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Observation of Significant Flavor-SU(3) Breaking in the Kaon Wave Function at 12<Q^{2}<25 GeV^{2} and Discovery of the Charmless Decay ψ(3770)→K_{S}^{0}K_{L}^{0}.
- Source :
-
Physical review letters [Phys Rev Lett] 2024 Mar 29; Vol. 132 (13), pp. 131901. - Publication Year :
- 2024
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Abstract
- We present cross sections for the reaction e^{+}e^{-}→K&#95;{S}^{0}K&#95;{L}^{0} at center-of-mass energies ranging from 3.51 to 4.95 GeV using data samples collected in the BESIII experiment, corresponding to a total integrated luminosity of 26.5 fb^{-1}. The ratio of neutral-to-charged kaon form factors at large momentum transfers (12<Q^{2}<25 GeV^{2}) is determined to be 0.21±0.01, which indicates a small but significant effect of flavor-SU(3) breaking in the kaon wave function, and, consequently, excludes the possibility that flavor-SU(3) breaking is the primary reason for the strong experimental violation of the pQCD prediction |F(π^{±})|/|F(K^{±})|=f&#95;{π}^{2}/f&#95;{K}^{2}, where F(π^{±}) and F(K^{±}) are the form factors, and f&#95;{π} and f&#95;{K} are the decay constants of charged pions and kaons, respectively. We also observe a significant signal for the charmless decay ψ(3770)→K&#95;{S}^{0}K&#95;{L}^{0} for the first time. Within a 1σ contour of the likelihood value, the branching fraction for ψ(3770)→K&#95;{S}^{0}K&#95;{L}^{0} is determined to be B=(2.63&#95;{-1.59}^{+1.40})×10^{-5}, and the relative phase between the continuum and ψ(3770) amplitudes is ϕ=(-0.39&#95;{-0.10}^{+0.05})π. The branching fraction is in good agreement with the S- and D-wave charmonia mixing scheme proposed in the interpretation of the "ρπ puzzle" between J/ψ and ψ(3686) decays.
Details
- Language :
- English
- ISSN :
- 1079-7114
- Volume :
- 132
- Issue :
- 13
- Database :
- MEDLINE
- Journal :
- Physical review letters
- Publication Type :
- Academic Journal
- Accession number :
- 38613263
- Full Text :
- https://doi.org/10.1103/PhysRevLett.132.131901