Observation of a Charmed Baryon Decaying to D0 p at a Mass Near 2.94 GeV/c2

TL;DR

This paper reports the discovery of a new charmed baryon near 2.94 GeV/c^2 decaying to D0 p, based on analysis of BaBar data, and measures properties of known baryons and decay modes.

Contribution

The study presents the first observation of a previously unobserved charmed baryon at 2.94 GeV/c^2 decaying to D0 p, expanding knowledge of charmed baryon spectrum.

Findings

Discovery of a new baryon at 2.94 GeV/c^2

Measured mass and width of the new state

Confirmed properties of the Λc(2880)^+ baryon

Abstract

A search for charmed baryons decaying to $D^0 p$ reveals two states: the $\Lambda_c(2880)^+$ baryon and a previously unobserved state at a mass of [$2939.8\pm 1.3 \text{(stat.)}\pm 1.0 \text{(syst.)}$]~\mevcc and with an intrinsic width of [$17.5\pm 5.2 \text{(stat.)}\pm 5.9 \text{(syst.)}$]~\mev. Consistent and significant signals are observed for the $K^-\pi^+$ and $K^-\pi^+\pi^-\pi^+$ decay modes of the $D^0$ in 287 ${\rm fb}^{-1}$ annihilation data recorded by the BaBar detector at a center-of-mass energy of 10.58~${\rm GeV}/c^2$. There is no evidence in the $D^+ p$ spectrum of doubly-charged partners. The mass and intrinsic width of the $\Lambda_c(2880)^+$ baryon and relative yield of the two baryons are also measured.