A Baryon is a composite particle made of three quarks, such as a Proton or Neutron. They make up nearly all the mass of matter in the universe. Baryons, along with Mesons, which comprise two quarks are Hadrons.
Electrons and Neutrinos (ν) are Leptons which are not made of quarks, but are elementary particles in their own right. Photons are examples of particles that are neither leptons or hadrons.
Baryon Acoustic Oscillations (BAO)
Baryon Oscillation Spectroscopic Survey (BOSS)
Lambda-CDM model (ΛCDM)
Sloan Digital Sky Survey (SDSS)