  Recently LHCb predicted spin 1 and spin 3 states D* s1(2860) and D* s3(2860)
which are studied through their strong decays, and are assigned to fit the
13D1and 13D3 states in the charm spectroscopy. In this paper,using the heavy
quark effective theory, we state that assigning D*s1(2860) as the mixing of
13D1 - 23S1 states, is rather a better justification to its observed
experimental values than a pure state. We study its decay modes variation with
hadronic coupling constant gxh and the mixing angle . We appoint spin 3 state
D* s3(2860) as the missing 1D 3- JP state, and also study its decay channel
behavior with coupling constant gyh. To appreciate the above results, we check
the variation of decay modes for their spin partners states i.e. 1D2 and 1D'2
with their masses and strong coupling constant i.e. gxh and gyh. Our
calculation using HQET approach give mixing angle between the 13D1 - 23S1 state
for D* s1(2860) to lie in the range (-1.6 radians < theta < -1.2 radians). Our
calculation for coupling constant values gives gxh to lie between value 0:17 <
gxh < 0:20 and gyh to be 0.40. We expect from experiments to observe this
mixing angle to verify our results.
