Latest in hep-lat

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Chromopolarizability of bottomonium from the $Υ(2S,3S,4S) \to Υ(1S,2S)ππ$ transitionsJun 13 2019We systemically study the dipion transitions $\Upsilon(2S,3S,4S) \to \Upsilon(1S,2S)\pi\pi$. We consider the mechanisms of the hadronization of soft gluons, the two bottomoniumlike states $Z_b(10610)$ and $Z_b(10650)$ exchanges, and the bottom meson loops. ... More
Towards the nucleon hadronic tensor from lattice QCDJun 12 2019We present the first calculation of the hadronic tensor on the lattice for the nucleon. The hadronic tensor can be used to extract the structure functions in deep inelastic scatterings and also provide information for the neutrino-nucleon scattering which ... More
Possible Molecular States Composed of Doubly Charmed Baryons with Couple-channel EffectJun 12 2019We systematically investigate the possible molecular states composed of (1) two spin-$\frac{3}{2}$ doubly charmed baryons, and (2) a pair of spin-$\frac{3}{2}$ and spin-$\frac{1}{2}$ doubly charmed baryons. The one-boson-exchange (OBE) model is used to ... More
Towards an UV fixed point in CDT gravityJun 11 2019CDT is an attempt to formulate a non-perturbative lattice theory of quantum gravity. We describe the phase diagram and analyse the phase transition between phase B and phase C (which is the analogue of the de Sitter phase observed for the spherical spatial ... More
A quantum walk with both a continuous-time and a continuous-spacetime limitJun 11 2019Nowadays, quantum simulation schemes come in two flavours. Either they are continuous-time discrete-space models (a.k.a Hamiltonian-based), pertaining to non-relativistic quantum mechanics. Or they are discrete-spacetime models (a.k.a Quantum Walks or ... More
Applying the tempered Lefschetz thimble method to the Hubbard model away from half-fillingJun 10 2019The tempered Lefschetz thimble method [arXiv:1703.00861] is a parallel-tempering algorithm to solve the sign problem in Monte Carlo simulations. It uses the flow time of the antiholomorphic gradient flow as a tempering parameter and is expected to tame ... More
Light axial-vector and vector resonances $X(2100)$ and $X(2239)$Jun 10 2019We study features of the resonances $X(2100)$ and $X(2239)$ by treating them as the axial-vector and vector tetraquarks with the quark content $ss \overline{s}\overline{s}$, respectively. The spectroscopic parameters of these exotic mesons are calculated ... More
Gauss law at a vertex in Lattice QCD and its gauge invariant Hilbert spaceJun 10 2019We solve the local Gauss law in lattice QCD in the presence of matter charges. This corresponds to constructing singlet states using Schwinger Bosons and Fermions of SU(3) group at each vertex of the lattice. We also calculate the action of various invariant ... More
Study of the pseudoscalar glueball in $J/ψ$ radiative decaysJun 09 2019We aim to explore the production rate of the pseudoscalar glueball in $J/\psi$ radiative decay by lattice QCD in quenched approximation. The calculation is performed on three anisotropic lattices with the spatial lattice spacing ranging from 0.222(2) ... More
$Nπ$-state contamination in lattice calculations of the nucleon pseudoscalar form factorJun 09 2019The nucleon-pion-state contribution in the QCD 3-point function of the pseudoscalar density is calculated to leading order in chiral perturbation theory. It predicts a nucleon-pion-state contamination in lattice estimates for the pseudoscalar form factor ... More
m_c and m_b from M_B_c and new estimate of f_B_c , M_B*_c and f_B*_cJun 09 2019We extract (for the first time) the correlated values of the running masses m_c and m_b from M_Bc using QCD Laplace sum rules (LSR) within stability criteria where pertubative (PT) expressions at N2LO and non-perturbative (NP) gluon condensates at LO ... More
Non-perturbative determination of improvement coefficients b_m and b_A-b_P and normalisation factor Z_m*Z_P/Z_A with N_f=3 Wilson fermionsJun 08 2019We non-perturbatively determine the normalisation constant Z_m*Z_P/Z_A as well as the Symanzik coefficients b_m and b_A-b_P, required in O(a) improved quark mass renormalisation with Wilson fermions. The strategy underlying their computation involves ... More
Quarkonium Phenomenology from a Generalised Gauss LawJun 06 2019We present an improved analytic parametrisation of the complex in-medium heavy quark potential derived rigorously from the generalised Gauss law. To this end we combine in a self-consistent manner a non-perturbative vacuum potential with a weak-coupling ... More
The CKM unitarity problem: A trace of new physics at the TeV scale?Jun 06 2019After the recent high precision determinations of $V_{us}$ and $V_{ud}$, the first row of the CKM matrix shows more than $4\sigma$ deviation from unitarity. Two possible scenarios beyond the Standard Model can be investigated in order to fill the gap. ... More
Phenomenological studies on the $B_{d,s}^0 \to J/ψf_0(500) [f_0(980)]$ decaysJun 06 2019Encouraged by the global agreement between theoretical predictions and experimental measurements for $B \to J/\psi V$ decays, we extend that perturbative QCD formalism to $B_{d,s}^0 \to J/\psi f_0(500) [f_0(980)]$ decays at the presently known next-to-leading ... More
Phenomenological studies on the $B_{d,s}^0 \to J/ψf_0(500) [f_0(980)]$ decaysJun 06 2019Jun 09 2019Encouraged by the global agreement between theoretical predictions and experimental measurements for $B \to J/\psi V$ decays, we extend that perturbative QCD formalism to $B_{d,s}^0 \to J/\psi f_0(500) [f_0(980)]$ decays at the presently known next-to-leading ... More
Lattice field theory with torsionJun 06 2019Inspired by the duality between gravity and defects in crystals, we study lattice field theory with torsion. The torsion is realized by a line defect of a lattice, namely a dislocation. As the first application, we perform the numerical computation for ... More
Off-shell quark bilinear operator Green's functions at two loopsJun 05 2019We construct the two loop Green's functions for a quark bilinear operator inserted at non-zero momentum in a quark 2-point function for the most general off-shell configuration. In particular we consider the quark mass operator, vector and tensor currents ... More
Partial wave decomposition on the lattice and its applications to the HAL QCD methodJun 05 2019The approximated partial wave decomposition method to the discrete data on a cubic lattice, developed by C. W. Misner, is applied to the calculation of $S$-wave hadron-hadron scatterings by the HAL QCD method in lattice QCD. We consider the Nambu-Bethe-Salpeter ... More
Chiral effective theories with a light scalar at one loopJun 05 2019There are indications that some theories with spontaneous symmetry breaking also feature a light scalar in their spectrum, with a mass comparable to the one of the Goldstone modes. In this paper, we compute the one-loop counterterms of a theory of Goldstone ... More
On the contribution of different coupling constants in the infrared properties of Yang-Mills theoryJun 04 2019We investigate the influence of the different vertices in the infrared regime of two-point correlation functions of Yang-Mills theory in Landau-gauge. This regime is studied using perturbation theory within a phenomenological massive model. We perform ... More
Dynamics and symmetries in chiral $SU(N)$ gauge theoriesJun 04 2019Dynamics and symmetry realization in various chiral gauge theories in four dimensions are investigated, generalizing a recent work by M. Shifman and the present authors, by relying on the standard 't Hooft anomaly matching conditions and on some other ... More
Adiabatic projection method with Euclidean time subspace projectionJun 03 2019Euclidean time projection is a powerful numerical tool that uses exponential decay to extract the low-energy information of quantum systems. The adiabatic projection method, which is based on Euclidean time projection, is a standard procedure for studying ... More
$B\to D^\ast\ellν$ at non-zero recoilJun 03 2019The current status of the lattice-QCD calculations of the form factors of the $B\to D^\ast\ell\nu$ semileptonic decay is reviewed. Particular emphasis is given to the most mature calculation at non-zero recoil coming from the Fermilab Lattice and MILC ... More
$B\to D^\ast\ellν$ at non-zero recoilJun 03 2019Jun 07 2019The current status of the lattice-QCD calculations of the form factors of the $B\to D^\ast\ell\nu$ semileptonic decay is reviewed. Particular emphasis is given to the most mature calculation at non-zero recoil coming from the Fermilab Lattice and MILC ... More
Mapping the Phases of Quantum Chromodynamics with Beam Energy ScanJun 03 2019We review the present status of the search for a phase transition and critical point as well as anomalous transport phenomena in Quantum Chromodynamics (QCD), with an emphasis on the Beam Energy Scan program at the Relativistic Heavy Ion Collider at Brookhaven ... More
New parametrization of the form factors in $\bar{B}\to D\ell\barν_\ell$ decaysJun 03 2019A new model-independent parametrization is proposed for the hadronic form factors in the semi-leptonic $\bar{B}\to D\ell\bar{\nu}_\ell$ decay. By a combined consideration of the recent experimental and lattice QCD data, we determine precisely the Cabibbo-Kobayashi-Maskawa ... More
$B_s\to D_s \ellν$ Form Factors for the full $q^2$ range from Lattice QCD with non-perturbatively normalized currentsJun 03 2019We present a lattice QCD determination of the $B_s \to D_s \ell\nu$ scalar and vector form factors over the full physical range of momentum transfer. The result is derived from correlation functions computed using the Highly Improved Staggered Quark (HISQ) ... More
Continuum limit in numerical simulations of the $\mathcal{N}=2$ Landau--Ginzburg modelJun 03 2019The $\mathcal{N}=2$ Landau--Ginzburg description provides a strongly-interacting Lagrangian realization of an $\mathcal{N}=2$ superconformal field theory. It is conjectured that one such example is given by the two-dimensional $\mathcal{N}=2$ Wess--Zumino ... More
Improved Gauss-law model and in-medium heavy quarkonium at finite density and velocityMay 31 2019We explore the in-medium properties of heavy-quarkonium states at finite baryo-chemical potential and finite transverse momentum based on a modern complex valued potential model. Our starting point is a novel, rigorous derivation of the generalized Gauss ... More
Monte Carlo Renormalization Flows in the Space of Relevant and Irrelevant Operators: Application to Three-Dimensional Clock ModelsMay 31 2019We present a way to visualize and quantify renormalization group flows in a space of observables computed using Monte Carlo simulations. We apply the method to classical three-dimensional clock models, i.e., the planar (XY) spin model perturbed by a $Z_q$ ... More
Impact on the decay rate of $B_s\to μ^+μ^-$ from the dispersive two-photon transitionMay 31 2019We study the long-distance contribution to $B_s\to\mu^+\mu^-$ decay, which is generated by the two-photon intermediate state via $B_s\to\gamma^*\gamma^*\to\mu^+\mu^-$ transition. It is found that the dispersive two-photon amplitude can interfere with ... More
Universality of the critical point mapping between Ising model and QCD at small quark massMay 30 2019The universality of the QCD equation of state near the critical point is expressed by mapping pressure as a function of temperature $T$ and baryon chemical potential $\mu$ in QCD to Gibbs free energy as a function of reduced temperature $r$ and magnetic ... More
A qubit regularization of the $O(3)$ sigma modelMay 30 2019We construct a qubit regularization of the $O(3)$ non-linear sigma model in two and three spatial dimensions using a quantum Hamiltonian with two qubits per lattice site. Using a worldline formulation and worm algorithms, we show that in two spatial dimensions ... More
Tensor network formulation of two dimensional gravityMay 30 2019We show how to formulate a lattice gauge theory whose naive continuum limit corresponds to two dimensional (Euclidean) quantum gravity including a positive cosmological constant. More precisely the resultant continuum theory corresponds to gravity in ... More
How much do charm sea quarks affect the charmonium spectrum?May 30 2019The properties of charmonium states are or will be intensively studied by the B-factories Belle II and BESIII, the LHCb and PANDA experiments and at a future Super-c-tau Factory. Precise lattice calculations provide valuable input and several results ... More
On the Equivalence of Three-Particle Scattering FormalismsMay 28 2019In recent years, different on-shell $\mathbf{3}\to\mathbf{3}$ scattering formalisms have been proposed to be applied to both lattice QCD and infinite volume scattering processes. We prove that the formulation in the infinite volume presented by Hansen ... More
Chiral phase transition in (2 + 1)-flavor QCDMay 28 2019The chiral phase transition temperature $T_{c}^{0}$ is a fundamental quantity of QCD. To determine this quantity we have performed simulations of (2 + 1)-flavor QCD using the Highly Improved Staggered Quarks (HISQ/tree) action on $N_{\tau}=6, 8$ and 12 ... More
Unitarity of the infinite-volume three-particle scattering amplitude arising from a finite-volume formalismMay 27 2019In a previous publication, two of us derived a relation between the scattering amplitude of three identical bosons, $\mathcal M_3$, and a real function referred to as the {divergence-free} K matrix and denoted $\mathcal K_{\text{df},3}$. The result arose ... More
$D$ mesons as a probe of Casimir effect for chiral symmetry breakingMay 27 2019We propose $D$ mesons as probes to investigate finite-volume effects for chiral symmetry breaking at zero and finite temperature. By using the $2+1$-flavor linear-sigma model with constituent light quarks, we analyze the Casimir effects for the $\sigma$ ... More
Large-$N$ $\mathbb{CP}^{N-1}$ sigma model on a Euclidean torus: \\ uniqueness and stability of the vacuumMay 25 2019In this paper we examine analytically the large-$N$ gap equation and its solution for the $2D$ $\mathbb{CP}^{N-1}$ sigma model defined on a Euclidean spacetime torus of arbitrary shape and size ($L, \beta)$, $\beta$ being the inverse temperature. It is ... More
Pion scattering in the isospin I=2 channel from elongated latticesMay 24 2019Pion-pion elastic scattering in the isospin I=2 channel is investigated in two-flavor dynamical lattice QCD. Six ensembles are used with lattices elongated in one of the spatial dimensions at two quark masses corresponding to a pion mass of 315 MeV and ... More
Heavy baryon spectroscopy from lattice QCDMay 24 2019In this report, the most recent and precise estimates of masses of ground state baryons using lattice QCD are discussed. Considering the prospects in the heavy baryon sector, lattice estimates for these are emphasized. The first and only existing lattice ... More
A Study of Stress-Tensor Distribution around Flux Tube in Abelian-Higgs ModelMay 24 2019We study the stress-tensor distribution around the flux tube in static quark and anti-quark systems based on the momentum conservation and the Abelian-Higgs (AH) model. We first investigate constraints on the stress-tensor distribution from the momentum ... More
A qubit model for U(1) lattice gauge theoryMay 23 2019A conceptually simple model for strongly interacting compact U(1) lattice gauge theory is expressed as operators acting on qubits. The number of independent gauge links is reduced to its minimum through the use of Gauss's law. The model can be implemented ... More
Full O(a) improvement in EQCDMay 23 2019EQCD is a 3D bosonic theory containing SU(3) and an adjoint scalar, which efficiently describes the infrared, nonperturbative sector of hot QCD and which is highly amenable to lattice study. We improve the matching between lattice and continuum EQCD by ... More
Hadron Spectroscopy and Resonances: ReviewMay 23 2019I review recent results on hadron spectroscopy using lattice QCD. In light of the discoveries in heavy baryon sector at LHCb over the past few years, lattice calculations in this regard are emphasized. Investigations on light baryon, heavy-heavy and heavy-light ... More
The nature of symmetry breaking in the superconducting ground stateMay 22 2019The order parameters which are thought to detect U(1) gauge symmetry breaking in a superconductor are both non-local and gauge dependent. For that reason they are also ambiguous as a guide to phase structure. We point out that a global subgroup of the ... More
The nature of symmetry breaking in the superconducting ground stateMay 22 2019Jun 06 2019The order parameters which are thought to detect U(1) gauge symmetry breaking in a superconductor are both non-local and gauge dependent. For that reason they are also ambiguous as a guide to phase structure. We point out that a global subgroup of the ... More
Light quark vacuum polarization at the physical point and contribution to the muon $g-2$May 22 2019We report on the computation of the connected light quark vacuum polarization with 2+1+1 flavors of HISQ fermions at the physical point and its contribution to the muon anomalous magnetic moment. Three ensembles, generated by the MILC collaboration, are ... More
Gluon propagator in two-color dense QCD: Massive Yang-Mills approach at one-loopMay 21 2019We study the Landau gauge gluon propagators in dense two-color QCD at quark chemical potential, $\mu_q$, in the range from 0.5 to 1.0 GeV not reachable by the perturbative method at weak coupling. In order to take into account the non-perturbative effects, ... More
Quantum Gravity from Causal Dynamical Triangulations: A ReviewMay 21 2019This topical review gives a comprehensive overview and assessment of recent results in Causal Dynamical Triangulations (CDT), a modern formulation of lattice gravity, whose aim is to obtain a theory of quantum gravity nonperturbatively from a scaling ... More
$P_c(4457)^+$, $P_c(4440)^+$, and $P_c(4312)^+$: molecules or compact pentaquarks?May 21 2019We update the estimations for the masses of the $(uud)_{8_c}(c\bar{c})_{8_c}$ and $(uds)_{8_c}(c\bar{c})_{8_c}$ pentaquark states by considering the isospin breaking effects. Their values are determined by calculating mass distances from the $\Sigma_c^{++}D^-$ ... More
Pseudoscalar flavor-singlet mesons from lattice QCDMay 20 2019We investigate the masses and mixing of $\eta$, $\eta'$ mesons in the framework of twisted mass lattice QCD with $N_f=2+1+1$ dynamical quark flavors. For the first time we perform a controlled chiral and continuum extrapolation to obtain physical results. ... More
Anomalous dimensions of potential top-partnersMay 20 2019We discuss anomalous dimensions of top-partner candidates in theories of Partial Compositeness. First, we revisit, confirm and extend the computation by DeGrand and Shamir of anomalous dimensions of fermionic trilinears. We present general results applicable ... More
Learning phase transitions: comparing PCA and SVMMay 20 2019A comparison of results from principal component analysis and support vector machine calculations is made for a variety of phase transitions in two-dimensional classical spin models.
Double-heavy axial-vector tetraquark $T_{bc;\bar{u}\bar{d}}^{0}$May 18 2019The spectroscopic parameters of the axial-vector tetraquark $T_{bc;\bar{u} \bar{d}}^{0}$ are calculated by means of the QCD two-point sum rule method. In computations we take into account contributions arising from various quark, gluon and mixed vacuum ... More
Two loop calculation of Yang-Mills propagators in the Curci-Ferrari modelMay 17 2019The Landau-gauge gluon and ghost correlation functions obtained in lattice simulations can be reproduced qualitatively and, to a certain extent, quantitatively if a gluon mass is added to the standard Faddeev-Popov action. This has been tested extensively ... More
Nucleon--Pion States from 2+1+1-flavor Lattice QCD at Physical Pion MassMay 15 2019The nucleon excited states which are supposed to be nucleon-pion states are extracted from the nucleon three-point correlator with the temporal component of the isovector axial current transferring nonzero momentum to the nucleon. This correlator shows ... More
Valence parton distribution function of pion from fine latticeMay 15 2019We present a lattice QCD study of valence parton distribution inside the pion within the framework of Large Momentum Effective Theory. We use a mixed action approach with 1-HYP smeared valence Wilson clover quarks on 2+1 flavor HISQ sea with the valence ... More
Aspects of the QCD $θ$-vacuumMay 15 2019This paper addresses two aspects concerning the $\theta$-vacuum of Quantum Chromodynamics. First, large-$N_c$ chiral perturbation theory is used to calculate the first two non-trivial cumulants of the distribution of the winding number, i.\,e. the topological ... More
Aspects of the QCD $θ$-vacuumMay 15 2019Jun 11 2019This paper addresses two aspects concerning the $\theta$-vacuum of Quantum Chromodynamics. First, large-$N_c$ chiral perturbation theory is used to calculate the first two non-trivial cumulants of the distribution of the winding number, i.\,e. the topological ... More
Solidification of Icosahedral Quasicrystals: Viewpoint Based on a Quaternion Orientational Order Parameter and the Formation of the E8 LatticeMay 14 2019In this article, the solidification phase transition between isotropic liquids and icosahedral quasicrystalline structures is classified by the application of a quaternion orientational order parameter. We suggest that the formation of the E8 lattice ... More
Symmetry, symmetry breaking, and pion parton distributionsMay 13 2019A symmetry-preserving approach to the two valence-body continuum bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, the electromagnetic pion elastic and transition form factors. ... More
The gradient flow coupling at high-energy and the scale of SU(3) Yang-Mills theoryMay 13 2019Using finite size scaling techniques and a renormalization scheme based on the Gradient Flow, we determine non-perturbatively the $\beta$-function of the $SU(3)$ Yang-Mills theory for a range of renormalized couplings $\bar g^2\sim 1-12$. We perform a ... More
Macroscopic observables from the comparison of local reference systemsMay 12 2019Parallel transport as dictated by a gauge field determines a collection of local reference systems. Comparing local reference systems in overlapping regions leads to an ensemble of algebras of relational kinematical observables for gauge theories including ... More
String confinement in 2-form lattice gauge theoryMay 11 2019We study the confinement between vortex strings in the dual lattice gauge theory of the abelian Higgs model. The dual lattice gauge theory is described by a 2-form gauge field. We calculate the string-antistring potential from the surface operator of ... More
Two- and three-pion finite-volume spectra at maximal isospin from lattice QCDMay 10 2019We present the three-pion spectrum with maximum isospin in a finite volume determined from lattice QCD, including, for the first time, excited states across various irreducible representations at zero and nonzero total momentum, in addition to the ground ... More
Square-Lattice Antiferromagnet Subjected to a Magnetic Field Aligned with the Order ParameterMay 10 2019The thermal properties of antiferromagnetic films -- in particular, the square-lattice antiferromagnet -- subjected to an external magnetic field pointing into the direction of the staggered magnetization are explored. The effective field theory analysis ... More
Spectral Reconstruction with Deep Neural NetworksMay 10 2019We explore artificial neural networks as a tool for the reconstruction of spectral functions from imaginary time Green's functions, a classic ill-conditioned inverse problem. Our ansatz is based on a supervised learning framework in which prior knowledge ... More
The hidden charm pentaquark states and $Σ_c\bar{D}^{(*)}$ interaction in chiral perturbation theoryMay 10 2019In this work, we employ the heavy hadron chiral perturbation theory (HHChPT) to calculate the $\Sigma_c\bar{D}^{(*)}$ potentials to the next-to-leading order. The contact, the one-pion exchange and the two-pion exchange interactions are included. Besides, ... More
Lattice QCD Study of the Nucleon-Charmonium InteractionMay 10 2019The $J/\psi$-nucleon interaction is studied by lattice QCD calculations. At the leading order of the derivative expansion, the interaction consists of four terms: the central, the spin-spin, and two types of tensor forces. We determine these spin-dependent ... More
Critical properties of the Néel-to-algebraic spin liquid transitionMay 09 2019The algebraic spin liquid is a long-sought-after phase of matter characterized by the absence of quasiparticle excitations, a low-energy description in terms of emergent Dirac fermions and gauge fields interacting according to (2+1)D quantum electrodynamics ... More
Charmonium resonances with $J^{PC}=1^{--}$ and $3^{--}$ from $\bar DD$ scattering on the latticeMay 09 2019We present a lattice QCD study of charmonium resonances and bound states with $J^{PC}=1^{--}$ and $3^{--}$ near the open-charm threshold, taking into account their strong transitions to $\bar DD$. Vector charmonia are the most abundant in the experimentally ... More
The Stochastic Feynman-Hellmann MethodMay 08 2019The Feynman-Hellmann method, as implemented by Bouchard et al. [1612.06963], was recently employed successfully to determine the nucleon axial charge. A limitation of the method was the restriction to a single operator and a single momentum during the ... More
Finite-size effects in exponential random graphs and cluster evaporationMay 08 2019In this Letter we find numerically the strong finite-size effects in the critical behavior of Erd\H{o}s-R\'enyi (ER) networks supplemented with chemical potentials for some motifs, in particular 2-stars and triangles. For the 2-star model above the critical ... More
Three-dimensional ferromagnetic CP(N-1) modelsMay 08 2019May 10 2019We investigate the critical behavior of three-dimensional ferromagnetic CP(N-1) models, which are characterized by a global U(N) and a local U(1) symmetry. We perform numerical simulations of a lattice model for N=2, 3, and 4. For N=2 we find a critical ... More
Chiral symmetry breaking, entanglement, and the nucleon spin decompositionMay 08 2019The nucleon is naturally viewed as a bipartite system of valence spin -- defined by its non-vanishing chiral charge -- and non-valence or sea spin. The sea spin can be traced over to give a reduced density matrix, and it is shown that the resulting entanglement ... More
A New Contribution To The Proton Spin Crisis: Non-Zero Boundary Surface Term Due To Confinement in QCDMay 08 2019The proton spin crisis still remains an unsolved problem in particle physics. It is suggested in the literature that the gauge invariant spin and orbital angular momentum of the quark and the gauge invariant total angular momentum of the gluon contribute ... More
Critical end points in (2+1)-flavor QCD with imaginary chemical potentialMay 08 2019We present here the results from an ongoing determination of the critical quark mass in simulations of (2+1)-flavor QCD with an imaginary chemical potential. Studies with unimproved actions found the existence of a critical quark mass value at which the ... More
Ab Inito Simulations of Light Nuclear Systems Using Eigenvector Continuation and Auxiliary Field Monte CarloMay 07 2019In this work, we discuss a new method for calculation of extremal eigenvectors and eigenvalues in systems or regions of parameter space where direct calculation is problematic. This technique relies on the analytic continuation of the power series expansion ... More
Holographic conformal transition and light scalarsMay 07 2019We present an holographic approach to strongly-coupled theories close to the conformal to non-conformal transition, trying to understand the presence of light scalars as recent lattice simulations seem to suggest. We find that the dilaton is always the ... More
$X(3872)$ as a four-quark state in a Dyson-Schwinger/Bethe-Salpeter approachMay 07 2019We generalise the framework of Dyson-Schwinger and Bethe-Salpeter equations for four-quark states to accommodate the case of unequal quark masses. As a first application, we consider the quantum numbers $I(J^{PC})=0(1^{++})$ of the $X(3872)$ and study ... More
Scattering phase shifts and mixing angles for an arbitrary number of coupled channels on the latticeMay 07 2019We present a lattice method for determining scattering phase shifts and mixing angles for the case of an arbitrary number of coupled channels. Previous lattice studies were restricted to mixing of up to two partial waves for scattering of two spin-$1/2$ ... More
Charmonium-nucleon interactions from 2+1 flavor lattice QCDMay 07 2019The charmonium-nucleon interaction is studied by the time-dependent HAL QCD method. We use a larger lattice volume and the relativistic heavy quark action for charm quark to obtain less systematic errors than those in our previous study. As a result, ... More
Magnetized baryons and the QCD phase diagram: NJL model meets the latticeMay 06 2019We determine the baryon spectrum of 1 + 1 + 1-flavor QCD in the presence of strong background magnetic fields using lattice simulations at physical quark masses for the first time. Our results show a splitting within multiplets according to the electric ... More
The flavor dependence of $m_\varrho / f_π$May 06 2019May 25 2019We calculate the $m_\varrho / f_\pi$ ratio in the chiral and continuum limit for $SU(3)$ gauge theory coupled to $N_f = 2,3,4,5,6$ fermions in the fundamental representation. Keeping all systematic effects under full control we find no statistically significant ... More
The flavor dependence of $m_\varrho / f_π$May 06 2019We calculate the $m_\varrho / f_\pi$ ratio in the chiral and continuum limit for $SU(3)$ gauge theory coupled to $N_f = 2,3,4,5,6$ fermions in the fundamental representation. Keeping all systematic effects under full control we find no statistically significant ... More
Nucleon isovector charges and twist-2 matrix elements with $N_f=2+1$ dynamical Wilson quarksMay 03 2019We present results from a lattice QCD study of nucleon matrix elements at zero momentum transfer for local and twist-2 isovector operator insertions. Computations are performed on gauge ensembles with non-perturbatively improved $N_f=2+1$ Wilson fermions, ... More
Screening without screening: baryon energy at high baryon densityMay 02 2019We compute the Coulomb interaction energy of dense sets of static quarks in a compact volume (much smaller than the lattice volume) containing one quark per lattice site. The quark color charges are combined into either a set of three-quark nucleon states, ... More
Resonance enhancement of Charm CPMay 02 2019May 09 2019It is suggested that a nearby $0^{++}$ resonance, $f_0$(1710) of mass $m_f=1723 MeV$ and width $\Gamma=139$ MeV is playing a significant role in efficiently providing the strong (CP-conserving) and weak (CP-odd) phase simultaneously in the recently observed ... More
Results and techniques for higher order calculations within the gradient flow formalismMay 02 2019We describe in detail the implementation of a systematic perturbative approach to observables in the QCD gradient-flow formalism. This includes a collection of all relevant Feynman rules of the five-dimensional field theory and the composite operators ... More
Removing Staggered Fermionic Matter in $U(N)$ and $SU(N)$ Lattice Gauge TheoriesMay 02 2019Gauge theories, through the local symmetry which is in their core, exhibit many local constraints, that must be taken care of and addressed in any calculation. In the Hamiltonian picture this is phrased through the Gauss laws, local constraints that restrict ... More
Tensor representations of lattice vertices from hypercubic symmetryMay 02 2019We present a symmetry-based method for obtaining suitable tensor descriptions of lattice vertex functions without spinor components. The approach is based on finding the polynomial functions of vertex momenta, which satisfy the appropriate tensor transformation ... More
Absence of chiral symmetry breaking in Thirring models in 1+2 dimensionsApr 30 2019The Thirring model is an interacting fermion theory with current-current interaction. The model in $1+2$ dimensions has applications in condensed-matter physics to describe the electronic excitations of Dirac materials. Earlier investigations with Schwinger-Dyson ... More
Absence of chiral symmetry breaking in Thirring models in 1+2 dimensionsApr 30 2019May 22 2019The Thirring model is an interacting fermion theory with current-current interaction. The model in $1+2$ dimensions has applications in condensed-matter physics to describe the electronic excitations of Dirac materials. Earlier investigations with Schwinger-Dyson ... More
A safe CFT at large chargeApr 30 2019We apply the large-charge limit to the first known example of a four-dimensional gauge-Yukawa theory featuring an ultraviolet interacting fixed point in all couplings. We determine the energy of the ground state in presence of large fixed global charges ... More
Meson-meson scattering in two-dimensional QCDApr 30 2019We extend the formalism pioneered by Callan, Coote and Gross to investigate the meson-meson scattering within the framework of 't Hooft model, i.e., the two-dimensional QCD in the $N_c\to \infty$ limit. We derive the analytic expressions for various two-body ... More
Stochastic Renormalization Group and Gradient FlowApr 30 2019A non-perturbative and continuous definition of RG transformations as stochastic processes is proposed, inspired by the observation that the functional RG equations for effective Boltzmann factors may be interpreted as Fokker-Planck equations. The result ... More
An overview of Quantum Cellular AutomataApr 29 2019Quantum cellular automata consist in arrays of identical finite-dimensional quantum systems, evolving in discrete-time steps by iterating a unitary operator G. Moreover the global evolution G is required to be causal (it propagates information at a bounded ... More