We consider a model in which Goldstone bosons, described by a SU(N) chiral nonlinear σ model, are coupled to an N-plet of colored fermions by means of a Yukawa interaction. We study the one-loop renormalization group flow and show that the non-Gaussian UV fixed point, which is present in the purely bosonic model, is lost because of fermion loop effects unless N is sufficiently large. We then add four-fermion contact interactions to the Lagrangian and show that in this case there exist several non-Gaussian fixed points. The strength of the contact interactions, predicted by the requirement that the theory flows towards a fixed point in the UV, is compared to the current experimental bounds. This toy model could provide an important building block of an asymptotically safe model of the weak interactions.
Fermions and Goldstone bosons in an asymptotically safe model / Bazzocchi, F; Fabbrichesi, M; Percacci, Roberto; Tonero, A; Vecchi, L.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 705:4(2011), pp. 388-392. [10.1016/j.physletb.2011.10.029]
Fermions and Goldstone bosons in an asymptotically safe model
Percacci, Roberto;
2011-01-01
Abstract
We consider a model in which Goldstone bosons, described by a SU(N) chiral nonlinear σ model, are coupled to an N-plet of colored fermions by means of a Yukawa interaction. We study the one-loop renormalization group flow and show that the non-Gaussian UV fixed point, which is present in the purely bosonic model, is lost because of fermion loop effects unless N is sufficiently large. We then add four-fermion contact interactions to the Lagrangian and show that in this case there exist several non-Gaussian fixed points. The strength of the contact interactions, predicted by the requirement that the theory flows towards a fixed point in the UV, is compared to the current experimental bounds. This toy model could provide an important building block of an asymptotically safe model of the weak interactions.File | Dimensione | Formato | |
---|---|---|---|
BFPTV.pdf
non disponibili
Licenza:
Non specificato
Dimensione
257.51 kB
Formato
Adobe PDF
|
257.51 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.