Observation of e + e − → η ϒ ( 2 S ) and search for e + e − → η ϒ ( 1 S ) , γ X b at s near 10.75 GeV

Physical review. D/Physical review. D. 2026 Open access

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Authors: Ichiro Adachi, L. Aggarwal, H. Ahmed, Y. H. Ahn, H. Aihara, N. Z. Akopov, Saleh A. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. R. Amos, Martin Angelsmark
+88 more N. Anh Ky, C. Antonioli, David M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, Rachid Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, Matthew J. Barrett, M. Bartl, J. Baudot, A. Baur, A. Beaubien, F. Becherer, Jürgen Becker, J. V. Bennett, F. U. Bernlochner, V. Bertacchi, M. Bertemes, E. Bertholet, M. Bessner, S. Bettarini, Vishal Bhardwaj, B. Bhuyan, F. Bianchi, T. Bilka, D. Biswas, A. Bobrov, Denis A. Bodrov, A. Bondar, G. Bonvicini, A. Boschetti, Andrzej Bozek, M. Bračko, P. Branchini, Roy A. Briere, Thomas E. Browder, A. Budano, S. Bussino, Q. Campagna, L. Cao, G. Casarosa, Claudia Cecchi, M.-C. Chang, P. Cheema, L. Chen, B. G. Cheon, C. Madaan, H. Chetri, K. Chilikin, J. F. Chin, K. Chirapatpimol, H.-E. Cho, K. Cho, S.-J. Cho, S.-K. Choi, S. Choudhury, J. A. Colorado-Caicedo, I. Consigny, S. Rai Choudhury, J. X. Cui, E. De La Cruz–Burelo, S. A. De La Motte, G. de Marino, G. De Nardo, G. De Pietro, Riccardo de Sangro, M. Destefanis, S. Dey, Angelo Di Canto, J. Dingfelder, Z. Doležal, I. Domínguez Jiménez, T. V. Dong, Xu Dong, M. Dorigo, K. Dugic, G. Dujany, P. Ecker, Denis A. Epifanov, J. Eppelt
DOI: 10.1103/9f61-rmvx
Cited by: 1
References: 35

Abstract

We present an analysis of the processes e + e − → η ϒ ( 1 S ) , η ϒ ( 2 S ) , and γ X b with X b → π + π − χ b J , χ b J → γ ϒ ( 1 S ) ( J = 1 , 2) reconstructed from γ γ π + π − ℓ + ℓ − ( ℓ = e , μ ) final states in 19.6 fb − 1 of Belle II data collected at four energy points near the peak of the ϒ ( 10753 ) resonance. Here, X b is a hypothetical bottomonium-sector partner of the X ( 3872 ) . In the process e + e − → η ϒ ( 2 S ) , we observe a signal with a significance that exceeds 6.0 σ when all energy points are combined. A signal with a significance of 4.2 σ is observed at a center-of-mass energy of 10.653 GeV, close to the B * B ¯ * threshold. At this energy, we measure σ ( η ϒ ( 2 S ) ) / σ ( π +

Fields of Study & Subjects

Quantum Chromodynamics and Particle Interactions Particle physics theoretical and experimental studies High-Energy Particle Collisions Research

Publication details

Journal / source
Physical review. D/Physical review. D.
Publisher
American Physical Society (APS)
Volume
113
Issue
5
Publication date
26 February 2026
Language
EN