Measurement of the shape of the ${\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}\overline{\nu }$ differential decay rate

Abstract

A measurement of the shape of the differential decay rate and the associated Isgur-Wise function for the decay ${\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}\overline{\nu }$ is reported, using data corresponding to $3f{b}^{-1}$ collected with the LHCb detector in proton-proton collisions. The ${\Lambda }_c^{+}{\mu }^{-}\overline{\nu }$(+ anything) final states are reconstructed through the detection of a muon and a ${\Lambda }_c^{+}$ baryon decaying into $p{K}^{-}{\pi }^{+}$, and the decays ${\Lambda }_b^0\to {\Lambda }_c^{+}{\pi }^{+}{\pi }^{-}{\mu }^{-}\overline{\nu }$ are used to determine contributions from ${\Lambda }_b^0\to {\Lambda }_c^{\star +}{\mu }^{-}\bar{\nu }$ decays. The measured dependence of the differential decay rate upon the squared four-momentum transfer between the heavy baryons, $q^2$, is compared with expectations from heavy-quark effective theory and from unquenched lattice QCD predictions.

Comments: published version, 24 pages, 5 figures, all figures and tables https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-016.html