Study of the Semileptonic decay Λc+ to Λe+νe BESIII recently reported the study of the Cabibbo-favored Semileptonic (SL) decay Λc+ -> Λe+νe [Phys. Rev. Lett. 129, 231803 (2022)], with the largest Λc threshold data sets collected at the center-of-mass energy region between 4.6 GeV and 4.7 GeV.
Precision measurements of hyperon radiative decay Λ → nγ The BESIII collaboration has reported the first absolute branching fraction and decay asymmetry of Λ → nγ via J/ψ→ΛΛbar process with 10 billion J/ψ data. This is the first measurement of radiative hyperon decays at an electron-positron collider experiment. The measured value of the branching fraction with improved precision, is 5.6 standard deviations different from the PDG average value. The results have been published in Physics Review Letter [Phys. Rev. Lett. 129, 212002 (2022)].
Observation of an Isoscalar Resonance with Exotic J^PC=1^(-+) Quantum Numbers in J/ψ→γηη' The BESIII collaboration reported the observation of an isoscalar resonance with exotic JPC=1-+ quantum numbers. This research is published in Physical Review Letters [Phys. Rev. Lett. 129, 192002 (2022)], accompanied by a detailed companion paper in Physical Review D [Phys. Rev. D 106, 072012 (2022)]. This is an observation of a new category of hadronic matter, which is an important step forward in low energy QCD.
Observation of a charged scalar a0(1817)* in Charmed-strange meson Ds decay The BESIII Collaboration recently reported the observation of an a0-like state with mass of 1.817 GeV/c2 in DS decays with the data sets collected at the center-of-mass energy region between 4.178 GeV and 4.226 GeV. The paper has been published online in Physical Review Letter. [Phys. Rev. Lett. 129, 182001 (2022) ].
Observation of J/ψ Electromagnetic Dalitz Decays to X(1835), X(2120) and X(2370) BESIII recently reports the first observation of J/ψ Electromagnetic (EM) Dalitz decays to X(1835), X(2120) and X(2370) and the measurement of the transition form factor of J/ψ to X(1835). It has been published online in the Journal of Physical Review Letter on July 9, 2022 [Phys. Rev. Lett. 129 (2022) 022002].
The most precise measurements of the Lambda Decay Parameter The BESIII collaboration has presented the most precise measurements of CP asymmetry and decay parameters with entangled Λ-Λbar pairs. The results are published in the journal Physical Review Letters 129, 131801 (2022) on Sep. 22 2022.
First observation of the direct production of a non-vector state in e+e- annihilation The BESIII Collaboration has observed the direct production of an axial vector particle, χc1(1P), in electron-positron (e+e-) annihilation. The paper has been published in Physical Review Letters [Phy. Rev. Lett. 129 (2022) 122001]. This is the first experimental observation of the direct production of a non-vector state in e+e- annihilation process.
First evidence for the first neutral open-strange hidden-charm tetraquark state The BESIII Collaboration recently reported the evidence of a new exotic multi-quark state, namely Zcs(3985)0. It is the neutral partner of the charged tetraquark Zcs(3985)+ observed in 2021 at BESIII. This is the first candidate of the neutral hidden-charm tetraquark with non-zero strangeness, which marks a new milestone in exploration of the genuine properties of the family of the exotic multi-quark hadrons. The paper has been published in Physical Review Letters [Phy. Rev. Lett. 129 (2022) 112003].
Observation of resonance structures in e+ e- → π+ π- ψ2(3823) The BESIII experiment recently reported an observation of resonance structures in the e+ e-→π+ π- ψ2(3823) process, and also achieved the most precise mass measurement of theψ2(3823) state. These results have been published in Physical Review Letters [Phys. Rev. Lett. 129, 102003 (2022)].
Observation of the X(2600) state The BESIII Collaboration recently reported the observation of a new state, X(2600), using 10 billion Jpsi decay events. It was published online in the Journal of Physical Review Letter on July 19, 2022 [Phys. Rev. Lett. 129 (2022) 042001].