Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

H. WAHLBERG Y ATLAS COLLABORATION

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2016

0031-9007

We measure the energy emitted by extensive air showers in the form of radio emission in thefrequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre AugerObservatory, we obtain a radiation energy of 15.8 ± 0.7 (stat) ± 6.7 (sys) MeV for cosmic rays withan energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadraticallywith the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principlecalculations shows agreement with our measurement. The radiation energy provides direct access tothe calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with ourresult thus allows the direct calibration of any cosmic-ray radio detector against the well-establishedenergy scale of the Pierre Auger Observatory.