Kara Renee Mattioli

TL;DR: An amplitude analysis of $B^0$ and $B^+$ decays reveals resonant contributions and a doubly charged spin-0 open-charm tetraquark candidate with a neutral partner, observed in the $D_s\pi$ channel using 9 fb^-1 LHCb data.

TL;DR: The LHCb detector observes the $$ {B}_c^{+}\to {\chi}_{c2}{\pi}^{+} $$ decay for the first time, with a significance exceeding seven standard deviations, and measures the relative branching fraction with respect to $$ {B}_c^{+}\to J/\psi {\pi}^{+} $$ to be $$ 0.37\pm 0.06\pm 0.02\pm 0.01 $$.

Abstract: A search for the doubly charmed baryon Ξcc+ is performed through its decay to the Λc+K−π+ final state, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. The data correspond to a total integrated luminosity of 9 fb−1. No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c2. Upper limits are set at 95% credibility level on the ratio of the Ξcc+ production cross-section times the branching fraction to that of Λc+ and Ξcc++ baryons. The limits are determined as functions of the Ξcc+ mass for different lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.