.21}(\mathrm{stat})\pm 0.10(\mathrm{syst})\pm 0.02(\mathcal{B})$, where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the ${\mathrm{\Xi }}_b(5945{)}^0$ baryon mass and natural width are also presented, using the ${\mathrm{\Xi }}_b^{-}{\pi }^{+}$ final state, where the ${\mathrm{\Xi }}_b^{-}$ baryon is reconstructed through the decays $J/\psi {\mathrm{\Xi }}^{-}$, $\psi (2S){\mathrm{\Xi }}^{-}$, $J/\psi \mathrm{\Lambda }{K}^{-}$, and $J/\psi {\mathrm{\Sigma }}^0{K}^{-}$. Finally, the fraction of ${\mathrm{\Xi }}_b^{-}$ baryons produced from ${\mathrm{\Xi }}_b(5945{)}^0$ decays is determined.

We discuss general momentum-dependent field redefinitions in the context of quantum-gravitational scattering amplitudes in general, and asymptotic safety in particular. Implementing such redefinitions at the lowest curvature order, we can bring the graviton propagator into tree-level form, avoiding issues of fiducial ghost poles and their associated violations of unitarity. We compute the beta function for Newton’s constant, and find an asymptotically safe fixed point whose critical exponent changes by 0.4% compared to not resolving the momentum-dependent field redefinition. This provides a strong indication that this fixed point does not feature extra degrees of freedom related to ghostly modes, and has a good chance of being related to a unitary theory.

We construct the superaction for the $T\overline{T}$ deformation of 2D free $\mathcal{N}=(1,1)$ supersymmetric model with a deformed superfield. We show that the $\mathcal{N}=(1,1)$ off-shell supersymmetry in the free theory is deformed under the $T\overline{T}$ deformation, which is incorporated in the deformed superfield. We interpret this superaction as an effective action of the Goldstone superfield for the partial spontaneous breaking of $\mathcal{N}=(2,2)$ supersymmetry to $\mathcal{N}=(1,1)$. We show that the unbroken and broken supersymmetry of the effective superaction corresponds to the off-shell $\mathcal{N}=(1,1)$ supersymmetry and the off-shell Fermi global nonlinear symmetry in the $T\overline{T}$-deformed theory, respectively. We demonstrate that this effective superaction can be obtained by the nonlinear realization of the partially broken global supersymmetry (PBGS) from the coset superspace. Furthermore, we reproduce the superaction by the constrained superfield method accompanied by a field redefinition.

When classical degrees of freedom and quantum degrees of freedom are consistently coupled, the former diffuse, while the latter undergo decoherence. Here, we construct a theory of quantum matter fields and Nordström gravity in which the space-time metric is treated classically. The dynamics is constructed via the classical-quantum path integral and is completely positive, trace preserving (CPTP) and respects the classical-quantum split. The weak-field limit of the model matches the Newtonian limit of the full covariant path integral, but it is easier to show that the theory is both diffeomorphism invariant and CPTP and has the appropriate classical limit.

We develop a fully analytical waveform model for precessing binaries with arbitrary spin vectors using post-Newtonian (PN) theory in the extreme mass-ratio limit and a hierarchical multiscale analysis. The analytical model incorporates leading PN order spin precession dynamics from spin-orbit, spin-spin, and quadrupole-monopole couplings, and 2PN order dissipative dynamics truncated to first order in the mass ratio $q\ll 1$. Due to the pure analytic nature of the model, the framework developed herein can readily be extended to both higher PN and higher-$q$ order. Although the PN series is asymptotic to this limit, our results can be used to estimate how precession affects the measurability of certain binary parameters, and to inform and compare with other waveform approximants, such as effective-one-body models, hybrid waveforms, and self-force calculations.

The Laser Interferometer Space Antenna (LISA) is a planned space-based observatory to measure gravitational waves in the millihertz frequency band. This frequency band is expected to be dominated by signals from millions of Galactic binaries and tens of merging massive black hole binaries. The LISA Data Challenge 2a is focused on robust signal extraction from a blend of these two types of gravitational wave signals. Here, we introduce a novel high performance and cost-effective global fit pipeline extracting and characterizing galactic binary and massive black hole binary signals and estimate the noise of the residual. We perform the pipeline in a time-evolving weekly analysis starting with an observation time of one week until we reach a full year. As expected we detect more galactic binaries and massive black hole binaries bringing the noise estimate of the residual closer to the instrument noise with each week of additional observation time. Furthermore, we present a novel maximum likelihood estimate-based algorithm for extracting multiple massive black hole binaries. Additionally, we demonstrate a massive black hole binary signal extraction with a more accurate LISA response, considering higher harmonic modes, in a noisy dataset.

In the presence of anisotropic neutrino and antineutrino fluxes, the quantum kinetic equations drive coherent oscillations in neutrino helicity, frequently referred to as spin oscillations. These oscillations depend directly on the absolute mass scale and Majorana phase, but are usually too transient to produce important effects. In this paper we present a full momentum-space analysis of Majorana neutrino spin oscillations in a snapshot of a three-dimensional neutron star merger simulation. We find an interesting angular dependence that allows for that resonant and adiabatic oscillations to occur along specific directions in a large volume of the merger remnant. The solid angle spanned by these directions is extremely narrow in general. We then analyze spin transformation in the presence of flavor transformation by characterizing how the effect’s resonance and timescale change during a fast-flavor instability. For this analysis, we derive a generalized resonance condition that poses a restrictive requirement for resonance to exist in any flavor channel. We determine that spin oscillations at all locations in the merger snapshot have a length scale that is too large for significant oscillations to be expected even where there exist resonant and adiabatic directions.

We reexamine production of primordial black holes in a supercooled phase transition. While a mere overdensity associated with a surviving false-vacuum patch does not imply formation of a black hole, it is possible for such a patch to evolve and create a black hole, thanks to the gradient energy stored in the bubble wall.

In the last two years, the dark dimension scenario has emerged as focal point of many research interests. In particular, it functions as a stepping stone to address the cosmological hierarchy problem and provides a colosseum for dark matter contenders. We reexamine the possibility that primordial black holes (PBHs) perceiving the dark dimension could constitute all of the dark matter in the Universe. We reassess limits on the abundance of PBHs as dark matter candidates from $\gamma$-ray emission resulting from Hawking evaporation. We reevaluate constraints from the diffuse $\gamma$-ray emission in the direction of the Galactic Center that offer the best and most solid upper limits on the dark matter fraction composed of PBHs. The revised mass range that allows PBHs to assemble all cosmological dark matter is estimated to be ${10}^{15}\lesssim M_{\mathrm{BH}}/\mathrm{g}\lesssim {10}^{21}$. We demonstrate that, due to the constraints from $\gamma$-ray emission, quantum corrections due to the speculative memory burden effect do not modify this mass range. We also investigate the main characteristics of PBHs that are localized in the bulk. We show that PBHs localized in the bulk can make all cosmological dark matter if ${10}^{11}\lesssim M_{\mathrm{BH}}/\mathrm{g}\lesssim {10}^{21}$. Finally, we comment on the black holes that could be produced if one advocates a space with two boundaries for the dark dimension.

The neutrino mixing parameters are expected to have renormalization group (RG) running effect in the presence of new physics. If the momentum transfers at production and detection mismatch with each other, the oscillation probabilities are generally modified and become dependent on not just the neutrino energy but also the momentum transfer. Even in the limit of vanishing baseline, the transition probability for the appearance channel is interestingly not zero. This would significantly affect the sensitivity of the genuine leptonic Dirac $CP$ phase. We further explore the possibility of combining the long- and short-baseline neutrino experiments to constrain such RG running effect for the purpose of guaranteeing the $CP$ measurement. To simulate the double dependence on the neutrino energy and momentum transfer, we extend the usual globes simulation of fixed baseline experiments and use a two-dimensional ${\chi }^2$ analysis to obtain sensitivities.

Heavy neutral gauge bosons arise in many motivated models of beyond the Standard Model Physics. Experimental searches require that such gauge bosons are above the TeV scale in most models which means that the tools of effective field theories, in particular the Standard Model effective field theory (SMEFT), are useful. We match the SMEFT to models with heavy $Z^{\prime }$ bosons, including effects of dimension-8 operators, and consider the restrictions on model parameters from electroweak precision measurements and from Drell Yan invariant mass distributions and forward-backward asymmetry, $A_{\mathrm{FB}}$, measurements at the LHC. The results demonstrate the model dependence of the resulting limits on SMEFT coefficients and the relatively small impact of including dimension-8 matching. In all cases, the limits from invariant mass distributions are stronger than from $A_{\mathrm{FB}}$ measurements in the $Z^{\prime }$ models we consider.

The maximal center gauge aims to detect center vortices by maximizing a gauge functional and then projecting onto the center elements of the respective group. The requirement for unrestricted maximization of the gauge functional has proven to be untenable because it was shown that it leads to an underestimation of the string tension. To counter this problem, the ensemble of local gauge maxima is investigated and it is found that the unrestricted maximization can be replaced by a maximization restricted to the Gaussian distributed part of the ensemble. Such restricted maximization weakens the problem of an underestimated string tension.