The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic

We revisit the procedure for comparing the pi pi spectral function measured in tau decays to that obtained in e+e- annihilation. We re-examine the isospin-breaking corrections using new experimental and theoretical input, and find improved agreement between the tau- --> pi- pi0 nu_tau branching f...

Descripción completa

Detalles Bibliográficos
Autores principales: Davier, M, Höcker, A, López-Castro, G, Malaescu, B, Mo, X H, Toledo Sanchez, G, Wang, P, Yuan, C Z, Zhang, Z
Lenguaje:eng
Publicado: 2009
Materias:
Particle Physics - Phenomenology
Acceso en línea:https://dx.doi.org/10.1140/epjc/s10052-009-1219-4
http://cds.cern.ch/record/1187123
_version_ 1780916480996540416
author Davier, M
Höcker, A
López-Castro, G
Malaescu, B
Mo, X H
Toledo Sanchez, G
Wang, P
Yuan, C Z
Zhang, Z
author_facet Davier, M
Höcker, A
López-Castro, G
Malaescu, B
Mo, X H
Toledo Sanchez, G
Wang, P
Yuan, C Z
Zhang, Z
author_sort Davier, M
collection CERN
description We revisit the procedure for comparing the pi pi spectral function measured in tau decays to that obtained in e+e- annihilation. We re-examine the isospin-breaking corrections using new experimental and theoretical input, and find improved agreement between the tau- --> pi- pi0 nu_tau branching fraction measurement and its prediction using the isospin-breaking-corrected e+e- --> pi+pi- spectral function, though not resolving all discrepancies. We recompute the lowest order hadronic contributions to the muon g-2 using e+e- and tau data with the new corrections, and find a reduced difference between the two evaluations. The new tau-based estimate of the muon magnetic anomaly is found to be 1.9 standard deviations lower than the direct measurement.
id cern-1187123
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2009
record_format invenio
spelling cern-11871232019-09-30T06:29:59Zdoi:10.1140/epjc/s10052-009-1219-4http://cds.cern.ch/record/1187123engDavier, MHöcker, ALópez-Castro, GMalaescu, BMo, X HToledo Sanchez, GWang, PYuan, C ZZhang, ZThe Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon MagneticParticle Physics - PhenomenologyWe revisit the procedure for comparing the pi pi spectral function measured in tau decays to that obtained in e+e- annihilation. We re-examine the isospin-breaking corrections using new experimental and theoretical input, and find improved agreement between the tau- --> pi- pi0 nu_tau branching fraction measurement and its prediction using the isospin-breaking-corrected e+e- --> pi+pi- spectral function, though not resolving all discrepancies. We recompute the lowest order hadronic contributions to the muon g-2 using e+e- and tau data with the new corrections, and find a reduced difference between the two evaluations. The new tau-based estimate of the muon magnetic anomaly is found to be 1.9 standard deviations lower than the direct measurement.arXiv:0906.5443BIHEP-TH-09-01CERN-OPEN-2009-007LAL-09-50oai:cds.cern.ch:11871232009-07-01
spellingShingle Particle Physics - Phenomenology
Davier, M
Höcker, A
López-Castro, G
Malaescu, B
Mo, X H
Toledo Sanchez, G
Wang, P
Yuan, C Z
Zhang, Z
The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title_full The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title_fullStr The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title_full_unstemmed The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title_short The Discrepancy Between Tau and $e^+ e^-$ Spectral Functions Revisited and the Consequences for the Muon Magnetic
title_sort discrepancy between tau and $e^+ e^-$ spectral functions revisited and the consequences for the muon magnetic
topic Particle Physics - Phenomenology
url https://dx.doi.org/10.1140/epjc/s10052-009-1219-4
http://cds.cern.ch/record/1187123
work_keys_str_mv AT davierm thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT hockera thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT lopezcastrog thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT malaescub thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT moxh thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT toledosanchezg thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT wangp thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT yuancz thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT zhangz thediscrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT davierm discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT hockera discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT lopezcastrog discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT malaescub discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT moxh discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT toledosanchezg discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT wangp discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT yuancz discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic
AT zhangz discrepancybetweentauandeespectralfunctionsrevisitedandtheconsequencesforthemuonmagnetic

Ejemplares similares