Related papers: The $Y(4230)$ as a $D_1 \bar{D}$ molecule
We use QCD sum rules to study the recently observed resonance-like structures in the $\pi^+\chi_{c1}$ mass distribution, $Z_1^+(4050)$ and $Z_2^+(4250)$, considered as $D^{*+}\bar{D}^{*0}$ and $D_1^+\bar{D}^0+ D^+\bar{D}_1^0$ molecules with…
We study the hadronic molecular states with the quark content $bc\bar{s}\bar{q}$ by investigating the interactions of the $\bar{B}_s D$, $\bar{B} D_s$, $\bar{B}_s^* D$, $\bar{B}^* D_s$, $\bar{B}_s D^*$, $\bar{B} D_s^*$, $\bar{B}_s^* D^*$,…
In this work, we construct the color-singlet-color-singlet type currents to study the masses and pole residues of charm-strange tetraquark states and their bottom analogs with $J^P$ = $0^+$ and $1^+$ by using two-point QCD sum rules, where…
In this work, the $S$- and $P$-wave $\bar{D}^\ast K^\ast$ interactions are studied in a coupled-channel formalism to understand the recently observed $X_0(2900)$ and $X_1(2900)$ at LHCb. The experimental event distributions can be well…
Several charmonium-like states above $D\bar{D}$ threshold have been discovered at the Belle and BABAR B-factories. Some of these states are produced via Initial State Radiation (e.g. Y(4260) and Y(4350)), and some are observed in B-meson…
Recently, the BESIII Collaboration reported a resonance $Y(2040)$ with $M=2034\pm13\pm9$ MeV and $\Gamma=234\pm30\pm25$ MeV in the process of $e^+e^-\rightarrow\omega\pi^0$. In addition, new measurements with much higher precision for the…
In this article, we choose the $[sc]_P[\bar{s}\bar{c}]_A-[sc]_A[\bar{s}\bar{c}]_P$ type tetraquark current to study the hadronic coupling constants in the strong decays $Y(4660)\to J/\psi f_0(980)$, $\eta_c \phi(1020)$,…
The $Y(4260)$ has been one of the most puzzling pieces among the so-called $XYZ$ states. In this paper, we try to gain insights into the structure of the $Y(4260)$ from the light-quark perspective. We study the dipion invariant mass…
We examine the status of charmonia like states by looking into the behaviour of the energy level differences and regularity in the behaviour of the leptonic decay widths of the excited charmonia states. The spectroscopic states are studied…
Since its discovery in 1977, the spin-parity of $\Xi(2030)$ has not been fully determined experimentally. The latest Particle Data Group (PDG) listing suggests it may be a baryon with $J=5/2$. Therefore, studying the mass spectrum and decay…
We demonstrate that the experimental information currently available for the Y(4660) is consistent with its being a f_0(980)psi' molecule. Possible experimental tests of our hypothesis are presented.
We have studied some possible four-quark and molecule contents of the X(3872) using double ratios of sum rules, which are more accurate than the usual simple ratios often used in the literature for getting the hadron masses. We found that…
We study hadronic molecules formed by a heavy meson and a nucleon, DN and D*N (BbarN and Bbar*N) systems. Respecting the heavy quark symmetry and chiral symmetry, we consider the DN-D*N (BbarN-Bbar*N$) mixing induced by the one boson…
We study the $P_{cs}(4459)^0$ recently observed by LHCb using the method of QCD sum rules. Our results support its interpretation as the $\bar D^* \Xi_c$ hadronic molecular state of either $J^P=1/2^-$ or $3/2^-$. Within the hadronic…
Experiments at the Juelich Cooler Synchrotron (COSY) have now found compelling evidence for a new resonant state in the two-baryon system with mass 2380 MeV and a width of 70 MeV. The structure, containing six valence quarks, constitutes a…
The Z^+(4430) observed by Belle is explained naturally as a threshold cusp in the D*(2010)Dbar_1(2420) system.
We present a study of the X(3940) state in the process e+e- -> J/psi D* Dbar. The X(3940) mass and width are measured to be (3942 +7 -6 +- 6)MeV/c^2 and Gamma=(37 + 26 - 15 +- 8 MeV. In the process e+e- -> J/psi D* D*bar we have observed…
In this work we study the $D^* \bar{D}^*$ current with QCD sum rules. We write the correlation function using the general current corresponding to the $D^* \bar{D}^*$ system and then use spin projectors to obtain the correlation function in…
The last two decades are marked by a renaissance in hadronic spectroscopy caused by the arrival of vast experimental information on exotic states in the spectrum of charmonium and bottomonium. Most of such states have properties at odds…
By assuming that Y(4260) either is a $D_1\bar{D}$ molecular state, or has sizeable couplings with $D_0 \bar{D}^*$ and $D_1^\prime \bar{D}$, we investigate several decay modes of Y(4260). Under the special kinematic configurations, triangle…