We have presented the leading twist quark transverse momentum-dependent parton distribution functions (TMDs) for the spin-1 heavy vector mesons $J/\psi$-meson and $\mathrm{\Upsilon }$-meson using the overlap of the light-front wave functions. We have computed their TMDs in the light-front holographic model (LFHM) as well as the light-front quark model (LFQM) and further compared the results with the Bethe-Salpeter (BSE) model. We have discussed the behavior of the TMDs with respect to momentum fraction carried by active quark ($x$) and the transverse quark momenta ($k_{\perp }$) in both the models. We have also calculated the $k_{\perp }$ moments of the quark in both the models and have compared the results with the BSE model. The predictions of LFQM are found to be in accord with the BSE model. Further, we have analyzed the leading twist parton distribution functions (PDFs) for both the heavy mesons in both the models and the results are found to be in accord with the basic light-front quantization (BLFQ) and BSE model.

We study the small-$x$ asymptotics of the leading-twist quark transverse momentum dependent parton distribution functions (TMDs) which encode couplings between the polarization of the quarks and that of their parent hadron, with at least one of the two polarizations in the transverse direction: the two worm-gear TMDs $g_{1T}$ and $h_{1L}^{\perp }$, and the pretzelosity $h_{1T}^{\perp }$. We apply the light cone operator treatment which has been developed in recent years to rewrite the TMD operator definitions at small-$x$ in terms of polarized dipole amplitudes, finding that in the flavor nonsinglet sector all three TMDs reduce in the small-$x$ limit to previously known polarized dipole amplitudes, and thus the large-$N_c$, linearized, double logarithmic approximation (DLA) asymptotics have all been solved for previously. We have compiled these asymptotics together with those of the other five flavor nonsinglet, leading-twist quark TMDs into a single unified table.

We investigate the properties of strangelets at finite temperature $T$, where an equivparticle model is adopted with both the linear confinement and leading-order perturbative interactions accounted for using density-dependent quark masses. The shell effects are examined by solving the Dirac equations for quarks in the mean-field approximation, which diminish with temperature as the occupation probability of each single-particle levels fixed by the Fermi-Dirac statistics, i.e., shell dampening. Consequently, instead of decreasing with temperature, the surface tension extracted from a liquid-drop formula increases with $T$ until reaching its peak at $T\approx 20–40\mathrm{MeV}$ with vanishing shell corrections, where the formula roughly reproduces the free energy per baryon of all strangelets. The curvature term, nevertheless, decreases with $T$ despite the presence of shell effects. The neutron and proton emission rates are fixed microscopically according to the external nucleon gas densities that are in equilibrium with strangelets, which generally increase with $T$ ($\lesssim 50\mathrm{MeV}$) for stable strangelets but decrease for those that are unstable against nucleon emission at $T=0$. The energy, free energy, entropy, charge-to-mass ratio, strangeness per baryon, and root-mean-square radius of $\beta$-stable strangelets obtained with various parameter sets are presented as well. The results indicated in this work are useful for understanding the products of binary compact star mergers and heavy-ion collisions.

The physics content of the QGSJET-III Monte Carlo generator of high energy hadronic collisions is described. In particular, a phenomenological implementation of higher twist corrections to hard parton scattering processes is discussed in some detail. Additionally addressed is the treatment of the so-called “color fluctuation” effects related to a decomposition of hadron wave functions into a number of Fock states characterized by different spatial sizes and different parton densities. Selected model results regarding the energy dependence of the total, elastic, and diffractive proton-proton cross sections are presented.

We analyze the two-body nonleptonic weak decays of charmed baryons, employing the pole approximation in tandem with the $SU(3{)}_F$ symmetry. We are able to make novel predictions for decay channels of ${\mathrm{\Omega }}_c^0\to {\mathbf{B}}_{n}P$ and ${\mathbf{B}}_{cc}\to {\mathbf{B}}_c^{A,S}P$ based on the experimental data of ${\mathbf{B}}_c^A\to {\mathbf{B}}_{n}P$. Here, ${\mathbf{B}}_n$, ${\mathbf{B}}_c^A$, ${\mathbf{B}}_c^S$, and ${\mathbf{B}}_{cc}$ are the low-lying octet, antitriplet charmed, sextet charmed and doubly charmed baryons, respectively, and $P$ is the pseudoscalar meson. Our findings reveal that the fitted effective Wilson coefficient ${\mathcal{C}}_{+}=0.469$ is notably smaller than the naïve expectation, and the low-lying pole approximation fails to account for $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to n{\pi }^{+},{\mathrm{\Xi }}^0{K}^{+})$, despite consistencies with the soft meson limit. We further recommend the decay channel ${\mathrm{\Xi }}_{cc}^{+}\to {\mathrm{\Xi }}_c^0{\pi }^{+}\to {\mathrm{\Xi }}^{-}{\pi }^{+}{\pi }^{+}{\pi }^{+}{\pi }^{-}$ for exploring evidence of ${\mathrm{\Xi }}_{cc}^{+}$, estimating the branching fraction at $(1.1\pm 0.6)\times {10}^{-3}$.

We discuss the self-consistency imposed by the analyticity of regular parts of form factors, appearing in the $z$ expansion for semileptonic $B$-meson decays, when fitted in different kinematic regions. Relying on the uniqueness of functions defined by analytic continuation, we propose four metrics which measure the departure from the ideal analytic self-consistency. We illustrate the process using Belle data for $B\to D\ell {\nu }_{\ell }$ with the two kinematic regions chosen as the five low-$z$ and the five high-$z$ bins. For this specific example, the metrics provide consistent indications that some choices (order of truncation, Boyd-Grinstein-Lebed or Bourrely-Caprini-Lellouch) made in the form of the $z$ expansion can be optimized. However, other choices ($z$ origin, location of isolated poles and threshold constraints) appear to have very little effect on these metrics. On the other hand, changing the kinetic regions affects the results and should also be considered in the optimization process. We briefly discuss the implication for optimization of the $z$ expansion for nucleon form factors relevant for neutrino oscillation experiments.

We propose a novel signature with four-photon final states to probe $CP$-violating (CPV) extended Higgs sectors via $f\overline{f}\to Z^{*}\to H_1{H}_2\to 4\gamma$ processes with $H_{1,2}$ being additional neutral Higgs bosons. We focus on the nearly Higgs alignment scenario, in which the discovered Higgs boson almost corresponds to a neutral scalar state belonging to the isospin doublet field with the vacuum expectation value $v\simeq 246\mathrm{GeV}$. We show that the branching ratios of $H_{1,2}\to \gamma \gamma$ can simultaneously be sizable when CPV phases in the Higgs potential are of order one due to the enhancement of charged-Higgs boson loops. Such branching ratios can be especially significant when the fermiophobic scenario is taken into account. As a simple example, we consider the general two Higgs doublet model, and demonstrate that the cross section for the four-photon process can be 0.1 fb at LHC with the masses of $H_{1,2}$ to be a few 100 GeV in the Higgs alignment limit under the constraints from electric dipole moments (EDMs) and LHC Run-II data. We also illustrate that the searches for EDMs and diphoton resonances at high-luminosity LHC play complementary roles to explore CPV extended Higgs sectors.

In this work, we study the production of $\mathrm{\Sigma }$ and $\mathrm{\Lambda }$ hyperons in strangeness-changing $\mathrm{\Delta }S=-1$ charged-current interactions of muon antineutrinos on nuclear targets. At the nucleon level, besides quasielastic scattering, we consider the inelastic mechanism in which a pion is produced alongside the hyperon. Its relevance for antineutrinos with energies below 2 GeV is conveyed in integrated and differential cross sections. We observe that the distributions on the angle between the hyperon and the final lepton are clearly different for quasielastic and inelastic processes. Hyperon final-state interactions, modeled with an intranuclear cascade, lead to a significant transfer from primary produced $\mathrm{\Sigma }$’s into final $\mathrm{\Lambda }$’s. They also cause considerable energy loss, which is apparent in hyperon energy distributions. We have investigated $\mathrm{\Lambda }$ production off ${}^{40}\mathrm{Ar}$ in the conditions of the recently reported MicroBooNE measurement. We find that the $\mathrm{\Lambda }\pi$ contribution, dominated by ${\mathrm{\Sigma }}^{*}(1385)$ excitation, accounts for about one third of the cross section.

A dark leptophilic scalar $({\varphi }_L)$ is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for ${\varphi }_L$ in the $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}{\varphi }_L$, ${\varphi }_L\to {\ell }^{+}{\ell }^{-}(\ell =e,\mu )$ process using $626{\mathrm{fb}}^{-1}$ of data collected by the Belle experiment near the $\mathrm{\Upsilon }(4S)$ resonance. We validate the backgrounds with multiple control regions in data, using a novel multiclass multivariate event classifier. In absence of a signal, we quote upper limits at the 90% confidence level on the coupling between ${\varphi }_L$ and leptons. Our bounds, obtained in a blinded approach, are 19% more constraining than the previous limits, averaged over the mass range $0.04\le m_{{\varphi }_L}\le 6.5\mathrm{GeV}$. We exclude the parameter space below 4 GeV favored by measurement of the anomalous magnetic moment of the muon.

Background channels with their expected strength and uncertainty levels are usually known in the searches of novel phenomena prior to the experiments are conducted at their design stage. We quantitatively study the projected sensitivities in terms of discovery potentials. These are essential for the optimizations of the experimental specifications as well as of the cost effectiveness in various investments. Sensitivities in counting analysis are derived with complete Poisson statistics and its continuous approximation, and are compared with those using maximum likelihood analysis in which additional measurables are included as signatures. The roles and effects due to uncertainties in the background estimates are studied. Two expected features to establish positive effects are verified and quantified: (i) In counting-only experiments, the required signal strength can be derived with complete Poisson analysis, and the continuous approximation would underestimate the results. (ii) Incorporating continuous variables as additional constraints would reduce the required signal strength relative to that of counting-only analysis. The formulations are applied to the case on the experimental searches of neutrinoless double beta decay in which both ambient and two-neutrino backgrounds are considered.

Perturbative quantum field theory (QFT) calculations in de Sitter space are riddled with contributions that diverge over time. These contributions often arise from loop integrals, which are notoriously hard to compute in de Sitter. We discuss an approach to evaluate loop integrals that contribute to equal-time correlators of a scalar field theory in a fixed de Sitter background. Our method is based on the Mellin-Barnes representation of correlation functions, which allows us to regulate loop divergences by adjusting the masses of the fields, or by gently deforming the underlying de Sitter spacetime. The resulting expressions have a similar structure as a standard answer from dimensional regularization in flat space QFT. These features of the regulator are illustrated with two examples, worked out in detail. Along the way, we illuminate the physical origin of these divergences and their interpretation with the machinery of the dynamical renormalization group. Our approach regulates the IR divergences of massless and massive particles in the same way. For massless scalars, the loop corrections can be incorporated as systematic improvements to the stochastic inflation framework, allowing for a more precise description of the IR dynamics of such fields in de Sitter.

We consider topological and nontopological regular soliton solutions in the Einstein-Maxwell-Skyrme theory. We analyze the properties of these solutions and determine their domains of existence. The dependence of the solutions on the gauge coupling and on the strength of the effective gravitational coupling are examined. Topologically trivial localized field configurations, pion stars, are shown to exist, as nonlinear gravitational bound states of the Skyrme field. Both spherically symmetric and axially symmetric pion stars are considered. We find that these solutions share many features with the usual (mini)boson stars. In particular they also exhibit a spiraling behavior and do not possess a flat space limit.

Twist operators implement symmetries in bounded regions of the space. Standard twists are a special class of twists constructed using modular tools. The twists corresponding to translations have interesting special properties. They can move continuously an operator from a region to a disjoint one without ever passing through the gap separating the two. In addition, they have generators satisfying the spectrum condition. We compute explicitly these twists for the two-dimensional chiral fermion field. The twist generator gives place to a new type of energy inequality where the smeared energy density is bounded below by an operator.

Dirac equations in a uniform magnetic field during inflation are analytically solved. By applying Bogoliubov transformation, the chiral asymmetry rate of fermions generated from asymptotic vacuum is $r=\tanh (\pi m/H)$, where $m$ is the Fermion mass and $H$ is the inflationary Hubble parameter, regardless of the presence or absence of a magnetic field. This means magnetic field does not contribute to the baryon asymmetry. Fermions generated from the in-vacuum state at higher Landau levels tend to transform to the lowest Landau level of the out-vacuum state, resulting in an insignificant impact of the highest Landau level on the reduced current. In addition, a stronger magnetic field enhances the reduced current, chiral density, and magnetization density, while the fermionic mass only enhances the three physical quantities when it is smaller than a certain threshold. Analytical results also indicate that the chiral density is nonzero only when mass and magnetic field coexist, meaning that the asymmetry of fermiomic particles and antiparticles is the result of the breaking of chirality and Bunch-Davies vacuum symmetry.

We explore the prospects of upcoming 21-cm surveys of cosmic dawn ($12\lesssim z\lesssim 30$) to provide cosmological information on top of upcoming cosmic microwave background (CMB) and large-scale structure surveys, such as CMB-S4, Simons Observatory (SO) and DESI. We focus on the effective number of relativistic species $N_{\mathrm{eff}}$ which is a promising observable for probing beyond the Standard Model theories. We show including upcoming 21-cm surveys such as the Square Kilometre Array (SKA) can allow probing a wide range of models for light particles at $2\sigma$ level achieving $2\sigma (N_{\mathrm{eff}})=0.034$ with CMB-S4, for example. Taking into account the degeneracy between $N_{\mathrm{eff}}$ and primordial helium fraction $Y_p$, one can achieve improvements in sensitivities to cosmological parameters, in particular, by more than a factor of 2 for $N_{\mathrm{eff}}$ and dark matter fractional energy density ${\omega }_c$.

The spin orientations of spinning binary black hole (BBH) mergers detected by ground-based gravitational wave detectors such as LIGO and Virgo can provide important clues about the formation of such binaries. However, these spin tilts, i.e., the angles between the spin vector of each black hole and the binary’s orbital angular momentum vector, can change due to precessional effects as the black holes evolve from a large separation to their merger. The tilts inferred at a frequency in the sensitive band of the detectors by comparing the signal with theoretical waveforms can thus be significantly different from the tilts when the binary originally formed. These tilts at the binary’s formation are well approximated in many scenarios by evolving the BBH backward in time to a formally infinite separation. Using the tilts at infinite separation also places all binaries on an equal footing in analyzing their population properties. In this paper, we perform parameter estimation for simulated BBHs and investigate the differences between the tilts one infers directly close to merger and those obtained by evolving back to infinite separation. We select simulated observations such that their configurations show particularly large differences in their orientations close to merger and at infinity. While these differences may be buried in the statistical noise for current detections, we show that in future plus-era ($\mathrm{A}+$ and $\mathrm{Virgo}+$) detectors, they can be easily distinguished in some cases. We also consider the tilts at infinity for BBHs in various spin morphologies and at the endpoint of the up-down instability. In particular, we find that we are able to easily identify the up-down instability cases as such from the tilts at infinity.

In a recent article [D. M. van Egmond and U. Reinosa, Phys. Rev. D 106, 074005 (2022)], we have identified new signatures for the Yang-Mills deconfinement transition, based on the finite-temperature longitudinal or (chromo-)electric gluon propagator as computed in the center-symmetric Landau gauge. Here, we generalize these considerations into a systematic study of the center symmetry identities obeyed by the correlation functions in this gauge. Any violation of these constraints signals the breaking of center symmetry and can thus serve as a probe for the deconfinement transition.

Within the framework of large-momentum effective theory (LaMET), we propose a hard-collinear factorization formula to extract the subleading-twist $B$-meson light-cone distribution amplitude (LCDA) from the quasidistribution amplitude calculated on the lattice. The one-loop matching coefficient and an integro-differential equation governing the evolution of the quasidistribution amplitude are derived. Our results could be useful either in evaluating the subleading-twist $B$-meson LCDA on the lattice or in the understanding the feasibility of LaMET on higher-twist distributions.

We develop a general algorithm that enables the consistent embedding of any four-dimensional static and spherically symmetric geometry into any five-dimensional single-brane braneworld model, characterized by an injective and nonsingular warp factor. Furthermore, we supplement the algorithm by introducing a method that allows one to, in principle, reconstruct 5D field theories that support the aforementioned geometries. This approach is based on a conformal transformation of the metric with the conformal factor being identified with the warp factor of the bulk geometry. The reconstructed theories depend solely on the induced brane geometry, since the warp factor is model-independently represented by a scalar field in the Lagrangian density. As a first application of our reconstruction method, we present for the first time a complete theory that supports the five-dimensional brane-localized extension of the Schwarzschild black hole, for any warp factor. The same method is subsequently utilized to illustrate the process of coherently embedding a de Sitter brane in braneworld models.