Eur. Phys. J. C (2012) 72: 2226
https://doi.org/10.1140/epjc/s10052-012-2226-4

Regular Article - Theoretical Physics

Does the enhancement observed in contain two P-wave higher charmonia?

¹ Research Center for Hadron and CSR Physics, Lanzhou University and Institute of Modern Physics of CAS, Lanzhou, 730000, China
² School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
³ Nuclear Theory Group, Institute of Modern Physics of CAS, Lanzhou, 730000, China
⁴ Tokyo Kasei University, 1-18-1 Kaga, Itabashi, Tokyo, 173-8602, Japan

^* e-mail: xiangliu@lzu.edu.cn

Received: 19 September 2012
Revised: 30 October 2012
Published online: 13 November 2012

Abstract

We solve a new puzzle raised by the observation of an enhancement structure Z(3930) in . If categorizing Z(3930) as χ _c2(2P), as suggested by Belle and BaBar, we must explain why χ _c0(2P) dominantly decaying into is missing in the invariant mass spectrum. In this work, we propose that the Z(3930) enhancement structure may contain two P-wave higher charmonia χ _c0(2P) and χ _c2(2P). We show that this assumption is supported by our analysis of the invariant mass spectrum and cosθ ^∗ distribution of . This observation would not only provide valuable information of two P-wave higher charmonia χ _c0(2P) and χ _c2(2P), but also serve as the crucial test of our novel proposal to the observed enhancement structure Z(3930), especially at the forthcoming BelleII and the approved SuperB.