git://git.uio.no / u / mrichter / AliRoot.git / blame
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1 | /////////////////////////////////////////////////////////////////////////// |
| 2 | // | |
| 3 | // Copyright 2010 | |
| 4 | // | |
| 5 | // This file is part of starlight. | |
| 6 | // | |
| 7 | // starlight is free software: you can redistribute it and/or modify | |
| 8 | // it under the terms of the GNU General Public License as published by | |
| 9 | // the Free Software Foundation, either version 3 of the License, or | |
| 10 | // (at your option) any later version. | |
| 11 | // | |
| 12 | // starlight is distributed in the hope that it will be useful, | |
| 13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 15 | // GNU General Public License for more details. | |
| 16 | // | |
| 17 | // You should have received a copy of the GNU General Public License | |
| 18 | // along with starlight. If not, see <http://www.gnu.org/licenses/>. | |
| 19 | // | |
| 20 | /////////////////////////////////////////////////////////////////////////// | |
| 21 | // | |
| 22 | // File and Version Information: | |
| 45d54d9a | 23 | // $Rev:: 176 $: revision of last commit |
| 24 | // $Author:: jseger $: author of last commit | |
| 25 | // $Date:: 2014-06-20 22:15:20 +0200 #$: date of last commit | |
| da32329d AM |
26 | // |
| 27 | // Description: | |
| 28 | // | |
| 29 | // | |
| 30 | // | |
| 31 | /////////////////////////////////////////////////////////////////////////// | |
| 32 | ||
| 33 | ||
| 34 | #ifndef NUCLEUS_H | |
| 35 | #define NUCLEUS_H | |
| 36 | ||
| 37 | ||
| 38 | #include <cmath> | |
| 39 | ||
| 40 | ||
| 41 | //This class holds the information for a target nucleus | |
| 42 | class nucleus | |
| 43 | { | |
| 44 | ||
| 45 | public: | |
| 46 | nucleus(); | |
| 47 | nucleus(const int Z, | |
| 48 | const int A, | |
| da32329d AM |
49 | const bool dAuCoherentProduction); |
| 50 | ~nucleus(); | |
| 51 | ||
| 52 | void init(); | |
| 53 | ||
| 54 | int Z () const { return _Z; } ///< returns atomic number of nucleus | |
| 55 | int A () const { return _A; } ///< returns nucleon number of nucleus | |
| 56 | // double woodSaxonRadius() const { return 1.2 * pow(_A, 1. / 3.); } ///< returns Wood-Saxon nuclear radius [fm] (Fermi model) | |
| 57 | double nuclearRadius () const; ///< returns nuclear radius [fm]; except for some special nuclei this is the Wood-Saxon radius (Fermi model) | |
| 58 | ||
| 59 | double formFactor(const double t) const; ///< computes form factor for given squared 4-momentum transfer | |
| 60 | double dipoleFormFactor(const double t, const double t0) const; // Dipole form factor with t0 as parameter | |
| 61 | double thickness (const double b) const; ///< calculates nuclear thickness function for given distance b in impact parameter space (Eq. 4 in KN, PRC 60) | |
| 62 | ||
| 63 | double Q0 () const { return _Q0; } | |
| 64 | double rho0() const { return _rho0; } | |
| 65 | ||
| 66 | ||
| 67 | private: | |
| 68 | ||
| 69 | double woodSaxonSkinDepth() const { return 0.53; } ///< returns surface (0.53 fm for Au) | |
| 70 | double fritiofR0 () const { return _r0 * pow(_A, (1./3.)); } ///< Fritiof _r0 (rws)/formfactor | |
| 71 | ||
| 72 | double rws(const double r) const | |
| be31281a | 73 | { //std::cout << "rws: " << r << " " << fritiofR0() << " " << woodSaxonSkinDepth() << std::endl; |
| 74 | const double x=exp(-(r - fritiofR0()) / woodSaxonSkinDepth()); | |
| 75 | return x/(1.+x); | |
| 76 | return 1.0 / (1. + exp((r - fritiofR0()) / woodSaxonSkinDepth())); } ///< Wood-Saxon nuclear density | |
| da32329d AM |
77 | |
| 78 | int _Z; ///< atomic number of nucleus | |
| 79 | int _A; ///< nucleon number of nucleus | |
| da32329d AM |
80 | bool _dAuCoherentProduction; ///< if true, production in d Au collisions is coherent, else incoherent |
| 81 | ||
| 82 | double _r0; | |
| 83 | double _rho0; | |
| 84 | double _Q0; | |
| 85 | ||
| 86 | }; | |
| 87 | ||
| 88 | ||
| 89 | #endif // NUCLEUS_H |