scholarly journals Near threshold enhancement of thepp¯mass spectrum inJ/Ψdecay

2005 ◽  
Vol 71 (5) ◽  
Author(s):  
A. Sibirtsev ◽  
J. Haidenbauer ◽  
S. Krewald ◽  
Ulf-G. Meißner ◽  
A. W. Thomas
2011 ◽  
Vol 02 ◽  
pp. 183-187
Author(s):  
◽  
Y. CHEN

Several measurements on light hadron spectroscopy have been achieved with Beijing Spectrometry III (BESIII). BESII results such as a near threshold enhancement on the [Formula: see text] invariants mass spectrum namely X(1860) and a resonance X(1835) have been confirmed with 225 million J/ψ data accumulated from June 12, 2009 to July 28, 2009. Along with some other preliminary BESIII results including observations of X(1870), X(2120) and X(2370); the first direct measurement of a0(980)/f0(980) mixing; and an improved measurement on the matrix element of decay η′ → ππη have been reported at the 4th international workshop on charm physics.


2021 ◽  
Vol 104 (5) ◽  
Author(s):  
M. Ablikim ◽  
M. N. Achasov ◽  
P. Adlarson ◽  
S. Ahmed ◽  
M. Albrecht ◽  
...  

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1985-1989 ◽  
Author(s):  
◽  
HONGXUN YANG

We observe a narrow enhancement near 2mp in the invariant mass spectrum of [Formula: see text] pairs from radiative [Formula: see text] decays. In the case of S-wave fit, the peak mass is below 2mp at [Formula: see text] and the total width is Γ<30MeV at the 90% confidence level. And we also find near-threshold enhancement in the invariant mass spectrum of [Formula: see text] in [Formula: see text] decays. The mass is m=2075±12(stat)±5(syst)MeV and width is Γ=90±35(stat)±9(syst)MeV. A [Formula: see text] near-threshold enhancement is also studied and it has m=1.50~1.65GeV, Γ=70~110MeV with [Formula: see text].


2003 ◽  
Vol 91 (2) ◽  
Author(s):  
J. Z. Bai ◽  
Y. Ban ◽  
J. G. Bian ◽  
X. Cai ◽  
J. F. Chang ◽  
...  

2010 ◽  
Vol 692 (2) ◽  
pp. 136-142 ◽  
Author(s):  
G.Y. Chen ◽  
H.R. Dong ◽  
J.P. Ma

2007 ◽  
Vol 22 (02n03) ◽  
pp. 617-620 ◽  
Author(s):  
◽  
O. Khakimova ◽  
M. Bashkanov ◽  
T. Skorodko ◽  
C. Bargholtz ◽  
...  

The reaction pn → dπ0π0 constitutes the most fundamental system for the study of the ABC effect - a puzzling threshold enhancement in the ππ invariant mass spectrum of the ππ system in double-pionic fusion to nuclear bound states. The first exclusive measurements of this reaction have now been carried out at CELSIUS-WASA. They exhibit a striking low-mass enhancement in the ππ invariant mass spectrum, prove it to be a σ-channel phenomenon and falsify conventional theoretical models, which predict an associated high-mass enhancement not present in the new exclusive data. In the kinematically complete data sample we observe a ΔΔ excitation, where the interaction between the two Δ obviously plays a crucial role for the generation of the ππ low-mass enhancement.


2007 ◽  
Vol 76 (3) ◽  
Author(s):  
C. Hanhart ◽  
Yu. S. Kalashnikova ◽  
A. E. Kudryavtsev ◽  
A. V. Nefediev

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