Conveners
Posters: On site
- Yuping GUO (Fudan University)
The world’s largest sample of $J/\psi$ events accumulated at the BESIII detector offers a unique opportunity to investigate $\eta$ and $\eta^′$ physics via two body $J/\psi$ radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in $\eta/\eta^′$ decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this...
Using $10.1 \times 10^9~ J/\psi$ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $\sqrt{s} = 3.097~\rm GeV$ and collected with the BESIII detector, we present a search for the rare semi-leptonic decay $J/\psi \to D^-e^+\nu_e + c.c.$ No excess of signal above background is observed, and an upper limit on the branching fraction $\mathcal{B}(J/\psi...
Based on analyzing $4.45~fb^{-1}$ data taken at seven center-of-mass energies ranging from 4.600 to $4.699~\rm GeV$ with the BESIII detector at the BEPCII collider, we measure the branching fractions for $\Lambda_c^+ \to \Sigma^+ + hadrons$ relative to $\Lambda_c^+ \to \Sigma^+ \pi^+ \pi^-$. By quoting the world average branching fraction of $\Lambda_c^+ \to \Sigma^+ \pi^+ \pi^-$, their...
With the worldly largest $\psi(2S)$ samples collected at BEESIII, systematic studies of the decays of $\eta_c(2S)$ are performed. As an example, the observation of the decay $\eta_c(2S) \to 3 (\pi^+ \pi^-)$ will be reported in this talk. Based on the 450M $\psi(2S)$ samples, the mass and width of $h_c$ are updated as well as the branching fraction of $\psi(2S) \to \pi^0 h_c$. In this talk,...
At BESIII, the lineshapes of $e^+e^- \to \phi \eta^\prime$, $\phi \eta$, $KK$, $\omega \pi^0$, $\eta \pi\pi$, $\omega \pi\pi$ are measured from 2.0 to $3.08~\rm GeV$, where resonant structures are observed in these processes. Multiple lineshapes of intermediate state are obtained by a partial wave analysis of $e^+e^- \to K^+ K^- \pi^0 \pi^0$, $K^+K^- \pi^0$ and the structures observed provide...
In this work, we interpret the newly $\eta_1(1855)$ resonance with exotic $J^{PC}=1^{-+}$ quantum numbers in the $I=0$ sector, reported by BESIII collaboration, as a dynamically generated state from the interaction between the lightest pseudoscalar mesons and vector mesons. The interaction is derived from the lowest order chiral Lagrangian from which the Weinberg-Tomozawa term is obtained,...
Based on a sample of $4.4 fb^{-1}$ of $e^+e^-$ annihilation data collected in the energy region between $4.6~\rm GeV$ and $4.7~\rm GeV$ with the BESIII detector at BEPCII, two singly Cabibbo-suppressed decays $\Lambda_c^+ \to \Sigma^0 K^+$ and $\Lambda_c^+ \to \Sigma^+ K_S^0$ are studied. New determinations of the BFs of $\Lambda_c \to \Sigma K$ decays, in particular the mode and $\Lambda_c^+...
Based on $4.4 fb^{-1}$ of $e^+e^-$ annihilation data collected in the energy region between $4.6~\rm GeV$ and $4.7~\rm GeV$ with the BESIII detector at the BEPCII collider, we search for semi-leptonic decays $\Lambda_c^+ \to \Lambda \pi^+ \pi^- e^+ \nu_e$ and $\Lambda_c^+ \to p K_S \pi^- e^+ \nu_e$, using double tag technique. The measurement of $\Lambda_c^+ \to \Lambda^* e^+ \nu_e$ is...
The isospin breaking and radiative decay widths of the positive-parity charm-strange mesons, $D^{∗}_{s0}$ and $D_{s1}$, and their predicted bottom-strange counterparts, $B^{∗}_{s0}$ and $B_{s1}$, as hadronic molecules are revisited. This is necessary, since the $B^{∗}_{s0}$ and $B_{s1}$ masses used in (Cleven et al., Eur Phys J A 50:149, 2014) were too small, in conflict with the heavy quark...
In the Standard Model, Flavor-changing-neutral-current (FCNC) in quark sector is predicted at loop level. In the lepton sector, the lepton-flavor-violation (LFV) was evident after the discovery of neutrino oscillation. In the SM, even considering the tiny masses and oscillation of neutrinos, the predicted decay rate for charged-lepton-flavor-violation (cLFV), such as muon-electron conversion,...
Based on $e^+e^-$ collision samples corresponding to an integrated luminosity of $4.4~ fb^{-1}$ collected with BESIII detector at center-of-mass energies between $4.6~\rm GeV$ to $4.7~\rm GeV$, the first partial wave analysis of the charmed baryonic decay $\Lambda_c^+ \to \Lambda \pi^+ \pi^0$ is performed. From the analysis results, the decays of $\Lambda_c^+ \to \Lambda \rho(770)^+$ and...
We investigate the process $B\to \bar{D}D_s \pi$ via several rescattering processes. It is shown that the triangle singularity (TS) peak around the $D^*K^*$ threshold generated from the $\chi_{c1}K^* D^*$ loop is relatively narrow, which may simulate the resonance-like structure $T_{c\bar{s}}(2900)$ recently observed by LHCb in the $D_s\pi$ spectrum. However, the TS peak around the $D_s^*\rho$...
We present a search for the lepton flavor violating decay $J/\psi \to e \mu$ using $8.998\times 10^9~ J/\psi$ events collected with the BESIII detector at the BEPCII $e^+e^-$ storage ring. No excess of signal above background is observed; we therefore set an upper limit on the branching fraction of $J/\psi \to e \mu < 4.5\times 10^{-9}$ at the 90% confidence level. Improving the previous best...
