Dr Jianbo Zhang
Zhejiang University, China
Thursday, August the 9th
Seminar Room, First Floor, Physics, University of Adelaide
Radially Excited States of 1P Charmonium and X(3872)
The first excited states of charmonium in $0^{++}$, $1^{++}$, $1^{+-}$ channels are numerically investigated with lattice QCD of improved gauge and Wilson fermion actions, formulated on anisotropic lattices. Having determined the mass of ground states, the masses of excited states can be extracted by a constrained curve fitting algorithm which gives the masses 3.825(88) GeV, 3.853(57) GeV, and 3.858(70) Gev for the first excited states in $0^{++}$, $1^{++}$, $1^{+-}$ channels, respectively. A node structure is also observed in the Bethe-Salpeter wave-function of the $1^{++}$ state. The mass of the radically excited $1^{++}$ state is close to the mass of the newly observed X(3872). It indicates that X(3872) can be the first excited state of $\chi_{c1}$.