Related papers: Tetraquark interpretation of $e^+ e^- \to \Upsilon…
We study the process $e^+e^-\to J/\psi\pi^{+}\pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and…
Evidence for a narrow baryon state at 1528 +- 2.6(stat) +- 2.1(syst) MeV is presented in quasi-real photoproduction on a deuterium target through the decay channel p,K0 to p,pi+,pi-. The statistical significance of the peak in the p,K0…
We have studied the masse spectra for the $cc\bar{b}\bar{b}$/$bb\bar{c}\bar{c}$ tetraquark states with quantum numbers $J^{P}=0^{\pm},1^{\pm}$, and $2^{+}$. We systematically construct the interpolating currents with various spin-parity…
We report the observation of two resonance-like structures in the $\pi^+ \chi_{c1}$ invariant mass distribution near 4.1 GeV in exclusive $B\to K\pi^+\chi_{c1}$ decays. A detailed Dalitz-plot analysis demonstrates that these structures…
We search for the charmless B^0 decay with final state particles p Lambdabar pi^- gamma using the full data sample that contains 772 * 10^6 B Bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB…
Very recently, the LHCb Collaboration observed distinct structures with the $cc\bar{c}\bar{c}$ in the $J/\Psi$-pair mass spectrum. In this work, we construct four scalar ($J^{PC} = 0^{++}$) $[8_c]_{Q\bar{Q^\prime}}\otimes [8_c]_{Q^\prime…
Angular and energy distributions for leptons and bottom quarks in the process e+e- --> t tbar --> l/b ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the…
Using a data sample of $772 \times 10^6$ BB pairs collected on the ${\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we report the observations of $B^0\to p{\bar p}\pi^+\pi^-$ and $B^+ \to…
We report the first observation of the processes $e^+e^-\to\Upsilon(\rm 1S,2S)\eta$ at $\sqrt{s}=10.866$~GeV with a $10.2\sigma$ and $16.5\sigma$ significance respectively. The measured Born cross sections are $\sigma(e^+e^- \to…
We study the tetraquark states with I^G J^{PC}=1^- 1^{-+} in the QCD sum rule. After exhausting all possible flavor structures, we analyses both the SVZ and finite energy sum rules. Both approaches lead to a mass around 1.6 GeV for the…
We report e+e- --> b anti-b cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the PEP-II e+e- collider. A total relative error of about 5% is reached in more than three…
An optimal-observable analysis of the angular and energy distributions of the leptons and bottom quarks in the process e+e- --> tt-bar --> l^{+-}/b(b-bar)... has been performed in order to measure the most general top-quark couplings to…
We report the first measurement of the exclusive cross sections $e^+e^-\to B\bar{B}$, $e^+e^-\to B\bar{B}^*$, and $e^+e^-\to B^*\bar{B}^*$ in the energy range from 10.63 GeV to 11.02 GeV. The $B$ mesons are fully reconstructed in a large…
Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESIII detector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 $\rm fb^{-1}$, the process…
We search for the doubly charmed baryonic decay $\bar{B}^0\to\Lambda_c^+\bar{\Lambda}_c^-$, in a data sample of $520\times10^6$ $B{\bar B}$ events accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric…
The mass and meson-current coupling of the diquark-antidiquark states with the quantum numbers $J^{P}=0^{+}$ and quark contents $Z_{q}=[cq][\bar {b} \bar q ]$ and $Z_{s}=[cs][\bar {b} \bar s]$ are calculated using two-point QCD sum rule…
Decays of the Y(5S) resonance to channels with B^+ and B^0 mesons are studied using a 23.6 fb^-1 data sample collected on the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. The fully reconstructed…
We report results of a search for the invisible decay of the Upsilon(1S) via the Upsilon(3S)->pi+pi-Upsilon(1S) transition using a data sample of 2.9 fb^{-1} at the Upsilon(3S) resonance. The data were collected with the Belle detector at…
The BABAR experiment has discovered a new narrow state, D^*_{sJ}(2317)^+, near 2.32 GeV in the inclusive D_s^+ pi^0 invariant mass distribution from e^+e^- annihilation data at energies near 10.6 GeV. The same experiment has also shown…
Recently, Belle Collaboration reported a new exotic state $Y(4620)$ with mass at 4625.9 MeV in the positronium annihilation process. Inspired by experiment, we study the tetraquark system $c\bar{s}s\bar{c}$ with quantum numbers…