| << Chapter < Page | Chapter >> Page > |
The last subdetector is the muon detector, which consists of slabs of iron that only muons (and neutrinos) can penetrate. Between the iron slabs are multiple types of muon-tracking elements that accurately measure the momentum of the muon. The muon detectors are important because the Higgs boson (discussed soon) can be detected through its decays to four muons—hence the name of the detector.
Once data is collected from each of the particle subdetectors, the entire collision event can be assessed. The energy of the i th particle is written
where is the absolute magnitude of the momentum of the i th particle, and is its rest mass.
The total energy of all particles is therefore
If all particles are detected, the total energy should be equal to the center-of-mass energy of the colliding beam machine ( W ). In practice, not all particles are identified, either because these particles are too difficult to detect (neutrinos) or because these particles “slip through.” In many cases, whole chains of decays can be “reconstructed,” like putting back together a watch that has been smashed to pieces. Information about these decay chains are critical to the evaluation of models of particle interactions.
Briefly compare the Van de Graaff accelerator, linear accelerator, cyclotron, and synchrotron accelerator.
Describe the basic components and function of a typical colliding beam machine.
the “linac” to accelerate the particles in a straight line, a synchrotron to accelerate and store the moving particles in a circular ring, and a detector to measure the products of the collisions
What are the subdetectors of the Compact Muon Solenoid experiment? Briefly describe them.
What is the advantage of a colliding-beam accelerator over one that fires particles into a fixed target?
In a colliding beam experiment, the energy of the colliding particles goes into the rest mass energy of the new particle. In a fix-target experiment, some of this energy is lost to the momentum of the new particle since the center-of-mass of colliding particles is not fixed.
An electron appears in the muon detectors of the CMS. How is this possible?
A charged particle in a 2.0-T magnetic field is bent in a circle of radius 75 cm. What is the momentum of the particle?
A proton track passes through a magnetic field with radius of 50 cm. The magnetic field strength is 1.5 T. What is the total energy of the proton?
965 GeV
Derive the equation using the concepts of centripetal acceleration ( Motion in Two and Three Dimensions ) and relativistic momentum ( Relativity )
Assume that beam energy of an electron-positron collider is approximately 4.73 GeV. What is the total mass ( W ) of a particle produced in the annihilation of an electron and positron in this collider? What meson might be produced?
According to
[link] ,
This is the mass of the upsilon (1S) meson first observed at Fermi lab in 1977. The upsilon meson consists of a bottom quark and its antiparticle
.
At full energy, protons in the 2.00-km-diameter Fermilab synchrotron travel at nearly the speed of light, since their energy is about 1000 times their rest mass energy. (a) How long does it take for a proton to complete one trip around? (b) How many times per second will it pass through the target area?
Suppose a created in a particle detector lives for . What distance does it move in this time if it is traveling at 0.900 c ? (Note that the time is longer than the given lifetime, which can be due to the statistical nature of decay or time dilation.)
0.135 fm; Since this distance is too short to make a track, the presence of the must be inferred from its decay products.
What length track does a traveling at 0.100 c leave in a bubble chamber if it is created there and lives for ? (Those moving faster or living longer may escape the detector before decaying.)
The 3.20-km-long SLAC produces a beam of 50.0-GeV electrons. If there are 15,000 accelerating tubes, what average voltage must be across the gaps between them to achieve this energy?
3.33 MV
Notification Switch
Would you like to follow the 'University physics volume 3' conversation and receive update notifications?
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|