Low-energy pi-pi and pi-K scatterings revisited in three-flavour resummed chiral perturbation theory
| dc.creator | Descotes-Genon, S. | |
| dc.date | 2007-03-14 | |
| dc.date | 2007-06-21 | |
| dc.date.accessioned | 2026-07-07T11:22:49Z | |
| dc.date.available | 2026-07-07T11:22:49Z | |
| dc.description | Chiral symmetry breaking may exhibit significantly different patterns in two chiral limits: N_f=2 massless flavours (m_u=m_d=0, m_s physical) and N_f=3 massless flavours (m_u=m_d=0=m_s=0). Such a difference may arise due to vacuum fluctuations of s-bar{s} pairs related to the violation of the Zweig rule in the scalar sector, and could yield a numerical competition between contributions counted as leading order and next-to-leading in the chiral expansions of observables. We recall and extend Resummed Chiral Perturbation Theory (ReChPT), a framework that we introduced previously to deal with such instabilities: it requires a more careful definition of the relevant observables and their one-loop chiral expansions. We analyse the amplitudes for low-energy pi-pi and pi-K scatterings within ReChPT, which we match in subthreshold regions with dispersive representations obtained from the solutions Roy and Roy-Steiner equations. Using a frequentist approach, we constrain the quark mass ratio as well as the quark condensate and the pseudoscalar decay constant in the N_f=3 chiral limit. The results mildly favour significant contributions of vacuum fluctuations suppressing the N_f=3 quark condensate compared to its N_f=2 counterpart. | |
| dc.description | 35 pages, 3 figures, accepted for publication in Eur. Phys. J. C | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0703154 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0703154 | |
| dc.identifier | Eur.Phys.J.C52:141-158,2007 | |
| dc.identifier | doi:10.1140/epjc/s10052-007-0359-7 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/194700 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Low-energy pi-pi and pi-K scatterings revisited in three-flavour resummed chiral perturbation theory | |
| dc.type | text |