Tagged Questions
1
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0answers
52 views
Matrix element approximation
In the formula for the decay width of $\Upsilon(4S)$ to B-mesons from $\text{e}^+\text{e}^-$ collisions:
$$\Gamma_{\Upsilon(4S)\to B\bar{B}}=\frac{\left|\underline{P}_B \right|}{8\pi ...
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0answers
47 views
Parton Distribution Functions, average cross section of the nucleon
Say we are given the scattering cross section for neutrinos from $d$ and $\bar{u}$ quarks as $\frac{d\sigma^{d}}{dQ^2}=\frac{G_F^2}{\pi}$, $\frac{d\sigma^{\bar{u}}}{dQ^2}=\frac{G_F^2}{\pi} (1-y)^2$, ...
3
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0answers
56 views
Can the mass of a SUSY particle depend on the process it participates in?
I believe that mass is property of every particle,as well as spin etc.Now I'm interested in SUSY particles in cMSSM model.Can it be,that mass of a SUSY particle (at one point in five parameter space) ...
2
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2answers
211 views
Why do physicists think that the electron is an elementary particle?
When we first discovered the proton and neutron, I'm sure scientists didn't think that it was made up of quark arrangements, but then we figured they could be and experiments proved that they were.
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1
vote
1answer
251 views
Definition of elementary particle [duplicate]
Possible Duplicate:
Why are atoms particles?
According to wikipedia an elementary particle or fundamental particle is a particle not known to have substructure.
Moreover, I've learned ...
1
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2answers
236 views
A basic confusion about what is an atom
Wikipedia defines atom as
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons.
and defines electron as:
The ...
