The quantum extension of classical finite elements, referred to as quantum finite elements (QFE) [R. C. Brower et al., Lattice ${\varphi }^4$ field theory on Riemann manifolds: Numerical tests for the 2-d Ising CFT on ${\mathbb{S}}^2$, Phys. Rev. D 98, 014502 (2018). and R. C. Brower et al., Lattice dirac fermions on a simplicial Riemannian manifold, Phys. Rev. D 95, 114510 (2017).], is applied to the radial quantization of 3D ${\varphi }^4$ theory on a simplicial lattice for the $\mathbb{R}\times {\mathbb{S}}^2$ manifold. Explicit counterterms to cancel the one- and two-loop ultraviolet defects are implemented to reach the quantum continuum theory. Using the Brower-Tamayo [Embedded Dynamics for ${\varphi }^4$ Theory, Phys. Rev. Lett. 62, 1087 (1989).] cluster Monte Carlo algorithm, numerical results support the QFE ansatz that the critical conformal field theory (CFT) is reached in the continuum with the full isometries of $\mathbb{R}\times {\mathbb{S}}^2$ restored. The Ricci curvature term, while technically irrelevant in the quantum theory, is shown to dramatically improve the convergence, opening the way for high precision Monte Carlo simulation to determine the CFT data; operator dimensions, trilinear operator product expansion couplings, and the central charge.

Spectrum of the low-lying ${\mathrm{\Omega }}_{cc}$ resonances with negative parity, which are assumed to be dominated by $sccq\overline{q}$ pentaquark components, is investigated using the chiral constituent quark model. Energies of the ${\mathrm{\Omega }}_{cc}$ resonances are obtained by considering the hyperfine interaction between quarks by exchanging a Goldstone boson. Possible $sccq\overline{q}$ configurations with spin-parity $1/2^{-}$, $3/2^{-}$, and $5/2^{-}$ are taken into account. Numerical results show that the lowest ${\mathrm{\Omega }}_{cc}$ resonances with negative parity may lie at $4050\pm 100\mathrm{MeV}$. In addition, the transitions of the ${\mathrm{\Omega }}_{cc}$ resonance to a pseudoscalar meson and a ground baryon state are also investigated within the chiral Lagrangian approach. We expect that these ${\mathrm{\Omega }}_{cc}$ resonances could be observed in the $D{\mathrm{\Xi }}_c$ channel by future experiments.

Using the approach based on conformal symmetry we calculate the two-loop coefficient function for the axial-vector contributions to two-photon processes in the $\overline{\mathrm{MS}}$ scheme. This is the last missing element for the complete next-to-next-to-leading order (NNLO) calculation of the pion transition form factor ${\gamma }^{*}\gamma \to \pi$ in perturbative QCD. The corresponding high-statistics measurement is planned by the Belle II collaboration and will allow one to put strong constraints on the pion light-cone distribution amplitude. The calculated NNLO corrections prove to be rather large and have to be taken into account. The same coefficient function determines the contribution of the axial-vector generalized parton distributions to deeply virtual Compton scattering (DVCS) which is investigated at the JLAB 12 GeV accelerator, by COMPASS at CERN, and in the future will be studied at the Electron Ion Collider EIC.

The charmoniumlike state $Y(4260)$ is described as predominantly a $D_1\overline{D}$ molecule in a coupled-channel quark model [Phys. Rev. D 96, 114022 (2017)]. The heavy quark spin symmetry (HQSS) thus implies the possible emergence of its heavy quark spin partners with molecular configurations as $D_1{\overline{D}}^{*}$ and $D_2^{*}{\overline{D}}^{*}$ below these charmed mesons’ thresholds. We analyze the probabilities of various intermediate charmed meson loops for $J^{PC}=1^{--}$ exotic state $Y(4360)$ and find that the channel $D_1{\overline{D}}^{*}$ couples more strongly around its mass regime, and the coupling behavior remains the same even if the mass of $Y(4360)$ is pushed closer to $D_1{\overline{D}}^{*}$ threshold. This enlightens that the most favorable molecular scenario for the $Y(4360)$ could be $D_1{\overline{D}}^{*}$, and hence it can be interpreted as HQSS partner of the $Y(4260)$. We also find the strong coupling behavior of $D_2^{*}{\overline{D}}^{*}$ channel with the $\psi (4415)$, which makes it a good candidate for a dominant $D_2^{*}{\overline{D}}^{*}$ molecule. We discuss the important decay patterns of these resonances to disentangle their long- and short-distance structures.

A precise knowledge of nuclear parton distribution functions (nPDFs) is—among other things—important for the unambiguous interpretation of hard process data taken in $pA$ and $AA$ collisions at the Relativistic Heavy Ion Collider (RHIC) and the LHC. The available fixed target data for deep inelastic scattering (DIS) and Drell-Yan (DY) lepton pair production mainly constrain the light quark distributions. It is hence crucial to include more and more collider data in global analyses of nPDFs in order to better pin down the different parton flavors, in particular the gluon distribution at small $x$. To help constrain the nuclear gluon PDF, we extend the nCTEQ15 analysis by including single inclusive hadron (SIH) production data from RHIC (PHENIX and STAR) and LHC (ALICE). In addition to the DIS, DY, and SIH datasets, we will also include LHC $W/Z$ production data. As the SIH calculation is dependent on hadronic fragmentation functions (FFs), we use a variety of FFs available in the literature to properly estimate this source of uncertainty. We study the impact of these data on the PDFs and compare with both the nCTEQ15 and nCTEQ15WZ sets. The calculations are performed using a new implementation of the nCTEQ code (ncteq++) including a modified version of incnlo, which allows faster calculations using precomputed grids. The extension of the nCTEQ15 analysis to include the SIH data represents an important step toward the next generation of PDFs.

The $Z_b(10610{)}^{\pm }$ and $Z_b(10650{)}^{\pm }$ are two bottomoniumlike structures discovered in the $\pi h_b(mP)$, $\pi \mathrm{\Upsilon }(nS)$ and $B^{*}{\overline{B}}^{(*)}+\mathrm{H}.\mathrm{c}.$ invariant mass spectra, where $m=\{1,2\}$ and $n=\{1,2,3\}$. Their nature is puzzling due to their charge, which forces its minimal quark content to be $b\overline{b}u\overline{d}$ ($b\overline{b}d\overline{u}$). Thus, it is necessary to explore four-quark systems in order to understand their inner structure. Additionally, their strong coupling to channels such as $\pi \mathrm{\Upsilon }$ and the closeness of their mass to $B^{*}{\overline{B}}^{(*)}$ thresholds stimulates a molecular interpretation. Within the framework of a constituent quark model which satisfactorily describes a wide range of properties of (non)conventional hadrons containing heavy quarks, we perform a coupled-channels calculation of the $I^G(J^{PC})=1^{+}(1^{+-})$ hidden-bottom sector including $B^{(*)}{\overline{B}}^{*}+\mathrm{H}.\mathrm{c}.$, $\pi h_b$, $\pi \mathrm{\Upsilon }$, and $\rho {\eta }_b$ channels. We analyze the line shapes in the different channels, describing the $\mathrm{\Upsilon }(5S)\to \pi B^{(*)}{\overline{B}}^{(*)}$ by means of the ${}^3{P}_0$ model. Since our description of the line shapes is promising, we perform the same coupled-channels calculation for the $Z_b$’s with $J^{--}$, where $J=\{0,1,2\}$. This allows us to obtain a fair description of the corresponding line shapes. The study of the analytic structure of the $S$-matrix suggests that the experimental $Z_b$ structures arise as a combination of several poles with $J^{PC}=0^{--}$, $1^{\pm -}$ and $2^{--}$ quantum numbers nearby the $B{\overline{B}}^{*}$ and $B^{*}{\overline{B}}^{*}$ thresholds.

In this work, we revisit the isospin violating decays of $X(3872)$ in a coupled-channel effective field theory. In the molecular scheme, the $X(3872)$ is interpreted as the bound state of ${\overline{D}}^{*0}{D}^0/{\overline{D}}^0{D}^{*0}$ and $D^{*-}{D}^{+}/D^{-}{D}^{*+}$ channels. In a cutoff-independent formalism, we relate the coupling constants of $X(3872)$ with the two channels to the molecular wave function. The isospin violating decays of $X(3872)$ are obtained by two equivalent approaches, which amend some deficiencies about this issue in literature. In the quantum field theory approach, the isospin violating decays arise from the coupling constants of $X(3872)$ to two dimeson channels. In the quantum mechanics approach, the isospin violating is attributed to wave functions at the origin. We illustrate that how to cure the insufficient results in literature. Within the comprehensive analysis, we bridge the isospin violating decays of $X(3872)$ to its inner structure. Our results show that the proportion of the neutral channel in $X(3872)$ is over 80%. As a by-product, we calculate the strong decay width of $X(3872)\to {\overline{D}}^0{D}^0{\pi }^0$ and radiative one $X(3872)\to {\overline{D}}^0{D}^0\gamma$. The strong decay width and radiative decay width are about 30 keV and 10 keV, respectively, for the binding energy from $-300\mathrm{keV}$ to $-50\mathrm{keV}$.

Longitudinal vector boson scattering provides an important probe of electroweak symmetry breaking, bringing sensitivity to physics beyond the Standard Model as well as constraining properties of the Higgs boson. It is a difficult process to study due to the small production cross section and challenging separation of the different polarization states. We study the sensitivity to longitudinal $WV$ vector boson scattering at the high-luminosity Large Hadron Collider in semi-leptonic final states. While these are characterized by larger background contributions compared to fully leptonic final states, they benefit from a higher signal cross section due to the enhanced branching fraction. We determine the polarization through full reconstruction of the event kinematics using the $W$ boson mass constraint and through the use of jet substructure. We show that with these techniques sensitivities around three standard deviations at the HL-LHC are achievable, which makes this channel competitive with its fully leptonic counterparts.

The search for supersymmetric particles is one of the major goals of the Large Hadron Collider (LHC). Supersymmetric top (stop) searches play a very important role in this respect, but the unprecedented collision rate to be attained at the next high luminosity phase of the LHC poses new challenges for the separation between any new signal and the standard model background. The massive parallelism provided by quantum computing techniques may yield an efficient solution for this problem. In this paper we show a novel application of the zoomed quantum annealing machine learning approach to classify the stop signal versus the background, and implement it in a quantum annealer machine. We show that this approach together with the preprocessing of the data with principal component analysis may yield better results than conventional multivariate approaches.

We study nonminimal extensions of Einstein-Maxwell theory with exact electromagnetic duality invariance. Any such theory involves an infinite tower of higher-derivative terms whose computation usually represents a challenging problem. Despite that, we manage to obtain a closed form of the action for all the theories with a quadratic dependence on the vector field strength. In these theories we find that the Maxwell field couples to gravity through a curvature-dependent susceptibility tensor that takes a peculiar form, reminiscent to that of Born-Infeld Lagrangians. We study the static and spherically symmetric black hole solutions of the simplest of these models, showing that the corresponding equations of motion are invariant under rotations of the electric and magnetic charges. We compute the perturbative corrections to the Reissner-Nordström solution in this theory, and in the case of extremal black holes we determine exactly the near-horizon geometry as well as the entropy. Remarkably, the entropy only possesses a constant correction despite the action containing an infinite number of terms. In addition, we find there is a lower bound for the charge and the mass of extremal black holes. When the sign of the coupling is such that the weak gravity conjecture is satisfied, the area and the entropy of extremal black holes vanish at the minimal charge.

We determine the leading Fock-state light front wave functions (LF-LFWFs) of the $\rho$ and $J/\psi$ mesons, for the first time from the Dyson-Schwinger and Bethe-Salpeter equations approach. A unique advantage of this method is that it renders a direct extraction of LF-LFWFs in presence of a number of higher Fock-states. Modulated by the current quark mass and driven by the dynamical chiral symmetry breaking, we find the $\rho$ and $J/\psi$ LF-LFWFs different in profile, i.e., the former are broadly distributed in $x$ (the longitudinal light-cone momentum fraction of meson carried by quark) while the latter are narrow. Moreover, the $\rho$ LF-LFWFs contribute less than 50% to the total Fock-state normalization, suggesting considerable higher Fock-states in $\rho$. We then use these LF-LFWFs to study the diffractive $\rho$ and $J/\psi$ electroproduction within the dipole picture. The calculated cross section shows general agreement with HERA data, except for growing discrepancy in $\rho$ production at low photon virtuality.

We present a field theoretical description of quarkyonic matter consisting of quark, nucleon, and ghost fields coupling to mesonic degrees of freedom. The ghosts are present to cancel overcounting of nucleon states that are Pauli blocked by the quark Fermi sea. Such a theory becomes an effective field theory of nucleons at low baryon density and as such will reproduce nucleonic matter phenomenology. This theory can accommodate chiral symmetry restoration and the dynamical generation of a shell of nucleons at the Fermi surface. It is valid for finite temperature and density. In such a theory, quark-nucleon duality is accomplished by inclusion of ghost fields so that the nucleons extra degrees of freedom, that are beyond those of quarks, are compensated by the ghost fields.

In this paper we systematically study a model of spherically symmetric polymer black holes recently proposed by Gambini, Olmedo, and Pullin (GOP). Within the framework of loop quantum gravity, the quantum parameters in the GOP model depend on the minimal area gap and the size of the discretization of the physical states. In this model, a spacelike transition surface takes the place of the classical singularity. By means of coordinate transformations, we first extend the metric to the white hole region, and find that the geometric structure of the quantum black hole is similar to the wormhole structure, and the radius of the most quantum region is equal to the wormhole radius. In addition, we show that the energy conditions are violated not only at the throat but also at the horizons and the spatial infinities. In order to show how the quantum effects affect the spacetimes, we calculate the Ricci and Kretschmann scalars at different places. It turns out that, as expected, the most quantum region is at the throat. Finally, we consider the quasinormal modes (QNMs) of massless scalar field perturbations, electromagnetic field perturbations, and axial gravitational perturbations. QNMs in the Eikonal limits are also considered. As anticipated, the spectrum of QNMs deviates from that of the classical case due to quantum effects. Interestingly, our results show that the quasinormal frequencies of the perturbations share the same qualitative tendency while setting quantum parameters with various values in this effective model, even if the potential deviations are different with different spins.

We investigate static and spherically symmetric stars disformally coupled to a scalar field. The scalar field is assumed to be shift symmetric, and hence the conformal and disformal factors of the metric coupled to matter are dependent only on the kinetic term of the scalar field. Assuming that the scalar field is linearly dependent on time, we consider a general shift-symmetric scalar-tensor theory and a general form of the matter energy-momentum tensor that allows for the anisotropic pressure and the heat flux in the radial direction. This is a natural starting point in light of how the gravitational field equations and the energy-momentum tensor transform under a disformal transformation. By inspecting the structure of the hydrostatic equilibrium equation in the presence of the derivative-dependent conformal and disformal factors, we show that the energy density and tangential pressure must vanish at the surface of a star. This fact is used to prove the disformal invariance of the surface of a star, which was previously subtle and unclear. We then focus on the shift-symmetric k-essence disformally coupled to matter and study the interior and exterior metric functions and scalar-field profile in more detail. It is found that there are two branches of the solution depending on the velocity of the scalar field. The disformally related metric functions of the exterior spacetime are also discussed.

Rapid sky localization of gravitational wave sources is crucial to enable prompt electromagnetic follow-ups. In this article, we present a novel semianalytical approach for sky localization of gravitational waves from compact binary coalescences. We use the Bayesian framework with an analytical approximation to the prior distributions for a given astrophysical model. We derive a semianalytical solution to the posterior distribution of source directions. This method only requires onefold numerical integral that marginalizes over the merger time, compared to the fivefold numerical integration otherwise needed in the Bayesian localization method. The performance of the method is demonstrated using a set of binary neutron stars (BNS) injections on Gaussian noise using LIGO-Virgo’s design and O2 sensitivity. We find the median of 90% confidence area in O2 sensitivity to be $\mathcal{O}({10}^2){\mathrm{deg}}^2$, comparable to that of the existing LIGO-Virgo online localization method Bayestar and parameter estimation toolkit lalinference. In the end, we apply this method to localize the BNS event GW170817 and find the 50% (90%) confidence region of $11{\mathrm{deg}}^2$ ($50{\mathrm{deg}}^2$). The detected optical counterpart of GW170817 resides within our 50% confidence area.

We investigate the impact of Coleman-Weinberg inflation on the stochastic gravity wave background spectrum emitted by intermediate-scale cosmic strings. The string network is partially inflated and reenters the horizon at later times after the end of inflation, such that the short string loops are not produced. This leads to a significant modification of the gravity wave spectrum that we explore in detail. We find that Coleman-Weinberg inflation can help to satisfy the Parkes Pulsar Timing Array (PPTA) bound for dimensionless string tension values in the range $G\mu >1.1\times {10}^{-10}$. We also identify the modified gravity wave spectra which, in the case of inflation, are compatible with the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) data. We then discuss the formation of monopoles and strings at the same breaking scale and the compatibility of the Monopole, Astrophysics and Cosmic Ray Observatory (MACRO) bound with the PPTA bound, and also with the NANOGrav data. Finally, an example of a realistic nonsupersymmetric $E_6$ model incorporating successful Coleman-Weinberg inflation is presented in which monopoles and strings both survive inflation and are present at an observable level.

We compute the leading corrections to the differential cross section for top-pair production via gluon fusion due to third-generation dimension-six operators at leading order in QCD. The Standard Model fields are assumed to couple only weakly to the hypothetical new sector. A systematic approach then suggests treating single insertions of the operator class containing gluon field strength tensors on the same footing as explicitly loop suppressed contributions from four-fermion operators. This is in particular the case for the chromomagnetic operator $Q_{(uG)}$ and the purely bosonic operators $Q_{(G)}$ and $Q_{(\phi G)}$. All leading order dimension-six contributions are consequently suppressed with a loop factor $1/16{\pi }^2$.

We calculate the amplitude for exclusive electroweak production of a pseudoscalar $D_s$ or a vector $D_s^{*}$ charmed strange meson on an unpolarized nucleon, through a charged current, in leading order in ${\alpha }_s$. We work in the framework of the collinear QCD approach where generalized gluon distributions factorize from perturbatively calculable coefficient functions. We include both $O(m_c)$ terms in the coefficient functions and $O(M_D)$ mass term contributions in the heavy meson distribution amplitudes. We show that this process may be accessed at future electron-ion colliders.

In this work, we investigate the open-charm decay process $\psi \to {\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ via the hadronic loop mechanism for vector charmonia above ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ threshold. The branching ratios of these vector charmonium states to ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ are estimated. The charmonium explanation of the $Y(4630)$ observed in $e^{+}{e}^{-}\to {\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ is tested. Furthermore, for the predicted higher vector charmonia above 4.7 GeV, the branching ratios $\mathcal{B}[\psi (nS)\to {\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c]$ with $n=7$, 8, 9 are found to be of the order of magnitude of ${10}^{-4}-{10}^{-3}$ while $\mathcal{B}[\psi (mD)\to {\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c]$ with $m=6$, 7, 8 are of the order of magnitude of ${10}^{-3}-{10}^{-2}$. The experimental signals of these missing charmonium states are discussed. The search for them may be an interesting topic in the future BESIII and Belle II experiments.

We study four-dimensional gauge theories coupled to fermions in the fundamental and mesonlike scalars. All requisite beta functions are provided for general gauge group and fermion representation. In the regime where asymptotic freedom is absent, we determine all interacting fixed points using perturbation theory up to three loop in the gauge and two loop in the Yukawa and quartic couplings. We find that the conformal window of ultraviolet fixed points is narrowed down by finite-$N$ corrections beyond the Veneziano limit. We also find a new infrared fixed point whose main features, such as scaling exponents, UV-IR connecting trajectories, and phase diagram, are provided. Both fixed points collide upon varying the number of fermion flavors $N_{\mathrm{f}}$, and conformality is lost through a saddle-node bifurcation. We further revisit the prospect for ultraviolet fixed points in the large-$N_{\mathrm{f}}$ limit where matter field fluctuations dominate. Unlike at weak coupling, we do not find clear evidence for new scaling solutions even in the presence of scalar and Yukawa couplings.