A muon (/ˈmjuːɒn/ MYOO-on; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a spin of 1⁄2, but with a much greater mass. It is classified as a lepton.
What did the muon experiment prove?
The most convincing experimental evidence for the time dilation in the direction of the motion comes from the cosmic muon experiments. Muons are created in the upper Earth’s atmosphere are secondary products of interactions between primary cosmic rays and the nuclei of atmospheric molecules.
How does a muon detector work?
Typical muon detectors consist of photomultiplying tubes lined with a scintillator, a material that emits light when struck by a charged particle. When a particle such as a muon bounces through the detector, the photomultiplying tube multiplies the current produced by the emitted light.
Is muon an antimatter?
They come in two types, matter and antimatter. The matter muon, like the matter electron, is negatively charged (so it’s known as a µ–), whilst the antimatter muon, like a positron, is positive (µ+). Muons’ longevity is quite impressive for a subatomic particle—they live an average of two millionths of a second.
What is the muon paradox?
Muons at rest in the atmosphere, decaying simultaneously, are subject to a universal time-dilatation effect when viewed from a moving frame and so are also observed to decay simultaneously in all such frames.
What is a muon and why is it important?
The muon is one of the fundamental subatomic particles, the most basic building blocks of the universe as described in the Standard Model of particle physics. Muons are similar to electrons but weigh more than 207 times as much. That’s about the difference between an adult person and a small elephant.
Why are muons unstable?
The muon is unstable because it decays into an electron and two neutrinos in about 2μs. But a muon is not in some sense an excited electron. Both particles are excitations in a quantum field and they are both as fundamental as each other.
How fast do muons travel?
Indeed most of the cosmic muons have a high energy and travel at speeds close to 300 000 km / second the speed of light in vacuum.
How are muons created?
Muons are generated in the Earth’s upper atmosphere by cosmic rays (high energy protons) colliding with atomic nuclei of molecules in the air.
How far can muons penetrate?
The muons that can penetrate water with thicknesses more than 1 m are relativistic (300-MeV, 2-GeV, 30 GeV and 300-GeV muons respectively have continuous slowing down approximation (CSDA) range of 1 m, 10 m, 100 m and 1000 m).
What is a muon in simple terms?
Definition of muon : an unstable lepton that is common in the cosmic radiation near the earth’s surface, has a mass about 207 times the mass of the electron, and exists in negative and positive forms.
Can the muon reach the ground?
Muons are created when cosmic rays traveling through space strike molecules in the atmosphere, some 10 kilometers above Earth’s surface. Even moving at nearly the speed of light, a muon should only be able to travel about 700 meters before it decays, so you might think no muons could ever reach Earth.
Is a muon a quark?
One family is made of the lighter quarks — the constituents of protons and neutrons — and the electron. Another has heavier quarks and the muon, and a third family has even heavier counterparts.
Why are muons so penetrating?
Since their interactions are very similar to those of the electron, a muon can be thought of as a much heavier version of the electron. Due to their greater mass, muons do not emit as much bremsstrahlung radiation; consequently, they are highly penetrating, much more so than electrons.
Can we create muons?
We can produce muons by taking a narrow, high-intensity beam of protons and running it into a target made of a metal, such as titanium. This produces a beam of another fundamental particle called the pion. Pions form a beam which fans out.
What is the lifetime of muons?
The muon has a lifetime of τµ = 2.197 µs.
Is there any evidence of time dilation?
Answer. There are several direct proofs of time dilation. Extremely accurate clocks have been flown on jet aircraft. When compared to identical clocks at rest, the difference found in their respective readings has confirmed Einstein’s prediction.
How does time dilation affect muons?
In terms of muons, time dilation is when a muon that is traveling at the speed of light experiences a slower time rate than that of an observer that is not moving at all. This makes it possible for muons to reach sea-level because to us as observers, we see a longer muon lifetime that is true of the muon.
What are the uses of muons?
Muons have applications across a very broad range of areas. We can use them for studying magnetism, superconductivity, diffusion and charge transport, chemical reactions and molecular dynamics. In many of these areas, they give us complementary information to other techniques such as neutron scattering.
What are muons made of?
Muons have the same negative charge as electrons but 200 times the mass. They are made when high-energy particles called cosmic rays slam into atoms in Earth’s atmosphere.
What do muons decay into?
Muons decay predominantly into an electron 1 and a pair of neutrinos, μ + → e + ν ¯ μ ν e , with photons possibly irradiated by one of the charged particles involved in the process.
Why do muons decay so fast?
Also, muons decay so rapidly that if they are not moving at relativistic speeds, they don’t last long enough to have much of an effect on anything. So, a muon has tremendous momentum relative to photons or electrons. Muons are identical to electrons, including their charge and “size” but have 1,000 times the mass.
How do muons interact with matter?
Muons, being charged particles, interact with matter by ionizing it. The loss of energy by muons passing throught he atmosphere is proportional to the amout of matter they traverse. The medium is usually characterized by its density (g/cm3) times the distance traveled in centimeters.
Does muon experience strong nuclear force?
Muon lifetime — key to the strength of the weak force The muon is an unstable subatomic particle decaying with a lifetime of approx. 2 microseconds (millionth of a second). This decay is governed by the weak force only and the muon’s lifetime has a relatively simple relationship to the strength of the weak force.
How much energy does it take to make a muon?
The mean energy of muons at sea level is still 4 GeV. Therefore the mean energy at creation is probably about 6 GeV. The atmosphere is so tenuous at higher altitudes that even at 15,000 m it is still only 175 g/cm2 deep. Typically, it is about here that most muons are generated.