Observation of the charmed baryon c+ and measurement of the isospin mass splittings of the c
We observe the c+ baryon decaying to Λc+π0 and measure the mass difference M(c+)-M(Λc+) to be 168.5±0.2 MeV/c2. We also measure the mass differences M(c++)-M(Λc+) and M(c0-M(Λc+) with improved precision and determine the isospin mass splittings M(c++)-M(c0) and M(c+)-M(c0) to be 1.1±0.4±0.1 MeV/c2 and 1.4±0.5±0.3 MeV/c2, respectively. Our results indicate that the light quark mass difference does not dominate the isospin mass splitting in c. © 1993 The American Physical Society.
