相关论文: I=0 scalar channel
Wilson Fermions with untwisted and twisted mass are widely used in lattice simulations. Therefore one important question is whether the twist angle and the lattice spacing affect the phase diagram. We briefly report on the study of the…
We first discuss the theoretical and phenomenological significance of the sigma meson ($\sigma$) in QCD. It is indicated that if the collective modes with the mass 500-600 MeV exists in the $I=J=0$ channel, various empirical facts in hadron…
The worldline representation of the one loop fermionic effective action is used to obtain the vertex operator for the pion and the sigma in QCD strings. The vertex operator of the scalar sigma is distinguished from that of the pseudo-scalar…
QCD-like theories provide testing grounds for truncations of functional equations at non-zero density, since comparisons with lattice results are possible due to the absence of the sign problem. As a first step towards such a comparison, we…
With sufficiently light up and down quarks the isovector ($a_0$) and isosinglet ($f_0$) scalar meson propagators are dominated at large distance by two-meson states. In the staggered fermion formulation of lattice quantum chromodynamics,…
Equal time, point to point correlation functions for spatially separated meson currents are calculated with respect to a variational construct for the ground state of QCD. Given such an ansatz we make no further approximations in the…
Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propagator. We first outline the basic algorithm used to compute a…
It is pointed out that the hadron spectroscopy should be a study of the structure of the QCD vacuum, low-energy elementary excitations on top of which are hadrons. Concentrating on the dynamical breaking of the chiral symmetry in the QCD…
The so far only known charmed non-strange scalar meson is dubbed as $D_0^*(2400)$ in the Review of Particle Physics. We show, within the framework of unitarized chiral perturbation theory, that there are in fact two $(I=1/2, J^P=0^+)$ poles…
We analyze the static QCD potential V_QCD(r) in the distance region 0.1 fm < r < 1 fm using perturbative QCD and OPE as basic theoretical tools. We assemble theoretical developments up to date and perform a solid and accurate analysis. The…
The purpose of this work is to study vector meson-octet baryon interactions with the aim to find dynamical generation of resonances in such systems. For this, we consider s-, t-, u-channel diagrams along with a contact interaction…
The chiral properties of the pseudoscalar mesons are studied numerically on a quenched $20^4$ lattice with the overlap fermion. We elucidate the role of the zero modes in the meson propagators, particularly that of the pseudoscalar meson.…
We investigate baryon-baryon interactions with strangeness $S=-2$ and isospin I=0 system from Lattice QCD. In order to solve this system, we prepare three types of baryon-baryon operators ($\Lambda-\Lambda$, $N-\Xi$ and $\Sigma-\Sigma$) for…
Experimentally, the doubly charm tetraquark channel $cc\bar q\bar q$ with $q\!=\!u,d$ features an exotic hadron, $T_{cc}$, with isospin $I\!=\!0$ near the $DD^*$ threshold, while no peak was observed for $I\!=\!1$. We present a lattice QCD…
The Carroll algebra is constructed as the $c\to0$ limit of the Poincare algebra and is associated to symmetries on generic null surfaces. In this paper, we begin investigations of Carrollian fermions or fermions defined on generic null…
The quark-level linear sigma model is revisited, in particular concerning the identification of the f_0(400-1200) (or \sigma(600)) scalar meson as the chiral partner of the pion. We demonstrate the predictive power of the linear sigma model…
We conduct a two-flavor ($N_f=2$) lattice QCD calculation of the elastic phase-shifts for pion-pion scattering in the scalar, isoscalar channel (the $\sigma$-meson). The calculation is performed for two quark masses corresponding to a pion…
We report on our progress in computing the excitation spectrum in Lattice QCD. We focus on the isospin 0, 1 and 2 channels using the stochastic LapH algorithm for the quark propagators. For the isospin-0 channel, a new glueball operator…
Following a model based on the $\rm{SU}(8)$ symmetry that treats heavy pseudo-scalars and heavy vector mesons on an equal footing, as required by heavy quark symmetry, we study the interaction of baryons and mesons in coupled channels…
Using conventional constituent-quark model, $I=1/2$ scalar $\kappa$, vector $K^\ast(892)$, and axial vector $K_1$ mesons are studied in the asqtad-improved staggered fermion with the wall-source and point-sink interpolators. The mass ratio…