Measurement of K-mu 3(0) form factors

Measurement of K-mu 3(0) form factors

This Letter reports on a new high precision measurement of the form factors of the KL → π± μ∓ νμ decay. The data sample of about 2.3 × 106 events was recorded in 1999 by the NA48 experiment at CERN. Studying the Dalitz plot density we measured a linear, λ+′ = (20.5 ± 2.2stat ± 2.4syst) × 10-3, and a...

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Hlavní autoři: Lai, A, Marras, D, Bevan, A, Dosanjh, R, Gershon, T, Hay, B, Kalmus, G, Lazzeroni, C, Munday, D, Olaiya, E, Parker, M, White, T, Wotton, SA, Barr, G, Bocquet, G, Ceccucci, A, Cuhadar-Doenszelmann, T, Cundy, D, D'Agostini, G, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Gorini, B, Govi, G
Médium: Journal article
Jazyk:English
Vydáno: 2007
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Shrnutí:This Letter reports on a new high precision measurement of the form factors of the KL → π± μ∓ νμ decay. The data sample of about 2.3 × 106 events was recorded in 1999 by the NA48 experiment at CERN. Studying the Dalitz plot density we measured a linear, λ+′ = (20.5 ± 2.2stat ± 2.4syst) × 10-3, and a quadratic, λ+″ = (2.6 ± 0.9stat ± 1.0syst) × 10-3 term in the power expansion of the vector form factor. No evidence was found for a second order term for the scalar form factor; the linear slope was determined to be λ0 = (9.5 ± 1.1stat ± 0.8syst) × 10-3. Using a linear fit our results were: λ+ = (26.7 ± 0.6stat ± 0.8syst) × 10-3 and λ0 = (11.7 ± 0.7stat ± 1.0syst) × 10-3. A pole fit of the form factors yields: mV = (905 ± 9stat ± 17syst)   MeV / c2 and mS = (1400 ± 46stat ± 53syst)   MeV / c2. © 2007 Elsevier B.V. All rights reserved.

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