This documentation was grabbed from the now defunct:
http://nuint.ps.uci.edu/nuance/documentation.htm

Output Format

Nuance can produce two types of output files – text and HBOOK N-tuples.

Text Output

The text output mode (enabled with the -k command line option or the TRAC input card) is best for driving a GEANT-type detector simulation.

An example event is shown below:
$ begin
$ nuance 3
$ vertex 811.5 -1030.4 -1681.7 5.86347E+04
$ track 14 1000.0000 1.00000 0.00000 0.00000 -1
$ track 2212 935.9840 -0.03219 -0.24434 0.96915 -1
$ info 2 949000 0.0000E+00
$ track 13 295.6312 0.15021 0.98821 -0.02950 -2
$ track 211 427.5731 0.66875 -0.66698 -0.32849 -2
$ track 2212 1212.7798 0.88658 -0.07320 0.45675 -2
$ track 13 295.6312 0.15021 0.98821 -0.02950 0
$ track 2212 1212.7798 0.88658 -0.07320 0.45675 0
$ track 111 382.1095 -0.73647 -0.35958 -0.57299 0
$ end


Each line begins with a text tag, indicating the information it contains.

• begin: Marks the start of the event.
• nuance: This line indicates the reaction mode for the event.
• vertex: The first three numbers are the x, y and z coordinate, in cm. The fourth number is the time, in simulation units (nominally seconds). If you are using a beam, it will be in the units you specified for the integrated luminosity.
• track: The track lines contain most of the information. The last number on the line is either -1 (initial state particle), -2 (final state particle before interactions) or 0 (the final state particle after interactions). Normally your detector simulation should only track particles with a status code of 0. The first number on the line is the particle code, using Particle Data Group/Lund conventions. An exception is that for coherent reactions, an ad hoc particle code is assigned for the target nucleus, since the PDG system does not encompass nuclei. For nuclei, the code is Z*1000+A, so Oxygen is particle code 8016.  The next number is the total energy of the particle. By default, this is in MeV. Starting with version 2.001 of the program, you can give an EGEV card to switch all output to GeV energy units. Note that for bound nucleon targets, the total energy will be less than the rest mass since the target is bound.Finally, the third, fourth and fifth numbers are the x, y and z direction cosines.
• info: The first two numbers are obsolete and/or irrelevant and are retained only for compatibility with Super-K software. The third number is the neutrino flux for this energy and direction. The units are the same as whatever the input flux is. This can be useful if you later want to re-weight events (after they have passed through detector simulation and reconstruction).
• end: marks the end of the event
• stop: (Not shown above) marks the end of the file.

N-tuple Output

The HBOOK (“column-wise”) N-tuple output is ideal for generator-level studies using PAW. By default, energies are expressed in units of MeV. Beginning with version 2.001 of the program, you can change to GeV units by giving an EGEV input card. Three new variables (iniQ, finQ and polar) have been added in version 3.000; they do not exist in N-tuples produced by version 2.xxx. The variables in the N-tuple are explained below:

• cc: (logical) True if the reaction is charged-current, false if neutral current
• bound: (logical) True if the target is a bound nucleon, false otherwise
• neutrino: PDG/Lund particle code of the neutrino
• target: PDG/Lund particle code of the target. Particle codes beginning with 41 are used for nuclei (coherent reactions).
• iniQ: Initial quark participating in hard scattering (for DIS only, 0 for other reactions). Added in Version 3.000.
• finQ: Outgoing quark from hard scattering (for DIS only, 0 for other reactions). Added in Version 3.000.
• lepton0: PDG/Lund identity of the initial out-going lepton. This is useful if tau neutrinos are involved, since the tau will be decayed and does not appear in the list of final-state leptonic products.
• polar: tau polarization projected onto tau direction; QE and DIS channels are modeled in detail (others assume full polarization, for now). Added in Version 3.000.
• channel: The reaction code of the event.
• qsq: q2 of the reaction. Note it is always negative.
• w: Mass of the hadronic system.
• x: Bjorken x defined as q2 /2M(Enu-Elepton)
• y: Scaling variable y defined as (Enu-Elepton)/Enu
• p_neutrino(4): 4-momentum of the incoming neutrino
• p_targ(5): 5-momentum of the target. The 5-th component is 3-momentum magnitude.
• vertex(4): x, y, z and t coordinates of the interaction vertex
• start(4): relevant only for upward muons; the coordinates of the primary neutrino interaction.
• depth: relevant only for upward muons; the distance from the primary interaction to the entry point in g/cm2
• flux: neutrino flux for this energy and direction; useful for reweighting events
• n_leptons: number of final-state particles in the leptonic system. Will be one unless a tau-neutrino is involved.
• p_ltot(5): total 5-momentum of the leptonic system. In tau events, this will be the primary tau momentum.
• lepton(n_leptons): PDG/Lund particle identity for each of the particles in the leptonic system.
• p_lepton(5,n_leptons): 5-momentum for each particle in the hadronic system.
• n_hadrons: number of final state particles in the hadronic system (after final state interactions).
• p_htot(5): total 5-momentum of the hadronic system.
• hadron(n_hadrons): PDG/Lund particle identity for each of the particles in the hadronic system.
• p_hadron(5,n_hadrons): 5-momentum for each particle in the hadronic system.

Reaction Channels

The reactions known to the program are described by a reaction code. For detailed information please refer to the xxCH cards in the file nuance_defaults.cards. The following is an overview of what the reaction codes mean: