First Measurements of Absolute Branching Fractions of the $\Xi_c^0$ Baryon at Belle

Y.B. Li , C.P. Shen , C.Z. Yuan , I. Adachi , H. Aihara , S. Al Said , D.M. Asner , T. Aushev , R. Ayad , I. Badhrees , Y. Ban , V. Bansal , C. Beleño , M. Berger , V. Bhardwaj , B. Bhuyan , T. Bilka , J. Biswal , A. Bondar , A. Bozek , M. Bračko , L. Cao , D. Červenkov , A. Chen , B.G. Cheon , K. Chilikin , K. Cho , S.-K. Choi , Y. Choi , D. Cinabro , S. Cunliffe , S. Di Carlo (1) , Z. Doležal , T.V. Dong , Z. Drásal , S. Eidelman , J.E. Fast , B.G. Fulsom , R. Garg , V. Gaur , N. Gabyshev , A. Garmash , A. Giri , P. Goldenzweig , D. Greenwald , B. Grube , K. Hayasaka , H. Hayashii , C.-L. Hsu , T. Iijima , K. Inami , G. Inguglia , A. Ishikawa , R. Itoh , M. Iwasaki , Y. Iwasaki , W.W. Jacobs , S. Jia , Y. Jin , D. Joffe , K.K. Joo , G. Karyan , T. Kawasaki , H. Kichimi , D.Y. Kim , H.J. Kim , J.B. Kim , K.T. Kim , S.H. Kim , K. Kinoshita , P. Kodyš , S. Korpar , D. Kotchetkov , P. Križan , R. Kroeger , P. Krokovny , T. Kumita , A. Kuzmin , Y.-J. Kwon , J.Y. Lee , S.C. Lee , L.K. Li , L. Li Gioi , J. Libby , D. Liventsev , M. Lubej , J. Macnaughton , M. Masuda , T. Matsuda , M. Merola , K. Miyabayashi , H. Miyata , R. Mizuk , G.B. Mohanty , R. Mussa , E. Nakano , M. Nakao , K.J. Nath , M. Nayak , M. Niiyama , S. Nishida , H. Ono , Y. Onuki , P. Pakhlov , G. Pakhlova , B. Pal , S. Pardi , S.-H. Park , S. Paul , T.K. Pedlar , R. Pestotnik , L.E. Piilonen , V. Popov , E. Prencipe , G. Russo , Y. Sakai , M. Salehi , S. Sandilya , L. Santelj , T. Sanuki , V. Savinov , O. Schneider , G. Schnell , J. Schueler , C. Schwanda , A.J. Schwartz , Y. Seino , K. Senyo , M.E. Sevior , T.-A. Shibata , J.-G. Shiu , B. Shwartz , E. Solovieva , M. Starič , M. Sumihama , T. Sumiyoshi , W. Sutcliffe , M. Takizawa , K. Tanida , Y. Tao , F. Tenchini , K. Trabelsi , M. Uchida , T. Uglov , Y. Unno , S. Uno , P. Urquijo , R. van Tonder , G. Varner , B. Wang , C.H. Wang , M.-Z. Wang , P. Wang , X.L. Wang , E. Won , S.B. Yang , H. Ye , J. Yelton , J.H. Yin , Y. Yusa , Z.P. Zhang , V. Zhilich , V. Zhukova

1 LAL - Laboratoire de l'Accélérateur Linéaire

We present the first measurements of absolute branching fractions of Ξc0 decays into Ξ-π+, ΛK-π+, and pK-K-π+ final states. The measurements are made using a dataset comprising (772±11)×106 BB¯ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB e+e- collider. We first measure the absolute branching fraction for B-→Λ¯c-Ξc0 using a missing-mass technique; the result is B(B-→Λ¯c-Ξc0)=(9.51±2.10±0.88)×10-4. We subsequently measure the product branching fractions B(B-→Λ¯c-Ξc0)B(Ξc0→Ξ-π+), B(B-→Λ¯c-Ξc0)B(Ξc0→ΛK-π+), and B(B-→Λ¯c-Ξc0)B(Ξc0→pK-K-π+) with improved precision. Dividing these product branching fractions by the result for B-→Λ¯c-Ξc0 yields the following branching fractions: B(Ξc0→Ξ-π+)=(1.80±0.50±0.14)%, B(Ξc0→ΛK-π+)=(1.17±0.37±0.09)%, and B(Ξc0→pK-K-π+)=(0.58±0.23±0.05)%. For the above branching fractions, the first uncertainties are statistical and the second are systematic. Our result for B(Ξc0→Ξ-π+) can be combined with Ξc0 branching fractions measured relative to Ξc0→Ξ-π+ to yield other absolute Ξc0 branching fractions.

Mots clés: Elementary Particles and Fields; electron positron: annihilation; electron positron: colliding beams; B: pair production; B-: hadronic decay; Xi/c0: hadronic decay; B-: branching ratio: measured; branching ratio: ratio: measured; BELLE; Upsilon(10570): electroproduction; missing-mass; KEK-B; experimental results; B- --> Antilambda/c+ Xi/c0; Xi/c0 --> Xi- pi+; Xi/c0 --> Lambda K- pi+; Xi/c0 --> p 2K- pi+; S041.465; S041.466; S041.721; S041.722; S048.1; S048.10; S048.12

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique des Hautes Energies - Phénoménologie [hep-ph]

Y.B. Li, C.P. Shen, C.Z. Yuan, I. Adachi, H. Aihara, et al.. First Measurements of Absolute Branching Fractions of the $\Xi_c^0$ Baryon at Belle. Physical Review Letters, 2019, 122 (8), pp.082001. ⟨10.1103/PhysRevLett.122.082001⟩. ⟨hal-01952704⟩