梁伟红 (广西师范大学) 2015强子物理与核物理前沿研讨会，中国科学院大学，2015年1月10-11日

Introduction and motivation CONTENTS Introduction and motivation Formalism Results and discussions Summary

Introduction and motivation The nature of the light scalar mesons is a topic of long-standing debate. In the Quark Model: meson Comparing with the Quark Model’s predictions, there exist much more light scalar mesons. Scalar mesons below 1 GeV: Possible structures:

Chiral Unitary Theory: [Oller and Oset, NPA620(1997)438]

[Oller and Oset, NPA620(1997)438]

testing the nature of the light scalar mesons is a good place for testing the nature of the light scalar mesons Experimental results: LHCb: PLB698(2011)115; PRD86(2012)052006; PRD87(2013)052001; PRD89(2014)092006; PRD90(2014)012003; Belle, PRL106(2011)121802; CDF, PRD84(2011)052012; D0, PRD85(2012)011103.

In this work: Considering the final state interactions between the meson pairs in chiral unitary theory, can be produced dynamically.

Formalism are the matrix elements of the Cabbibo-Kobayashi-Maskawa (CKM) matrix, related to the Cabbibo angle: The pair is allowed to hadronize into a pair of pseudoscalar mesons.

(direct mechanism) (rescattering mechanism) (rescattering mechanism)

3-momentum cut off renormalization scheme divergent 3-momentum cut off renormalization scheme following the Bethe-Salpeter Equation in coupled channels: Diagrammatical representation of BS equation.

The V matrix elements are taken from V is the potential which is obtained from the lowest order chiral Lagrangian for PS-PS interaction, ——the pion decay constant There are 5 coupled channels: The V matrix elements are taken from [Oller and Oset, NPA620(1997)438] [Gamermann, Oset, PRD76(2007)074016]

Results and discussions [LHCb, 2014] Clean case:

Exp. Conclusion: Our results agree with the experimental results. This gives a strong support to the idea of the low lying scalar mesons as being formed from the interaction of pairs of pseudoscalar mesons. Exp.

Summary

Thank you for your attention!