paper

First observation of $I^_{c} (2595)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$ and $I^_{c} (2625)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$

arXiv:2503.21413 · doi:10.1007/JHEP08(2025)065

Abstract

By analysing $e^{+} e^{-}$ annihilation data corresponding to an integrated luminosity of 368.48~pb $^{- 1}$ collected at the centre-of-mass energies of $s = 4.918$ and $4.951$ ~GeV with the BESIII detector, we report the first observation of $I^_{c} (2595)^{+}$ and $I^_{c} (2625)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$ with statistical significances of 7.9 $I ¨ $ and 11.8 $I ¨ $ , respectively. The branching fractions of $I^_{c} (2595)^{+}$ and $I^_{c} (2625)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$ are measured to be $(59.5 \pm 11. 1_{stat.} \pm 7. 9_{syst.}) %$ and $(41.0 \pm 5. 2_{stat.} \pm 3. 3_{syst.}) %$ , respectively. The absolute branching fraction of $I^_{c} (2595)^{+}$ is consistent with the expectation of the mechanism referred to as the threshold effect, proposed for the strong decays of $I^_{c} (2595)^{+}$ within uncertainty.

20 pages, 4 figures

First observation of I^c​(2595)+→I^c+​I¨0I¨0 and I^c​(2625)+→I^c+​I¨0I¨0

Abstract

First observation of $I^_{c} (2595)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$ and $I^_{c} (2625)^{+} \to I^_{c}^{+} I ¨ ^{0} I ¨ ^{0}$