# International Workshop on Partial Wave Analyses and Advanced Tools for Hadron Spectroscopy

Mar 13 – 17, 2017
Europe/Zurich timezone

## The a_1(1260) lineshape measured in D -> 4pi decays

Mar 14, 2017, 5:00 PM
30m

### Speaker

Mr Philippe d'Argent (Ruprecht-Karls-Universitaet Heidelberg (DE))

### Description

The decay $D^{0} \rightarrow \pi^{+}\pi^{-}\pi^{+}\pi^{-}$, with $D^{0} \rightarrow a_1(1260)^{+} \pi^{-}$ being the dominant intermediate state, provides an excellent environment to study the properties of the $a_1(1260)$ meson. We present new measurements of the $a_1(1260)$’s mass and width using data collected with the CLEO-c detector. The $a_1(1260)$ contribution is disentangled from the other occurring decay channels by means of a full five-dimensional amplitude analysis. A state-of-the-art parameterization of the $a_1(1260)$ lineshape is used taking into account the resonant three-pion substructure. In addition, several other lineshape models are tested. As we observe a significant dependence of the measured width on the chosen parameterization, a quasi-model-independent study of the lineshape is performed as well.

### Primary authors

Mr Philippe d'Argent (Ruprecht-Karls-Universitaet Heidelberg (DE)) Jeremy Peter Dalseno (University of Bristol (GB)) Jonas Rademacker (University of Bristol (GB))

### Co-authors

Jack Benton (University of Bristol (GB)) Evelina Mihova Gersabeck (Ruprecht-Karls-Universitaet Heidelberg (DE)) Samuel Thomas Harnew (University of Bristol (GB)) Paras Naik (University of Bristol (GB)) Claire Prouve (University of Bristol (GB)) Nicola Anne Skidmore (University of Bristol (GB))