The Ξ0ð−Þ b → Ξcð3055Þþð0Þ ð→ Dþð0Þ ΛÞπ− decay chains are observed, and the spin-parity of Ξcð3055Þþð0Þ baryons is determined for the first time. The measurement is performed using protonproton collision data at a center-of-mass energy of ffiffi s p ¼ 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1, recorded by the LHCb experiment between 2016 and 2018. The spin-parity of the Ξcð3055Þþð0Þ baryons is determined to be 3=2þ with a significance of more than 6.5σ (3.5σ) compared to all other tested hypotheses. The up-down asymmetries of the Ξ0ð−Þ b → Ξcð3055Þþð0Þ π− transitions are measured to be −0.92 0.10 0.05 (−0.92 0.16 0.22), consistent with maximal parity violation, where the first uncertainty is statistical and the second is systematic. These results support the hypothesis that the Ξcð3055Þþð0Þ baryons correspond to the first D-wave λ-mode excitation of the Ξc flavor triplet.
First Determination of the Spin-Parity of Ξc(3055)+,0 Baryons
De Angelis, C.;Dettori, F.;Fabiano, F.;Manca, G.;Oldeman, R.;Saitta, B.;
2025-01-01
Abstract
The Ξ0ð−Þ b → Ξcð3055Þþð0Þ ð→ Dþð0Þ ΛÞπ− decay chains are observed, and the spin-parity of Ξcð3055Þþð0Þ baryons is determined for the first time. The measurement is performed using protonproton collision data at a center-of-mass energy of ffiffi s p ¼ 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1, recorded by the LHCb experiment between 2016 and 2018. The spin-parity of the Ξcð3055Þþð0Þ baryons is determined to be 3=2þ with a significance of more than 6.5σ (3.5σ) compared to all other tested hypotheses. The up-down asymmetries of the Ξ0ð−Þ b → Ξcð3055Þþð0Þ π− transitions are measured to be −0.92 0.10 0.05 (−0.92 0.16 0.22), consistent with maximal parity violation, where the first uncertainty is statistical and the second is systematic. These results support the hypothesis that the Ξcð3055Þþð0Þ baryons correspond to the first D-wave λ-mode excitation of the Ξc flavor triplet.File | Dimensione | Formato | |
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PhysRevLett.134.081901.pdf
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