Test of lepton flavour universality in K(+) -> l(+)nu decays

Lazzeroni, C; Romano, A; Ceccucci, A; Danielsson, H; Falaleev, V; Gatignon, L; Lopezl, Sg; Hallgren, B; Maier, A; Peters, A; Piccini, M; Riedler, P; Dyulendarova, M; Frabetti, Pl; Kekelidze, V; Madigozhin, D; Marinova, E; Molokanova, N; Movchan, S; Potrebenikov, Y; Shkarovskiy, S; Zinchenko, A; Rubin, P; Baldini, W; Ramusino, Ac; Dalpiaz, P; Fiorini, M; Gianoli, A; Norton, A; Petrucci, F; Savrie, M; Wahl, H; Bizzeti, A; Bucci, Francesca; Iacopini, Enrico; Lenti, M; Veltri, M; Eppard, K; Hita Hochgesand, M; Kleinknecht, K; Renk, B; Wanke, R; Winhart, A; Winston, R; Olotov, V; Duk, V; Gushchin, E; Ambrosino, F; Di Filippo, D; Massarotti, P; Napolitano, M; Palladino, V; Saracino, G; Anzivino, G; Imbergamo, E; Piandani, R; Sergi, A; Cenci, P; Pepe, M; Costantini, F; Doble, N; Giudici, S; Pierazzini, G; Sozzi, M; Venditti, S; Balev, S; Collazuol, G; Dileila, L; Gallorini, S; Goudzovski, E; Lamanna, G; Marinelli, I; Ruggiero, G; Cerri, C; Fantechi, R; Kurshetsov, V; Obraztsov, V; Popov, I; Semenov, V; Yushchenko, O; D'Agostini, G; Leonardi, E; Serra, M; Valente, P; Fucci, A; Salamon, A; Bloch Devaux, B; Peyaud, B; Engelfried, J; Coward, D; Kozhuharov, V; Litov, L; Arcidiacono, R; Bifani, S; Biino, C; Dellacasa, G; Marchetto, F; Numao, T; Retiere, F.; Antonelli, . A.; M. M. o. u. l. s. o. n., . R. Raggi; Spadaro, . T.

doi:10.1016/j.physletb.2011.02.064

A precision test of lepton flavour universality has been performed by measuring the ratio RK of kaon leptonic decay rates K+ → e+ν and K+ → μ+ν in a sample of 59 813 reconstructed K+ → e+ν candidates with (8.71 ± 0.24)% background contamination. The result RK = (2.487 ± 0.013) × 10−5 is in agreement with the Standard Model expectation.

Test of lepton flavour universality in K(+) -> l(+)nu decays / Lazzeroni C; Romano A; Ceccucci A; Danielsson H; Falaleev V; Gatignon L; Lopezl SG; Hallgren B; Maier A; Peters A; Piccini M; Riedler P; Dyulendarova M; Frabetti PL; Kekelidze V; Madigozhin D; Marinova E; Molokanova N; Movchan S; Potrebenikov Y; Shkarovskiy S; Zinchenko A; Rubin P; Baldini W; Ramusino AC; Dalpiaz P; Fiorini M; Gianoli A; Norton A; Petrucci F; Savrie M; Wahl H; Bizzeti A; Bucci F; Iacopini E; Lenti M; Veltri M; Eppard K; Hita-Hochgesand M; Kleinknecht K; Renk B; Wanke R; Winhart A; Winston R; Olotov V; Duk V; Gushchin E; Ambrosino F; Di Filippo D; Massarotti P; Napolitano M; Palladino V; Saracino G; Anzivino G; Imbergamo E; Piandani R; Sergi A; Cenci P; Pepe M; Costantini F; Doble N; Giudici S; Pierazzini G; Sozzi M; Venditti S; Balev S; Collazuol G; DiLeila L; Gallorini S; Goudzovski E; Lamanna G; Marinelli I; Ruggiero G; Cerri C; Fantechi R; Kurshetsov V; Obraztsov V; Popov I; Semenov V; Yushchenko O; D'Agostini G; Leonardi E; Serra M; Valente P; Fucci A; Salamon A; Bloch-Devaux B; Peyaud B; Engelfried J; Coward D; Kozhuharov V; Litov L; Arcidiacono R; Bifani S; Biino C; Dellacasa G; Marchetto F; Numao T; Retiere F,A. Antonelli, M. Moulson,R. Raggi,T. Spadaro. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - STAMPA. - 698:(2011), pp. 105-114. [10.1016/j.physletb.2011.02.064]