Observation of {Lambda}_b^0 → D+pπ−π− and {Lambda}_b^0 → D*+pπ−π− decays

Abstract

The multihadron decays {Lambda}_b^0 → D+pπ−π− and {Lambda}_b^0 → D*+pπ−π− are observed in data corresponding to an integrated luminosity of 3 fb−1, collected in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV by the LHCb detector. Using the decay {Lambda}_b^0 → {Lambda}_c^{+} π+π−π− as a normalisation channel, the ratio of branching fractions is measured to beBΛb0→D+pπ−π−BΛb0→Λc0π+π−π−×BD+→K−π+π+BΛc0→pK−π−=5.35±0.21±0.16%,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\frac{\\mathcal{B}\\left({\\Lambda}_b^0\ o {D}^{+}p{\\pi}^{-}{\\pi}^{-}\\right)}{\\mathcal{B}\\left({\\Lambda}_b^0\ o {\\Lambda}_c^0{\\pi}^{+}{\\pi}^{-}{\\pi}^{-}\\right)}\ imes \\frac{\\mathcal{B}\\left({D}^{+}\ o {K}^{-}{\\pi}^{+}{\\pi}^{+}\\right)}{\\mathcal{B}\\left({\\Lambda}_c^0\ o {pK}^{-}{\\pi}^{-}\\right)}=\\left(5.35\\pm 0.21\\pm 0.16\\right)\\%, $$\\end{document}where the first uncertainty is statistical and the second systematic. The ratio of branching fractions for the {Lambda}_b^0 → D*+pπ−π− and {Lambda}_b^0 → D+pπ−π− decays is found to beBΛb0→D∗+pπ−π−BΛb0→D+pπ−π−×BD∗+→D+π0+BD∗+→D+γ=61.3±4.3±4.0%.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\frac{\\mathcal{B}\\left({\\Lambda}_b^0\ o {D}^{\\ast +}p{\\pi}^{-}{\\pi}^{-}\\right)}{\\mathcal{B}\\left({\\Lambda}_b^0\ o {D}^{+}p{\\pi}^{-}{\\pi}^{-}\\right)}\ imes \\left(\\mathcal{B}\\left({D}^{\\ast +}\ o {D}^{+}{\\pi}^0\\right)+\\mathcal{B}\\left({D}^{\\ast +}\ o {D}^{+}\\gamma \\right)\\right)=\\left(61.3\\pm 4.3\\pm 4.0\\right)\\%. $$\\end{document}