Pre-defined selections¶

The following selections are available in this library, divided in separate namespaces according to which subdetector they focus on.

Trigger¶

Under namespace NSL::Selections::Trigger

Name	Description	Parameters
HasPhysicsTrigger	Check if the event is triggered by a physics trigger	None

HasPhysicsTrigger¶

This selection simply returns the value of NAIA::EventSummary::IsPhysicsTrigger()

Tof¶

Under namespace NSL::Selections::Tof

Name	Description	Parameters
BetaInRange	Check if the Tof beta measurement is in a given range	Range lower bound, Range upper bound, Beta measurement type
ChargeInRange	Check if the Tof charge measurement is in a given range	Range lower bound, Range upper bound, Charge measurement type
GoodPathlength	Check if a given combination of Tof layers have a well defined track pathlength	A 4-bit bitset encoding the layer pattern to be checked
Chi2CooLessThan	Check if the spatial chi-square of the ToF clusters is less than given value	Upper bound
Chi2TimeLessThan	Check if the temporal chi-square of the ToF clusters is less than given value	Upper bound

BetaInRange¶

This selection checks if the Tof beta is within a specified range. You can specify the beta range, as well as the BetaType to check.

ChargeInRange¶

This selection checks if the Tof charge is within a specified range. You can specify the charge range, as well as the ChargeType to check.

GoodPathlength¶

This selection checks if the Tof layers have a well defined pathlength. This means that either the Tracker track (or the Tof linear interpolation based on the clusters position) crosses the Tof paddles from top to bottom (and doesn’t intercept the sides). You can specify which layers should be checked by passing a 4-bit bitset when creating the selection.

The 4 bits are associated with Tof layers in order from least significant to most significant (or right-to-left, if you will), meaning that if you want to check only Upper Tof layers the corresponding value is 0b0011, while for Lower Tof is 0b1100 (and 0b1111 for all 4 layers).

Chi2CooLessThan¶

This selection checks if the normalized chi-square of the Tof clusters spatial reconstruction is less than given value. You can specify the upper bound.

Chi2TimeLessThan¶

This selection checks if the normalized chi-square of the Tof clusters temporal reconstruction is less than given value. You can specify the upper bound.

Tof Standalone¶

Under namespace NSL::Selections::TofSt

Name	Description	Parameters
BetaInRange	Check if the Tof beta measurement is in a given range	Range lower bound, Range upper bound, Beta measurement type
ChargeInRange	Check if the Tof charge measurement is in a given range	Range lower bound, Range upper bound, Charge measurement type
Chi2CooLessThan	Check if the spatial chi-square of the ToF clusters is less than given value	Upper bound
Chi2TimeLessThan	Check if the temporal chi-square of the ToF clusters is less than given value	Upper bound
InnerFiducialVolume	Check if the Tof track lies within a pre-defined fiducial volume defined on the individual tracker planes of the Inner Tracker	None
L1FiducialVolume	Check if the Tof track lies within a pre-defined fiducial volume defined on the L1 tracker plane.	None
L9FiducialVolume	Check if the Tof track lies within a pre-defined fiducial volume defined on the L9 tracker plane.	None

The standalone selections for Tof are constructed from the particle 0 Tof objects, but this reconstruction avoids using any information from the Tracker track. It’s meant to be used for the Track reconstruction efficiency evaluation. The first four cuts coincide with the non standalone version, whose description is given in the Tof section. Note that the ChargeInRange cut uses NAIA::TofBaseData::ChargeNoPL, instead of NAIA::TofBaseData::Charge, due to an unresolved bug with the latter in the current version of NAIA (1.2). The fiducial volume cuts are meant to ensure that the event lies within the tracker volume, using only the linear track given by Tof clusters. See the namesake selections in Full Track section for their description.

Trd Standalone¶

Under namespace NSL::Selections::TrdSt

Name	Description	Parameters
InnerFiducialVolume	Check if the Trd track lies within a pre-defined fiducial volume defined on the individual tracker planes of the Inner Tracker	None
L1FiducialVolume	Check if the Trd track lies within a pre-defined fiducial volume defined on the L1 tracker plane.	None
L9FiducialVolume	Check if the Trd track lies within a pre-defined fiducial volume defined on the L9 tracker plane.	None

The standalone selections for Trd are constructed using the Tof extrapolation to select TRD hits, without using any information from the Tracker track. Meant to be used for the Track reconstruction efficiency evaluation. The fiducial volume cuts are meant to ensure that the event lies within the tracker volume, using only the linear track given by Trd hits. See the namesake selections in Full Track section for their description.

InnerTracker¶

Under namespace NSL::Selections::InnerTracker

Name	Description	Parameters
ChargeInRange	Check if the Inner Tracker charge measurement is in a given range	Range lower bound, Range upper bound, Charge measurement type
ChargeRMSLessThan	Check if the Inner Tracker charge RMS is less than a given value	Upper bound, Charge measurement type
HitPattern	Check if the track hits satisfy the canonical pattern*	None
NHitsGreaterThan	Check if the track has at least a minimum number of hits on a given side	Lower bound, Tracker side
NGoodClustersGreaterThan	Check if the track has at least a minimum number of hits with a good charge status	Lower bound, Cluster status mask

ChargeInRange¶

This selection checks if the Inner Tracker charge is within a specified range. You can specify the charge range, as well as the ChargeRecoType to check.

ChargeRMSLessThan¶

This selection checks if the Inner Tracker charge RMS is lower than a specified value. You can specify the upper limit, as well as the ChargeRecoType to check.

HitPattern¶

This selection checks if the Inner Tracker hits satisfy the canonical L2 && (L3 || L4) && (L5 || L6) && (L7 || L8) pattern.

NHitsGreaterThan¶

This selection checks if the Inner Tracker track has at least a minimum number of hits on a given side. You can specify the lower limit of hits, as well as the Tracker side to consider.

NGoodClustersGreaterThan¶

This selection checks if the Inner Tracker track has at least a minimum number of clusters with a good status on a given side. You can specify the lower limit of hits, as well as the mask to compare the hit status against (see here for details on the charge status word).

Full Track¶

Under namespace NSL::Selections::Track

Track-related selections¶

Name	Description	Parameters
ChiSquareLessThan	Check if the Track chi-square is less than a specified threshold, for a given side, fit and span.	Upper bound, tracked side, track fit algorithm, track span.
InnerFiducialVolume	Check if the Track lies within a pre-defined fiducial volume defined on the individual tracker planes of the Inner Tracker.	Track fit algorithm, track span.
L1FiducialVolume	Check if the Track lies within a pre-defined fiducial volume defined on the L1 tracker plane.	Track fit algorithm, track span.
L9FiducialVolume	Check if the Track lies within a pre-defined fiducial volume defined on the L9 tracker plane.	Track fit algorithm, track span.
HitCut	Check if the Track has a hit on a given tracker layer.	Layer J-number (1…9).
L1NormResidualLessThan	Check if the normalized residual on L1 is below a specified threshold, for a given fit.	Upper bound, track fit algorithm.

ChiSquareLessThan¶

This selection checks if the track has chi-square per degree of freedom less than a specified threshold, on a given side. You need to specify a track fit algorithm and a track span.

InnerFiducialVolume¶

This selection checks if the track lies inside a pre-defined fiducial volume within the Inner Tracker. This fiducial volume is defined removing the most external part of the inner tracker layers. You need to specify a track fit algorithm and a track span.

Fiducial volume definition¶

Layer	R boundary	Y boundary
L2	62 cm	40 cm
L3 / L4	46 cm	44 cm
L5 / L6	62 cm	36 cm
L7 / L8	46 cm	44 cm

L1FiducialVolume¶

This selection checks if the track lies inside a pre-defined fiducial volume within the L1 plane. This fiducial volume is defined removing the most external part of the L1 plane. You need to specify a track fit algorithm and a track span.

Fiducial volume definition¶

Layer	R boundary	Y boundary
L1	62 cm	47 cm

L9FiducialVolume¶

This selection checks if the track lies inside a pre-defined fiducial volume within the L9 plane. This fiducial volume is defined removing the most external part of the L1 plane. You need to specify a track fit algorithm and a track span.

Fiducial volume definition¶

Layer	R boundary	Y boundary
L9	43 cm	29 cm

HitCut¶

This selection checks if the Track has a hit on a given tracker layer (effectively equivalent to check TrTrackR::GetHitLJ in gbatch).

L1NormResidualLessThan¶

Check if the normalized residual on L1, defined as \(\chi^2_{IL1} \cdot NDoF_{IL1} - \chi^2_{Inner} \cdot NDoF_{Inner}\), is below a specified threshold, for a given fit.

L1NormResidualLessThan¶

Check if the normalized residual on L1, defined as \(\chi^2_{IL1} \cdot NDoF_{IL1} - \chi^2_{Inner} \cdot NDoF_{Inner}\), is below a specified threshold, for a given fit.

Tracker Layer Charges¶

Under namespace NSL::Selections::TrackerLayer

Name	Description	Parameters
ChargeInRange	Check if the Tracker charge (combination of X and Y measurements) of a particular layer is in a given range	Layer J-number (1…9), Range lower bound, Range upper bound, Charge measurement type
ChargeStatus	Check if the Track cluster on a particular layer has a good status (checked using the default `0x10013D` mask)	Layer J-number (1…9)
ChargeAsymmetry	Check if the relative difference between Tracker charge on X and Y views for a particular layer is below a specified threshold	Layer J-number (1…9), Upper bound, Charge measurement type

LayerChargeInRange¶

This selection checks if the Tracker charge of a particular layer is in a given range. This check is based on the combined charge estimation from both X and Y sides. You can specify the charge range, as well as the ChargeRecoType to check.

LayerChargeStatus¶

This selection checks if the Tracker charge of a particular layer has a good status word. See here for details on the charge status word.

LayerChargeAsymmetry¶

This selection checks if the Tracker charge asymmetry for a particular layer is below a specified threshold. The asymmetry is defined as ((Q_X - Q_Y) / (Q_X + Q_Y)).

Unbiased External Layer¶

Under namespace NSL::Selections::UnbExtLayer

Name	Description	Parameters
UnbExtLayerHitCut	Checks if there is a hit on either L1 or L9	Layer J-number (1 or 9)
UnbExtLayerChargeInRange	Checks if the unbiased charge of external layers (L1 and L9) is within a given range	Layer J-number (1 or 9), Range lower bound, Range upper bound

UnbExtLayerHitCut¶

This selection checks the presence of a hit on external layers (L1 or L9). It is meant to constrain the denominator selection for the Inner Tracker efficiency.

UnbExtLayerChargeInRange¶

This selection checks if the unbiased charge of external layers (L1 or L9) is within a given range. It is meant to constrain the denominator selection for the Inner Tracker efficiency.

Event Summary¶

Under namespace NSL::Selections::EvSummary

Name	Description	Parameters
NAccLessThan	Check if number of fired Acc clusters are less than given value	Upper bound
NTofClusterLessThan	Check if number of hit Tof clusters are less than given value	Upper bound
NTrTrackLessThan	Check if number of reconstructed tracks are less than given value	Upper bound

These selections use the Event Summary informations to require a stricter sample for efficiencies calculation. They are meant to correct the time dependence of Layer 1 efficiency, ensuring a clean selection of events for its denominator.

NAccLessThan¶

This selection checks if the number of fired Acc clusters is less than a given value. You can specify the upper bound.

NTofClusterLessThan¶

This selection checks if the number of hit Tof clusters is less than a given value. You can specify the upper bound.

NAccLessThan¶

This selection checks if the number of reconstructed tracks is less than a given value. You can specify the upper bound.

RTI¶

Under namespace NSL::Selections

Name	Description	Parameters
DefaultRTISelection	Default RTI selection as in Pass8 Twiki	NAIA::RTIInfo object, is_photon_polarization_run boolean
PG_ProtonRTISelection	PG Proton Analysis RTI selection	NAIA::RTIInfo object, UTC time in seconds

DefaultRTISelection¶

Standard collection of cuts on RTI, used in many analyses. It’s derived from the AMS Pass8 Twiki.

PG_ProtonRTISelection¶

This selection is used in the PG Proton Analysis to increase statistics at low rigidity (mainly for SEP events).

Auxiliary Cuts¶

Under namespace NSL::Selections::Aux

Name	Description	Parameters
MassCutProton	Cuts charge 1 light particles (pions and kaons) based on 1/Beta	track fit algorithm, track span, Beta measurement type

MassCutProton¶

This selection is derived from the AMS Twiki and is used to clean the proton sample from light particles produced by interactions (pions and kaons). It can be applied on both ISS data and Monte Carlo to clean the selected sample and the denominator of the L1 efficiency.

Common Selections¶

There is a set of selections recommended by the MIT group for nuclei analysis, and they are commonly referred to as “common selections”. These selections are a special case of the predefined selections listed above in this page, but where the selection parameters are tuned with respect to the particle charge under exam.

These specialized versions of predefined selections can be found under the NSL::Selections::Common namespace, with the same exact class name as their base version.

PG-ProtonAnalysisSelection¶

The global header NSL/PG-ProtonAnalysisSelection.h includes the current proton selection used in Perugia for the Daily and SEP analyses, using NSL cuts. It contains the primary selection for counts (selection) and all the numerators and denominators of efficiencies (den_l1 and num_l1 for Layer 1 eff, den_tf and num_tf for the ToF eff…).