TABLE OF CONTENTS
- 1. /distributions
- 1.1. distributions/gauss
- 1.2. distributions/novo
- 1.3. distributions/woods_saxon
- 1.4. distributions/Sigmoid
- 1.5. distributions/Fermi
- 1.6. distributions/bW
- 1.7. distributions/RelBW
- 1.8. distributions/BlattWeisskopf
- 1.9. distributions/markusPostFormFactor
/distributions [ Modules ]
NAME
module distributions
PURPOSE
This module contains various distribution functions:
- Gaussian
- Breit-Wigner, relativistic and non-relativistic
- Novosibirsk
- Woods-Saxon (aka Sigmoid)
- Fermi
- Blatt-Weisskopf
distributions/gauss [ Functions ]
[ Top ] [ distributions ] [ Functions ]
NAME
real function gauss(x, x0, w)
PURPOSE
Returns the value of the Gaussian distribution at x.
INPUTS
- real :: x --- the argument (where the function is evaluated)
- real :: x0 --- pole parameter
- real :: w --- width parameter
distributions/novo [ Functions ]
[ Top ] [ distributions ] [ Functions ]
NAME
real function novo(x, x0, s, t)
PURPOSE
Returns the value of the Novosibirsk distribution at x.
INPUTS
- real :: x --- the argument (where the function is evaluated)
- real :: x0 --- pole parameter
- real :: s --- width parameter sigma
- real :: t --- skewness parameter tau
distributions/woods_saxon [ Functions ]
[ Top ] [ distributions ] [ Functions ]
NAME
real function woods_saxon(x, f0, x0, dx)
PURPOSE
Returns the value of the Woods-Saxon distribution at x.
INPUTS
- real :: x --- the argument (where the function is evaluated)
- real :: f0 --- normalization constant, approximately equals the value at x=0
- real :: x0 --- 'radius' parameter
- real :: dx --- 'diffuseness' parameter
distributions/Sigmoid [ Functions ]
[ Top ] [ distributions ] [ Functions ]
NAME
real function Sigmoid(x, x0, dx)
PURPOSE
Returns the value of the sigmoid function, which used for smooth turning on and off of individual subprocesses, smooth approximation to Heaviside function:
- Sigm -> 1 for x -> infty, Sigm -> 0 for x -> -infty for dx > 0
- Sigm -> 0 for x -> infty, Sigm -> 1 for x -> -infty for dx < 0
INPUTS
- real :: x --- the argument (where the function is evaluated)
- real :: x0 --- cutoff point
- real :: dx --- 'diffuseness' parameter, width of cutoff
distributions/Fermi [ Functions ]
[ Top ] [ distributions ] [ Functions ]
NAME
real function Fermi(E, mu, T)
PURPOSE
Returns the value of the Fermi distribution for the energy E, chemical potential mu and temperature T.
INPUTS
- real :: E --- energy in GeV
- real :: mu --- chemical potential in GeV
- real :: T --- temperature in GeV
distributions/bW [ Functions ]
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NAME
real function bW(x,pole,width)
PURPOSE
Returns the value of the non-relativistic Breit-Wigner distribution at x with a given pole and width.
INPUTS
- real :: x, pole, width
distributions/RelBW [ Functions ]
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NAME
real function RelBW(x,pole,width)
NOTES
Returns the value of the relativistic Breit-Wigner distribution at x with a given pole and width.
INPUTS
- real :: x --- invariant mass sqrt(p_nu*p^nu) [GeV]
- real :: pole --- pole mass [GeV]
- real :: width --- width [GeV]
NOTES
Evaluates the spectral function of a particle with given mass and gamma at p^nu p_nu= x**2. Normalized to Integral(RelBW) from p**2=(0,infinity)GeV**2 = 1
distributions/BlattWeisskopf [ Functions ]
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NAME
real function BlattWeisskopf(x,l)
NOTES
Returns the function value of the Blatt-Weisskopf-Functions, which govern the momentum dependence of the width of a resonance decaying into AB. See e.g. Effenberger Dr. thesis, page 28
INPUTS
- real :: x -- = p_ab *R with p_ab = Relative Momentum of outgoing particles AB and R = Interaction-Radius
- integer :: l -- angular Momentum of outgoing particles AB
distributions/markusPostFormFactor [ Functions ]
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NAME
real function markusPostFormFactor(mass, pole, srts0, lambda)
PURPOSE
See Post's Phd thesis, page 35, eq. (3.22).