1–5 Sept 2026
University of Sussex
Europe/London timezone

Symmetry breaking in the Nambu-Jona-Lasinio Model using the FRG

1 Sept 2026, 17:06
1m
Large Lecture Theatre (Jubilee Building)

Large Lecture Theatre

Jubilee Building

Speaker

Freddie Matthew King (University of Sussex)

Description

Investigation of supposedly non-renormalisable four-fermion interactions using the FRG reveals non-trivial fixed points that recover predictivity. Scale-symmetry breaking and mass generation can be seen in Gross–Neveu theory, which involves only 'scalars' (​ψbarψ). We extend these ideas to the Nambu-Jona-Lasinio model, which includes a 'pseudo-scalar' (ψγ5barψ) such that there is an overall U(1)xU(1) global symmetry. The flow of this theory is equivalent to Gross–Neveu, but the appearance of non-analytic operators calls for clarification, which we achieve via partial bosonisation. This makes breaking of the global U(1) symmetry manifest, which may open a route to studying pion-like Goldstone modes in a more exact setting.

Affiliation University of Sussex
Career status PhD student

Authors

Charlie Cresswell-Hogg Daniel Litim (University of Sussex) Freddie Matthew King (University of Sussex)

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