理论物理所

Talks

Location: Home>Activities>Talks

(Seminar) The power of EFT: Deriving the electroweak Standard Model

09/04 2018
  • Title (Seminar) The power of EFT: Deriving the electroweak Standard Model
  • Speaker
  • Date
  • Venue
    • Abstract

    CAS Key Laboratory of Theoretical Physics

    Institute of Theoretical Physics

     Chinese Academy of Sciences

    Seminar

    Title

    题目

    		 The power of EFT: Deriving the electroweak Standard Model

    Speaker

    报告人

    Prof. Ulf-G. Meissner

     中国科学院国际人才计划国际杰出学者

    Affiliation

    所在单位

    University of Bonn / Jülich Research Center

    Date

    日期

    		 2018年9月4日（周二）上午10:00

    Venue

    地点

    		 Conference Room 322, ITP main building

    Abstract

    摘要

    		 In this talk, I revisit the problem of deriving local gauge invariance with spontaneous symmetry breaking in the context of an effective field theory. Previous derivations were based on the condition of tree-order unitarity. However, the modern point of view considers the Standard Model as the leading order approximation to an effective field theory. As tree-order unitarity is in any case violated by higher-order terms in an effective field theory, it is instructive to investigate a formalism which can be also applied to analyze higher-order interactions. I consider an effective field theory of massive vector bosons interacting with a massive scalar field.  The conditions of generating the right number of constraints for systems with spin-one particles and perturbative renormalizability as well as the separation of scales at one-loop order are imposed. These conditions imply severe restrictions on the coupling constants of the interaction terms. Except for the strengths of the  self-interactions of the scalar field, that can not be determined at this order from the analysis of three- and four-point functions, one recovers the gauge-invariant Lagrangian with spontaneous symmetry breaking in the unitary gauge as the leading order approximation to an effective field theory. I also outline the additional work that is required to finish this program.

    Contact person

    所内联系人

    		 郭奉坤