Measurement of K0e3 form factors

Lai, A.; Marras, D.; Bevan, A.; Dosanjh, R. S.; Gershon, T. J.; Hay, B.; Kalmus, G. E.; Lazzeroni, C.; Munday, D. J.; Olaiya, E.; Parker, M. A.; White, T. O.; Wotton, S. A.; Barr, G.; Bocquet, G.; Ceccucci, A.; Cuhadar Donszelmann, T.; Cundy, D.; D'Agostini, G.; Doble, N.; Falaleev, V.; Gatignon, L.; Gonidec, A.; Gorini, B.; Govi, G.; Grafstrom, P.; Kubischta, W.; Lacourt, A.; Norton, A.; Palestini, S.; Panzer Steindel, B.; Taureg, H.; Velasco, M.; Wahl, H.; Cheshkov, C.; Hristov, P.; Kekelidze, V.; Litov, L.; Madigojine, D.; Molokanova, N.; Potrebenikov, Y. U.; Stoynev, S.; Zinchenko, A.; Knowles, I.; Martin, V.; Sacco, R.; Walker, A.; Contalbrigo, M.; Dalpiaz, P.; Duclos, J.; Frabetti, P. L.; Gianoli, A.; Martini, M.; Petrucci, F.; Savrie, M.; Bizzeti, Andrea; Calvetti, M.; Collazuol, G.; Graziani, G.; Iacopini, E.; Lenti, M.; Martelli, F.; Veltri, M.; Becker, H. G.; Eppard, K.; Eppard, M.; Fox, H.; Kalter, A.; Kleinknecht, K.; Koch, U.; Kopke, L.; Lopes Da Silva, P.; Marouelli, P.; Pellmann, I.; Peters, A.; Renk, B.; Schmidt, S. A.; Schonharting, V.; Schue, Y.; Wanke, R.; Winhart, A.; Wittgen, M.; Chollet, J. C.; Fayard, L.; Iconomidou Fayard, L.; Ocariz, J.; Unal, G.; Wingerter Seez, I.; Anzivino, G.; Cenci, P.; Imbergamo, E.; Lubrano, P.; Mestvirishvili, A.; Nappi, A.; Pepe, M.; Piccini, M.; Bertanza, L.; Carosi, R.; Casali, R.; Cerri, C.; Cirilli, M.; Costantini, F.; Fantechi, R.; Giudici, S.; Mannelli, I.; Pierazzini, G.; Sozzi, M.; Cheze, J. B.; Cogan, J.; De Beer, M.; Debu, P.; Formica, A.; Granier De Cassagnac, R.; Mazzucato, E.; Peyaud, B.; Turlay, R.; Vallage, B.; Holder, M.; Maier, A.; Ziolkowski, M.; Arcidiacono, R.; Biino, C.; Cartiglia, N.; Marchetto, F.; Menichetti, E.; Pastrone, N.; Nassalski, J.; Rondio, E.; Szleper, M.; Wislicki, W.; Wronka, S.; Dibon, H.; Fischer, G.; Jeitler, M.; Markytan, M.; Mikulec, I.; Neuhofer, G.; Pernicka, M.; Taurok, A.; Widhalm, L.

doi:10.1016/j.physletb.2004.08.076

The semileptonic decay of the neutral K meson, K0L → π± e∓ ν (Ke3 ), was used to study the strangeness-changing weak interaction of hadrons. A sample of 5.6 million reconstructed events recorded by the NA48 experiment was used to measure the Dalitz plot density. Admitting all possible Lorentz-covariant couplings, the form factors for vector (f+(q2)), scalar (fS) and tensor (fT) interactions were measured. The linear slope of the vector form factor λ+ = 0.0284 ± 0.0007 ± 0.0013 and values for the ratios |fS/f+(0)| = 0.015 +0.007-0.010 ± 0.012 and |fT/f+(0)| = 0.05 +0.03-0.04 ± 0.03 were obtained. The values for fS and fT are consistent with zero. Assuming only vector–axial-vector couplings, λ+ = 0.0288 ± 0.0004 ± 0.0011 and a good fit consistent with pure V–A couplings were obtained. Alternatively, a fit to a dipole form factor yields a pole mass of M = 859 ± 18 MeV, consistent with the K∗(892) mass.

Measurement of K0e3 form factors / A., L., D., M., A., B., R. S., D., T. J., G., B., H., G. E., K., C., L., D. J., M., E., O., M. A., P., T. O., W., S. A., W., G., B., G., B., A., C., T., C.D., D., C., G., D., N., D., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - STAMPA. - 604:1-2(2004), pp. 1-10. [10.1016/j.physletb.2004.08.076]