The origin of cosmic rays with ultra-high energies (UHE) remains mystery.In our paper*, we have discussed whether dense quark matter – quark-gluon plasma, formed in the centers of neutron stars or Quark Stars (QS), could be a source of these UHE cosmic rays. QS, in particular, are more likely candidates for being the source of UHE cosmic rays, although for a long time, they remained unobserved. A recent study** proposed that the low-mass companion of the black hole in GW190814 might be a strange quark star. In the talk we continue to discuss that the QS’s matter, could be a source of the UHE particles. Results from the RHIC and LHC experiments on ultrarelativistic heavy ion collisions suggest that the quark-gluon matter produced in such collisions displaying collective behavior. This behavior could lead to the formation of a coherent group of partons (CGP). A collision between a parton and the CGP, similar to a photon colliding with a high-energy electron, could result in the parton gaining energy through the in-verse Compton effect, thereby accelerating without an external field.