The decays
χ
c
1
→
J
/
ψ
μ
+
μ
−
and
χ
c
2
→
J
/
ψ
μ
+
μ
−
are observed and used to study the resonance parameters of the
χ
c
1
and
χ
c
2
mesons. The masses of these states are measured to be
m
(
χ
c
1
)
=
3510.71
±
0.04
(
stat
)
±
0.09
(
syst
)
 
 
MeV
and
m
(
χ
c
2
)
=
3556.10
±
0.06
(
stat
)
±
0.11
(
syst
)
 
 
MeV
, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference
m
(
χ
c
2
)
−
m
(
χ
c
1
)
=
45.39
±
0.07
(
stat
)
±
0.03
(
syst
)
 
 
MeV
. The natural width of the
χ
c
2
meson is measured to be
Γ
(
χ
c
2
)
=
2.10
±
0.20
(
stat
)
±
0.02
(
syst
)
 
 
MeV
. These results are in good agreement with and have comparable precision to the current world averages.