Alpha Magnetic Spectrometer measurements unveil a new class of Primary Cosmic Rays

Jun 1, 2020 Off Comments in Announcement by

The rigidity dependence of the Ne, Mg, and Si fluxes compared to rigidity dependence of the He, C, and O fluxes above 86.5 GV. Spectral indices of Ne, Mg and Si are smaller than those of He, C and O. The difference of spectral indices is -0.045 ± 0.008, this unexpected result is an evidence that the Ne,Mg, and Si and He, C, and O are two different classes of primary cosmic rays.

 

The Alpha Magnetic Spectrometer (AMS) collaboration, has published a series of precision measurements of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), analyzed in the rigidity range 2.15 GV to 3.0 TV.
These measurements were collected by the AMS, a spectrometer located on the International Space Station (ISS).
The Ne, Mg and Si spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way.
Unexpectedly, the rigidity dependence of primary cosmic rays Ne, Mg and Si spectra is different from the rigidity dependence of primary cosmic rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of primary cosmic rays.

The measurements are published in "Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer" Phys. Rev. Lett. 124, 211102 and the article has been indicated as "editor's suggestion".