Detailed study of the K ^sup ±^ [arrow right] [pi] ^sup 0^ [pi] ^sup 0^ e ^sup ±^ [nu] (K^sub e4^^sup 00^) decay properties

• Published in: The journal of high energy physics Vol. 2014; no. 8; p. 1
• Main Authors: Batley, J R, Kalmus, G, Lazzeroni, C, Munday, D J, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Cabibbo, N, Ceccucci, A, Cundy, D, Falaleev, V, Fidecaro, M, Gatignon, L, Gonidec, A, Kubischta, W, Maier, A, Patel, M, Peters, A, Balev, S, Gersabeck, E, Goudzovski, E, Kekelidze, V, Kozhuharov, V, Litov, L, Madigozhin, D, Molokanova, N, Polenkevich, I, Stoynev, S, Monnier, E, Swallow, E, Rubin, P, Walker, A, Baldini, W, Ramusino, A Cotta, Dalpiaz, P, Damiani, C, Fiorini, M, Gianoli, A, Petrucci, F, Savrié, M, Scarpa, M, Wahl, H, Bizzeti, A, Lenti, M, Veltri, M, Calvetti, M, Celeghini, E, Iacopini, E, Ruggiero, G, Behler, M, Gersabeck, M, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Martin, T Fonseca, Shieh, M, Szleper, M, Cenci, P, Pepe, M, Petrucci, Mc, Anzivino, G, Imbergamo, E, Raggi, M, Cerri, C, Fantechi, R, Collazuol, G, Dilella, L, Lamanna, G, Mannelli, I, Michetti, A, Costantini, F, Sozzi, M, Venditti, S, Bloch-devaux, B, Cheshkov, C, Chèze, J B, Derré, J, Marel, G, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Cartiglia, N, Marchetto, F, Bifani, S, Clemencic, M, Lopez, S Goy, Dibon, H, Markytan, M, Mikulec, I, Neuhofer, G, Widhalm, L
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.08.2014
• Subjects: High energy physics
• ISSN: 1029-8479
• DOI: 10.1007/JHEP08(2014)159

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A sample of 65210 K ^sup ±^ [arrow right] [pi] ^sup 0^ [pi] ^sup 0^ e ^sup ±^ [nu] (K^sub e4^^sup 00^) decay candidates with 1% background contamination has been collected in 2003-2004 by the NA48/2 collaboration at the CERN SPS. A study of the differential rate provides the first measurement of the hadronic form factor variation in the plane (M ^sub ππ^^sup 2^,M ^sub e[nu]^^sup 2^) and brings evidence for a cusp-like structure in the distribution of the squared [pi] ^sup 0^ [pi] ^sup 0^ invariant mass around ... Exploiting a model independent description of this form factor, the branching ratio, inclusive of radiative decays, is obtained using the K ^sup ±^ [arrow right] [pi] ^sup 0^ [pi] ^sup 0^ [pi] ^sup ±^ decay mode as normalization. It is measured to be BR(K^sub e4^^sup 00^) = (2.552 ± 0.010^sub stat^ ± 0.010^sub syst^ ± 0.032^sub ext^) × 10^sup -5^, which improves the current world average precision by an order of magnitude while the 1.4% relative precision is dominated by the external uncertainty from the normalization mode. A comparison with the properties of the corresponding mode involving a [pi] ^sup +^ [pi] ^sup -^ pair (K^sub e4^^sup +-^) is also presented.