Sin2beta from K ---> pi neutrino anti-neutrino

Apr, 1994
10 pages
Published in:
  • Phys.Lett.B 333 (1994) 221-227
e-Print:
Report number:
  • MPI-PHT-94-19,
  • TUM-T31-59-94

Citations per year

19942001200820152022024681012
Abstract:
We point out that the measurement of just the two branching fractions \linebreak B(K +π +ννˉ)B(K~+\to\pi~+\nu\bar\nu) and B(KLπ 0ννˉ)B(K_L\to\pi~0\nu\bar\nu) can in a theoretically clean manner determine sin2β\sin 2\beta almost independently of mtm_t and VcbV_{cb}. This allows to obtain an interesting relation between the CP asymmetry ACP(ψKS)A_{CP}(\psi K_S) in B physics and the branching ratios for these two rare K decays. The recently calculated next-to-leading order QCD corrections improve the accuracy of this analysis. We find typically Δsin2β=±0.11\Delta\sin 2\beta=\pm 0.11 provided B(\kpn) and B(\klpn) are measured within ±10%\pm 10\% accuracy. With decreasing uncertainty in ΛMS\Lambda_{\overline{MS}} and mcm_c this error could be reduced to Δsin2β<±0.10\Delta\sin 2\beta < \pm 0.10. The determination of sin2α\sin 2\alpha and sin2γ\sin 2\gamma on the other hand is rather poor. However respectable determinations of the Wolfenstein parameter η\eta and of Vtd\mid V_{td}\mid can be obtained.
  • K: rare decay
  • rare decay: K
  • K+: semileptonic decay
  • semileptonic decay: K+
  • K0(L): semileptonic decay
  • semileptonic decay: K0(L)
  • K: branching ratio
  • CKM matrix matrix
  • unitarity
  • B0: nonleptonic decay