paper

First measurements of absolute branching fractions of $I^_{c}^{0}$ at Belle

arXiv:1811.09738 · doi:10.1103/PhysRevLett.122.082001

Abstract

We present the first measurements of absolute branching fractions of $I^_{c}^{0}$ decays into $I^^{-} I ¨ ^{+}$ , $I^ K^{-} I ¨ ^{+}$ , and $p K^{-} K^{-} I ¨ ^{+}$ final states. The measurements are made using a data set comprising $(772 \pm 11) \times 1 0^{6}$ $B B ˉ$ pairs collected at the $I^¥ (4 S)$ resonance with the Belle detector at the KEKB $e^{+} e^{-}$ collider. We first measure the absolute branching fraction for $B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}$ using a missing-mass technique; the result is $B (B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}) = (9.51 \pm 2.10 \pm 0.88) \times 1 0^{- 4}$ . We subsequently measure the product branching fractions $B (B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}) B (I^_{c}^{0} \to I^^{-} I ¨ ^{+})$ , $B (B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}) B (I^_{c}^{0} \to I^ K^{-} I ¨ ^{+})$ , and $B (B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}) B (I^_{c}^{0} \to p K^{-} K^{-} I ¨ ^{+})$ with improved precision. Dividing these product branching fractions by the result for $B^{-} \to I^ˉ _{c}^{-} I^_{c}^{0}$ yields the following branching fractions: $B (I^_{c}^{0} \to I^^{-} I ¨ ^{+}) = (1.80 \pm 0.50 \pm 0.14) %$ , $B (I^_{c}^{0} \to I^ K^{-} I ¨ ^{+}) = (1.17 \pm 0.37 \pm 0.09) %$ , and $B (I^_{c}^{0} \to p K^{-} K^{-} I ¨ ^{+}) = (0.58 \pm 0.23 \pm 0.05) %.$ For the above branching fractions, the first uncertainties are statistical and the second are systematic. Our result for $B (I^_{c}^{0} \to I^^{-} I ¨ ^{+})$ can be combined with $I^_{c}^{0}$ branching fractions measured relative to $I^_{c}^{0} \to I^^{-} I ¨ ^{+}$ to yield other absolute $I^_{c}^{0}$ branching fractions.

7 pages, 3 figures, 1 table; accepted for publication as a Letter in Physical Review Letters

First measurements of absolute branching fractions of I^c0​ at Belle

Abstract

First measurements of absolute branching fractions of $I^_{c}^{0}$ at Belle