Elegent::BSWModel Class Reference

Bourelly, Soffer and Wu model of p-p and p-anti p elastic scattering. More...

#include <BSWModel.h>

Inheritance diagram for Elegent::BSWModel:

Classes
struct	Trajectory
	a Regge trajectory More...

Public Types
enum	ModeType { mPomReg, mPom, mReg }
	available modes More...

Public Member Functions
void	Configure (ModeType _mode=mPomReg, bool _presampled=true)
virtual void	Init ()
	sets up model parameters and data members
virtual void	Print () const
	prints model info
virtual TComplex	Amp (double t) const
	Amplitude in t-space. More...
virtual TComplex	Prf (double b) const
	Profile function (amplitude in b-space). More...
virtual void	ForcePresampling (bool value)
	Sets the presampling option, if available. More...
double	Ft (double t) const
	F(t), Eq. (4) More...
TComplex	Rt (Trajectory tr, double t) const
	generic Regge trajectory amplitude, Eq. (7) More...
TComplex	R0t (double t) const
	the sum of allowed Regge trajctories (A2, rho, omega) More...
TComplex	S0 (double t) const
	S_0(s), Eq(3) More...
TComplex	Omega0t (double t) const
	the Bessel transform of (s, b) in Eq. (2) More...
TComplex	Omega0b (double b) const
	(s, b)
TComplex	prf0 (double b) const
	the profile function with b in GeV^-1
void	BuildSample (unsigned int samples)
	samples the prf0 function
TComplex	SampleEval (double b) const
	interpolates (linearly) the sample at point b
Public Member Functions inherited from Elegent::Model
std::string	CompileFullLabel () const
	compiles a human readable string from fullLabel
std::string	CompileShortLabel () const
	compiles a human readable string from shortLabel

Static Public Member Functions
static TComplex	Omega0t_J0 (double t, double *par, const void *vobj)
static TComplex	prf0_J0 (double b, double *par, const void *vobj)

Public Attributes
enum Elegent::BSWModel::ModeType	mode
bool	presampled
	flag whether the presampled mode is on
double	c
	the pomeron exchange parameters
double	cp
double	a
double	f
double	m1
double	m2
double	asq
double	m1sq
double	m2sq
Trajectory	A2
	the 3 Regge trajectories
Trajectory	rho
Trajectory	omega
TComplex	regge_fac
	constants to resolve ambiguities in the source papers More...
signed int	k_u
	u = -|u| exp(i * (2 k pi - pi))
signed int	k_lnu
	ln u = |ln u| exp(i * (al + 2 k_lnu pi)), al = atan2(Im ln u, Re ln u) in (-pi, +pi)
double	upper_bound_t
	integration variables
double	precision_t
double	upper_bound_b
double	precision_b
bool	integ_workspace_initialized
unsigned long	integ_workspace_size_b
gsl_integration_workspace *	integ_workspace_b
unsigned long	integ_workspace_size_t
gsl_integration_workspace *	integ_workspace_t
TComplex	S00
	S_0(0)
double	data_db
	the sampling-step size
unsigned int	data_N
	the number of sampled points
std::vector< double >	data_re
	the sampled real and imaginary values of prf0(b)
std::vector< double >	data_im
Public Attributes inherited from Elegent::Model
Label	fullLabel
	full label (e.g. for figure legend)
Label	shortLabel
	short label (e.g. for object names in ROOT files)

Detailed Description

Bourelly, Soffer and Wu model of p-p and p-anti p elastic scattering.

References: [1] BOURRELY C., SOFFER, J. and WU, T. T., Phys. Rev. D19 (1979) 3249 [2] BOURRELY C., SOFFER, J. and WU, T. T., Nucl. Phys. B247 (1984) 15 [3] BOURRELY C., SOFFER, J. and WU, T. T., Eur. Phys. J. C28 (2003) 97-105 [4] BOURRELY C., SOFFER, J. and WU, T. T., Eur. Phys. J. C71 (2011) 1601

Member Enumeration Documentation

enum Elegent::BSWModel::ModeType

available modes

Enumerator
mPomReg	both Pomeron and Reggeon contributions
mPom	only Pomeron contribution
mReg	only Reggeon contribution

Member Function Documentation

TComplex BSWModel::Amp ( double  t ) const

virtual

Amplitude in t-space.

Normalisation is such that \( dsigma/dt = (\hbar c)^2 * \pi / (s p^2) * |Amp(t)|^2 \) Differential cross-section can be obtained as Constants::sig_fac * |Amp(t)|^2

Parameters

t	in GeV^-2, t < 0

Implements Elegent::Model.

virtual void Elegent::BSWModel::ForcePresampling ( bool  )

inlinevirtual

Sets the presampling option, if available.

This option determines whether calling Init would presample relevant distributions (typically b distributions) for faster Amp calls. This behaviour is, in contrary, undesirable for evaluating s distributions.

Reimplemented from Elegent::Model.

double BSWModel::Ft

(

double

t

)

const

F(t), Eq. (4)

Eq. (4) in [3]

TComplex BSWModel::Omega0t

(

double

t

)

const

the Bessel transform of (s, b) in Eq. (2)

Eq. (2) in [3] written in t-space (cf. Eq. (7) in [1]) S00 = S0(0) instead of S0(t) is used here, valid for high s only !!

TComplex BSWModel::Prf ( double  b ) const

virtual

Profile function (amplitude in b-space).

Normalisation is such that \( Amp(t) = 2 p \sqrt{s} \int db b Prf() J_0(b \sqrt{-t}) \)

Parameters

b

in fm.

Implements Elegent::Model.

TComplex BSWModel::R0t

(

double

t

)

const

the sum of allowed Regge trajctories (A2, rho, omega)

Sum over all allowed Regge trajectories, as defined in the text below Eq. (7) in [3]. version below.

TComplex BSWModel::Rt	(	Trajectory	tr,
		double	t
	)		const

generic Regge trajectory amplitude, Eq. (7)

Eq. (7) in [3] NOTE: the equation is missing signs that make the difference between pp and app, corrected version below.

NOTE: as s0 = 1 GeV^2, it is simply left out of the formula below.

TComplex BSWModel::S0

(

double

t

)

const

S_0(s), Eq(3)

Eq. (3) in [3]

Member Data Documentation

TComplex Elegent::BSWModel::regge_fac

constants to resolve ambiguities in the source papers

Omega0 = S0*F + R0 / s / regge_fac

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The documentation for this class was generated from the following files:

• src/libElegent/interface/BSWModel.h
• src/libElegent/src/BSWModel.cc