Dalitz plot analysis of the D^+ -> K^-pi^+pi^+ decay

TL;DR

This paper presents a detailed Dalitz plot analysis of the D^+ -> K^-pi^+pi^+ decay using CLEO-c data, improving resonance modeling and including isospin contributions to better fit the experimental data.

Contribution

It introduces an improved isobar model and a quasi-model-independent approach, incorporating isospin-two pi^+pi^+ S-wave contributions for enhanced data description.

Findings

Better agreement with data using modified isobar model

Successful measurement of K pi S wave magnitude and phase

Inclusion of isospin-two pi^+pi^+ S-wave improves fit

Abstract

We perform a Dalitz plot analysis of D^+ -> K^-pi^+pi^+ decay with the CLEO-c data set of 572 pb^-1 of e^+e^- collisions accumulated at the psi(3770). This corresponds to 1.6 million D^+D^- pairs from which we select 140793 candidate events with a small background of 1.1%. We compare our results with previous measurements using the isobar model. We modify the isobar model with improved description of some of the contributing resonances, and get better agreement with our data. We also consider a quasi-model-independent approach and measure the magnitude and phase of the contributing K pi S wave in the range of invariant masses from the threshold to the maximum in this decay. This gives an improved descriptions of our data over the isobar model. Finally we allow for an isospin-two pi^+pi^+ S-wave contribution, and find that adding this to both the isobar model and quasi-model-independent approach gives the best description of our data.