All Questions
Tagged with scattering-cross-section particle-physics
113
questions
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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
1
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52
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What is the difference between the center of mass energy of partons, and the invariant mass of the particles after a collision?
In a paper about the Atlas experiment (https://arxiv.org/abs/2103.01918) differential cross sections of $pp→ZZ→4\ell$
are being presented. However these cross-sections are functions of the invariant ...
- 172
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58
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Reducing Inelastic Electron-Proton's Scattering Cross Section to Rosenbluth's Formula
I'm currently studying electron-proton scattering from Halzen & Martin's book (Quarks & Leptons : An Introductory Course in Modern Particle Physics). I found that the cross section for the ...
5
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230
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Another "real vs virtual particle" one: calculate the full diagram or $\sigma \times \mathrm{BR}$?
I have recently been forced to think about something I always thought that I understood but that, in reality, I could not be more confused about.
Suppose I want to study the LHC prospects for ...
- 1,742
2
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1
answer
335
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Calculating Cross Section in terms of barns (help with converting from natural units)
I am trying to calculate the Glashow resonance to get something in terms of barns but I am getting confused switching between natural units and non-natural units. The Glashow Resonance is given by the ...
- 133
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124
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How to derive the modified Mott formula (with target recoil) using quantum field theory?
The differential cross-section of relativistic point electron off a static Coulomb potential provided by a point charge with density $\rho(\vec x)=e\delta^{(3)}(\vec x)$ is given by the Mott formula (...
- 11.8k
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148
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QFT Scattering Cross Section Integral
I came across this integral studying QFT regarding what I think it may be the calculation of a 2$\rightarrow$2 particle scattering cross section.
$$I = \int \frac{dp_3}{(2\pi)^32E_3} \frac{d p_4}{(2\...
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Star equations of hydrostatic equilibrium for a mix of 2 fleebly interacting gases/fluids and interaction term
For a single matter species, the equations of hydrostatic equilibirum for a star are
\begin{eqnarray}
\nabla^2 \phi &=& 4\pi G \rho\\
\vec{\nabla} P + \rho \vec{\nabla}\phi &=&0
\end{...
- 182
1
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1
answer
66
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Meaning of (collider1)x(collider2) in phenomenology papers
In some phenomenology papers in particle physics, often the cross section is shown as a function of some parameter of the model given a certain centre of mass energy of a specific collider. However, ...
- 363
3
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495
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Phase space factor for a two-body decay
I was trying to understand how pion decays to muons and not electrons because of helicity suppression. So I was trying to figure out the ratio of the decay widths.
PDG review for kinematics (...
- 131
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104
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Collinear Divergences and SCET (Soft Collinear Effective Theory)
Can someone elaborate on how to treat collinear divergences in massless fermionic theories, such as the massless QED? Some very basic words on where do we can find such divergences and how to cure ...
- 3,992
2
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2
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74
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How to estimate $d$-wave nuclear scattering cross section?
I would like to estimate the $\ell=2$ ($d$-wave) contribution to elastic scattering cross section (or scattering length) for collisions such as $n$-$n$ and $n$-$p$ at low energy (a few MeV or less). I ...
- 59.6k
3
votes
2
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137
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Luminosity of an elastic proton-proton scatter
Suppose you have a proton beam ($E=500\,\textrm{MeV})$ with a current of $$6 \cdot 10^{-12}\,\textrm{A} $$ that is colliding with a gaseous hydrogen target which is $3\,\textrm{cm}$ thick. The total ...
- 308
1
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1
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183
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Do electrons scatter off of the up quarks inside protons and neutrons?
Since they are different types of fermions, and of opposite charge, and the up quark has only 2/3 of a 'full' charge; is its trajectory changed as much by scattering off of a same-charge down quark?
...
- 4,509
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1
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222
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Kinematics of 4 body decays for Higgs to 4 leptons
I would like to calculate the decay width of the Higgs boson $h$ to 4 leptons via $ZZ^*$ intermediate states. I just did a similar calculation for $h$ to $W^{\pm}$ and 2 fermions via $WW^*$, so I am ...
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