Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userRecent Results on Hadron Spectroscopy from BESIII
121
0
0.0
(
0
)
Authors
Beijiang Liu
Ask ChatGPT about the research
No Arabic abstract
Hadron spectroscopy is one of the most important physics goals of BESIII. BESIII brings great opportunities to study the XYZ states of charmonium by directly producing the Y states up to 4.6 GeV. High statistics of charmonium decays collected at BESIII provide an excellent place for hunting gluonic excitations and studying the excited baryons. Recent results of light hadron spectroscopy and charmonium spectroscopy from BESIII will be reported.
rate research
Read More
BESIII experiment has collected about 20 fb$^{-1}$ luminosity data between $sqrt{s}=3.8$ and 4.7 GeV via $e^{+}e^{-}$ collision. In this talk, we present the recent $XYZ$ results at BESIII, including mass and width measurements of $Y(4220)$, search for $Y$ states with rare decay modes, isospin parity determination of $Z_{c}^{0}(3900)$ as well as the mass and width determination, and search for new decay modes of $X(3872)$.
Recent results on light hadron spectroscopy are reported, with special emphasis on the evidence for a narrow baryonic state decaying to Ks p and Ks pbar, compatible with the pentaquark state theta^+ observed by fixed target experiments. The data were collected with the ZEUS detector at HERA using an integrated luminosity of 121 pb^-1. The analyses were performed in the central rapidity region of inclusive deep inelastic scattering at an ep centre-of-mass energy of 300-318 GeV. Evidence for a narrow resonance in the Ks p and Ks pbar invariant mass spectrum is obtained, with mass 1521.5 pm 1.5(stat)^{+2.8}_{-1.7}(syst) and width consistent with the experimental resolution. If the Ks p part of the signal is identified with the strange pentaquark theta^+, the Ks pbar part is the first evidence for its antiparticle, thetabar^-. Supporting results on other light hadron resonances are also discussed.
Using 58 million $J/psi$ and 14 million $psi(2S)$ events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays $J/psi$ and $psi(2S) to Lambda bar{Lambda} pi^0$ and $Lambda bar{Lambda} eta$ are measured, and the decays of $J/psi$ and $psi(2S)$ to $n K^0_S bar{Lambda}+c.c.$ are observed and measured for the first time. Finally, $R$ measurement data taken with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV are fitted to determine resonance parameters of the high mass charmonium states, $psi(3770)$, $psi(4040)$, $psi(4160)$, and $psi(4415)$. The Beijing Electron Collider is being upgraded to a two-ring collider (BEPCII) with a design luminosity of $1 times 10^{33}$cm$^{-2}$ s$^{-1}$ at 3.89 GeV and will operate between 2 and 4.2 GeV in the center of mass. With this luminosity, the new BESIII detector will beable to collect, for example, 10 billion $J/psi$ events in one year of running. BEPCII and BESIII are currently nearing completion, and commissioning of both is expected to begin in mid-2008.
One of the basic motivations of the KLOE and KLOE-2 collaborations is the test of fundamental symmetries and the search for phenomena beyond the Standard Model via the hadronic and leptonic decays of ground-state mesons and via their production in the fusion of virtual gamma quanta exchanged between colliding electrons and positrons. This contribution includes brief description of results of recent analysis of the KLOE data aimed at (i) the search for the dark matter boson, (ii) determination of the hadronic and light-by-light contributions to the g-2 muon anomaly and (iii) tests of QCD anomalies.
Lattice QCD has matured to a degree where it is now possible to study excited hadrons as they truly appear in nature, as short-lived resonant enhancements decaying into multiple possible final states. Through variational analysis of matrices of correlation functions computed with large bases of interpolating fields it has proven possible to extract many excited state energy levels, and these can be used to constrain the hadron-hadron scattering amplitudes in which hadron resonances can be observed. Recent progress is illustrated with several examples including coupled-channel scattering in the $pi eta, Koverline{K}$ and $pipi, Koverline{K}, etaeta$ systems in which the $a_0, f_0$ scalar mesons appear.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
