## src/form_factor/form_factor_2p [ Modules ]

NAME

Module form_factor_2p

USAGE

use form_factor_2p

DESCRIPTION

This module contains the different form factors for two point amplitudes.

OUTPUT

It exports four functions: * a20 -- a function to compute A^{2,0} * a21 -- a function to compute A^{2,1} * a22 -- a function to compute A^{2,2} * b22 -- a function to compute B^{2,2} Note that a2xx and b2xx are generic functions which can be called either with a set of integers or with an integer whose bits represents the set

USES

* precision (src/module/precision_golem.f90) * generic_function_2p (src/integrals/two_point/generic_function_2p.f90) * matrice_s (src/kinematic/matrice_s.f90) * array (src/module/array.f90) * form_factor_type (src/module/form_factor_type.f90) * constante (src/module/constante.f90)

## src/form_factor/form_factor_2p/a20_b [ Functions ]

NAME

Function a20_b

USAGE

type(form_factor) = a20_b(b_pin)

DESCRIPTION

This function defines the form factor A^{2,0}.

INPUTS

* b_pin -- an integer whose bits represent an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable b_ref)

SIDE EFFECTS

No side effect, it uses the value of the global variables b_ref and s_mat_p

RETURN VALUE

The result returned is of the type form_factor It returns an array of three complex (type ki) corresponding to the real part, imaginary part of the coefficient in front 1/epsilon^2, the real part, imaginary part of the 1/epsilon term and the real part, imaginary part of the constant term.

EXAMPLE

## src/form_factor/form_factor_2p/a20_s [ Functions ]

NAME

Function a20_s

USAGE

type(form_factor) = a20_s(set)

DESCRIPTION

This function defines the form factor A^{2,0}.

INPUTS

* set -- an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable set_ref)

SIDE EFFECTS

No side effect

RETURN VALUE

The result returned is of the type form_factor It returns an array of three complex (type ki) corresponding to the real part, imaginary part of the coefficient in front 1/epsilon^2, the real part, imaginary part of the 1/epsilon term and the real part, imaginary part of the constant term.

EXAMPLE

## src/form_factor/form_factor_2p/a21_b [ Functions ]

NAME

Function a21_b

USAGE

type(form_factor) = a21_b(l1,b_pin)

DESCRIPTION

This function defines the form factor A^{2,1}(l_1).

INPUTS

* l1 -- an integer corresponding to a label in the set of the three remaining propagators * b_pin -- an integer whose bits represent an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable b_ref)

SIDE EFFECTS

No side effect, it uses the value of the global variables b_ref and s_mat_p

RETURN VALUE

The result returned is of the type form_factor It returns an array of three complex (type ki) corresponding to the real part, imaginary part of the coefficient in front 1/epsilon^2, the real part, imaginary part of the 1/epsilon term and the real part, imaginary part of the constant term.

EXAMPLE

## src/form_factor/form_factor_2p/a21_s [ Functions ]

NAME

Function a21_s

USAGE

type(form_factor) = a21_s(l1,set)

DESCRIPTION

This function defines the form factor A^{2,1}(l_1).

INPUTS

* l1 -- an integer corresponding to a label in the set of the three remaining propagators * set -- an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable set_ref)

SIDE EFFECTS

No side effect

RETURN VALUE

EXAMPLE

## src/form_factor/form_factor_2p/a22_b [ Functions ]

NAME

Function a22_b

USAGE

type(form_factor) = a22_b(l1,l2,b_pin)

DESCRIPTION

This function defines the form factor A^{2,2}(l1,l2).

INPUTS

* l1 -- an integer corresponding to a label in the set of the three remaining propagators * l2 -- an integer corresponding to a label in the set of the three remaining propagators * b_pin -- an integer whose bits represent an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable b_ref)

SIDE EFFECTS

No side effect, it uses the value of the global variables b_ref and s_mat_p

RETURN VALUE

EXAMPLE

## src/form_factor/form_factor_2p/a22_s [ Functions ]

NAME

Function a22_s

USAGE

type(form_factor) = a22_s(l1,l2,set)

DESCRIPTION

This function defines the form factor A^{2,2}(l1,l2).

INPUTS

* l1 -- an integer corresponding to a label in the set of the three remaining propagators * l2 -- an integer corresponding to a label in the set of the three remaining propagators * set -- an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable set_ref)

SIDE EFFECTS

No side effect

RETURN VALUE

EXAMPLE

## src/form_factor/form_factor_2p/b22_b [ Functions ]

NAME

Function b22_b

USAGE

type(form_factor) = b22_b(b_pin)

DESCRIPTION

This function defines the form factor B^{2,2}.

INPUTS

* b_pin -- an integer whose bits represent an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable b_ref)

SIDE EFFECTS

No side effect, it uses the value of the global variables b_ref and s_mat_p

RETURN VALUE

EXAMPLE

## src/form_factor/form_factor_2p/b22_s [ Functions ]

NAME

Function b22_s

USAGE

type(form_factor) = b22_s(set)

DESCRIPTION

This function defines the form factor B^{2,2}.

INPUTS

* set -- an array of integers of rank 1 corresponding to the label of the propagators pinched (removed from the original set which is in the global variable set_ref)

SIDE EFFECTS

No side effect

RETURN VALUE