Measurement of masses and branching ratios of Ξ + c and Ξ 0 c baryons
Abstract
We report a measurement of the
Ξ
+
c
and
Ξ
0
c
baryon masses, and the branching ratios for various
Ξ
c
decays, using
140
fb
−1
of data collected by the Belle experiment at the KEKB
e
+
e
−
collider.The mass splitting
m
Ξ
0
c
−
m
Ξ
+
c
is found to be
2.9±0.5MeV/
c
2
; this measurement is three times as precise as the current world average. We measure the branching ratios
Γ(
Ξ
+
c
→ΛKππ)/Γ(
Ξ
+
c
→Ξππ)=0.32±0.03±0.02
and
Γ(
Ξ
0
c
→pKKπ)/Γ(
Ξ
0
c
→Ξπ)=0.33±0.03±0.03
, with improved precision, and measure
Γ(
Ξ
+
c
→p
K
0
S
K
0
S
)/Γ(
Ξ
+
c
→Ξππ)=0.087±0.016±0.014
,
Γ(
Ξ
0
c
→ΛKπ)/Γ(
Ξ
0
c
→Ξπ)=1.07±0.12±0.07
and
Γ(
Ξ
0
c
→Λ
K
0
S
)/Γ(
Ξ
0
c
→Ξπ)=0.21±0.02±0.02
for the first time. In
Ξ
0
c
decays to the
p
K
−
K
−
π
+
final state, we find evidence for the process
Ξ
0
c
→p
K
−
K
¯
∗
(892
)
0
and measure the fraction of decays via this process to be
0.51±0.03±0.01
.