An extremely energetic cosmic ray observed by a surface detector array

Area of Science:

• Astrophysics
• Particle Physics
• Cosmic Ray Physics

Background:

• Cosmic rays are highly energetic charged particles originating from outer space.
• The most energetic cosmic rays are believed to originate from extragalactic sources.
• Detecting these rare, high-energy events necessitates instruments with substantial collecting areas.

Purpose of the Study:

• To report the detection of an extremely energetic particle by the Telescope Array experiment.
• To analyze the energy and arrival direction of this detected particle.
• To explore potential origins and implications of this high-energy cosmic ray event.

Main Methods:

• Utilized the surface detector array of the Telescope Array experiment for particle detection.
• Calculated the energy of the detected particle.
• Determined the arrival direction of the particle to trace its cosmic origin.

Main Results:

• Successfully detected an extremely energetic particle with an energy of approximately 40 joules.
• The particle's arrival direction was traced back to a void in the large-scale structure of the Universe.
• The data suggests a potential discrepancy with current astrophysical models.

Conclusions:

• The detected particle's origin from a cosmic void presents a significant anomaly.
• Possible explanations include substantial deflection by intergalactic magnetic fields.
• Alternative hypotheses involve an unknown local extragalactic source or gaps in current particle physics understanding.