COSMIC RAYS

We study ultrahigh-energy cosmic rays, the highest-energy particles in the Universe, with three primary questions in mind:

• Can we determine the composition of the highest-energy particles (protons or heavier nuclei) electromagnetically, without reference to particle physics models? And, once we do, can we use this knowledge to constrain, in turn, particle physics at super-LHC energies using observations of collisions between cosmic-rays and atoms in the Earth's atmosphere?

• Can we identify at least one likely nearby source of ultrahigh-energy cosmic rays?

• What can we learn about the astrophysics of the systems that accelerate the highest energy particles, when the first source is found? 

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Selected Publications: 

• Reconstructing Galactic magnetic fields from local measurements for backtracking ultra-high-energy cosmic rays
  Tsouros, Edenhofer, Ensslin, Mastorakis, Pavlidou 2023, A&A

• What do the highest-energy cosmic-ray data suggest about possible new physics around 50 TeV? 
  Pavlidou and Tomaras 2019, Phys. Rev. D.

• Deflections of ultra-high energy cosmic rays by the Milky Way magnetic field: how well can they be corrected?
  Magkos and Pavlidou 2019, JCAP

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Our cosmic-ray research is funded by the Hellenic Foundation for Research and Innovation through project CIRCE.