Version: SMASH-3.2
OSCAR collisions format
Process types

The OSCAR particles format follows the general block structure of the OSCAR format. We distinguish between two versions, OSCAR2013 and OSCAR1999. Additional information about OSCAR standard can be found here.
Enabling the OSCAR output for collisions in the config.yaml file (see Output), a so-called full_event_history.oscar file is produced when executing SMASH. It allows for a certain degree of flexibility, see Content-specific output options for further details.
Collision output always gives a list of collisions/decays/box wall crossings plus optionally initial and final configuration.

See also Collision output in box modus.

Note
The particle and event end lines for both OSCAR 2013 and 1999 formats are identical as in the OSCAR particles format.

Oscar2013

Oscar2013 is an ASCII (text) human-readable output following the OSCAR 2013 standard. The format specifics are the following:

File header

#!OSCAR2013 full_event_history t x y z mass p0 px py pz pdg ID charge
# Units: fm fm fm fm GeV GeV GeV GeV GeV none none
# SMASH_version

The header consists of 3 lines starting with '#'. They contain the following information:

  1. Output version (OSCAR2013) and the type of output (particle_lists), followed by the substructure of the particle lines
  2. Units of the quantities in the particle lines
  3. SMASH version

File header for extended output
If desired, the OSCAR2013 output can be extended by additional particle properties. This requires enabling the extended output in the configuration file, see the Extended switch in content-specific output options for further details. The header of the extended OSCAR output is structured identically to the non-extended version, but simply contains more columns because of the additional entries:

#!OSCAR2013 particle_lists t x y z mass p0 px py pz pdg ID charge ncoll form_time xsecfac proc_id_origin proc_type_origin time_last_coll pdg_mother1 pdg_mother2 baryon_number strangeness
# Units: fm fm fm fm GeV GeV GeV GeV GeV none none e none fm none none none fm none none none none
# SMASH_version

Event block header
The OSCAR2013 format is based on a block structure, where each block corresponds to one interaction. Each block starts with a line formatted as follows:

# interaction in nin out nout rho density weight tot_weight partial part_weight type proc_type

where

  • nin: Number of ingoing particles (initial state particles)
  • nout: Number of outgoing particles (final state particles)
  • density: Density at the interaction point
  • tot_weight: Total weight of the interaction. This is the total cross section in case of a scattering and the total decay width in case of a decay. If there is no weight for the specific process, e.g. a wall crossing, it's value is 0.0
  • part_weight: The partial weight of the interaction. This is the specific weight for the chosen final state
  • proc_type: The type of the underlying process. See Process types for possible types

Note, that "interaction", "in", "out", "rho", "weight", "partial" and "type" are no variables, but words that are printed.

Oscar1999

Oscar1999 is an ASCII (text) human-readable output following the OSCAR 1999 standard. The format specifics are the following:

File header

# OSC1999A
# full_event_history
# smash <version>
# Block format:
# nin nout density tot_weight part_weight proc_type
# id pdg 0 px py pz p0 mass x y z t
# End of event: 0 0 event_number
#

The header consists of 8 lines starting with '#', of which the last one is basically empty. They contain the following information:

  1. The specific OSCAR1999 version the formatting follows - OSC1999A
  2. The filename
  3. The SMASH version with which the oputput was generated
  4. - 7. Info on the block structure

Block header
Each output block starts with a line of the following format:

nin nout density tot_weight part_weight proc_type

With

  • nin: Number of ingoing particles (initial state particles)
  • nout: Number of outgoing particles (final state particles)
  • density: Density at the interaction point
  • tot_weight: Total weight of the interaction. This is the total cross section in case of a scattering and the total decay width in case of a decay. If there is no weight for the specific process, e.g. a wall crossing, it's value is 0.0
  • part_weight: The partial weight of the interaction. This is the specific weight for the chosen final state
  • proc_type: The type of the underlying process. See Process types for possible types

If the Print_Start_End option is set (see content-specific output options for details), (nin, nout) = (0, Nparticles) in the initial timestep and (nin, nout) = (Nparticles, 0) in the final timestep.