Related papers: $D\bar{D}$ interactions are weak near threshold in…

We discuss a model-independent estimator of the likelihood of the compositeness of a shallow S-wave bound or virtual state. The approach is based on an extension of Weinberg's relations in Phys. Rev. 137, B672 (1965) and it relies only on…

I comment on a paper by Christoph Hanhart and Alexey Nefediev, published in Phys. Rev. D 106, 114003 (2022). The authors discuss the interpretation of mesons close to their lowest decay threshold and present a mechanism for the formation of…

The high-$T_c$ cuprates are possible candidates for d-wave superconductivity, with the Cooper pair wave function belonging to a non-trivial irreducible representation of the lattice point group. We argue that this d-wave symmetry is related…

We first extract the binding energy $\bar \Lambda$ and decay constants of the D wave heavy meson doublets $(1^{-},2^{-})$ and $(2^{-},3^{-})$ with QCD sum rule in the leading order of heavy quark effective theory. Then we study their pionic…

We propose an effective field theory incorporating light SU(3)-flavour and heavy quark spin symmetry to describe charmed meson-antimeson bound states. At lowest order the effective field theory entails a remarkable simplification: it only…

We perform the energy spectra calculating for the $S$-wave $\bar{Q}Q\bar{q}q$ (where $Q=c,b$ and $q=u,d,s$) system within two constituent quark models. The bound states of $B^*\bar{B}^*$ with $I(J^{PC})=1(0^{++}),~1(1^{+-}),~0(2^{++})$ and…

Motivated by the LHCb Collaboration's observation of a doubly charmed tetraquark state $T_{cc}(3875)$, we systematically investigate the existence of doubly charmed pentaquark states using the resonating group method based on the QDCSM…

In this work, we systematically investigate the pentaquark systems with quark contents $qqqq\bar{c}$ with the analyzed total spin and parity quantum numbers of $J^{P}=\frac{1}{2}^{-}$, $J^{P}=\frac{3}{2}^{-}$ and $J^{P}=\frac{5}{2}^{-}$, in…

We show that under a number of rather plausible assumptions QCD spectrum may contain a number of mesons which have not been predicted or observed. Such states will have the quantum numbers of two existing mesons and masses very close to the…

Lattice quantum chromodynamics is used to constrain the interactions of two octet baryons at the SU(3) flavor-symmetric point, with quark masses that are heavier than those in nature (equal to that of the physical strange quark mass and…

In this work, we investigate the SU(3) flavor symmetry, heavy quark spin symmetry and their breaking effects in the di-meson systems. We prove the existence of the $[\bar{D}_{s}^{*}D_{s}^{*}]^{0^{++}}$,…

With a quark level interaction, we give a unified description of the loosely bound molecular systems composed of the heavy flavor hadrons $(\bar{D},\bar{D}^*)$, $(\Lambda_c, \Sigma_c, \Sigma_c^*)$, and $(\Xi_c, \Xi_c^\prime,\Xi_c^*)$. Using…

We study the possibility that the scalar mesons exist as four-quark states. The energy shift of two pseudoscalar mesons as a function of spatial lattice size makes a distinction between bound states and scattering states of four-quark…

We present a lattice QCD calculation of the S-wave interactions between the spin-1/2 doubly charmed baryons ($\Xi_{cc},\Omega_{cc}$) and Goldstone bosons ($\pi,K,\bar{K}$) using the $N_f=2+1$ CLQCD ensembles with lattice spacing $a =…

We argue that due to isospin and U-spin invariance of strong low-energy interactions the S-wave scattering lengths a^0_0 and a^1_0 of bar-KN scattering with isospin I=0 and I = 1 satisfy the low-energy theorem a^0_0 + 3 a^1_0 = 0 valid to…

We present results for the low-lying spectrum of D and D_s mesons from a lattice QCD calculation on 2+1 flavor Clover-Wilson configurations generated by the PACS-CS collaboration. In particular S- and P-wave states of charmed and…

We consider production of overall neutral pairs consisting of heavy $D^{(*)}$ or $B^{(*)}$ meson and antimeson in the processes, where the pair can be created in an $S$-wave, such as $e^+e^- \to \pi^0 \, D^* \bar D^{(*)}$ and $e^+e^- \to…

Traditional dark matter models, eg. WIMPs, assume dark matter is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by Born approximation. Most direct detection…

We use lattice QCD to investigate the spectrum of the $\bar{b} \bar{b} u d$ four-quark system with quantum numbers $I(J^P) = 0(1^+)$. We use five different gauge-link ensembles with $2+1$ flavors of domain-wall fermions, including one at…

The LHCb Collaboration discovered a double-charm tetraquark $T_{cc}^{+}$ with a very small width. We investigate the $T_{cc}^{+}$ as a $DD^{*}$ molecule with $J^{P}=1^{+}$ in the framework of the one-boson-exchange potential model. The…