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arXiv · hep-ex/0203031

Evidence for new interference phenomena in the decay D+ to K- pi+ mu+ nu

The FOCUS Collaboration
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Abstract

Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present evidence for a small, even spin K- π+ amplitude that interferes with the dominant K*0 component in the K-pi+ mu- nu final state. Although this interference significantly distorts the decay angular distributions, the new amplitude creates only a very small distortion to the observed kaon pion mass distribution when integrated over the other kinematic variables describing the decay. Our data can be described by K*0 interference with either a constant amplitude or broad spin zero resonance.

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The FOCUS Collaboration. 2002-03-19. Evidence for new interference phenomena in the decay D+ to K- pi+ mu+ nu. https://doi.org/10.1016/s0370-2693(02)01715-x

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