All Questions
Tagged with scattering particle-physics
151
questions
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52
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Square of the Feynman amplitude for $a +b\to c+d$ and its reverse
In quantum field theory, if a process $a +b\to c+d$ is allowed by a certain interaction Lagrangian (hermitian), the reverse process, $c+d\to a+b$, must also be allowed (as far as I understand) by the ...
- 11.8k
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73
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Mandelstam variables sign
I am self-studying the book "Quantum Field Theory and the Standard Model" by Schwartz, on page 99 (paragraph "Mandelstam variables"), the context is the $2\rightarrow 2$ scattering ...
- 613
-1
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13
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Jet events and Deeep Inelastic Scattering (Scaling Behavior) at the same time?
I am a philosopher of physics, so I already apologize for potential ignorance. I have also graduated in physics, but I now analyze problems on another level and also forgot some of the mathematical ...
1
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83
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Doubt in $e^{+}e^{-}\rightarrow W^{+}W^{-}$ scattering
I am trying to understand how to compute the scattering amplitude for the process $e^{+}e^{-}\rightarrow W^{+}W^{-}$, as a reference one could look at Peskin chapter 21.
What I do not understand is ...
- 475
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34
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Relation bitween Mandelstam Variables in three-body final state
What is the relation between Mandelstam variables in the three body final state?
There are 5 independent Mandelstam variables. What is the relationship between them?
- 11
3
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1
answer
112
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Regge Theory interpretation
I have a question on the physical interpretation of the Regge limit,
$$s\gg4m^2\gg|t|$$
where we are in the s-channel physical region and s and t the Mandelstam invariants. Usually, the $s$ is taken ...
- 71
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45
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Elastic vs inelastic scattering in particle physics
Does elastic scattering occur via the Z boson and inelastic scattering via the W boson? If so, why? Does it have something to do with the fact that interactions via the Z boson don't change quark ...
- 105
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46
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Rutherford scattering closest approach distance
Consider a particle 1 moving towards a particle 2 at rest. In class, my teacher said that in order to derive the minimum approach distance when the impact parameter ( b ) is 0, we had to use ...
- 319
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1
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How does one describe individual particles in QFT in practice?
A similar question was posted on this site at least ten times, but not quite in this formulation, and with no satisfactory answers, so I give it another try.
Quantum field theory textbooks almost ...
- 290
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56
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High energy collision of two proton
Suppose there are two protons ( as we have in LHC). One proton is coming from +ve z axis and other from -ve z axis toward the collision point(origin). Both proton collide with equal velocity. Now as ...
- 49
8
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2
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How does a photon "cheat" its way past a neutron?
I learnt here Is a neutron deflected sideways by a laser beam? that a photon beam has no influence on the motion of a free neutron in the first and second approximation. Now I'm interested in what ...
- 10.6k
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179
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Is a neutron deflected sideways by a laser beam?
Is a freely moving neutron deflected sideways when a laser beam is directed at it from the side? It would be great if the question could be considered from the two points of view that the laser beam ...
- 10.6k
1
vote
1
answer
72
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Inconsistency in the $2\to 2$ kinematics
I must be confusing something horribly, because this should be very simple, but I am keep getting inconsistent results in the basic 2->2 scattering kinematics.
Let the process be $$a(p_1) + b(p_2) \...
- 857
2
votes
1
answer
143
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Proof that Bjorken-$x$ is positive
For a $t$-channel deep inelastic scattering process the Bjorken-$x$ is defined as:
$$x=\frac{Q^2}{2p_2\cdot q},$$
where $Q^2:=-q^2$ [in the $(+,-,-,-)$ Minkowski sign convention], $q$ is the ...
- 337
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49
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Relation between matrix element of a process with its crossed processes
Consider a process in particle physics denoted by, $$(1) \quad a+b\to c+d$$ which is related to the reverse process $$(2)\quad c+d\to a+b.$$ By virtue of the hermiticity of the interaction Hamiltonian,...
- 11.8k