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Observation of an Excited Meson State with the ATLAS Detector

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • G. Aad
  • B. Abbott
  • J. Abdallah
  • S. Abdel Khalek
  • O. Abdinov
  • R. Aben
  • B. Abi
  • Lotte Ansgaard Thomsen
  • Sascha Mehlhase
  • Morten Dam Jørgensen
  • Almut Maria Pingel
  • Ask Emil Løvschall-Jensen
  • Alejandro Alonso Diaz
  • James William Monk
  • Lars Egholm Pedersen
  • Gorm Aske Gram Krohn Galster
A search for excited states of the B±c meson is performed using 4.9  fb−1 of 7 TeV and 19.2  fb−1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay B±c→J/ψπ±. The state appears in the m(B±cπ+π−)−m(B±c)−2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5  MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the B±c meson, B±c(2S).
OriginalsprogEngelsk
Artikelnummer212004
TidsskriftPhysical Review Letters
Vol/bind113
ISSN0031-9007
DOI
StatusUdgivet - 3 jul. 2014

ID: 130019368