Merge pull request #1088 in B2/basf2 from feature/B2Xsnunubar_evtgen_model-r06-01 to release/06-01

* commit 'e1d7eb1529c97836390e73448bea834431a5cc1d':
  Merge pull request #594 in B2/basf2 from feature/Bugfix-B2Xsnunubar-evtgen-model to main
  Merge pull request #560 in B2/basf2 from feature/B2Xsnunubar_evtgen_model to main

Author: GiacomoXT

generators/evtgen/models/include/EvtBtoXsnunu_FERMI.h

@@ -0,0 +1,120 @@
+/**************************************************************************
+ * basf2 (Belle II Analysis Software Framework)                           *
+ * Author: The Belle II Collaboration                                     *
+ *                                                                        *
+ * See git log for contributors and copyright holders.                    *
+ * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
+ **************************************************************************/
+
+#pragma once
+
+#include "EvtGenBase/EvtDecayIncoherent.hh"
+#include "EvtGenBase/EvtParticle.hh"
+#include <string>
+
+namespace Belle2 {
+  class EvtBtoXsnunu_FERMI : public  EvtDecayIncoherent {
+
+    /** The evtgen model to produce non-resonant B-> Xs nu nubar decay sample.
+     *
+     * In this model, kinematics of two neutrinos is not carefully considered. Di-neutrino just decay by EvtGenKine::PhaseSpace
+     *
+     * This model adopts the Fermi motion model which is used for EvtBtoXsll model.
+     *
+     * The momentums of b-quark and spectator quark are determined by the Fermi motion model.
+     * The decay of b-quark is determined by dGdsb probability density function from [arXiv:1509.06248v2].
+     *
+     * This model requires 6 parameters: m_ms, m_mq, m_pf, m_mxmin, m_mb_prob, m_ms_prob.
+     * m_mb_prob and m_ms_prob are used to calculate dGdsb. m_mb_prob=4.68 and m_ms_prob=0.1 are used in [arXiv:0902.0160].
+     * In [arXiv:hep-ph/9603237], m_mb_prob=4.8 and m_ms_prob=0.2 are used for B->Xs l l decay.
+     * m_ms and m_mq are masses of s-quark and the spectator quark for the Fermi motion model. They are related with the kinematics of Xs.
+     * m_pf is the Fermi motion momentum used in the Fermi motion model.
+     * m_mxmin is the minimum mass of Xs.
+     *
+     * You can use the model as follows:
+     *
+     * Decay MyB-
+     * 1.0 anti-Xsu anti-nu_e nu_e           BTOXSNUNU_FERMI 0.2 0.0 0.461 1.1 4.8 0.2;
+     * Enddecay
+     */
+
+  public:
+
+    /**
+     * Constructor.
+     */
+    EvtBtoXsnunu_FERMI() {}
+
+    /**
+     * Destructor.
+     */
+    virtual ~EvtBtoXsnunu_FERMI();
+
+    /**
+     * The function which returns the name of the model.
+     */
+    std::string getName();
+
+    /**
+     * The function which makes a copy of the model.
+     */
+    EvtDecayBase* clone();
+
+    /**
+     * The function to sets a maximum probability.
+     * In this model, noProbMax() is called because maximum probability is determined by m_dGdsbProbMax
+     */
+    void initProbMax();
+
+    /**
+     * The function for an initialization.
+     */
+    void init();
+
+    /**
+     * The function to determine kinematics of daughter particles based on dGdsb distribution.
+     */
+    void decay(EvtParticle* p);
+
+    /**
+     * The function returns the probability density value depending on sb.
+     */
+    double dGdsbProb(double _sb);
+
+    /**
+     * The function returns a momentum of b quark.
+     * The distribution of the momentum is based on the Fermi motion model.
+     */
+    double FermiMomentum(double pf);
+
+    /**
+     * The function returns a probability based on the Fermi motion model.
+     * @pf Fermi motion momentum for the Fermi motion model
+     */
+    double FermiMomentumProb(double pb, double pf);
+
+  private:
+    /** The maximum value of dGdsb.   */
+    double m_dGdsbProbMax{0.0};
+
+    /** mass of s-quark for the Fermi motion model and EvtGenKine::PhaseSpace.   */
+    double m_ms{0.2};
+
+    /** mass of spectator quark for the Fermi motion model.   */
+    double m_mq{0.0};
+
+    /** Parameter for the Fermi motioin model.   */
+    double m_pf{0.461};
+
+    /** Minimum mass of Xs.   */
+    double m_mxmin{1.1};
+
+    /** b-quark mass to calculate dGdsb.   */
+    double m_mb_prob{4.8};
+
+    /** s-quark mass to calculate dGdsb.   */
+    double m_ms_prob{0.2};
+
+  };
+
+} // Belle 2 Namespace

generators/evtgen/models/include/EvtKnunu.h

@@ -0,0 +1,63 @@
+/**************************************************************************
+ * basf2 (Belle II Analysis Software Framework)                           *
+ * Author: The Belle II Collaboration                                     *
+ *                                                                        *
+ * See git log for contributors and copyright holders.                    *
+ * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
+ **************************************************************************/
+
+#pragma once
+
+#include "EvtGenBase/EvtParticle.hh"
+#include "EvtGenBase/EvtDecayAmp.hh"
+#include <string>
+
+class EvtParticle;
+
+namespace Belle2 {
+  class EvtKnunu : public  EvtDecayAmp {
+
+    /** The evtgen model to produce B-> K nu nubar decay sample.
+     * From factors are based on [arXiv:1409.4557v2].
+     */
+
+  public:
+
+    /**
+     * Constructor.
+     */
+    EvtKnunu() {}
+
+    /**
+     * Destructor.
+     */
+    virtual ~EvtKnunu();
+
+    /**
+     * The function which returns the name of the model.
+     */
+    std::string getName();
+
+    /**
+     * The function which makes a copy of the model.
+     */
+    EvtDecayBase* clone();
+
+    /**
+     * The function for an initialization.
+     */
+    void init();
+
+    /**
+     * The function to calculate a quark decay amplitude.
+     */
+    void decay(EvtParticle* p);
+
+    /**
+     * The function to sets a maximum probability.
+     */
+    void initProbMax();
+
+  };
+
+} // Belle 2 Namespace

generators/evtgen/models/include/EvtKstarnunu_REV.h

@@ -0,0 +1,63 @@
+/**************************************************************************
+ * basf2 (Belle II Analysis Software Framework)                           *
+ * Author: The Belle II Collaboration                                     *
+ *                                                                        *
+ * See git log for contributors and copyright holders.                    *
+ * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
+ **************************************************************************/
+
+#pragma once
+
+#include "EvtGenBase/EvtParticle.hh"
+#include "EvtGenBase/EvtDecayAmp.hh"
+#include <string>
+
+class EvtParticle;
+
+namespace Belle2 {
+  class EvtKstarnunu_REV : public  EvtDecayAmp {
+
+    /** The evtgen model to produce B-> Kstar nu nubar decay sample.
+     * From factors are based on [arXiv:1503.05534v3].
+     */
+
+  public:
+
+    /**
+     * Constructor.
+     */
+    EvtKstarnunu_REV() {}
+
+    /**
+     * Destructor.
+     */
+    virtual ~EvtKstarnunu_REV();
+
+    /**
+     * The function which returns the name of the model.
+     */
+    std::string getName();
+
+    /**
+     * The function which makes a copy of the model.
+     */
+    EvtDecayBase* clone();
+
+    /**
+     * The function for an initialization.
+     */
+    void init();
+
+    /**
+     * The function to calculate a quark decay amplitude.
+     */
+    void decay(EvtParticle* p);
+
+    /**
+     * The function to sets a maximum probability.
+     */
+    void initProbMax();
+
+  };
+
+} // Belle 2 Namespace