| Thème(s) : |
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Physique/Physique des Hautes Energies - Expérience
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| Titre : |
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Precise Measurement of the e+ e- --> pi+ pi- (gamma) Cross Section with the Initial-State Radiation Method at BABAR |
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| Auteur : |
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J. P. Lees1, V. Poireau1, V. Tisserand1, D. Bernard2, M. Verderi2, N. Arnaud3, M. Davier3, D. Derkach3, G. Grosdidier3, F. Le Diberder3, A. M. Lutz3, B. Malaescu3, P. Roudeau3, M. H. Schune3, A. Stocchi3, L. L. Wang3, G. Wormser3, S. Akar4, E. Ben-Haim4, M. Bomben4, G. R. Bonneaud4, H. Briand4, G. Calderini4, J. Chauveau4, O. Hamon4, Ph. Leruste4, G. Marchiori4, J. Ocariz4, S. Sitt4, S. Emery5, G. Hamel de Monchenault5, G. Vasseur5, Ch. Yeche5 |
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| Laboratoire : |
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| Résumé : |
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A precise measurement of the cross section of the process $e^+e^-\to\pi^+\pi^-(\gamma)$ from threshold to an energy of 3GeV is obtained with the initial-state radiation (ISR) method using $232\invfb$ of data collected with the BaBar detector at $e^+e^-$ center-of-mass energies near 10.6GeV. The ISR luminosity is determined from a study of the leptonic process $e^+e^-\to\mu^+\mu^-(\gamma)\gamma_{\rm ISR}$, which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process $e^+e^-\to\pi^+\pi^-(\gamma)$ is obtained with a systematic uncertainty of 0.5% in the dominant $\rho$ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $\pi\pi$ cross section from threshold to 1.8GeV is $(514.1 \pm 2.2({\rm stat}) \pm 3.1({\rm syst}))\times 10^{-10}$. |
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| Collaboration/Projet : |
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BABAR |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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Date de publication ou d'écriture : |
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2012 |
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| Nom du périodique : |
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| Physical Review D (Phys. Rev. D) |
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American Physical Society |
| ISSN |
1550-7998 (eISSN : 1550-2368) |
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| Volume : |
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86 |
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| Page/Article : |
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032013 |
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| Commentaire : |
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See paper for full list of authors - 58 pages, 56 figures, to be submitted to Phys. Rev. D |
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