include/apfel/zeromasscoefficientfunctionspol_sl.h

0001 //
0002 // APFEL++ 2017
0003 //
0004 // Author: Valerio Bertone: valerio.bertone@cern.ch
0005 //
0006
0007 #pragma once
0008
0009 #include "apfel/expression.h"
0010
0011 namespace apfel
0012 {
0013   /**
0014    * @defgroup NCMasslesspol Zero-mass coefficient functions for longitudinally polarised DIS
0015    * Collection of the Zero-mass coefficient functions up to
0016    * O(&alpha;<SUB>s</SUB>) for g<SUB>4</SUB> and g<SUB>L</SUB>, and
0017    * up to O(&alpha;<SUB>s</SUB><SUP>2</SUP>) for g<SUB>1</SUB>.
0018    * @note The expression for g1 are taken from:
0019    * https://inspirehep.net/literature/353973.
0020    */
0021   ///@{
0022   /**
0023    * @defgroup NLOzmpol NLO zero-mass coefficient functions
0024    * @ingroup NCMasslesspol
0025    */
0026   ///@{
0027   /**
0028    * @brief O(&alpha;<SUB>s</SUB>) non-singlet coefficient function
0029    * for g<SUB>4</SUB>.
0030    */
0031   class G41ns: public Expression
0032   {
0033   public:
0034     G41ns();
0035     double Regular(double const& x)  const;
0036     double Singular(double const& x) const;
0037     double Local(double const& x)    const;
0038   };
0039
0040   /**
0041    * @brief O(&alpha;<SUB>s</SUB>) non-singlet coefficient function
0042    * for g<SUB>L</SUB>.
0043    */
0044   class GL1ns: public Expression
0045   {
0046   public:
0047     GL1ns();
0048     double Regular(double const& x) const;
0049   };
0050
0051   /**
0052    * @brief O(&alpha;<SUB>s</SUB>) non-singlet coefficient function
0053    * for g<SUB>1</SUB>.
0054    */
0055   class G11ns: public Expression
0056   {
0057   public:
0058     G11ns();
0059     double Regular(double const& x)  const;
0060     double Singular(double const& x) const;
0061     double Local(double const& x)    const;
0062   };
0063
0064   /**
0065    * @brief O(&alpha;<SUB>s</SUB>) gluon coefficient function for for
0066    * g<SUB>1</SUB>.
0067    */
0068   class G11g: public Expression
0069   {
0070   public:
0071     G11g();
0072     double Regular(double const& x) const;
0073   };
0074   ///@}
0075
0076   /**
0077    * @defgroup NNLOzmpol NNLO zero-mass coefficient functions
0078    * @ingroup NCMasslesspol
0079    */
0080   ///@{
0081   /**
0082    * @brief O(&alpha;<SUB>s</SUB><SUP>2</SUP>) non-singlet-plus
0083    * coefficient function for F2.
0084    */
0085   class G12nsp: public Expression
0086   {
0087   public:
0088     G12nsp(int const& nf);
0089     double Regular(double const& x)  const;
0090     double Singular(double const& x) const;
0091     double Local(double const& x)    const;
0092   private:
0093     int const _nf;
0094   };
0095
0096   /**
0097    * @brief O(&alpha;<SUB>s</SUB><SUP>2</SUP>) pure-singlet
0098    * coefficient function for F2.
0099    */
0100   class G12ps: public Expression
0101   {
0102   public:
0103     G12ps();
0104     double Regular(double const& x) const;
0105   };
0106
0107   /**
0108    * @brief O(&alpha;<SUB>s</SUB><SUP>2</SUP>) gluon coefficient
0109    * function for F2.
0110    */
0111   class G12g: public Expression
0112   {
0113   public:
0114     G12g();
0115     double Regular(double const& x) const;
0116   };
0117   ///@}
0118   ///@}
0119 }