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Author (up) Campanario, F.; Czyz, H.; Gluza, J.; Gunia, M.; Riemann, T.; Rodrigo, G.; Yundin, V.
Title Complete QED NLO contributions to the reaction e(+)e(-) -> mu(+)mu(-)gamma and their implementation in the event generator PHOKHARA Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 114 - 27pp
Keywords B-Physics; Standard Model
Abstract KLOE and Babar have an observed discrepancy of 2% to 5% in the invariant pion pair production cross section. These measurements are based on approximate NLO mu(+)mu(-)gamma cross section predictions of the Monte Carlo event generator PHOKHARA7.0. In this article, the complete NLO radiative corrections to mu(+)mu(-)gamma production are calculated and implemented in the Monte Carlo event generator PHOKHARA9.0. Numerical reliability is guaranteed by two independent approaches to the real and the virtual corrections. The novel features include the contribution of pentagon diagrams in the virtual corrections, which form a gauge-invariant set when combined with their box diagram partners. They may contribute to certain distributions at the percent level. Also the real emission was complemented with two-photon final state emission contributions not included in the generator PHOKHARA7.0. We demonstrate that the numerical influence reaches, for realistic charge-averaged experimental setups, not more than 0.1% at KLOE and 0.3% at BaBar energies. As a result, we exclude the approximations in earlier versions of PHOKHARA as origin of the observed experimental discrepancy.
Address [Campanario, F.; Rodrigo, G.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia 46980, Spain, Email: francisco.campanario@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000332506600004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1725
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Author (up) Campanario, F.; Czyz, H.; Gluza, J.; Jelinski, T.; Rodrigo, G.; Tracz, S.; Zhuridov, D.
Title Standard model radiative corrections in the pion form factor measurements do not explain the a(mu) anomaly Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 7 Pages 076004 - 5pp
Keywords
Abstract In this paper, we address the question of whether the almost four standard deviations difference between theory and experiment for the muon anomalous magnetic moment a(mu) can be explained as a higher-order Standard Model perturbation effect in the pion form factor measurements. This question has, until now, remained open, obscuring the source of discrepancies between the measurements. We calculate the last radiative corrections for the extraction of the pion form factor, which were believed to be potentially substantial enough to explain the data within the Standard Model. We find that the corrections are too small to diminish existing discrepancies in the determination of the pion form factor for different kinematical configurations of low-energy BABAR, BES-III and KLOE experiments. Consequently, they cannot noticeably change the previous predictions for a(mu) and decrease the deviations between theory and direct measurements. To solve the above issues, new data and better understanding of low-energy experimental setups are needed, especially as new direct a(mu) measurements at Fermilab and J-PARC will provide new insights and substantially shrink the experimental error.
Address [Campanario, Francisco; Rodrigo, German; Tracz, Szymon] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46980 Valencia, Spain, Email: henryk.czyz@us.edu.pl
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000489577800008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4168
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Author (up) Czyz, H.; Ivashyn, S.; Korchin, A.; Shekhovtsova, O.
Title Two-photon form factors of the pi(0), eta, and eta ' mesons in the chiral theory with resonances Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 85 Issue 9 Pages 094010 - 10pp
Keywords
Abstract We have developed a phenomenological approach which describes very well the pi(0), eta and eta' meson production in the two-photon interactions. The simultaneous description of the pi(0), eta and eta' meson two-photon form factors is consistent with data in the spacelike region, with the exception of the pi(0) BABAR data. The obtained form factors are implemented in the event generator EKHARA and the simulated cross sections are presented. Uncertainties in the measured form factors coming from the model dependence in Monte Carlo simulations are studied. The model predictions for the form factor slopes at the origin are given and the high-Q(2) limit is also discussed.
Address [Czyz, Henryk] Univ Silesia, Inst Phys, PL-40007 Katowice, Poland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000303859600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1012
Permanent link to this record