In:
The European Physical Journal C, Springer Science and Business Media LLC, Vol. 80, No. 8 ( 2020-08)
Kurzfassung:
Using a sample of $$1.31\times 10^{9} ~J/\psi $$ 1.31 × 10 9 J / ψ events collected with the BESIII detector, we perform a study of $$J/\psi \rightarrow \gamma K{\bar{K}}\eta '$$ J / ψ → γ K K ¯ η ′ . X (2370) is observed in the $$K{\bar{K}}\eta '$$ K K ¯ η ′ invariant-mass distribution with a statistical significance of $$8.3\sigma $$ 8.3 σ . Its resonance parameters are measured to be $$M=2341.6\pm 6.5 \, \text {(stat.)} \pm 5.7 \, \text {(syst.)}~ \hbox {MeV}/c^{2}$$ M = 2341.6 ± 6.5 (stat.) ± 5.7 (syst.) MeV / c 2 and $$\Gamma = 117\pm 10 \, \text {(stat.)}\pm 8 \, \text {(syst.)}~\hbox {MeV}$$ Γ = 117 ± 10 (stat.) ± 8 (syst.) MeV . The product branching fractions for $$J/\psi \rightarrow \gamma X(2370),X(2370)\rightarrow K^{+}K^{-}\eta '$$ J / ψ → γ X ( 2370 ) , X ( 2370 ) → K + K - η ′ and $$J/\psi \rightarrow \gamma X(2370),X(2370)\rightarrow K_{S}^{0}K_{S}^{0}\eta '$$ J / ψ → γ X ( 2370 ) , X ( 2370 ) → K S 0 K S 0 η ′ are determined to be $$(1.79\pm 0.23\, \text {(stat.)}\pm 0.65\,\text {(syst.)})\times 10^{-5}$$ ( 1.79 ± 0.23 (stat.) ± 0.65 (syst.) ) × 10 - 5 and $$(1.18\pm 0.32\, \text {(stat.)}\pm 0.39\, \text {(syst.)})\times 10^{-5}$$ ( 1.18 ± 0.32 (stat.) ± 0.39 (syst.) ) × 10 - 5 , respectively. No evident signal for X (2120) is observed in the $$K{\bar{K}}\eta '$$ K K ¯ η ′ invariant-mass distribution. The upper limits for the product branching fractions of $${\mathcal {B}}(J/\psi \rightarrow \gamma X(2120)\rightarrow \gamma K^{+} K^{-} \eta ')$$ B ( J / ψ → γ X ( 2120 ) → γ K + K - η ′ ) and $${\mathcal {B}}(J/\psi \rightarrow \gamma X(2120)\rightarrow \gamma K_{S}^{0} K_{S}^{0} \eta ')$$ B ( J / ψ → γ X ( 2120 ) → γ K S 0 K S 0 η ′ ) are determined to be $$1.49\times 10^{-5}$$ 1.49 × 10 - 5 and $$6.38\times 10^{-6}$$ 6.38 × 10 - 6 at the 90% confidence level, respectively.
Materialart:
Online-Ressource
ISSN:
1434-6044
,
1434-6052
DOI:
10.1140/epjc/s10052-020-8078-4
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2020
ZDB Id:
1397769-6
ZDB Id:
1459069-4
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