Guy Wilkinson

Abstract:

A search is performed in the invariant mass spectrum of the $B_c^{+}\pi^{+}\pi^{-}$ system for the excited $B_c^{+}$ states $B_c(2^{1}S_{0})^+$ and $B_c(2^{3}S_{1})^+$ using a data sample of $pp$ collisions collected by the LHCb experiment at the centre-of-mass energy of $\sqrt{s} = 8 \,{\mathrm{TeV}}$, corresponding to an integrated luminosity of $2 \,{\mathrm{fb^{-1}}}$. No evidence is seen for either state. Upper limits on the ratios of the production cross-sections of the $B_c(2^{1}S_{0})^+$ and $B_c(2^{3}S_{1})^+$ states times the branching fractions of ${B_c(2^{1}S_{0})^+} \to {B_c^{+}\pi^{+}\pi^{-}}$ and ${B_c(2^{3}S_{1})^+} \to {B_c^{*+}\pi^{+}\pi^{-}}$ over the production cross-section of the $B_c^{+}$ state are given as a function of their masses. They are found to be between 0.02 and 0.14 at $95\%$ confidence level for $B_c(2^{1}S_{0})^+$ and $B_c(2^{3}S_{1})^+$ in the mass ranges $[6830, 6890] \,{\mathrm{MeV}}/c^{2}$ and $[6795,6890] \,{\mathrm{MeV}}/c^{2}$, respectively.

Abstract:

© 2018, The Author(s). A search is performed in the invariant mass spectrum of the B c + π + π − system for the excited B c + states B c (2 1 S 0 ) + and B c (2 3 S 1 ) + using a data sample of pp collisions collected by the LHCb experiment at the centre-of-mass energy of s=8 TeV, corresponding to an integrated luminosity of 2 fb −1 . No evidence is seen for either state. Upper limits on the ratios of the production cross-sections of the B c (2 1 S 0 ) + and B c (2 3 S 1 ) + states times the branching fractions of B c (2 1 S 0 ) + → B c + π + π − and B c (2 3 S 1 ) + → B c * + π + π − over the production cross-section of the B c + state are given as a function of their masses. They are found to be between 0.02 and 0.14 at 95% confidence level for B c (2 1 S 0 ) + and B c (2 3 S 1 ) + in the mass ranges [6830, 6890] MeV/c 2 and [6795, 6890] MeV/c 2 , respectively.[Figure not available: see fulltext.].

Abstract:

A search for B + → D s + K + K − decays is performed using pp collision data corresponding to an integrated luminosity of 4.8 fb −1 , collected at centre-of-mass energies of 7, 8 and 13 TeV with the LHCb experiment. A significant signal is observed for the first time and the branching fraction is determined to be ℬ(B+→Ds+K+K−)=(7.1±0.5±0.6±0.7)×10−6,where the first uncertainty is statistical, the second systematic and the third due to the uncertainty on the branching fraction of the normalisation mode B+→Ds+D¯0. A search is also performed for the pure annihilation decay B + → D s + ϕ. No significant signal is observed and a limit of ℬ(B+→Ds+ϕ) < 4.9×10−7(4.2×10−7) is set on the branching fraction at 95% (90%) confidence level.[Figure not available: see fulltext.].

Abstract:

We perform quantum-correlated measurements of the decay D → K S 0 π+π−π0 using a data sample corresponding to an integrated luminosity of 0.82 fb−1 collected at the ψ(3770) resonance by the CLEO-c detector. The value of the CP -even fraction F+ is determined to be 0.238 ± 0.012 ± 0.012. The strong-phase differences are also measured in different regions of K S 0 π+π−π0 phase space by binning around the intermediate resonances present. The potential sensitivity of the results for determining the CKM angle γ from B± → D(K S 0 π+π−π0)K± decays is also discussed.