1. School of Physical Science and Technology
The oddball Y(4140) as the
cousin of Y(3930)
Xiang Liu
School of Physical Science and Technology
Lanzhou University
Xiang Liu & S. L. Zhu, Phys.Rev.D80, (2009)
Xiang Liu, Z. G. Luo, Y. R. Liu and S. L. Zhu, Eur.Phys.J.C61: (2009)
Xiang Liu, Phys.Lett. B680, (2009)
Xiang Liu & H.W. Ke, Phys.Rev.D80, (2009)
QNP09 October , at IHEP, China

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

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

4. = - 90 MeV

5. What is the structure for Y(4140)?
Wavefunction

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

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

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

10. 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

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

12. 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).

13. Thank you for your attention !

14. Backup slides

15. 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.

16. 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.