Publication Date:
2020-08-01
Description:
Using a sample of $$1.31imes 10^{9} ~J/psi $$1.31×109J/ψ events collected with the BESIII detector, we perform a study of $$J/psi
ightarrow gamma K{ ar{K}}eta '$$J/ψ→γKK¯η′. X(2370) is observed in the $$K{ ar{K}}eta '$$KK¯η′ invariant-mass distribution with a statistical significance of $$8.3sigma $$8.3σ. Its resonance parameters are measured to be $$M=2341.6pm 6.5 , ext {(stat.)} pm 5.7 , ext {(syst.)}~ hbox {MeV}/c^{2}$$M=2341.6±6.5(stat.)±5.7(syst.)MeV/c2 and $$Gamma = 117pm 10 , ext {(stat.)}pm 8 , ext {(syst.)}~hbox {MeV}$$Γ=117±10(stat.)±8(syst.)MeV. The product branching fractions for $$J/psi
ightarrow gamma X(2370),X(2370)
ightarrow K^{+}K^{-}eta '$$J/ψ→γX(2370),X(2370)→K+K-η′ and $$J/psi
ightarrow gamma X(2370),X(2370)
ightarrow K_{S}^{0}K_{S}^{0}eta '$$J/ψ→γX(2370),X(2370)→KS0KS0η′ are determined to be $$(1.79pm 0.23, ext {(stat.)}pm 0.65,ext {(syst.)})imes 10^{-5}$$(1.79±0.23(stat.)±0.65(syst.))×10-5 and $$(1.18pm 0.32, ext {(stat.)}pm 0.39, ext {(syst.)})imes 10^{-5}$$(1.18±0.32(stat.)±0.39(syst.))×10-5, respectively. No evident signal for X(2120) is observed in the $$K{ ar{K}}eta '$$KK¯η′ invariant-mass distribution. The upper limits for the product branching fractions of $${mathcal {B}}(J/psi
ightarrow gamma X(2120)
ightarrow gamma K^{+} K^{-} eta ')$$B(J/ψ→γX(2120)→γK+K-η′) and $${mathcal {B}}(J/psi
ightarrow gamma X(2120)
ightarrow gamma K_{S}^{0} K_{S}^{0} eta ')$$B(J/ψ→γX(2120)→γKS0KS0η′) are determined to be $$1.49imes 10^{-5}$$1.49×10-5 and $$6.38imes 10^{-6}$$6.38×10-6 at the 90% confidence level, respectively.
Print ISSN:
1434-6044
Electronic ISSN:
1434-6052
Topics:
Physics
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