A sample of 7253 K+/- -> pi(+/-)e(+)e(-)(gamma) decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR = (3.11 +/- 0.12) x 10(-7), where the uncertainty includes also the model dependence. The shape of the form factor W(z), where z = (M-ee/M-K)(2) was parameterized according to several models, and, in particular, the slope delta of the linear form factor W(z) = W-0(1 + delta z) was determined to be delta = 2.32 +/- 0.18. A possible CP violating asymmetry of K+ and K- decay widths was investigated, and a conservative upper limit of 2.1 X 10(-2) at 90% CL was established. (C) 2009 Elsevier B.V. All rights reserved.
Precise measurement of the K ± → π ± e + e - decay / J. R., Batley; A. J., Culling; G., Kalmus; C., Lazzeroni; D. J., Munday; M. W., Slater; S. A., Wotton; R., Arcidiacono; G., Bocquet; N., Cabibbo; A., Ceccucci; D., Cundy; V., Falaleev; M., Fidecaro; L., Gatignon; A., Gonidec; W., Kubischta; A., Norton; A., Maier; M., Patel; A., Peters; S., Balev; P. L., Frabetti; E., Goudzovski; P., Hristov; V., Kekelidze; V., Kozhuharov; L., Litov; D., Madigozhin; E., Marinova; N., Molokanova; I., Polenkevich; Y., Potrebenikov; S., Stoynev; A., Zinchenko; E., Monnier; E., Swallow; R., Winston; P., Rubin; A., Walker; W., Baldini; A. C., Ramusino; P., Dalpiaz; C., Damiani; M., Fiorini; A., Gianoli; M., Martini; F., Petrucci; M., Savrie; M., Scarpa; H., Wahl; Bizzeti, Andrea; M., Calvetti; E., Celeghini; E., Iacopini; M., Lenti; F., Martelli; G., Ruggiero; M., Veltri; M., Behler; K., Eppard; K., Kleinknecht; P., Marouelli; L., Masetti; U., Moosbrugger; C. M., Morales; B., Renk; M., Wache; R., Wanke; A., Winhart; D., Coward; A., Dabrowski; T. F., Martin; M., Shieh; M., Szleper; M., Velasco; M. D., Wood; G., Anzivino; P., Cenci; E., Imbergamo; A., Nappi; M., Pepe; M. C., Petrucci; M., Piccini; M., Raggi; M., Valdata Nappi; C., Cerri; R., Fantechi; G., Collazuol; L., Dilella; G., Lamanna; I., Mannelli; A., Michetti; F., Costantini; N., Doble; L., Fiorini; S., Giudici; G., Pierazzini; M., Sozzi; S., Venditti; B., Bloch Devaux; C., Cheshkov; J. B., Cheze; M. D., Beer; J., Derre; G., Marel; E., Mazzucato; B., Peyaud; B., Vallage; M., Holder; M., Ziolkowski; S., Bifani; C., Biino; N., Cartiglia; M., Clemencic; S. G., Lopez; F., Marchetto; H., Dibon; M., Jeitler; M., Markytan; I., Mikulec; G., Neuhofer; L., Widhalm. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - STAMPA. - 677:5(2009), pp. 246-254. [10.1016/j.physletb.2009.05.040]
Precise measurement of the K ± → π ± e + e - decay
BIZZETI, Andrea;
2009
Abstract
A sample of 7253 K+/- -> pi(+/-)e(+)e(-)(gamma) decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR = (3.11 +/- 0.12) x 10(-7), where the uncertainty includes also the model dependence. The shape of the form factor W(z), where z = (M-ee/M-K)(2) was parameterized according to several models, and, in particular, the slope delta of the linear form factor W(z) = W-0(1 + delta z) was determined to be delta = 2.32 +/- 0.18. A possible CP violating asymmetry of K+ and K- decay widths was investigated, and a conservative upper limit of 2.1 X 10(-2) at 90% CL was established. (C) 2009 Elsevier B.V. All rights reserved.
| File | Dimensione | Formato | |
|---|---|---|---|
|
0903.3130.pdf
Open access
Tipologia:
Versione pubblicata dall'editore
Dimensione
316.53 kB
Formato
Adobe PDF
|
316.53 kB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris
