pi/K -> e nu branching ratios to O(e^2 p^4) in Chiral Perturbation Theory
| dc.creator | Cirigliano, Vincenzo | |
| dc.creator | Rosell, Ignasi | |
| dc.date | 2007-07-30 | |
| dc.date.accessioned | 2026-07-07T12:42:23Z | |
| dc.date.available | 2026-07-07T12:42:23Z | |
| dc.description | We calculate the ratios R_{e/mu}^{(P)} = Gamma(P -> e nu)/Gamma (P -> mu nu) (P=pi,K) in Chiral Perturbation Theory to order e^2 p^4. We complement the one- and two-loop effective theory results with a matching calculation of the local counterterm, performed within the large-$N_C$ expansion. We find R_{e/mu}^{(π)} = (1.2352 \pm 0.0001)*10^{-4} and R_{e/mu}^{(K)} = (2.477 \pm 0.001)*10^{-5}, with uncertainty induced by the matching procedure and chiral power counting. Given the sensitivity of upcoming new measurements, our results provide a clean baseline to detect or constrain effects from weak-scale new physics in these rare decays. As a by-product, we also update the theoretical analysis of the individual pi/K -> \ell nu modes. | |
| dc.description | 40 pages, 4 figures, 3 tables | |
| dc.identifier | https://arxiv.org/abs/0707.4464 | |
| dc.identifier | http://arxiv.org/abs/0707.4464 | |
| dc.identifier | JHEP 0710:005,2007 | |
| dc.identifier | doi:10.1088/1126-6708/2007/10/005 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/220058 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | pi/K -> e nu branching ratios to O(e^2 p^4) in Chiral Perturbation Theory | |
| dc.type | text |