Splittings of 2-- and 1-- 1D states:

states
mass difference
(MeV)
ψ(3836)
ψ(3770)
≅ 55
Υ(10162)
Υ(10129)
≅ 33



This nicely follows the 1/√(flavor mass) rule
for flavor independence:

1/√(mc) : 1/√(mb) = 5 : 3

flavor masses are from Phys. Rev. D27, 1527 (1983)
The ψ(3836) has disappeared from PDG Tables!