梁伟红梁伟红(广西师范大学广西师范大学)2015强子物理与核物理前沿研讨会，中国科学院大学，强子物理与核物理前沿研讨会，中国科学院大学，2015年年1月月10-11日日1CONTENTS Introduction and motivation Formalism Results and discussions Summary2 The nature of the light scalar mesons is a topic of long-standing debate.Introduction and motivation Comparing with the Quark Models predictions, there exist much more light scalar mesons.Scalar mesons below 1 GeV:Possible structures:In the Quark Model: meson 3Chiral Unitary Theory:Oller and Oset, NPA620(1997)4384Oller and Oset, NPA620(1997)4385 is a good place fortesting the nature of the light scalar mesonsLHCb: 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.Experimental results:6Considering the final state interactions between the meson pairs in chiral unitary theory, can be produced dynamically.In this work:7FormalismThe pair is allowed to hadronize into a pair of pseudoscalar mesons. are the matrix elements of the Cabbibo-Kobayashi-Maskawa (CKM) matrix, related to the Cabbibo angle:89(direct mechanism)(rescattering mechanism)(rescattering mechanism)1011Diagrammatical representation of BS equation.divergent3-momentum cut off renormalization schemefollowing the Bethe-Salpeter Equation in coupled channels:12V is the potential which is obtained from the lowest order chiral Lagrangian for PS-PS interaction,the pion decay constantThere are 5 coupled channels:The V matrix elements are taken from Oller and Oset, NPA620(1997)438Gamermann, Oset, PRD76(2007)074016131415Clean case:LHCb, 2014Results and discussions1617Exp.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.18Summary19Thank you for your attention!20