The muon (; 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. As with other leptons, the muon is not known to have any sub-structure – that is, it is not thought to be composed of any simpler particles.
The muon is an unstable subatomic particle with a mean lifetime of 2.2 μs, much longer than many other subatomic particles. As with the decay of the non-elementary neutron (with a lifetime around 15 minutes), muon decay is slow (by subatomic standards) because the decay is mediated only by the weak interaction (rather than the more powerful strong interaction or electromagnetic interaction), and because the mass difference between the muon and the set of its decay products is small, providing few kinetic degrees of freedom for decay. Muon decay almost always produces at least three particles, which must include an electron of the same charge as the muon and two types of neutrinos.
Like all elementary particles, the muon has a corresponding antiparticle of opposite charge (+1 e) but equal mass and spin: the antimuon (also called a positive muon). Muons are denoted by μ− and antimuons by μ+. Formerly, muons were called "mu mesons", but are not classified as mesons by modern particle physicists (see § History), and that name is no longer used by the physics community.
Muons have a mass of 105.66 MeV/c2, which is approximately 207 times that of the electron, me. More precisely, it is 206.7682830(46) me.Due to their greater mass, muons accelerate more slowly than electrons in electromagnetic fields, and emit less bremsstrahlung (deceleration radiation). This allows muons of a given energy to penetrate far deeper into matter because the deceleration of electrons and muons is primarily due to energy loss by the bremsstrahlung mechanism. For example, so-called "secondary muons", created by cosmic rays hitting the atmosphere, can penetrate the atmosphere and reach Earth's land surface and even into deep mines.
Because muons have a greater mass and energy than the decay energy of radioactivity, they are not produced by radioactive decay. However they are produced in great amounts in high-energy interactions in normal matter, in certain particle accelerator experiments with hadrons, and in cosmic ray interactions with matter. These interactions usually produce pi mesons initially, which almost always decay to muons.
As with the other charged leptons, the muon has an associated muon neutrino, denoted by νμ, which differs from the electron neutrino and participates in different nuclear reactions.
i have many doubts about muon anti neutrino and tau anti neutrino...some are
1. is it so tough to detect them...anyone detected them ?
2. do they decay?
3. do they react with other particles like electrons,protons etc?
can anyone give some information about them?
[SOLVED] myuon decay
First, sorry for my English. I'm not very well in it... Please, try to understand.
I wrote this problem in "Introductory Physics", but some man sayed its not "introductory", so I decided to post it in "Advenced Physcis".
The problem.
We have reaction: \mu \rightarrow e...
Homework Statement
The most precise measurement of the anomalous magnetic moment of the muon (g-2) is performed at Brookhaven (USA). In this experiment muons are held in a circular orbit in a 14 m diameter ring, with momentum 3.098 GeV. On average how many laps of the ring the muon will do...
Homework Statement
Consider an atom composed of a proton nucleus and an orbiting negatively charged muon (which has a mass of 207*(mass of an electron)). What difference, if any, would you expect between the Zeeman Effect in such atoms and in ordinary hydrogen atoms? (Hint: the muon has spin...
Hi.
I have an assignment where a muon gets caught in a zinc atom (Z=30) at n=2. I'm supposed to calculate the energy of the photon that is emitted in the transition to n=1.
I have managed to calculate the energy of this photon, but I'm having a little trouble determining the validity of my...
Cosmic Ray Muon Production Altitude is not right!
Hi there,
I wrote a Programm to calculate the cosmic ray muon intensity on different altitudes. I dedicated this programm from the intensity of the primary cosmic rays and the intercations in the atmosphere.
First a Proton with the Energy...
I am looking at muons being lost as they travel through a concrete bunker (with various things inside). The minimum energy (mean) for a muon to go through the walls is about 1.82GeV, and for the stuff inside (flakes of magnesium) it is 2.7GeV. For a piece of heavy metal it is 0.13GeV (it's...
The muon energy loss equation (at high energies) is:
-dE/dx = a(E) + b(E)E
where a(E) represents the ionization losses (Bethe equation), and b(E) represents radiative losses (bremsstrahlung, pair production, photo-nuclear).
From what I have read, at high energies for high-Z materials...
I have been looking at the flux of muons (as secondary cosmic ray particles) at the Earth's surface as a function of both energy and angle from the zenith. From what I have read, the flux follows a squared cos theta relationship with angle from the zenith and several attempts have been made to...
A muon is observed to travel 800 meters before disintigrating. The lifetime of a muon is 2 * 10 ^ -6. So the observer concludes that the muon traveled at a speed of
4 * 10^8 m/s which is faster than c.
Why is the observer wrong?
I though it was impossible for anything to travel faster...
Homework Statement
a muon moving in a straight line enters a region w/ speed of 5 x 10^6 m/s. it then slowed down at a rate of 1.25 m/s^2. how far does the muon take to stop??
Homework Equations
2ad + square of initial velocity = square of final velocity
The Attempt at a...
Hallo everybody!
Is there anybody dealing with CMS stuff?
Let's share infos here, and let's discuss the stuff related to Compact Muon Solenoid experiment simulations.
I am a student, and have to work on H-->2mu ee- (Higgs to muon+ muon- electron positron)
Plz, leave here any related...
Second generation leptons muon & tau as quantum excitiation of electrons?
We know that in the hydrogen atom, the levels of the electron are quantized n=1, n=2, n=3 which can explain the ryderg constant and photon emission spectrum. the electron can be explained by a quantum wave function, and...
free neutrons are unstable: would a muon in say uranium be "stable"?
free neutrons are unstable: would a muon in say uranium be "stable"?
free neutrons decompose and have a half-life of about 15 minutes.
neutrons bound in a nucleus, especially in a magic shell configuration like helium-4 or...
OK, I'm currently in the process of designing an experiment to measure the rest lifetime of the muon, using a vertical stack of four flat scintillation detectors separated by lead plates, and coincidence electronics, Time-Amplitude converter, etc. to acquire data from the cosmic ray muons...
I was actually pondering the existence of modern electronics, and the ability of a magnetic generator which applies a force to move electrons in a copper wire. As another energy source is used to turn the turbine (e.g coal, fuel - combustion, nuclear), the magnets apply a electromagnetic force...
The positive pion decays into a muon and a neutrino. The pion has rest mass m_\pi , the muon has m_\mu , while the neutrino has m_v = 0. Assuming the original pion was at rest, use conservation of momentum and energy to show that the speed of the muon is given by:
\frac{u}{c} = \frac{...
A few years ago BNL did some experiments measuring muon g-2. At the time there was a significant enough difference from the calculations based on the Standard Model to raise questions about SM. Since then I've seen papers indicating that SM was probably OK, with the discrepancy being due to...
I'm speaking of the Muon decay experiment which showed no additional gravitationally related time effects in a centrifuge...
Firstly does anyone have a real reference for the experiment? All I find are offhand mentions of it. The only identifying info I've gotten on it was that it was in 1966...
I've been doing some research on Muon spectroscopy, and am not that far in the physics world yet. I've got kind of a fuzzy picture of what goes on, but could use some help in identifying some key concepts. The information I have been getting is from the following paper
Muon-Spin Rotation...
The electron in the Hydrogen atom can be replaced by the heavier muon resulting in a muonic atom. The muonic atom is not stable because the muon lives for 2.2 ms on average and then it decays into an electron and two neutrinos. However some very fast experiments can be performed on the muonic...
Need HELP! Muon Lifetime Experiment
I just recently collected data from a muon lifetime determination experiment. The data was presented in the form of two columns: x = time (microseconds) and y = counts/bin. After plotting this xy into a graph I found that my muon lifetime was 2.12 (close...
How are the electron neutrino, the muon neutrino and the tau neutrino different from each other (except for the leptonic number they carry)?
I heard they BEHAVE like their associated Lepton (el., muon, tau). If so, in what way?
Thanks.
I am new to this matter, but I was reading a problem about how as the muon travels at .98c, that it's half life is increased by an approximate factor of 5.
What I have trouble with is when using the Lorentz transform, why time dilation is calculated in the moving system at the same X and V...
i have a question
i have to do this problem
i know somewhat how it sets up but what do u take from the initial condition? do u take the distance the muon travels?
can someone help me set this bad boy up
Suppose a muon produced as a result of a cosmic ray colliding with a nucleus in the...