The electron neutrino is a subatomic particle with the symbol νe and the properties of both the electron and neutrino elementary particles, though it has no charge. It was discovered by Arthur B. McDonald and his team in 2002, who won the Nobel Prize in physics in 2015 because of this discovery. Learn everything you need to know about this exciting new discovery below!
What Is an Electron?
An electron is a subatomic particle with a negative electrical charge. It forms part of an atom’s nucleus, along with protons and neutrons (which have positive charges). An electron has about 1/1800th of a proton’s mass and spin, which means it cannot be isolated from an atom or ion (though it can orbit an atom without being tied to it). In compounds, electrons usually share their energy with atoms in molecules, forming bonds. The number of electrons that surround an atom determines its chemical properties, such as its magnetic and electrical states. Electron Neutrinos: Electron neutrinos are elementary particles that are released when high-energy cosmic rays collide with Earth’s atmosphere. They are one of three types of neutrinos—the other two being muon neutrinos and tau neutrinos—and they interact very rarely with other matter, so they pass through our planet undetected most of the time. However, scientists at Fermilab discovered that sometimes these neutrinos oscillate into another type of neutrino en route to detectors on Earth. Scientists had previously believed that oscillations could only happen between different flavors of neutrinos, but now we know there are certain circumstances where oscillations can occur between different types of neutrinos. This discovery was awarded the 2015 Nobel Prize in Physics. So What Is an Electron Neutrino? Well, remember how I said earlier that a neutrino doesn’t have any charge? That makes sense because electron neutrinos aren’t charged, so it would make sense for them to not possess any charge either. Instead of having no charge, though, they actually have a very small amount of negative (-1) electric charge.
What Is a Neutrino?
A neutrino is an elementary particle that carries no electric charge and has a very small mass. In fact, it’s smaller than an atom of any element on Earth. They’re born in nuclear reactions, such as those found in stars, and travel through space without interacting with anything except for matter (like electrons). The electron neutrino, in particular, is produced by beta decay and captured by electron-rich atoms like oxygen. How? Well, when an unstable atomic nucleus emits a beta particle—an electron or positron—it turns into a different type of nucleus. This new nucleus can capture the energy from that emitted electron, emitting another kind of neutral particle: a neutrino. Scientists have been studying these elusive particles since 1930 and still aren’t sure how they work; more experiments are underway to figure them out! It could be many years before scientists know all there is to know about neutrinos. But even then, there will probably be questions left unanswered. For example, why do some subatomic particles have mass while others don’t? And what is dark matter made of? As we learn more about these tiny particles, our understanding of physics deepens. And who knows what else we might discover along the way… It’s fun to think about. Science is awesome. So let’s talk about it.
How Are Neutrinos Measured?
Using underground labs, neutrinos are measured in three different ways. The first is detecting when a neutrino interacts with an atomic nucleus, called elastic scattering. The second way is through oscillation: each type of neutrino can transform into any other type. This means that as neutrinos travel from their source in our Sun or nuclear reactors on Earth, some of them will appear to vanish from our detection mechanisms as they transform from one type into another and continue on their journey. Finally, scientists can detect neutrinos by looking for particles created when they interact with matter. For example, if a neutrino collides with an atom’s nucleus, it may produce muons (heavy electrons), which we can detect using particle detectors like those at CERN’s Large Hadron Collider (LHC). Muons can also be used to measure how many neutrinos are reaching Earth from space. The number of observed electron antineutrinos—the kind produced by nuclear fission—is lower than expected. Scientists think that there must be another type of neutrino out there that transforms into electron antineutrinos en route to Earth. They call these missing types sterile neutrinos because they don’t seem to interact with normal matter in any way. Sterile neutrinos could explain why physicists have been unable to find all of the Higgs boson predicted by current theories about how elementary particles work. The nature of dark matter—the mysterious substance that makes up most of our universe—may also depend on sterile neutrinos. In fact, understanding what role sterile neutrinos play in physics would help us understand more about everything from cosmic rays to how much mass is contained within an atom. Currently, two experiments are attempting to find these elusive particles: XENON1T at Italy’s Gran Sasso National Laboratory and China Jinping Underground Laboratory-1000.
What’s Next?
Physicists have just announced they’ve observed evidence of a long-sought subatomic particle—the electron neutrino. What’s so special about it? For one thing, it could help us figure out what happened at the beginning of our universe when everything was concentrated into an extremely hot, dense mass. But, in addition to science history, what do you need to know about electron neutrinos in practice? We have all your questions answered here.
As for how scientists found them and their potential impact on physics as we know it, that’s where things get really interesting. The team from CERN, an international physics laboratory near Geneva, Switzerland discovered three separate events that appeared to be caused by electron neutrinos interacting with protons in water molecules. In total, they detected 15 million interactions between electron antineutrinos and protons over a period of six months. As you might imagine, finding evidence of a new subatomic particle is no easy task—especially when it comes to something like an electron neutrino. To detect these elusive particles, researchers use a method called inverse beta decay.
