include/apfel/betaqcdqed.h

0001 //
0002 // APFEL++ 2017
0003 //
0004 // Author: Valerio Bertone: valerio.bertone@cern.ch
0005 //
0006
0007 #pragma once
0008
0009 namespace apfel
0010 {
0011   /**
0012    * @name QCDxQED mixed beta function
0013    * Coefficients of the QCDxQED mixed \f$\beta\f$ function.
0014    * Reference: https://arxiv.org/pdf/hep-ph/9803211.pdf
0015    */
0016   ///@{
0017   /**
0018    * @brief \f$O(\alpha_s\alpha)\f$ coefficient of the QCD \f$\beta\f$
0019    * function.
0020    * @param nf: the number of active flavours
0021    * @return \f$\beta^{(\alpha_s\alpha)}(n_f)\f$
0022    */
0023   double beta1qcdqed(int const& nf);
0024
0025   /**
0026    * @brief \f$O(\alpha\alpha_s)\f$ coefficient of the QCD \f$\beta\f$
0027    * function.
0028    * @param nf: the number of active flavours
0029    * @return \f$\beta^{(\alpha\alpha_s)}(n_f)\f$
0030    */
0031   double beta1qedqcd(int const& nf);
0032   ///@}
0033 }