The first observation of the decay ηc (2 S ) → p p ̄ 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 and 8 TeV. The ηc(2S) resonance is produced in the decay B+ →[cc ̄]K+. The product of branching fractions normalised to that for the J/ψ intermediate state, Rηc(2S), is measured to be B ( B + → η c ( 2 S ) K + ) × B ( η c ( 2 S ) → p p ̄ ) − 2 Rηc(2S)≡ B(B+→J/ψK+)×B(J/ψ→pp ̄) =(1.58±0.33±0.09)×10 , where the first uncertainty is statistical and the second systematic. No signals for the decays B+ → X(3872)(→ pp ̄)K+ and B+ → ψ(3770)(→ pp ̄)K+ are seen, and the 95% confidence level upper limits on their relative branching ratios are found to be RX(3872) < 0.25 × 10−2 and Rψ(3770) < 0.10. In addition, the mass differences between the ηc (1 S ) and the J /ψ states, between the ηc (2 S ) and the ψ (2 S ) states, and the natural width of the ηc(1S) are measured as MJ/ψ −Mηc(1S) =110.2±0.5±0.9MeV, Mψ(2S) − Mηc (2S) = 52.5 ± 1.7 ± 0.6 MeV, ηc(1S) =34.0±1.9±1.3MeV.

Observation of η<inf>c</inf>(2S)→pp¯ and search for X(3872)→pp¯ decays / Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., Andrews, J.E., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 769:(2017), pp. 305-313. [10.1016/j.physletb.2017.03.046]

Observation of ηc(2S)→pp¯ and search for X(3872)→pp¯ decays

Capriotti, L.;Casse, G.;Sarti, A.;Sciubba, A.;
2017

Abstract

The first observation of the decay ηc (2 S ) → p p ̄ 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 and 8 TeV. The ηc(2S) resonance is produced in the decay B+ →[cc ̄]K+. The product of branching fractions normalised to that for the J/ψ intermediate state, Rηc(2S), is measured to be B ( B + → η c ( 2 S ) K + ) × B ( η c ( 2 S ) → p p ̄ ) − 2 Rηc(2S)≡ B(B+→J/ψK+)×B(J/ψ→pp ̄) =(1.58±0.33±0.09)×10 , where the first uncertainty is statistical and the second systematic. No signals for the decays B+ → X(3872)(→ pp ̄)K+ and B+ → ψ(3770)(→ pp ̄)K+ are seen, and the 95% confidence level upper limits on their relative branching ratios are found to be RX(3872) < 0.25 × 10−2 and Rψ(3770) < 0.10. In addition, the mass differences between the ηc (1 S ) and the J /ψ states, between the ηc (2 S ) and the ψ (2 S ) states, and the natural width of the ηc(1S) are measured as MJ/ψ −Mηc(1S) =110.2±0.5±0.9MeV, Mψ(2S) − Mηc (2S) = 52.5 ± 1.7 ± 0.6 MeV, ηc(1S) =34.0±1.9±1.3MeV.
2017
Branching fraction CP violation Flavor physics Rare decay Hadron-Hadron scattering (experiments)
01 Pubblicazione su rivista::01a Articolo in rivista
Observation of η<inf>c</inf>(2S)→pp¯ and search for X(3872)→pp¯ decays / Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., Andrews, J.E., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 769:(2017), pp. 305-313. [10.1016/j.physletb.2017.03.046]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1074676
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