dc.contributor |
Universitat Ramon Llull. La Salle |
dc.contributor |
CERN |
dc.contributor.author |
Calvo Gómez, Míriam |
dc.contributor.author |
Camboni, Alessandro |
dc.contributor.author |
Vilasís Cardona, Xavier |
dc.contributor.author |
LHCb Collaboration - CERN |
dc.date.accessioned |
2020-07-07T14:27:51Z |
dc.date.available |
2020-07-07T14:27:51Z |
dc.date.created |
2013 |
dc.date.issued |
2013-10-14 |
dc.identifier.uri |
http://hdl.handle.net/2072/376350 |
dc.format.extent |
15 p. |
dc.language.iso |
eng |
dc.publisher |
American Physical Society |
dc.relation.ispartof |
Physical Review D, 2013, Vol. 88 , No.7 (Octubre) |
dc.rights |
L'accés als continguts d'aquest document queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons:http://creativecommons.org/licenses/by/4.0/ |
dc.rights |
© CERN |
dc.source |
RECERCAT (Dipòsit de la Recerca de Catalunya) |
dc.subject.other |
Gran col·lisionador d'hadrons (França i Suïssa) |
dc.subject.other |
Partícules (Física nuclear) |
dc.subject.other |
Col·lisions (Física nuclear) |
dc.title |
First observation of ¯¯¯B0→J/ψK+K− and search for ¯¯¯B0→J/ψϕ decays |
dc.type |
info:eu-repo/semantics/article |
dc.type |
info:eu-repo/semantics/publishedVersion |
dc.subject.udc |
539 - Constitució física de la matèria |
dc.embargo.terms |
cap |
dc.identifier.doi |
https://doi.org/10.1103/PhysRevD.88.072005 |
dc.rights.accessLevel |
info:eu-repo/semantics/openAccess |
dc.description.abstract |
The first observation of the ¯¯¯B0→J/ψK+K− decay is presented with a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions at a center-of-mass energy of 7 TeV collected with the LHCb detector. The branching fraction is measured to be B(¯¯¯B0→J/ψK+K−)=(2.53±0.31±0.19)×10−6, where the first uncertainty is statistical and the second is systematic. An amplitude analysis of the final state in the ¯¯¯B0→J/ψK+K− decay is performed to separate resonant and nonresonant contributions in the K+K− spectrum. Evidence of the a0(980) resonance is reported with statistical significance of 3.9 standard deviations. The corresponding product branching fraction is measured to be B(¯¯¯B0→J/ψa0(980),a0(980)→K+K−)=(4.70±3.31±0.72)×10−7, yielding an upper limit of B(¯¯¯B0→J/ψa0(980),a0(980)→K+K−)<9.0×10−7 at 90% confidence level. No evidence of the resonant decay ¯¯¯B0→J/ψϕ is found, and an upper limit on its branching fraction is set to be B(¯¯¯B0→J/ψϕ)<1.9×10−7 at 90% confidence level. |