A search is performed for the decay \(\lambda\frac{0}{b}\)→pKη' using pp collision data collected with the LHCb detector at centre-of-mass energies of \(\sqrt{s}\) = 7TeV and \(\sqrt{s}\) = 8TeV, corresponding to an integrated luminosity of 3 fb\(^-\)\(^1\). The search is performed in two decay channels; the η' is reconstructed through the decays η'→\(\pi^+\pi^-\gamma\) and η'→\(\pi^+\pi^-\eta\). In the η'→\(\pi^+\pi^-\gamma\) decay channel 117 ± 15(stat.) ± 10(sys.) signal events are observed and 45 ± 8(stat.) ± 2(sys.) signal events are observed in the η'→\(\pi^+\pi^-\eta\) decay channel. The combined statistical significance of these signals is 12.0σ, therefore this is the first observation of the decay \(\lambda\frac{0}{b}\)→pKη' . The branching fraction of the decay \(\lambda\frac{0}{b}\)→pKη' is measured relative to the decay B\(^+\)→K\(^+\)η'. The ratio of branching fractions is measured to be \(\frac{\beta(\lambda\frac{0}{b}→pKη')}{\beta(B^+→K^+η'}\)= 0.120 ± 0.013(stat.) ± 0.013(sys.). Using the world average value for the branching fraction of the decay B\(^+\)→K\(^+\)η', the branching fraction of \(\lambda\frac{0}{b}\)→pKη' is measured to be, \(\beta\)\((\lambda\frac{0}{b}→pKη')\) = 8.48 ± 0.88(stat.) ± 0.97(sys.) x 10\(^-\)\(^6\) . This is the first observation of a b-baryon decaying to an η.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:768313 |
| Date | January 2018 |
| Creators | Williams, Timothy |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/8814/ |
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