A study of meson production at LHCb is performed on proton–proton collision data, corresponding to 3.0 of integrated luminosity collected at centre-of-mass energies = 7 and 8. The fraction of Υ mesons originating from χ decays is measured as a function of the transverse momentum in the rapidity range. The radiative transition of the meson to Υ is observed for the first time. The χ mass is determined to be (Formula presented.) where the first uncertainty is statistical and the second is systematic.
Bibliographical noteFunding Information:
We thank K.-T. Chao, H. Han, V. G. Kartvelishvili, J.-P. Lansberg A. K. Likhoded, A. V. Luchinsky, S. V. Poslavsky and H.-S. Shao for inspiring and fruitful discussions on P-wave bottomonia production. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); NSFC (China); CNRS/IN2P3 (France); BMBF, DFG, HGF and MPG (Germany); SFI (Ireland); INFN (Italy); FOM and NWO (The Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FANO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). The Tier1 computing centres are supported by IN2P3 (France), KIT and BMBF (Germany), INFN (Italy), NWO and SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom). We are indebted to the communities behind the multiple open source software packages on which we depend. We are also thankful for the computing resources and the access to software R&D tools provided by Yandex LLC (Russia). Individual groups or members have received support from EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union), Conseil général de Haute-Savoie, Labex ENIGMASS and OCEVU, Région Auvergne (France), RFBR (Russia), XuntaGal and GENCAT (Spain), Royal Society and Royal Commission for the Exhibition of 1851 (United Kingdom).
© 2014, CERN for the benefit of the LHCb collaboration.
All Science Journal Classification (ASJC) codes
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)