TY - JOUR

T1 - Observation of Significant Flavor-SU(3) Breaking in the Kaon Wave Function at 12

AU - BESIII Collaboration

AU - Ablikim, M.

AU - Achasov, M. n.

AU - Николаев, Иван Борисович

AU - Мучной, Николай Юрьевич

PY - 2024/3/25

Y1 - 2024/3/25

N2 - We present cross sections for the reaction e^{+}e^{-}→K_{S}^{0}K_{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_{π}^{2}/f_{K}^{2}, where F(π^{±}) and F(K^{±}) are the form factors, and f_{π} and f_{K} are the decay constants of charged pions and kaons, respectively. We also observe a significant signal for the charmless decay ψ(3770)→K_{S}^{0}K_{L}^{0} for the first time. Within a 1σ contour of the likelihood value, the branching fraction for ψ(3770)→K_{S}^{0}K_{L}^{0} is determined to be B=(2.63_{-1.59}^{+1.40})×10^{-5}, and the relative phase between the continuum and ψ(3770) amplitudes is ϕ=(-0.39_{-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.

AB - We present cross sections for the reaction e^{+}e^{-}→K_{S}^{0}K_{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_{π}^{2}/f_{K}^{2}, where F(π^{±}) and F(K^{±}) are the form factors, and f_{π} and f_{K} are the decay constants of charged pions and kaons, respectively. We also observe a significant signal for the charmless decay ψ(3770)→K_{S}^{0}K_{L}^{0} for the first time. Within a 1σ contour of the likelihood value, the branching fraction for ψ(3770)→K_{S}^{0}K_{L}^{0} is determined to be B=(2.63_{-1.59}^{+1.40})×10^{-5}, and the relative phase between the continuum and ψ(3770) amplitudes is ϕ=(-0.39_{-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.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85188666391&origin=inward&txGid=ff88f9f94c37bee6cf48740f3e218d35

UR - https://pubmed.ncbi.nlm.nih.gov/38613263/

UR - https://www.mendeley.com/catalogue/889dca3a-44ff-3493-9cfc-22de6fad8ddd/

U2 - 10.1103/PhysRevLett.132.131901

DO - 10.1103/PhysRevLett.132.131901

M3 - Article

C2 - 38613263

VL - 132

SP - 131901

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 13

M1 - 131901

ER -