Related papers: On the possibility to observe higher $n^3D_1$ bott…
In this paper we study the reaction $e^+ e^- \to (D^* \bar D^*)^{\pm} \pi^{\mp}$ in which the BESIII collaboration has claimed the existence of a $1^+$ resonance, named $Z_c(4025)$, in the $D^*\bar D^*$ invariant mass spectrum with a mass…
We propose that the $X(3915)$ observed in the $J/\psi\,\omega$ channel is the same state as the $\chi_{c2}(3930)$, and the $X(3960)$, observed in the $D_s^+D_s^-$ channel, is an $S$-wave $D_s^+ D_s^-$ hadronic molecule. In addition, the…
The electric dipole moment of the muon (d_mu) is evaluated in supersymmetric models with nonzero neutrino masses and large neutrino mixing arising from the seesaw mechanism. It is found that if the seesaw mechanism is embedded in the…
We use a near-threshold parameterization with explicit inclusion of the Castillejo-Dalitz-Dyson poles, which is more general than the effective range expansion, to study the bottomonium-like states $Z_b(10610)$ and $Z_b(10650)$. In terms of…
We study the Upsilon(3S,2S)->eta Upsilon(1S) and Upsilon(3S,2S)->pi+pi- Upsilon(1S) transitions with 122 million Upsilon(3S) and 100 million Upsilon(2S) mesons collected by the BaBar detector at the PEP-II asymmetric energy e+e- collider.…
The hint of a pseudoscalar toponium state at the Large Hadron Collider (LHC) opens a new avenue for studying a novel class of QCD (quasi-)bound states with comparable formation and decay times. Compared with charmonium and bottomonium,…
The process $e^{+}e^{-}\rightarrow D_{s}^{\ast+}D_{s}^{\ast-}$ is studied with a semi-inclusive method using data samples at center-of-mass energies from threshold to 4.95 GeV collected with the BESIII detector operating at the Beijing…
Agreement with the measured electronic widths of the $\psi(4040)$, $\psi(4415)$, and $\Upsilon (11019)$ resonances is shown to be reached if two effects are taken into account: a flattening of the confining potential at large distances and…
We discuss the possible production and discovery channels in $e^+e^-$ and $pp$ machines of the $X_b$, the bottomonium counterpart of $X(3872)$ and the putative isoscalar analogue of the charged bottomonium-like states $Z_b$ discovered by…
The energies and widths of $DNN$ quasi-bound states with isospin I=1/2 are evaluated in two methods, the fixed center approximation to the Faddeev equation and the variational method approach to the effective one-channel Hamiltonian. The…
Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the $B_q$ (q=n,s) mesons are shown to be in full agreement with experiment if a universal…
The feasibility of observing ditauonium, the bound state of two tau leptons, at $e^+e^-$ colliders (BES III at $\sqrt{s} = 3.78$ GeV, Belle II at $\sqrt{s} = 10.6$ GeV, a future super tau-charm factory (STCF) at $\sqrt{s} \approx…
Charmonium states can decay into pairs of $D$ and $\overline{D}$ mesons if their masses are above the allowed decay thresholds. In general $c\bar{c}$ states near threshold will also undergo mixing with $D\overline{D}$ molecular (or…
We calculated the energy and the size of the three-deuteron muonic molecule (3d 2e^- \mu^-) = D_3 \mu. It turns out that this system possesses two equilibrium positions, one at distances typical for muonic molecules and a second one at the…
We review recent studies on exotic states at the Belle experiment. The results include: (1) The measurement of the cross sections of $\gamma \gamma \to \omega \phi$, $\phi\phi$, and $\omega \omega$ for masses that range from threshold to…
The observed cross sections for $e^+e^-\rightarrow \mu^+\mu^-$ at energies from 3.8 to 4.6 GeV are measured using data samples taken with the BESIII detector operated at the BEPCII collider. We measure the muonic widths and determine the…
The contribution of the low-lying nucleon resonances $P_{33}(1232)$, $P_{11}(1440)$ $D_{13}(1520)$ and $S_{11}(1535)$ to the invariant mass spectra of di-electrons stemming from the exclusive processes $pp\to pp e^+e^-$ and $pn\to pn…
We perform a theoretical study of the decay process $\Upsilon \to D^{-} \bar{B}^{0} D_s^{+}$ in search of the doubly heavy tetraquark states $T_{bc\bar{s}}$ with quark content $bc\bar{s}\bar{d}$. These $T_{bc\bar{s}}$ states are assumed to…
Recoil correction appears at $O(\frac{1}{M})$, which turns out to be very essential for the hadronic molecules with heavy flavor. In the past, we always thought that the recoil corrections were unfavorable to the formation of the molecular…
We examine the electronic width ratios of Upsilon resonances below the BBbar threshold by means of an effective (Cornell-type) QCD potential incorporating 1/m_b corrections obtained from a prior fit to the bottomonium spectrum. From our…