include/apfel/splittingfunctionstrans_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 TransSF Transversely polarised splitting functions
0015    * @ingroup SLSplittings
0016    * @note References: https://arxiv.org/pdf/hep-ph/9706511v2.pdf,
0017    * https://lib-extopc.kek.jp/preprints/PDF/2000/0032/0032201.pdf,
0018    * https://arxiv.org/pdf/hep-ph/9805295v1.pdf
0019    */
0020   ///@{
0021   ///@}
0022   /**
0023    * @defgroup LOtranssf LO splitting functions
0024    * @ingroup TransSF
0025    */
0026   ///@{
0027   /**
0028    * @brief Space-like O(&alpha;<SUB>s</SUB>) non-singlet transversely polarised
0029    * splitting function.
0030    */
0031   class P0transns: public Expression
0032   {
0033   public:
0034     P0transns();
0035     double Regular(double const&)    const;
0036     double Singular(double const& x) const;
0037     double Local(double const& x)    const;
0038   };
0039
0040   /**
0041    * @brief Space-like O(&alpha;<SUB>s</SUB>) gluon-gluon linearly
0042    * polarised splitting function.
0043    * @note
0044    */
0045   class P0transgg: public Expression
0046   {
0047   public:
0048     P0transgg(int const& nf);
0049     double Regular(double const& x)  const;
0050     double Singular(double const& x) const;
0051     double Local(double const& x)    const;
0052   private:
0053     int const _nf;
0054   };
0055   ///@}
0056
0057   /**
0058    * @defgroup NLOtranssf NLO splitting functions
0059    * @ingroup TransSF
0060    */
0061   ///@{
0062   /**
0063    * @brief Space-like O(&alpha;<SUB>s</SUB><SUP>2</SUP>) non-singlet-plus
0064    * transversely polarised splitting function.
0065    */
0066   class P1transnsp: public Expression
0067   {
0068   public:
0069     P1transnsp(int const& nf);
0070     double Regular(double const& x)  const;
0071     double Singular(double const& x) const;
0072     double Local(double const& x)    const;
0073   protected:
0074     int const _nf;
0075     double    _a2;
0076   };
0077
0078   /**
0079    * @brief Space-like O(&alpha;<SUB>s</SUB><SUP>2</SUP>) non-singlet-minus
0080    * transversely polarised splitting function.
0081    */
0082   class P1transnsm: public P1transnsp
0083   {
0084   public:
0085     P1transnsm(int const& nf);
0086     double Regular(double const& x) const;
0087   };
0088
0089   /**
0090    * @brief Space-like O(&alpha;<SUB>s</SUB><SUP>2</SUP>) gluon-gluon linearly
0091    * polarised splitting function.
0092    * @note
0093    */
0094   class P1transgg: public Expression
0095   {
0096   public:
0097     P1transgg(int const& nf);
0098     double Regular(double const& x)  const;
0099     double Singular(double const& x) const;
0100     double Local(double const& x)    const;
0101   private:
0102     int const _nf;
0103     double    _a2;
0104   };
0105   ///@}
0106 }