Zetta Particles – Definition and Explanations of Ultra high energy cosmic rays

What is Zetta Particles?

In physics, here’s an example of the Zetta particles… You take a tennis ball. Service hit. Throwing at a speed of 200 km / hour (124 mph). Can you imagine the energy? Focus on small particles, like protons. Your proton then becomes a zetta particle, which has an energy of 10 21 electronvolts, a number denoted by the zetta prefix.

High-energy cosmic rays from outer space striking Earth’s atmosphere pose a real puzzle.

Zetta particles are particles whose estimated energy is of the order of ZeV (10 21 eV, or about 100 J).

The current energy records for an observed particle are:
  • by the Fly’s Eye at the University of Utah, a 3.5 x 1020eV zetta-particle in October 1991. Probably a proton or a light atomic nucleus which possessed an energy equivalent to that of a tennis ball struck by a good player.
  • by AGASA (Akeno Giant Air Shower Array), a particle shower resulting from a 2 x 1020 eV zetta-particle on December 3, 1993. The source is not identified but should be only a few tens of mega-parsecs away from Earth.

These are the most energetic phenomena known in nature. According to Scientific American of January 1999, AGASA has only detected a total of 5 events since 1991.

One of the reasons for the surprise of encountering such energetic phenomena (beyond the simple unknown of their origin) is that the particles which cross space interact with the background of fossil microwave radiation (cosmic microwave background, in English) and gradually (but quickly) lose their energy until they drop significantly below 5*1019eV or 50 Eev, which is known as the Greisen-Zatsepin-Kuzmin (GZK) limit. For this reason, the zetta-particles should either be formed very close to the Earth (but the scientists would then expect a phenomenon that is extremely easy to observe given the energies to be implemented), or remain insensitive to this interaction (and this leaves little room for particles clearly identified or known today).

However, some theorists now believe that the exceptional nature of observations at these very high energies could remain compatible with the Greisen-Zatsepin-Kuzmin (GZK) limit, its statistical characteristics and the current state of knowledge in theoretical physics.

In practice, some observations from the Akeno Giant Air Shower Array (AGASA) seem to indicate a strong correlation between the most powerful events and galaxy clusters.

Cosmic ray flux versus particle energy
The differential energy spectrum of cosmic rays has a power-law character (in a twice-logarithmic scale – an inclined line) (minimum energies – yellow zone, solar modulation, average energies – blue zone, GKP, maximum energies – purple zone, extragalactic CPs). Sven Lafebre, CC BY-SA 3.0, via Wikimedia Commons

History of the 1st observation concerning the Zetta Particles

The first observation of a cosmic ray with an energy greater than 10 20  eV (Electronvolt) was made by John Linsley during the experiment conducted at Volcanic Ranch in New Mexico in 1962 . Since then cosmic rays with even higher energies have been observed, among them also the particle that has been called “Oh-My-God ” : at least two dozen similar events have been recorded, which confirm the real existence of this type of particles.

This type of particle is very rare, the energy of most cosmic rays is generally between 10 7 and 10 10  electron volts (the Oh-My-God it was detected in the afternoon of October 15, 1991 , above Dugway (Utah), by the Fly’s Eye Cosmic Ray Detector of the Utah State University. The particle had an energy of 3.2 × 10 20  eV.

Cosmic Rays | Let’s talk about science

Sources: PinterPandai, CERN, American Association for the Advancement of Science (AAAS)Universe Today – via phys.org


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