DV Creating LUND Files

The LUND format

LUND Header

Column	Quantity
1	Number of Particles
2	Number of Target Nucleons
3	Number of Target Protons
4	Target Polarization
5	Beam Polarization
6	x
7	y
8	W
9	[math]\displaystyle{ Q^2 }[/math]
10	[math]\displaystyle{ \nu }[/math]

Where

1:Number of Particles

This line tells how many particles follow the header line. For Moller Scattering, this number should always be 2.

2:Number of Target Nucleons

For this simulation, only an electron-electron collision is considered. This quantity is always set to 1 for the one stationary electron we consider the incident electron scattering from.

3:Number of Target Protons

For Moller Scattering, there are no target protons. This number is set to 1, but does not have any effect within the GEMC simulations.

4:Target Polarization

This represents the polarization of the target material, either positive or negative 1. This value is always set to 1 and has no effect within the GEMC simulations.

5:Beam Polarization

This represents the polarization of the electron beam, either negative or positive 1. This value is always set to positive 1.

6:x

This represents the Bjorken x scaling variable.

[math]\displaystyle{ x=\frac{-q^2}{2p\cdot q}=\frac{-q^2}{2M\nu} }[/math]

[math]\displaystyle{ where\ M\ is\ the\ rest\ mass-energy\ of\ the\ proton\ M\approx 938MeV }[/math]

7:y

[math]\displaystyle{ y=\frac{p\cdot q}{p\cdot k} }[/math]

9:[math]\displaystyle{ Q^2 }[/math]

This represents the squared 4-momentum-transfer vector q of the exchanged virtual photon.

[math]\displaystyle{ Q^2\equiv -q^2 }[/math]

10:[math]\displaystyle{ \nu }[/math]

This represents the energy loss between scattering electrons.

[math]\displaystyle{ \nu = \frac{p\cdot q}{M} }[/math]

This can be written in the Lab frame as:

[math]\displaystyle{ \nu=E-E' }[/math]

[math]\displaystyle{ where\ E\ and\ E'\ are\ the\ initial\ and\ final\ electron\ energies. }[/math]