Abstract
We study the application of the exact renormalisation group to a many-fermion system with a short-range attractive force. We introduce a boson field to describe pairing effects, and take a simple ansatz for the effective action. We derive a set of approximate flow equations for the effective coupling including boson and fermionic fluctuations. The initial conditions are obtained by renormalising the interaction to fit the scattering length in vacuum. At some critical value of the running scale, the numerical solutions show a phase transition to a gapped phase. Standard results are recovered if we omit the boson loops. When boson fluctuations are included, we find that their contributions are significant only in the small-gap regime. © 2004 Elsevier B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 287-294 |
| Number of pages | 7 |
| Journal | Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 605 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 13 Jan 2005 |
Keywords
- Attractive force (application of exact renormalization group to many-fermion system with short-range attractive force, introducing boson field to describe pairing effects and simple ansatz for effective action); Field theory (effective; exact renormalization group treatment of pairing in many-fermion systems in framework inspired by); Renormalization group theory (exact renormalization group treatment of pairing in many-fermion systems in framework inspired by effective field theory); Fermions Role: PRP (Properties) (exact renormalization group treatment of pairing in many-fermion systems in framework inspired by effective field theory); Elementary particle force; Potential energy (pairing; exact renormalization group treatment of pairing in many-fermion systems in framework inspired by effective field theory)