A Non-parametric Approach to the D+ to K*0bar mu+ nu Form Factors

TL;DR

This paper presents the first non-parametric measurements of D+ to K*0bar mu+ nu form factors using a large experimental dataset, challenging traditional assumptions and providing new insights into decay dynamics.

Contribution

It introduces a non-parametric method to measure D+ decay form factors without relying on spectroscopic pole dominance assumptions.

Findings

Reasonable agreement with pole dominance assumptions

First measurements of certain form factor ratios

Insights into s-wave interference effects

Abstract

Using a large sample of D+ -> K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscopic pole dominance and measured form factor ratios.