HAWC observations of the acceleration of very-high-energy cosmic rays in the Cygnus Cocoon

Cosmic rays with energies up to a few PeV are known be accelerated within the Milky Way. Traditionally, it has been presumed that supernova remnants were main source of very-high-energy cosmic but theoretically is difficult get protons and observationally there simply no evidence support as sources hadrons above tens TeV. One possible those Galactic Center region. Here we report observations 1-100 TeV gamma coming from 'Cygnus Cocoon', which superbubble surrounding region OB2 massive star formation. These likely produced by 10-1000 freshly CRs originating enclosed forming Cygnus OB2. Hitherto was not such regions could accelerate particles these energies. The measured flux originated hadronic interactions. spectral shape emission profile Cocoon changes GeV energies, reveals transport historical activity in superbubble.