Observation of Ξ_b⁰ → Ξ⁰ J/ψ and evidence for Ξ_b⁰ → Ξ⁰ ψ(2S) decays

@misc{aaij2026observation,
  title = {{Observation of $Ξ_b^0 \to Ξ^0 J/ψ$ and evidence for $Ξ_b^0 \to Ξ^0 ψ(2S)$ decays}},
  author = {Roel Aaij and Mohammed Abdelfatah and Ahmed Sameh Wagih Abdelmotteleb and Carlos Abellan Beteta and Fernando Jesus Abudinén and Thomas Ackernley and Ayomide Matthew Adefisoye and Bernardo Adeva and Marco Adinolfi and Patrik Harri Adlarson and Christina Agapopoulou and Christine Angela Aidala and Simon Akar and Kazuyoshi Akiba and Hussain Hassan A Al Saleh and Pietro Albicocco and Johannes Albrecht and Ramunas Aleksiejunas and Federico Alessio and Paula Alvarez Cartelle and Sandra Amato and Jake Lewis Amey and Yasmine Amhis and Zachariah Benjamin Amos and Liupan An and Lucio Anderlini and Pasquale Andreola and Mirco Andreotti and Sergio Andres Estrada and Alessia Anelli and Dong Ao and Carolina Arata and Flavio Archilli and Zaratsyan Areg and Matteo Argenton and Sergio Arguedas Cuendis and Lisa Arnone and Marina Artuso and Elie Aslanides and Rita Ataíde da Silva and Michele Atzeni and Benjamin Audurier and Juliette Authier and David Bacher and Irene Bachiller Perea and Sebastian Bachmann and Marie Bachmayer and John Back and Maoze Bai and Ziyu Bai and Vladislav Balagura and Anna Balboni and Wander Baldini and Zachary Baldwin and Luca Balzani and Haoran Bao and Juan Baptista de Souza Leite and Carlos Javier Barbero Pretel and Matteo Barbetti and Ivanildo Rui Barbosa},
  howpublished = {HAL},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.15251},
  eprint = {2609.15251},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05759411v1},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Observation of Ξ_b^0 → Ξ^0 J/ψ and evidence for Ξ_b^0 → Ξ^0 ψ(2S) decays
AU  - Roel Aaij
AU  - Mohammed Abdelfatah
AU  - Ahmed Sameh Wagih Abdelmotteleb
AU  - Carlos Abellan Beteta
AU  - Fernando Jesus Abudinén
AU  - Thomas Ackernley
AU  - Ayomide Matthew Adefisoye
AU  - Bernardo Adeva
AU  - Marco Adinolfi
AU  - Patrik Harri Adlarson
AU  - Christina Agapopoulou
AU  - Christine Angela Aidala
AU  - Simon Akar
AU  - Kazuyoshi Akiba
AU  - Hussain Hassan A Al Saleh
AU  - Pietro Albicocco
AU  - Johannes Albrecht
AU  - Ramunas Aleksiejunas
AU  - Federico Alessio
AU  - Paula Alvarez Cartelle
AU  - Sandra Amato
AU  - Jake Lewis Amey
AU  - Yasmine Amhis
AU  - Zachariah Benjamin Amos
AU  - Liupan An
AU  - Lucio Anderlini
AU  - Pasquale Andreola
AU  - Mirco Andreotti
AU  - Sergio Andres Estrada
AU  - Alessia Anelli
AU  - Dong Ao
AU  - Carolina Arata
AU  - Flavio Archilli
AU  - Zaratsyan Areg
AU  - Matteo Argenton
AU  - Sergio Arguedas Cuendis
AU  - Lisa Arnone
AU  - Marina Artuso
AU  - Elie Aslanides
AU  - Rita Ataíde da Silva
AU  - Michele Atzeni
AU  - Benjamin Audurier
AU  - Juliette Authier
AU  - David Bacher
AU  - Irene Bachiller Perea
AU  - Sebastian Bachmann
AU  - Marie Bachmayer
AU  - John Back
AU  - Maoze Bai
AU  - Ziyu Bai
AU  - Vladislav Balagura
AU  - Anna Balboni
AU  - Wander Baldini
AU  - Zachary Baldwin
AU  - Luca Balzani
AU  - Haoran Bao
AU  - Juan Baptista de Souza Leite
AU  - Carlos Javier Barbero Pretel
AU  - Matteo Barbetti
AU  - Ivanildo Rui Barbosa
PY  - 2026
DA  - 2026/09/14
PB  - HAL
DO  - 10.48550/arxiv.2609.15251
UR  - https://hal.science/hal-05759411v1
AB  - The first search for the beauty baryon decays Ξ_b^0 → Ξ^0 J/ψ and Ξ_b^0 → Ξ^0 ψ(2S) is presented using the proton-proton collision dataset collected by the LHCb experiment between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb^−1. The first observation of the decay Ξ_b^0 → Ξ^0 J/ψ is reported and evidence of the decay Ξ_b^0 → Ξ^0 ψ(2S) is presented. The Ξ^0 hyperon is fully reconstructed for the first time at an LHC experiment, which is achieved using the Ξ^0 → Λπ^0 decay. The ratio of the branching fractions is measured as (calB(Ξ_b^0 → Ξ^0 ψ(2S)))/(calB(Ξ_b^0 → Ξ^0 J/ψ)) = 0.59 ± 0.19 (stat) ± 0.04 (syst).
ER  -