RT Journal Article
T1 Observation of ηc(2S) →pp¯ and search for X(3872) →pp¯ decays
A1 LHCb Collaboration, 
A1 Adeva Andany, Bernardo
A1 Borsato, Martino
A1 Chobanova, Veronika
A1 Cid Vidal, Xabier
A1 Dosil Suárez, Álvaro
A1 Fernández Albor, Víctor Manuel
A1 Gallas Torreira, Abraham Antonio
A1 García Pardiñas, Julián
A1 Hernando Morata, José Ángel
A1 Lemos Cid, Edgar
A1 Lucio Martínez, Miriam
A1 Martínez Santos, Diego
A1 Plo Casasus, Máximo
A1 Prisciandaro, Jessica
A1 Ramos Pernas, Miguel
A1 Romero Vidal, Antonio
A1 Saborido Silva, Juan José
A1 Sanmartín Sedes, Brais
A1 Santamarina Ríos, Cibrán
A1 Vázquez Regueiro, Pablo
A1 Vieites Díaz, María
A1 Vázquez Sierra, Carlos
AB The first observation of the decay ηc(2S) →pp¯pis reported using proton–proton collision data corre-sponding to an integrated luminosity of 3.0fb−1recorded by the LHCb experiment at centre-of-mass energies of7 and 8TeV. The ηc(2S)resonance is produced in the decay B+→[c¯c]K+. The product of branching fractions normalised to that for the J/ψintermediate state, Rηc(2S), is measured to beRηc (2S) ≡B(B+→ηc(2S)K+)×B(ηc(2S)→ p¯p )B(B+→ J/ψ K+)×B( J/ψ → p¯p )= (1.58±0.33±0.09)×10−2,where the first uncertainty is statistical and the second systematic. No signals for the decays B+→X(3872)(→p¯p)K+and B+→ψ(3770)(→p¯p)K+are seen, and the 95% confidence level upper limits on their relative branching ratios are found to be RX(3872)<0.25 ×10−2and Rψ(3770)<0.10. In addition, the mass differences between the ηc(1S)and the J/ψstates, between the ηc(2S)and the ψ(2S)states, and the natural width of the ηc(1S)are measured asM J/ψ − Mηc (1S) = 110.2±0.5 ±0.9MeV,Mψ(2S) − Mηc (2S) = 52.5±1.7±0.6MeV, ηc (1S) = 34.0±1.9±1.3MeV.
PB Elsevier
SN 0370-2693
YR 2017
FD 2017
LK http://hdl.handle.net/10347/22483
UL http://hdl.handle.net/10347/22483
LA eng
NO Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., ... & Cartelle, P. A. (2017). Observation of ηc(2S) →pp¯ and search for X(3872) →pp¯ decays. Physics Letters B, 769, 305-313
DS Minerva
RD 23 abr 2026