The observation of a wide peaking structure in the Bc+ γ mass spectrum is reported using proton-proton collision data collected by the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^−1. The statistical significance over the background-only hypothesis exceeds seven standard deviations. The width of the observed structure is larger than the expectation from a single-peak hypothesis, and is well described by an effective minimal model consisting of two narrow peaks located at 6704.8 ± 5.5 ± 2.8 ± 0.3 MeV/c2 and 6752.4 ± 9.5 ± 3.1 ± 0.3 MeV/c2. The uncertainty terms are statistical, systematic, and associated to the knowledge of the Bc+ mass, respectively. The measured peak locations are in line with theoretical predictions for lowest excited P-wave Bc+ states, marking the first observation of orbitally excited beauty-charm mesons and providing important insights into the internal dynamics of hadrons containing two heavy quarks.

Aaij, R., Abdelmotteleb, A. s. w., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A. a., et al. (2025). Observation of Orbitally Excited Bc+ States. PHYSICAL REVIEW LETTERS, 135(23), 1-11 [10.1103/fc8j-tb8k].

Observation of Orbitally Excited Bc+ States

Carbone, A.;Ferrari, F.;Galli, D.;Patrignani, C.;Spedicato, E.;Zenesini, F.;
2025

Abstract

The observation of a wide peaking structure in the Bc+ γ mass spectrum is reported using proton-proton collision data collected by the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^−1. The statistical significance over the background-only hypothesis exceeds seven standard deviations. The width of the observed structure is larger than the expectation from a single-peak hypothesis, and is well described by an effective minimal model consisting of two narrow peaks located at 6704.8 ± 5.5 ± 2.8 ± 0.3 MeV/c2 and 6752.4 ± 9.5 ± 3.1 ± 0.3 MeV/c2. The uncertainty terms are statistical, systematic, and associated to the knowledge of the Bc+ mass, respectively. The measured peak locations are in line with theoretical predictions for lowest excited P-wave Bc+ states, marking the first observation of orbitally excited beauty-charm mesons and providing important insights into the internal dynamics of hadrons containing two heavy quarks.
2025
Aaij, R., Abdelmotteleb, A. s. w., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A. a., et al. (2025). Observation of Orbitally Excited Bc+ States. PHYSICAL REVIEW LETTERS, 135(23), 1-11 [10.1103/fc8j-tb8k].
Aaij, R.; Abdelmotteleb, A.  s.  w.; Abellan Beteta, C.; Abudinén, F.; Ackernley, T.; Adefisoye, A.  a.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapop...espandi
File in questo prodotto:
File Dimensione Formato  
2025-AR-60-Obs_of_Orbitally_Excited_Bcp_States-PRL.pdf

accesso aperto

Tipo: Versione (PDF) editoriale / Version Of Record
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 591.2 kB
Formato Adobe PDF
591.2 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1036753
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 0
social impact