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Measurement of $b$-hadron branching fractions for two-body decays into charmless charged hadrons

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Original languageEnglish
Pages (from-to)037
Number of pages1
JournalJournal of High Energy Physics
Volume1210
Early online date13 Jun 2012
DOIs
Publication statusPublished - Oct 2012

Abstract

Based on data corresponding to an integrated luminosity of 0.37 fb^-1 collected by the LHCb experiment in 2011, the following ratios of branching fractions are measured: <br />B(B0 -&gt; pi+ pi-) / B(B0 -&gt; K+pi-) = 0.262 +/- 0.009 +/- 0.017, <br />(fs/fd) * B(Bs -&gt; K+K-) / B(B^0 -&gt; K+pi-) = 0.316 +/- 0.009 +/- 0.019, <br />(fs/fd) * B(Bs -&gt;pi+ K-) / B(B0 -&gt; K+pi-) = 0.074 +/- 0.006 +/- 0.006, <br />(fd/fs) * B(B0 -&gt; K+K-) / B(Bs -&gt; K+K-) = 0.018 {+ 0.008 - 0.007} +/- 0.009, <br />(fs/fd) * B(Bs -&gt; pi+pi-) / B(B0 -&gt; pi+pi-) = 0.050 {+ 0.011 - 0.009} +/- 0.004, <br />B(Lambda_b -&gt; p pi-) / B(Lambda_b -&gt; p K-) = 0.86 +/- 0.08 +/- 0.05, where the first uncertainties are statistical and the second systematic. Using the current world average of B(B0 -&gt; K+pi-) and the ratio of the strange to light neutral B meson production fs/fd measured by LHCb, we obtain: <br />B(B0 -&gt; pi+pi-) = (5.08 +/- 0.17 +/- 0.37) x 10^-6, <br />B(Bs -&gt; K+K-) = (23.0 +/- 0.7 +/- 2.3) x 10^-6, <br />B(Bs -&gt; pi+K-) = (5.4 +/- 0.4 +/- 0.6) x 10^-6, <br />B(B0 -&gt; K+K-) = (0.11 {+ 0.05 - 0.04} +/- 0.06) x 10^-6, <br />B(Bs -&gt; pi+pi-) = (0.95 {+ 0.21 - 0.17} +/- 0.13) x 10^-6. <br />The measurements of B(Bs -&gt; K+K-), B(Bs -&gt; pi+ K-) and B(B0 -&gt; K+K-) are the most precise to date. The decay mode Bs -&gt; pi+pi- is observed for the first time with a significance of more than 5 sigma.

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