Session D10 - Charm Quark States.
ORAL session, Saturday afternoon, May 01
Governor's Square 11, Adam's Mark Hotel
The orbitally-excited states D_1 and D_2 form degenerate doublet in the heavy-quark symmetry limit with hyperfine mass splitting proportional to 1/m_c. Measurement of the value of the mass splitting between these states is an important test of HQET predictions for intermediate mass c-quark and it provides valuable input to theoretical treatment of the corrections to the infinite mass quark limit.
The D_1 and D_2* states have been observed in CDF using Run II data, in the decay channels D_1, D_2* -> D*+ pi-. This is the first observation of these states in hadron colliders, and their observation has been possible thanks to the excellent performances of the CDF detector, in particular the silicon displaced vertex trigger.
The mass difference between the two states can be resolved and a measurement of the D_1 and D_2* masses is presented.