Class ActsFatras::Hit¶
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class ActsFatras::Hit¶
A simulation hit on a surface.
This is the undigitized, truth hit, i.e. just a recording of the particle state at the surface intersection. Since Fatras is surface-based, the hit position is always constrained to a surface. Depending on the simulated interactions the momentum state before and after might differ and is thus stored as two separate four-vectors.
Public Types
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using Scalar = Acts::ActsScalar¶
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using Vector3 = Acts::ActsVector<3>¶
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using Vector4 = Acts::ActsVector<4>¶
Public Functions
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Hit() = default¶
Construct default hit with (mostly) invalid information.
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inline Hit(Acts::GeometryIdentifier geometryId, Barcode particleId, const Vector4 &pos4, const Vector4 &before4, const Vector4 &after4, int32_t index_ = -1)¶
Construct from four-position and four-momenta.
All quantities are given in the global coordinate system. It is the users responsibility to ensure that the position correspond to a position on the given surface.
- Parameters
geometryId – Geometry identifier of the surface
particleId – Particle identifier of the particle that created the hit
pos4 – Particle space-time four-vector on the surface
before4 – Particle four-momentum before the interaction
after4 – Particle four-momentum after the interaction
index_ – Hit index along the particle trajectory
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inline Scalar depositedEnergy() const¶
Energy deposited by the hit.
- Returns positive
if the particle lost energy when it passed the surface
- Returns negative
if magic was involved
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inline constexpr Acts::GeometryIdentifier geometryId() const¶
Geometry identifier of the hit surface.
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inline constexpr int32_t index() const¶
Hit index along the particle trajectory.
- Returns negative
if the hit index is undefined.
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inline constexpr Barcode particleId() const¶
Particle identifier of the particle that generated the hit.
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inline auto position() const¶
Three-position, i.e. spatial coordinates without the time.
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using Scalar = Acts::ActsScalar¶