Abstrakt
We present the first measurements of absolute branching fractions of Xi(0)(c) decays into Xi(-)pi(+), Lambda K-pi(+), and pK(-)K(-)pi(+) final states. The measurements are made using a dataset comprising (772 +/- 11) x 10(6) B (B) over bar pairs collected at the (sic)(4S) resonance with the Belle detector at the KEKB e(+)e(-)collider.
We first measure the absolute branching fraction for B- -> (Lambda) over bar (-)(c)Xi(0)(c) using a missing-mass technique; the result is B(B- -> (Lambda) over bar (-)(c)Xi(0)(c)) = (9.51 +/- 2.10 +/- 0.88) x 10(-4). We subsequently measure the product branching fractions B(B- -> (Lambda) over bar (-)(c)Xi(0)(c))B(Xi(0)(c) -> Xi(-)pi(+)), B(B- -> (Lambda) over bar (-)(c)Xi(0)(c))B(Xi(0)(c) -> Lambda K-pi(+)), and B(B- -> (Lambda) over bar (-)(c)Xi(0)(c))B(Xi(0)(c) -> pK(-)K(-)pi(+)) with improved precision.
Dividing these product branching fractions by the result for B- -> (Lambda) over bar (-)(c)Xi(0)(c) yields the following branching fractions: B(Xi(0)(c) -> Xi(-)pi(+)) = (1.80 +/- 0.50 +/- 0.14)%, B(Xi(0)(c) -> Lambda K-pi(+)) = (1.17 +/- 0.37 +/- 0.09)%, and B(Xi(0)(c) -> pK(-)K(-)pi(+) ) = 0.58 +/- 0.23 +/- 0.05)%. For the above branching fractions, the first uncertainties are statistical and the second are systematic.
Our result for B(Xi(0)(c) -> Xi(-)pi(+)) can be combined with Xi(0)(c) branching fractions measured relative to Xi(0)(c) -> Xi(-)pi(+) to yield other absolute Xi(0)(c) branching fractions.