ParticleIdUtils.hh

// -*- C++ -*-
//
// This file is part of MCUtils -- https://bitbucket.org/andybuckley/mcutils
// Copyright (C) 2013-2016 Andy Buckley <andy.buckley@cern.ch>
//
// Embedding of MCUtils code in other projects is permitted provided this
// notice is retained and the MCUtils namespace and include path are changed.
//
#ifndef RIVET_PARTICLEIDUTILS_HH
#define RIVET_PARTICLEIDUTILS_HH


#include "Rivet/Tools/ParticleName.hh"
#include "Rivet/Math/MathUtils.hh"

namespace Rivet {
  namespace PID {




    inline int abspid(int pid) { return abs(pid); }

    enum Location { nj=1, nq3, nq2, nq1, nl, nr, n, n8, n9, n10 };

    inline unsigned short _digit(Location loc, int pid) {
      //  PID digits (base 10) are: n nr nl nq1 nq2 nq3 nj (cf. Location)
      int numerator = (int) std::pow(10.0, (loc-1));
      return (abs(pid)/numerator) % 10;
    }

    inline int _extraBits(int pid) {
      return abs(pid)/10000000;
    }

    inline int _fundamentalID(int pid) {
      if (_extraBits(pid) > 0) return 0;
      if (_digit(nq2,pid) == 0 && _digit(nq1,pid) == 0) {
        return abs(pid) % 10000;
      } else if (abs(pid) <= 100) {
        return abs(pid);
      } else {
        return 0;
      }
    }





    inline bool isNucleus(int pid) {
      // a proton can also be a Hydrogen nucleus
      if (abs(pid) == 2212) return true;
      // new standard: +/- 10LZZZAAAI
      if ((_digit(n10,pid) == 1) && (_digit(n9,pid) == 0)) {
        // charge should always be less than or equal to baryon number
        // the following line is A >= Z
        if ((abs(pid)/10)%1000 >= (abs(pid)/10000)%1000) return true;
      }
      return false;
    }

    inline int nuclZ(int pid) {
      // A proton can also be a Hydrogen nucleus
      if (abs(pid) == 2212) { return 1; }
      if (isNucleus(pid)) return (abs(pid)/10000) % 1000;
      return 0;
    }
    inline int Z(int pid) { return nuclZ(pid); }

    inline int nuclA(int pid) {
      // A proton can also be a Hydrogen nucleus, and we might as well also allow single neutrons
      if (abs(pid) == 2212 || abs(pid) == 2112) { return 1; }
      if (isNucleus(pid)) return (abs(pid)/10) % 1000;
      return 0;
    }
    inline int A(int pid) { return nuclA(pid); }

    inline int nuclNlambda(int pid) {
      // a proton can also be a Hydrogen nucleus
      if (abs(pid) == 2212) { return 0; }
      if (isNucleus(pid)) return _digit(n8,pid);
      return 0;
    }
    inline int lambda(int pid) { return nuclNlambda(pid); }





    inline bool isReggeon(int pid) {
      return pid == 110 || pid == 990 || pid == 9990;
    }

    inline bool isMeson(int pid) {
      if (_extraBits(pid) > 0) return false;
      // exotica
      if (_digit(n,pid) > 0 && _digit(n,pid) < 9) return false;
      const int aid = abs(pid);
      if (aid == 130 || aid == 310 || aid == 210) return true; //< special cases for kaons
      if (aid <= 100) return false;
      if (_digit(nq1,pid) != 0) return false;
      if (_digit(nq2,pid) == 0) return false;
      if (_digit(nq3,pid) == 0) return false;
      if (_digit(nq2,pid) < _digit(nq3,pid)) return false;
      // EvtGen uses some odd numbers
      if (aid == 150 || aid == 350 || aid == 510 || aid == 530) return true;
      // Pomeron, Reggeon, etc.
      if (isReggeon(pid)) return false; //true; //< WTF?
      // Check for illegal antiparticles
      if (_digit(nj,pid) > 0 && _digit(nq3,pid) > 0 && _digit(nq2,pid) > 0 && _digit(nq1,pid) == 0) {
        return !(_digit(nq3,pid) == _digit(nq2,pid) && pid < 0);
      }
      return false;
    }

    inline bool isBaryon(int pid) {
      if (_extraBits(pid) > 0) return false;
      // exotica
      if (_digit(n,pid) > 0 && _digit(n,pid) < 9) return false;
      if (abs(pid) <= 100) return false;
      if (_fundamentalID(pid) <= 100 && _fundamentalID(pid) > 0) return false;
      if (abs(pid) == 2110 || abs(pid) == 2210) return true; 
      if (_digit(nj,pid) == 0) return false;
      if (_digit(nq1,pid) == 0 || _digit(nq2,pid) == 0 || _digit(nq3,pid) == 0) return false;
      return true;
      // if ((_digit(nq1,pid) >= _digit(nq2,pid) && _digit(nq2,pid) >= _digit(nq3,pid)) ||
      //     (_digit(nq1,pid) > _digit(nq3,pid) && _digit(nq3,pid) > _digit(nq2,pid)) || //< case 6b for lighter quarks in J=1
      //     (_digit(nq3,pid) > _digit(nq1,pid) && _digit(nq1,pid) > _digit(nq2,pid))) //< case 6e for extra states in excited multiplets
      //   return true;
      // return false;
    }

    // Check to see if this is a valid diquark
    inline bool isDiquark(int pid) {
      if (_extraBits(pid) > 0) return false;
      if (abs(pid) <= 100) return false;
      if (_fundamentalID(pid) <= 100 && _fundamentalID(pid) > 0) return false;
      if (_digit(nq1,pid) == 0) return false;
      if (_digit(nq2,pid) == 0) return false;
      if (_digit(nq3,pid) != 0) return false;
      if (_digit(nq1,pid) < _digit(nq2,pid)) return false;
      if (_digit(nj,pid) > 0  && _digit(nq3,pid) == 0 && _digit(nq2,pid) > 0 && _digit(nq1,pid) > 0) return true; // diquark signature
      // EvtGen uses the diquarks for quark pairs, so, for instance, 5501 is a valid "diquark" for EvtGen
      // if (_digit(nj) == 1 && _digit(nq2) == _digit(nq1)) {    // illegal
      //    return false;
      // } else {
      //  return true;
      // }
      return false;
    }
    inline bool isDiQuark(int pid) { return isDiquark(pid); }

    inline bool isPentaquark(int pid) {
      // a pentaquark is of the form 9abcdej,
      // where j is the spin and a, b, c, d, and e are quarks
      if (_extraBits(pid) > 0) return false;
      if (_digit(n,pid) != 9)  return false;
      if (_digit(nr,pid) == 9 || _digit(nr,pid) == 0)  return false;
      if (_digit(nj,pid) == 9 || _digit(nl,pid) == 0)  return false;
      if (_digit(nq1,pid) == 0)  return false;
      if (_digit(nq2,pid) == 0)  return false;
      if (_digit(nq3,pid) == 0)  return false;
      if (_digit(nj,pid) == 0)  return false;
      // check ordering
      if (_digit(nq2,pid) > _digit(nq1,pid))  return false;
      if (_digit(nq1,pid) > _digit(nl,pid))  return false;
      if (_digit(nl,pid) > _digit(nr,pid))  return false;
      return true;
    }

    inline bool isHadron(int pid) {
      if (_extraBits(pid) > 0) return false;
      if (isMeson(pid)) return true;
      if (isBaryon(pid)) return true;
      if (isPentaquark(pid)) return true;
      return false;
    }





    inline bool isLepton(int pid) {
      if (_extraBits(pid) > 0) return false;
      if (_fundamentalID(pid) >= 11 && _fundamentalID(pid) <= 18) return true;
      return false;
    }

    inline bool isSUSY(int pid) {
      // Fundamental SUSY particles have n = 1 or 2
      if (_extraBits(pid) > 0) return false;
      if (_digit(n,pid) != 1 && _digit(n,pid) != 2)  return false;
      if (_digit(nr,pid) != 0)  return false;
      // Check fundamental part for SM PID on which it is based
      if (_fundamentalID(pid) == 0)  return false;
      return true;
    }

    inline bool isRhadron(int pid) {
      // An R-hadron is of the form 10abcdj,
      // where j is the spin and a, b, c, and d are quarks or gluons
      if (_extraBits(pid) > 0) return false;
      if (_digit(n,pid) != 1)  return false;
      if (_digit(nr,pid) != 0)  return false;
      // Make sure this isn't a SUSY particle
      if (isSUSY(pid)) return false;
      // All R-hadrons have at least 3 core digits
      if (_digit(nq2,pid) == 0)  return false;
      if (_digit(nq3,pid) == 0)  return false;
      if (_digit(nj,pid) == 0)  return false;
      return true;
    }
    inline bool isRHadron(int pid) { return isRhadron(pid); }

    inline bool isTechnicolor(int pid) {
      if (_extraBits(pid) > 0) return false;
      return _digit(n,pid) == 3;
    }

    inline bool isExcited(int pid) {
      if (_extraBits(pid) > 0) return false;
      return _digit(n,pid) == 4;
    }

    inline bool isKK(int pid) {
      if (_extraBits(pid) > 0) return false;
      const int ndigit = _digit(n,pid);
      return ndigit == 5 || ndigit == 6;
    }

    inline bool isGraviton(int pid) {
      return pid == 39;
    }

    inline bool isBSM(int pid) {
      return isSUSY(pid) || isRhadron(pid) || isTechnicolor(pid) ||
        isExcited(pid) || isKK(pid) || isGraviton(pid);
    }

    inline bool _isValid(int pid) {
      // Starting with 99 means anything goes (but nothing is known)
      if (_digit(n,pid) == 9 && _digit(nr,pid) == 9) return true;
      // Check that extra bits are only used for nuclei
      if (_extraBits(pid) > 0) return isNucleus(pid);
      // Check that it fits into a standard non-nucleus convention
      if (isBSM(pid)) return true;
      if (isHadron(pid)) return true;
      if (_digit(n,pid) == 9 && _digit(nr,pid) == 0) return false; // could only have been a tentative hadron, but !isHadron
      if (isDiquark(pid)) return true;
      if (isReggeon(pid)) return true;
      // // Quark digit orderings required by the standard
      // if (_digit(nq1,pid) != 0 && _digit(nq1,pid) < _digit(nq2,pid)) return false;
      // if (_digit(nq2,pid) != 0 && _digit(nq2,pid) < _digit(nq3,pid)) return false;
      // Final check on fundamental ID
      return (_fundamentalID(pid) > 0);
    }
    inline bool isValid(int pid) { return _isValid(pid); }





    inline bool _hasQ(int pid, int q) {
      if (abs(pid) == q) return true; //< trivial case!
      if (!_isValid(pid)) return false;
      if (_extraBits(pid) > 0) return false;
      if (_fundamentalID(pid) > 0) return false;
      return _digit(nq3,pid) == q || _digit(nq2,pid) == q || _digit(nq1,pid) == q;
    }

    inline bool hasDown(int pid) { return _hasQ(pid, 1); }
    inline bool hasUp(int pid) { return _hasQ(pid, 2); }
    inline bool hasStrange(int pid) { return _hasQ(pid, 3); }
    inline bool hasCharm(int pid) { return _hasQ(pid, 4); }
    inline bool hasBottom(int pid) { return _hasQ(pid, 5); }
    inline bool hasTop(int pid) { return _hasQ(pid, 6); }





    inline int jSpin(int pid) {
      const int fund = _fundamentalID(pid);
      if (fund > 0) {
        // some of these are known
        if (fund > 0 && fund < 7) return 2;
        if (fund == 9) return 3;
        if (fund > 10 && fund < 17) return 2;
        if (fund > 20 && fund < 25) return 3;
        return 0;
      } else if (_extraBits(pid) > 0) {
        return 0;
      }
      return abs(pid) % 10;
    }

    inline int sSpin(int pid) {
      // Handle invalid cases first
      if (!isMeson(pid)) return 0;
      if (_digit(n,pid) == 9 && _digit(nr,pid) == 0) return 0; // tentative ID
      // Special generic DM particles with defined spins
      const int fund = _fundamentalID(pid);
      if (fund == 51 || fund == 54) return 1;
      if (fund == 52) return 2;
      if (fund == 53 || fund == 55) return 3;
      // Calculate from nl and nj digits
      const int inl = _digit(nl,pid);
      const int js = _digit(nj,pid);
      if (inl == 0 && js >= 3) return 1;
      else if (inl == 0  && js == 1) return 0;
      else if (inl == 1  && js >= 3) return 0;
      else if (inl == 2  && js >= 3) return 1;
      else if (inl == 1  && js == 1) return 1;
      else if (inl == 3  && js >= 3) return 1;
      // Default to zero
      return 0;
    }

    inline int lSpin(int pid) {
      // Handle invalid cases first
      if (!isMeson(pid)) return 0;
      if (_digit(n,pid) == 9 && _digit(nr,pid) == 0) return 0; // tentative ID
      // Calculate from nl and nj digits
      const int inl = _digit(nl,pid);
      const int js = _digit(nj,pid);
      if (inl == 0 && js == 3) return 0;
      else if (inl == 0 && js == 5) return 1;
      else if (inl == 0 && js == 7) return 2;
      else if (inl == 0 && js == 9) return 3;
      else if (inl == 0 && js == 1) return 0;
      else if (inl == 1 && js == 3) return 1;
      else if (inl == 1 && js == 5) return 2;
      else if (inl == 1 && js == 7) return 3;
      else if (inl == 1 && js == 9) return 4;
      else if (inl == 2 && js == 3) return 1;
      else if (inl == 2 && js == 5) return 2;
      else if (inl == 2 && js == 7) return 3;
      else if (inl == 2 && js == 9) return 4;
      else if (inl == 1 && js == 1) return 1;
      else if (inl == 3 && js == 3) return 2;
      else if (inl == 3 && js == 5) return 3;
      else if (inl == 3 && js == 7) return 4;
      else if (inl == 3 && js == 9) return 5;
      // Default to zero
      return 0;
    }





    inline int charge3(int pid) {
      static int ch100[100] = { -1, 2,-1, 2,-1, 2,-1, 2, 0, 0,
                                -3, 0,-3, 0,-3, 0,-3, 0, 0, 0,
                                0, 0, 0, 3, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 3, 0, 0, 3, 0, 0, 0,
                                0, -1, 0, 0, 0, 0, 0, 0, 0, 0,
                                0, 6, 3, 6, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
      const unsigned short q1 = _digit(nq1,pid);
      const unsigned short q2 = _digit(nq2,pid);
      const unsigned short q3 = _digit(nq3,pid);
      const int ida = abs(pid);
      const int sid = _fundamentalID(pid);
      int charge = 0;
      if (ida == 0 || _extraBits(pid) > 0) {// ion or illegal
        return 0;
      } else if (sid > 0 && sid <= 100) {// use table
        if (ida == 1000017 || ida == 1000018 || ida == 1000034) charge = 0;
        else if (ida > 1000050 && ida <= 1000060) charge = 0; // ?
        else if (ida > 50 && ida <= 60) charge = 0; // Generic DM
        else if (ida == 5100061 || ida == 5100062) charge = 6;
        else charge = ch100[sid-1];
      } else if (_digit(nj,pid) == 0) {// KL, Ks, or undefined
        return 0;
      } else if (isMeson(pid)) {// mesons
        if (q2 == 3 || q2 == 5) {
          charge = ch100[q3-1] - ch100[q2-1];
        } else {
          charge = ch100[q2-1] - ch100[q3-1];
        }
      } else if (isDiQuark(pid)) {// diquarks
        charge = ch100[q2-1] + ch100[q1-1];
      } else if (isBaryon(pid)) {// baryons
        charge = ch100[q3-1] + ch100[q2-1] + ch100[q1-1];
      } else {// unknown
        return 0;
      }
      if (pid < 0) charge *= -1;
      return charge;
    }

    inline int threeCharge(int pid) { return charge3(pid); }

    inline int abscharge3(int pid) { return std::abs(charge3(pid)); }

    inline double charge(int pid) { return charge3(pid)/3.0; }

    inline double abscharge(int pid) { return abscharge3(pid)/3.0; }





    inline bool isCharged(int pid) {
      return charge3(pid) != 0;
    }

    inline bool isNeutral(int pid) {
      return charge3(pid) == 0;
    }





    inline bool isQuark(int pid) {
      return in_closed_range(abs(pid), 1, 6);
    }

    inline bool isGluon(int pid) {
      return pid == GLUON;
    }

    inline bool isParton(int pid) {
      return isGluon(pid) || isQuark(pid);
    }

    inline bool isPhoton(int pid) {
      return pid == PHOTON;
    }

    inline bool isElectron(int pid) {
      return abs(pid) == ELECTRON;
    }

    inline bool isMuon(int pid) {
      return abs(pid) == MUON;
    }

    inline bool isTau(int pid) {
      return abs(pid) == TAU;
    }

    inline bool isChargedLepton(int pid) {
      const long apid = abs(pid);
      return apid == 11 || apid == 13 || apid == 15;
    }
    // Alias
    inline bool isChLepton(int pid) { return isChargedLepton(pid); }

    inline bool isNeutrino(int pid) {
      const long apid = abs(pid);
      return apid == 12 || apid == 14 || apid == 16;
    }


    inline bool isWplus(int pid) {
      return pid == WPLUSBOSON;
    }

    inline bool isWminus(int pid) {
      return pid == WMINUSBOSON;
    }

    inline bool isW(int pid) {
      return abs(pid) == WPLUSBOSON;
    }

    inline bool isZ(int pid) {
      return pid == Z0BOSON;
    }

    inline bool isHiggs(int pid) {
      return pid == HIGGSBOSON || pid == 26; //< @todo Check on 26 still needed? (used in HERWIG SUSY, for example)
    }



    // /// Determine if the PID is that of a d/dbar
    // inline bool isDown(int pid) { return abs(pid) == DQUARK; }

    // /// Determine if the PID is that of a u/ubar
    // inline bool isUp(int pid) { return abs(pid) == UQUARK; }

    inline bool isStrange(int pid) { return abs(pid) == SQUARK; }

    inline bool isCharm(int pid) { return abs(pid) == CQUARK; }

    inline bool isBottom(int pid) { return abs(pid) == BQUARK; }

    inline bool isTop(int pid) { return abs(pid) == TQUARK; }





    inline bool isHeavyFlavour(int pid) {
      return hasCharm(pid) || hasBottom(pid) || hasTop(pid);
    }

    // /// Determine if the particle is a light-flavour flavour hadron or parton
    // inline bool isLightFlavour(int pid) {
    //   return !isHeavyFlavour();
    // }

    inline bool isHeavyParton(int pid) {
      return isParton(pid) && isHeavyFlavour(pid);
    }

    inline bool isLightParton(int pid) {
      return isParton(pid) && !isHeavyFlavour(pid);
    }


    inline bool isHeavyMeson(int pid) {
      return isMeson(pid) && isHeavyFlavour(pid);
    }

    inline bool isHeavyBaryon(int pid) {
      return isBaryon(pid) && isHeavyFlavour(pid);
    }

    inline bool isHeavyHadron(int pid) {
      return isHadron(pid) && isHeavyFlavour(pid);
    }

    inline bool isLightMeson(int pid) {
      return isMeson(pid) && !isHeavyFlavour(pid);
    }

    inline bool isLightBaryon(int pid) {
      return isBaryon(pid) && !isHeavyFlavour(pid);
    }

    inline bool isLightHadron(int pid) {
      return isHadron(pid) && !isHeavyFlavour(pid);
    }


    inline bool isBottomMeson(int pid) {
      return hasBottom(pid) && isMeson(pid);
    }

    inline bool isBottomBaryon(int pid) {
      return hasBottom(pid) && isBaryon(pid);
    }

    inline bool isBottomHadron(int pid) {
      return hasBottom(pid) && isHadron(pid);
    }


    inline bool isCharmMeson(int pid) {
      return isMeson(pid) && hasCharm(pid) &&
        !hasBottom(pid);
    }

    inline bool isCharmBaryon(int pid) {
      return isBaryon(pid) && hasCharm(pid) &&
        !hasBottom(pid);
    }

    inline bool isCharmHadron(int pid) {
      return isHadron(pid) && hasCharm(pid) &&
        !hasBottom(pid);
    }


    inline bool isStrangeMeson(int pid) {
      return isMeson(pid) && hasStrange(pid) &&
        !(hasBottom(pid) || hasCharm(pid));
    }

    inline bool isStrangeBaryon(int pid) {
      return isBaryon(pid) && hasStrange(pid) &&
        !(hasBottom(pid) || hasCharm(pid));
    }

    inline bool isStrangeHadron(int pid) {
      return isHadron(pid) && hasStrange(pid) &&
        !(hasBottom(pid) || hasCharm(pid));
    }





    inline bool isStrongInteracting(int pid) {
      return isParton(pid) || isHadron(pid);
    }

    inline bool isEMInteracting(int pid) {
      return isCharged(pid) || isPhoton(pid);
    }

    inline bool isWeakInteracting(int pid) {
      return !isGluon(pid) && !isGraviton(pid);
    }





    inline bool isGenSpecific(int pid) {
      return in_range(pid, 80, 101);
    }

    inline bool isResonance(int pid) {
      return isW(pid) || isZ(pid) || isHiggs(pid) || isTop(pid);
    }

    inline bool isTransportable(int pid) {
      // return !isResonance(pid) && !isParton(pid) && !isGenSpecific(pid);
      return isPhoton(pid) || isHadron(pid) || isLepton(pid);
    }





    inline bool isSameSign(PdgId a, PdgId b) { return a*b >= 0; }
    inline bool isOppSign(PdgId a, PdgId b) { return !isSameSign(a, b); }
    inline bool isSameFlav(PdgId a, PdgId b) { return abs(a) == abs(b); }
    inline bool isOppFlav(PdgId a, PdgId b) { return !isSameFlav(a, b); }

    inline bool isOSSF(PdgId a, PdgId b) { return isOppSign(a, b) && isSameFlav(a, b); }
    inline bool isSSSF(PdgId a, PdgId b) { return isSameSign(a, b) && isSameFlav(a, b); }
    inline bool isOSOF(PdgId a, PdgId b) { return isOppSign(a, b) && isOppFlav(a, b); }
    inline bool isSSOF(PdgId a, PdgId b) { return isSameSign(a, b) && isOppFlav(a, b); }


  }
}

#endif