Eur. Phys. J. A (2014) 50: 76
https://doi.org/10.1140/epja/i2014-14076-y

Regular Article - Theoretical Physics

Strong decays of χ_cJ(2P) and χ_cJ(3P)

¹ Department of Physics, Nanjing Normal University and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, 210023, Nanjing, China
² Department of Physics, Zunyi Normal College, 563002, Zunyi, China

^* e-mail: jlping@njnu.edu.cn

Received: 16 February 2014
Revised: 22 March 2014
Accepted: 1 April 2014
Published online: 21 April 2014

Abstract

In the framework of the chiral quark model, the mass spectrum of χ _cJ (J = 0, 1, 2, n = 1, 2, 3) is studied with the Gaussian expansion method. Using the wave functions obtained in the study of mass spectrum, the open charm two-body strong decay widths of these states are calculated by using the ³ P ₀ model. The results show that the masses of χ _cJ (1P) and χ _c2(2P) are consistent with the experimental data. But the strong decay width of χ _c2(2P) is three times that of the experimental value. The decay width of χ _c1(2P) is sensitive to its mass. In the quark-antiquark picture, the width is about 385 MeV. However, if the channel coupling effects shift its mass to 3872 MeV, its decay width will be around 1 MeV. The possibility of assigning the state X(3872) as χ _c1(2P) cannot be excluded. To assign X(3915) as χ _c0(2P) is disfavored, due to the unmatching of decay channel. For the χ _cJ (3P) states, no states have been assigned. The possible candidates of χ _c0(3P) are X(4160) and X(4140). Their masses are close to the theoretical ones. The experimental branching ratio of X(4160), is compatible with that of χ _c0(3P), 0.07. However the broad decay width of X(4160) cannot be explained by the open charm two-body decay. To assign X(4140) as χ _c0(3P) is also possible, due to the compatibility of the total decay width, the further measurement of decay modes of X(4140) are expected to justify the assignment.