a storm in a “t” cup
DESCRIPTION
A storm in a “T” cup. Or how (not) to make transverse projections at the LHC. Usual geometry and momentum projection. In (1+3)d:. - PowerPoint PPT PresentationTRANSCRIPT
A storm in a “T” cup
Or how (not) to make transverse projections at the LHC
Usual geometry and momentum projection
What to do with time-like component of P when projecting to (1+2)d?
Various options possible & used to construct time-like component: (Here labelled “T”, “V”, “o”)Differences, pros & cons not widely appreciated.
In (1+3)d:
Option 1/3The “T” projectionMass-preserving
Option 2/3The “V” projectionSpeed preserving
After this projection the 1+2-dimensional inner product is no longer M2
However, the 1+2 dimensional speed is preserved:
Option 3/3The “o” projectionAlways massless
A graphical representation
Hierarchy easily proved to be:
Partitioning events
Reconstruct parent masses by summing (1+3) or (1+2) vectors
Operations “add” and “project” do not commute
Example:
Procedures given for constructing variables for given hypothesis
Example of fully leptonictop pair decay
How existing variables fit in ourcategorisation
What common computer libraries
offer