School of Physical Science and Technology The oddball Y(4140) as the cousin of Y(3930) Xiang Liu xiangliu@lzu.edu.cn School of Physical Science and Technology Lanzhou University Xiang Liu & S. L. Zhu, Phys.Rev.D80, 017502 (2009) Xiang Liu, Z. G. Luo, Y. R. Liu and S. L. Zhu, Eur.Phys.J.C61:411-428 (2009) Xiang Liu, Phys.Lett. B680, 137-140 (2009) Xiang Liu & H.W. Ke, Phys.Rev.D80, 034009 (2009) QNP09 October 21-25 2009, at IHEP, China

CDF experiment observed Y(4140) See Phys.Rev.Lett.102:242002,2009 Y(4140) C parity: + G parity: +

Belle Collaboration BaBar Collaboration Phys.Rev.Lett.94:182002 (2005) Phys.Rev.Lett.101: 082001 (2008)

= - 90 MeV

What is the structure for Y(4140)? Wavefunction

Effective Potential For details, see Xiang Liu, Z. G. Luo, Y. R. Liu, S.L. Zhu, Eur.Phys.J.C61:411-428,2009

The shape of the potential of Y(4140) and Y(3930)

Decay Patterns of Y (4140) and Y (3930)

Open charm two-body decays S-wave D-wave Such a D-wave decay width should be much smaller than that for the above hidden charm S-wave decay mode! The open-charm decay widths are comparable to the hidden-charm decay width

Xiang Liu & H.W. Ke Phys.Rev.D80, 034009 (2009)

Summary We proposed a uniform molecular state assignment for Y(4140) and Y(3930) Their hidden-charm decay, open-charm decay, radiative decay are important and interesting to test molecular state assignment for Y(4140) and Y(3930). Confirming Y(4140) in other experiments is important. Belle and Babar experiments. We suggest the measurment of the line shape of the photon spectrum of the radiative decay of Y(4140) and Y(3930).

Thank you for your attention !

Backup slides

Charmonium Y (4140) lies well above the open charm decay threshold. Charmoniums with this mass would decay into an open charm pair dominantly. The branching fraction of its hidden charm decay mode is expected to be tiny. Thus, both the narrow width of Y (4140) and its large hidden charm decay pattern disfavor the conventional charmonium interpretation.

Tetraquark state Tetraquarks will fall apart into a pair of charmed mesons very easily. As a tetraquark, the width of Y (4140) would be around several hundred MeV instead of 12 MeV as observed by CDF. Hybrid state The B meson decay process does not provide a glue-rich environment as in the Upsilon/charmonium annihilation. So the possibility of Y (4140) being a hybrid state is small.