Using a data sample of \left(2.712\pm 0.014\right)\times {10}^{9}\psi \left(3686\right)events collected at a center-of-mass energy of \sqrt{s}=3.686GeV by the BESIII detector, we search for the rare electromagnetic Dalitz decays {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi (J=0,1,2) via the radiative transitions \psi \left(3686\right)\rightarrow \gamma {\chi }_{cJ}. No statistically significant {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi signals are observed. The upper limits on the branching fractions of {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi (J=0,1,2), excluding the \phi \rightarrow e^{+}e^{-}resonance contribution, are set to be 2.4\times {10}^{-7}, 6.7\times {10}^{-7}, and 4.1\times {10}^{-7}at the 90% confidence level, respectively. This is the first search for the electromagnetic Dalitz transitions of the P-wave charmonium {\chi }_{cJ}states to a light vector meson.
Search for the electromagnetic Dalitz decays 𝜒𝑐𝐽 →𝑒+𝑒−𝜙
Garzia, I.;Melendi, F. M.;
2026
Abstract
Using a data sample of \left(2.712\pm 0.014\right)\times {10}^{9}\psi \left(3686\right)events collected at a center-of-mass energy of \sqrt{s}=3.686GeV by the BESIII detector, we search for the rare electromagnetic Dalitz decays {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi (J=0,1,2) via the radiative transitions \psi \left(3686\right)\rightarrow \gamma {\chi }_{cJ}. No statistically significant {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi signals are observed. The upper limits on the branching fractions of {\chi }_{cJ}\rightarrow e^{+}e^{-}\phi (J=0,1,2), excluding the \phi \rightarrow e^{+}e^{-}resonance contribution, are set to be 2.4\times {10}^{-7}, 6.7\times {10}^{-7}, and 4.1\times {10}^{-7}at the 90% confidence level, respectively. This is the first search for the electromagnetic Dalitz transitions of the P-wave charmonium {\chi }_{cJ}states to a light vector meson.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
