Study of $D_J$ meson decays to $D^+\pi^-$, $D^0 \pi^+$ and $D^{*+}\pi^-$ final states in pp collision

TL;DR

This paper reports on the observation and analysis of various $D_J$ meson resonances in pp collision data at 7 TeV, including their properties, spin-parity, and new structures around 2500-3000 MeV.

Contribution

First detailed study of $D_J$ meson decays to multiple final states in pp collisions at 7 TeV, identifying new resonances and measuring their properties.

Findings

Observation of $D_1(2420)^0$ and $D^*_2(2460)$ resonances in multiple decay channels.

Identification of two natural parity and two unnatural parity resonances between 2500 and 2800 MeV.

Detection of structures around 3000 MeV in all studied final states.

Abstract

A study of $D^+\pi^-$, $D^0 \pi^+$ and $D^{*+}\pi^-$ final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 $fb^{-1}$, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The $D_1(2420)^0$ resonance is observed in the $D^{*+}\pi^-$ final state and the $D^*_2(2460)$ resonance is observed in the $D^+\pi^-$, $D^0 \pi^+$ and $D^{*+}\pi^-$ final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the $D^{*+}\pi^-$, $D^+\pi^-$ and $D^0 \pi^+$ final states.