Observation of Two NewN*Resonances in the Decayψ(3686)→pp¯π

Abstract

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109) MeV/c2 and width of 340(-30-58)(+30+110) MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34) MeV/c2 and width of 250(-24-21)(+14+69) MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Analysis of the hidden-bottom tetraquark mass spectrum with the QCD sum rules

“…[22], we study the two-body strong decays Z ± c (3900) → J/ψπ ± , η c ρ ± , (DD * ) ± with the QCD sum rules in details. We take into account both the connected and disconnected Feynman diagrams, and pay special attentions to matching the hadron side with the QCD side of the correlation functions to obtain solid duality, the predicted width Γ Zc(3900) = 54.2 ± 29.8 MeV is consistent with the experimental data [16,17], and supports assigning the Z ± c (3900) to be the diquark-antidiquark type axialvector tetraquark state [20]. In Ref.…”

“…In 2013, the BESIII collaboration (also the Belle collaboration) observed the Z ± c (3900) in the π ± J/ψ mass spectrum [16,17]. Later, the BESIII collaboration observed the Z ± c (4025) near the (D * D * ) ± threshold [18], and the Z ± c (4020) in the π ± h c mass spectrum [19].…”

Evidence for Exotic Hadron Contributions toΛb0→J/ψpπ−Decays

“…Their absence could arise from decreased couplings of the higher N Ã excitations to the simple production and decay channels [19] and possibly also from experimental difficulties in identifying broad resonances and insufficient statistics at high masses in scattering experiments. The possibility of high-mass, low-spin N Ã states is explored by including two very significant, but unconfirmed, resonances claimed by the BESIII Collaboration in ψð2SÞ → ppπ 0 decays [20]: 1=2 þ Nð2300Þ and 5=2 − Nð2570Þ. A nonresonant J P ¼ 1=2 − pπ − Swave component is also included.…”

Analysis of the Axialvector Doubly Heavy Tetraquark States with QCD Sum Rules

“…In 2013, the BESIII (also the Belle) collaboration observed the Z ± c (3900) in the π ± J/ψ invariant mass spectrum [19,20]. Furthermore, the BESIII collaboration observed the Z ± c (4025) near the (D * D * ) ± threshold [21], and observed the Z ± c (4020) in the π ± h c invariant mass spectrum [22].…”