From: morsch Date: Mon, 24 Mar 2003 16:47:29 +0000 (+0000) Subject: GrayParticle -> SlowNucleon X-Git-Url: http://git.uio.no/git/?p=u%2Fmrichter%2FAliRoot.git;a=commitdiff_plain;h=a1d6420360f2925ac2e794b52a94603996034a10 GrayParticle -> SlowNucleon --- diff --git a/EVGEN/AliGenGrayParticles.cxx b/EVGEN/AliGenGrayParticles.cxx deleted file mode 100644 index 4bf739245c6..00000000000 --- a/EVGEN/AliGenGrayParticles.cxx +++ /dev/null @@ -1,206 +0,0 @@ -/************************************************************************** - * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * - * * - * Author: The ALICE Off-line Project. * - * Contributors are mentioned in the code where appropriate. * - * * - * Permission to use, copy, modify and distribute this software and its * - * documentation strictly for non-commercial purposes is hereby granted * - * without fee, provided that the above copyright notice appears in all * - * copies and that both the copyright notice and this permission notice * - * appear in the supporting documentation. The authors make no claims * - * about the suitability of this software for any purpose. It is * - * provided "as is" without express or implied warranty. * - **************************************************************************/ - -/* -$Log$ -Revision 1.5 2003/01/07 14:11:43 morsch -Comminication with gray particle model and collision geometry added. - -Revision 1.4 2003/01/06 10:09:57 morsch -Use AliGrayParticleModel. - -Revision 1.3 2002/12/02 10:02:40 morsch -Corrections introduced by F. Silker: -- SetBetaSource -- Particle type according to charge. - -Revision 1.2 2002/10/14 14:55:35 hristov -Merging the VirtualMC branch to the main development branch (HEAD) - -Revision 1.1.2.1 2002/10/10 16:40:08 hristov -Updating VirtualMC to v3-09-02 - -Revision 1.1 2002/10/08 13:53:17 morsch -Gray particle generator, first commit. - -*/ - -/* - Generator for gray nucluons in pA interactions. - Source is modelled by a relativistic Maxwell distributions. - Original code by Ferenc Sikler - */ - -#include -#include - -#include "AliCollisionGeometry.h" -#include "AliGenGrayParticles.h" -#include "AliGrayParticleModel.h" - - ClassImp(AliGenGrayParticles) - - AliGenGrayParticles::AliGenGrayParticles():AliGenerator(-1) -{ -// Default constructor - fGrayParticleModel = 0; - fCollisionGeometry = 0; -} - -AliGenGrayParticles::AliGenGrayParticles(Int_t npart) - :AliGenerator(npart) -{ -// Constructor - fName = "GrayParticles"; - fTitle = "Generator for gray particles in pA collisions"; - SetPmax(); - SetTarget(); - SetNominalCmsEnergy(); - SetCharge(); - SetTemperature(); - SetBetaSource(); - fGrayParticleModel = new AliGrayParticleModel(); - fCollisionGeometry = 0; -} - -//____________________________________________________________ -AliGenGrayParticles::~AliGenGrayParticles() -{ -// Destructor - delete fGrayParticleModel; -} - - -void AliGenGrayParticles::Init() -{ - // - // Initialization - // - Float_t kMass = TDatabasePDG::Instance()->GetParticle(kProton)->Mass(); - fMomentum = fCMS/2. * fZTarget / fATarget; - fBeta = fMomentum / TMath::Sqrt(kMass * kMass + fMomentum * fMomentum); -} - - -void AliGenGrayParticles::Generate() -{ - // - // Generate one event - // - // - // Communication with Gray Particle Model - // - Int_t np, nn; - - Float_t b = fCollisionGeometry->ImpactParameter(); - printf("AliGenGrayParticles: Impact parameter from Collision Geometry %f \n", b); - - fGrayParticleModel->GetNumberOfGrayNucleons(fCollisionGeometry, np, nn); - - // - Float_t p[3]; - Float_t origin[3] = {0., 0., 0.}; - Float_t polar [3] = {0., 0., 0.}; - Int_t nt, i; - for(i = 0;i < fNpart; i++) { - Int_t kf; - if(fCharge==1) kf = kProton; - else kf = kNeutron; - GenerateSlow(fCharge, fTemperature, fBetaSource, p); - - SetTrack(fTrackIt, -1, kf, p, origin, polar, - 0., kPNoProcess, nt, 1.); - - KeepTrack(nt); - } -} - - - - -void AliGenGrayParticles::GenerateSlow(Int_t charge, Double_t T, Double_t beta, Float_t* q) -/* - Emit a slow nucleon with "temperature" T [GeV], - from a source moving with velocity beta - Three-momentum [GeV/c] is given back in q[3] -*/ - -{ - Double_t m, pmax, p, f, theta, phi; - - TDatabasePDG * pdg = TDatabasePDG::Instance(); - const Double_t kMassProton = pdg->GetParticle(kProton) ->Mass(); - const Double_t kMassNeutron = pdg->GetParticle(kNeutron)->Mass(); - - /* Select nucleon type */ - if(charge == 0) m = kMassNeutron; - else m = kMassProton; - - /* Momentum at maximum of Maxwell-distribution */ - - pmax = TMath::Sqrt(2*T*(T+sqrt(T*T+m*m))); - - /* Try until proper momentum */ - /* for lack of primitive function of the Maxwell-distribution */ - /* a brute force trial-accept loop, normalized at pmax */ - - do - { - p = Rndm() * fPmax; - f = Maxwell(m, p, T) / Maxwell(m , pmax, T); - } - while(f < Rndm()); - - /* Spherical symmetric emission */ - theta = TMath::ACos(2. * Rndm() - 1.); - phi = 2. * TMath::Pi() * Rndm(); - - /* Determine momentum components in system of the moving source */ - q[0] = p * TMath::Sin(theta) * TMath::Cos(phi); - q[1] = p * TMath::Sin(theta) * TMath::Sin(phi); - q[2] = p * TMath::Cos(theta); - - /* Transform to system of the target nucleus */ - /* beta is passed as negative, because the gray nucleons are slowed down */ - Lorentz(m, -beta, q); - - /* Transform to laboratory system */ - Lorentz(m, fBeta, q); -} - -Double_t AliGenGrayParticles::Maxwell(Double_t m, Double_t p, Double_t T) -{ -/* Relativistic Maxwell-distribution */ - Double_t ekin; - ekin = TMath::Sqrt(p*p+m*m)-m; - return (p*p * exp(-ekin/T)); -} - - -void AliGenGrayParticles::Lorentz(Double_t m, Double_t beta, Float_t* q) -{ -/* Lorentz transform in the direction of q[2] */ - - Double_t gamma = 1/sqrt(1-beta*beta); - Double_t energy = sqrt(m*m + q[0]*q[0] + q[1]*q[1] + q[2]*q[2]); - q[2] = gamma * (q[2] + beta*energy); -} - - - - - - - diff --git a/EVGEN/AliGenGrayParticles.h b/EVGEN/AliGenGrayParticles.h deleted file mode 100644 index f7f350552f1..00000000000 --- a/EVGEN/AliGenGrayParticles.h +++ /dev/null @@ -1,56 +0,0 @@ -#ifndef ALIGENGRAYPARTICLES_H -#define ALIGENGRAYPARTICLES_H -/* Copyright(c) 198-1999, ALICE Experiment at CERN, All rights reserved. * - * See cxx source for full Copyright notice */ - -/* $Id$ */ - -#include "AliGenerator.h" -class AliGrayParticleModel; - -class AliGenGrayParticles : public AliGenerator -{ -public: - AliGenGrayParticles(); - AliGenGrayParticles(Int_t npart); - virtual ~AliGenGrayParticles(); - virtual void Init(); - virtual void Generate(); - virtual void SetPmax(Float_t pmax = 10.) {fPmax = pmax;} - virtual void SetNominalCmsEnergy(Float_t energy = 14000.) {fCMS = energy;} - virtual void SetTarget(Float_t a=208, Float_t z=82) {fATarget = a; fZTarget = z;} - virtual void SetCharge(Int_t c = 1) {fCharge = c;} - virtual void SetTemperature(Double_t t = 0.05) {fTemperature = t;} - virtual void SetBetaSource(Double_t b = 0.05) {fBetaSource = b;} - // - virtual void SetGrayParticleModel(AliGrayParticleModel* model) - {fGrayParticleModel = model;} - virtual Bool_t NeedsCollisionGeometry() {return kTRUE;} - virtual void SetCollisionGeometry(AliCollisionGeometry* geom) - {fCollisionGeometry = geom;} - - protected: - void GenerateSlow(Int_t charge, Double_t T, Double_t beta, Float_t* q); - Double_t Maxwell(Double_t m, Double_t p, Double_t t); - void Lorentz(Double_t m, Double_t beta, Float_t* q); - protected: - Float_t fCMS; // Center of mass energy - Float_t fMomentum; // Target nucleus momentum - Float_t fBeta; // Target nucleus beta - Float_t fPmax; // Maximum slow nucleon momentum - Float_t fATarget; // Target nucleus mass number - Float_t fZTarget; // Target nucleus charge number - Int_t fCharge; // Slow nucleon charge - Float_t fTemperature; // Source Temperature - Float_t fBetaSource; // Source beta - // - AliGrayParticleModel* fGrayParticleModel; // The gray particle model - ClassDef(AliGenGrayParticles,1) // Gray Particle Generator -}; -#endif - - - - - - diff --git a/EVGEN/AliGrayParticleModel.cxx b/EVGEN/AliGrayParticleModel.cxx deleted file mode 100644 index 9aef18d5567..00000000000 --- a/EVGEN/AliGrayParticleModel.cxx +++ /dev/null @@ -1,23 +0,0 @@ -/************************************************************************** - * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * - * * - * Author: The ALICE Off-line Project. * - * Contributors are mentioned in the code where appropriate. * - * * - * Permission to use, copy, modify and distribute this software and its * - * documentation strictly for non-commercial purposes is hereby granted * - * without fee, provided that the above copyright notice appears in all * - * copies and that both the copyright notice and this permission notice * - * appear in the supporting documentation. The authors make no claims * - * about the suitability of this software for any purpose. It is * - * provided "as is" without express or implied warranty. * - **************************************************************************/ - -/* -$Log$ -*/ - - -#include "AliGrayParticleModel.h" -#include "AliCollisionGeometry.h" -ClassImp(AliGrayParticleModel) diff --git a/EVGEN/AliGrayParticleModel.h b/EVGEN/AliGrayParticleModel.h deleted file mode 100644 index 77e9b3b0084..00000000000 --- a/EVGEN/AliGrayParticleModel.h +++ /dev/null @@ -1,27 +0,0 @@ -#ifndef ALIGRAYPARTICLEMODEL_H -#define ALIGRAYPARTICLEMODEL_H -/* Copyright(c) 198-1999, ALICE Experiment at CERN, All rights reserved. * - * See cxx source for full Copyright notice */ - -/* $Id$ */ - -#include "TObject.h" -class AliCollisionGeometry; - -class AliGrayParticleModel : public TObject -{ -public: - AliGrayParticleModel() {;} - virtual ~AliGrayParticleModel(){;} - virtual void GetNumberOfGrayNucleons(AliCollisionGeometry* geo, Int_t& np, Int_t& nn) {;} - - protected: - ClassDef(AliGrayParticleModel,1) // Gray Particle Model -}; -#endif - - - - - -