The first observation of the decay eta(c)(2S) -> p (p) over bar is reported using proton -proton collision data corresponding to an integrated luminosity of 3.0 fb(-1) recorded by the LHCb experiment at centre -of -mass energies of 7, 8 TeV. The eta c(2S) resonance is produced in the decay B+ [c (c) over bar ]K+. The product of branching fractions normalised to that for the intermediate state R-eta c,(2s), is measured to be R-eta c,(2s) equivalent to B(B+-> eta c (2S)K+) x B(eta c(2s)(2S) -> p<<(p)over bar> )/B(B+ -> J/psi k(+)) x B(J/psi -> p<<(p)over bar> ) = (1.58 +/- 0.33 +/- 0.09) x 10(-2), where the first uncertainty is statistical, the second systematic. No signals for the decays B+ -> X(3872)(-> p (p) over bar )K+, B+ psi(3770)(-> p (p) over bar )K+ are seen, the 95\% confidence level upper limits on their relative branching ratios are found to be R-x(3872) < 0.25 x 10(-2), R-psi(3770) < 0.10. In addition the mass differences between the nc(1S), the J/psi states between the eta(c)(2S), the eta(c)(2S) states, the natural width of the psi(1S) are measured as M-J/psi - M-eta c(7s)= 110.2 +/- 0.5 +/- 0.9 MeV, M psi(2S) - M-eta c (2S) = 52.5 +/- 1.7 +/- 0.6 MeV Gamma(eta c) (1s) = 34.0 +/- 1.9 +/- 1.3 MeV.

Observation of eta(c)(2S) -> p(p)over-bar, search for X(3872) ->p(p)over-bar decays

Bursche A.;Chen S.;Dettori F.;Lai A.;Manca G.;Oldeman R.;Saitta B.;
2017-01-01

Abstract

The first observation of the decay eta(c)(2S) -> p (p) over bar is reported using proton -proton collision data corresponding to an integrated luminosity of 3.0 fb(-1) recorded by the LHCb experiment at centre -of -mass energies of 7, 8 TeV. The eta c(2S) resonance is produced in the decay B+ [c (c) over bar ]K+. The product of branching fractions normalised to that for the intermediate state R-eta c,(2s), is measured to be R-eta c,(2s) equivalent to B(B+-> eta c (2S)K+) x B(eta c(2s)(2S) -> p<<(p)over bar> )/B(B+ -> J/psi k(+)) x B(J/psi -> p<<(p)over bar> ) = (1.58 +/- 0.33 +/- 0.09) x 10(-2), where the first uncertainty is statistical, the second systematic. No signals for the decays B+ -> X(3872)(-> p (p) over bar )K+, B+ psi(3770)(-> p (p) over bar )K+ are seen, the 95\% confidence level upper limits on their relative branching ratios are found to be R-x(3872) < 0.25 x 10(-2), R-psi(3770) < 0.10. In addition the mass differences between the nc(1S), the J/psi states between the eta(c)(2S), the eta(c)(2S) states, the natural width of the psi(1S) are measured as M-J/psi - M-eta c(7s)= 110.2 +/- 0.5 +/- 0.9 MeV, M psi(2S) - M-eta c (2S) = 52.5 +/- 1.7 +/- 0.6 MeV Gamma(eta c) (1s) = 34.0 +/- 1.9 +/- 1.3 MeV.
File in questo prodotto:
File Dimensione Formato  
1-s2.0-S0370269317302344-main.pdf

accesso aperto

Tipologia: versione editoriale
Dimensione 713.83 kB
Formato Adobe PDF
713.83 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/11584/239485
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 19
social impact