TY - JOUR AU - LHCb Collaboration (Aaij, R. et al AU - Garcia Martin, L. M. AU - Henry, L. AU - Jashal, B. K. AU - Martinez-Vidal, F. AU - Oyanguren, A. AU - Remon Alepuz, C. AU - Ruiz Vidal, J. AU - Sanchez Mayordomo, C. PY - 2019 DA - 2019// TI - Observation of the Lambda(0)(b) -> chi(c1) (3872)pK(-) decay T2 - J. High Energy Phys. JO - Journal of High Energy Physics SP - 028 EP - 20pp VL - 09 IS - 9 PB - Springer KW - B physics KW - Branching fraction KW - Exotics KW - Hadron-Hadron scattering (experiments) AB - Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9 fb(-1) of integrated luminosity at the centre-of-mass energies of 7, 8, and 13 TeV, respectively, the decay Lambda(0)(b) -> chi(c1)(3872)pK(-) with chi(c1)(3872) -> J/psi pi(+)pi(-) is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. It is found that (58 +/- 15)% of the decays proceed via the two-body intermediate state chi(c1)(3872)Lambda(1520). The branching fraction with respect to that of the Lambda(0)(b) -> psi(2S)pK(-) decay mode, where the psi(2S) meson is reconstructed in the J/psi pi(+)pi(-) final state, is measured to be: B(Lambda(0)(b) -> chi(c1)(3872)pK(-))/B (Lambda(0)(b) -> psi(2S)pK(-)) x B(chi(c1)(3872) -> J/psi pi(+)pi(-))/B(psi(2S) -> J/psi pi(+)pi(-)) = (5.4 +/- 1.1 +/- 0.2) x 10(-2), where the first uncertainty is statistical and the second is systematic. SN - 1029-8479 UR - https://arxiv.org/abs/1907.00954 UR - https://doi.org/10.1007/JHEP09(2019)028 DO - 10.1007/JHEP09(2019)028 LA - English N1 - WOS:000490789700001 ID - LHCbCollaborationAaij_etal2019 ER -