Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions and allow searches for physics beyond the standard model. We present the first results on isospin amplitudes in b-baryon decays, using data corresponding to an integrated luminosity of 8.5 fb-1, collected with the LHCb detector in pp collisions at center of mass energies of 7, 8, and 13 TeV. The isospin amplitude ratio |A1(Λb0→J/ψς0)/A0(Λb0→J/ψΛ)|, where the subscript on A indicates the final-state isospin, is measured to be less than 1/21.8 at 95% confidence level. The Cabibbo suppressed Ξb0→J/ψΛ decay is observed for the first time, allowing for the measurement |A0(Ξb0→J/ψΛ)/A1/2(Ξb0→J/ψΞ0)|=0.37±0.06±0.02, where the uncertainties are statistical and systematic, respectively.

Isospin Amplitudes in Λb0 →J/ψ Λ (ς0) and Ξb0 →J/ψ Ξ0 (Λ) Decays

Brundu D.;Bursche A.;Chen S.;Dettori F.;Manca G.;Oldeman R.;Saitta B.;Sun J.;
2020-01-01

Abstract

Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions and allow searches for physics beyond the standard model. We present the first results on isospin amplitudes in b-baryon decays, using data corresponding to an integrated luminosity of 8.5 fb-1, collected with the LHCb detector in pp collisions at center of mass energies of 7, 8, and 13 TeV. The isospin amplitude ratio |A1(Λb0→J/ψς0)/A0(Λb0→J/ψΛ)|, where the subscript on A indicates the final-state isospin, is measured to be less than 1/21.8 at 95% confidence level. The Cabibbo suppressed Ξb0→J/ψΛ decay is observed for the first time, allowing for the measurement |A0(Ξb0→J/ψΛ)/A1/2(Ξb0→J/ψΞ0)|=0.37±0.06±0.02, where the uncertainties are statistical and systematic, respectively.
File in questo prodotto:
File Dimensione Formato  
PhysRevLett.124.111802.pdf

accesso aperto

Tipologia: versione editoriale
Dimensione 386.12 kB
Formato Adobe PDF
386.12 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/11584/302817
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 2
social impact