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

Mass generation at a fixed point: A Functional Renormalization Group Study of the tricritical O(N) model in d=3 and N=∞

3 Sept 2026, 10:00
20m
Gallery Room 1 (Bramber House)

Gallery Room 1

Bramber House

Speaker

Dr Shunsuke Yabunaka (ASRC, JAEA)

Description

Renormalization group (RG) fixed points are commonly associated with scale invariance and a divergent correlation length. We show that this connection can fail in the tricritical O(N) model in three dimensions in the limit N→∞. Revisiting the line of fixed points identified by Bardeen, Moshe, and Bander, we use the functional renormalization group to clarify the mechanism leading to mass generation at its singular endpoint (the BMB fixed point). We demonstrate that the generated mass is nonuniversal and originates from the nonanalytic structure of the effective potential. We show that the critical exponent ν which takes the value ν=1/2 along the regular part of the BMB line, that is, for 0≤λ<λBMB, jumps to ν=1/3 on the singular part of this line with the BMB FP, corresponding to λ=λBMB, being the pivotal point between these two regimes. We also show how its singular potential emerges dynamically along the renormalization flow.

Affiliation Advanced Science Research Center, Japan Atomic Energy Agency
Link to paper https://arxiv.org/abs/2606.12269
Career status Senior

Author

Dr Shunsuke Yabunaka (ASRC, JAEA)

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