spine.utils.pid

Module with functions/classes used to identify particle species.

Classes

TemplateParticleIdentifier([use_table, ...])

Class which uses dE/dx templates to do particle identification.

class spine.utils.pid.TemplateParticleIdentifier(use_table=True, use_mpv=False, include_pids=(2, 3, 4, 5), optimize_rr=False, max_rr=100, optimize_orient=True, tracking_mode='step_next', **tracker)

Class which uses dE/dx templates to do particle identification.

The basics of template-based PID are as follows: - Chunk a track into chunks - Identify the dE/dx of the tracks in each chunk - Try to match the dE/dx profile to a known particle template

Methods

__call__(points, depositions, end_point[, ...])	Evaluate the agreement between each PID template and the particle track of interest.
chi2(dedxs, rrs, pid)	Computes a chi2 score given a set of observed/expected dE/dx values.
expected_dedxs(rrs, pid)	Computes the expected dE/dx values given a set of residual ranges.
minimize_rr(dedxs, rrs, pid)	Find the residual range which minimises the chi2 fit between the observed dE/dx values and the spline fit to the template.

minimize_rr(dedxs, rrs, pid)

Find the residual range which minimises the chi2 fit between the observed dE/dx values and the spline fit to the template.

Parameters:

• dedxs (np.ndarray) –

  19. Measured values of dedxs at a set of unknown residual ranges

• rrs (np.ndarray) –

  19. Residual ranges assuming the particle came to a complete stop

• pid (int) – Particle species enumerator

Returns:

• float – Value of the residual range at the end of the track

• float – Value of the chi2 for the optimal residual range

chi2(dedxs, rrs, pid)

Computes a chi2 score given a set of observed/expected dE/dx values.

Parameters:

• dedxs (np.ndarray) –

  19. Measured values of dedxs at a set of known residual ranges

• rrs (np.ndarray) –

  19. Residual range values (one per track segment)

• pid (int) – Particle species enumerator

Returns:

Chi2 agreement value

Return type:

float

expected_dedxs(rrs, pid)

Computes the expected dE/dx values given a set of residual ranges.

Parameters:

• rrs (np.ndarray) –

  19. Residual range values (one per track segment)

• pid (int) – Particle species enumerator

Returns:

Expected dE/dxs values from a table or the theory

Return type:

np.ndarray