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Why do the physicists hunt the most exciting of the ghost particles



Every second of every day you are bombarded by trillions of trillions of subatomic particles and showers down from the depths of space. They blow through you with the strength of a cosmic hurricane that blows at almost the speed of light. They come from all over the sky, all day and night. They penetrate into the Earth's magnetic field and our protective atmosphere as much butter.

Yet the hair on the top of your head is not even ruffled.

What happens?

] These little little bullets are called neutrinor, a term that constituted in 1934 by the brilliant physicist Enrico Fermi. The word is vaguely Italian for "a little neutral," and their existence was hypothesis to explain a very curious nuclear reaction. [The Biggest Unsolved Mysteries in Physics]

Sometimes elements feel a little … unstable. And if they leave themselves alone for too long, they fall apart and transform themselves into something else, something a little easier on the periodic table. In addition, a small electron would appear. But in the 1

920s, cautious and detailed observations of these precipitates found small, niggling deviations. The total energy at the beginning of the process was a little bit larger than the energy that came out. The math did not complement. Odd.

So, some physicists concocted a whole new particle out of whole fabric. Something to carry away the missing energy. Slightly small, slightly light, slightly free. Something that could slip through its detectors unnoticed.

A small, neutral. And neutrino.

It took another couple of decades to confirm their existence – it is so lame and funny and jealous they are. But in 1956, neutrinos went to the growing family of known, measured, confirmed particles.

And so it got weird.

The problem began with the discovery of the muon, which temporarily occurred at the same time as the neutrino idea began to gain ground: the 1930s. The mouse is almost exactly like an electron. Same charge. The same spin. But it is different in a crucial way: It is heavier, over 200 times more massive than its siblings, the electron.

Muons participates in their own kind of reactions, but do not tend to be long. Due to their impressive mass, they are very unstable and quickly decay to smaller-sized showers ("fast" here within a microsecond or two).

It's all good and good, why do mouths sit in the neutrino story?

Physicists noted that decay reactions that suggested that neutrino existed always had an electron out and never a muon. In other reactions, muons would pop out, not electrons. To explain these findings, they motivated that neutrinos always matched electrons in these decomposition reactions (and not any other type of neutrino), while the electron had to moan with a hitherto undetected type of neutrino. electron-friendly neutrino would not be able to explain the observations from the muon events. [Wacky Physics: The Coolest Little Particles in Nature]

And so the hunt went on. And again. And again. It was only in 1962 that physicists finally got a lock on the second type of neutrino. It was originally called "neutretto", but more rational heads were superior to the system calling it muon-neutrino, as it always mated in response to the muon.

Okay so two confirmed neutrinos. Did nature get more for us? In 1975, scientists at the Stanford Linear Accelerator Center aimed deep through mountains of monotonous data to reveal the presence of a smoother sibling of the fine electron and fierce muon: hulking rope, clocking into a whopping 3,500 times the mass of the electron. It's a great particle!

So immediately the question became: If there is a family of three particles, can the electron, the muon and the rope … be the third neutrino to pair with this new-found creature?

Maybe, maybe not. Maybe there are only the two neutrins. Maybe there are four. Perhaps 17. Nature has not just met our expectations earlier, so no need to start now.

Over the decades, physicists convinced themselves to use a variety of experiments and observations that a third neutrino should exist. But it was not until the millennium, 2000, that a specially designed experiment at Fermilab (called the humorous DONUT experiment, for Direct Observation of NOW Tau, and no, I do not make it up) finally got enough confirmed observations to properly claim a discovery.

So why do we care so much about neutrinos? Why have we been chasing them for over 70 years, from before the Second World War to modern times? Why have generations of scientists been so fascinated by these small, neutral?

The reason is that neutrinos continue to live beyond our expectations. For a long time, we weren't even sure they were there. For a long time, we were convinced that they were completely massless, until the experiments irritated that they must have mass. Exactly "how much" remains a modern problem. And neutrinos have this annoying habit of changing character when traveling. That's right, as a neutrino travels in flight, it can change masks among the three flavors.

It may even still be an extra neutrino out there that does not participate in any common interactions – something called the sterile neutrino, which physicists are looking for hungry for.

In other words, neutrinos constantly challenge everything we know about physics. And if there is one thing we need, both in the past and in the future, it is a good challenge.

Paul M. Sutter is an astrophysicist at Ohio State University host of [19659028] Question a Spaceman and Space Radio and author of Your place in the universe .

Originally published on ] Live Science .


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