The LCFIVertex package: Vertexing, flavour tagging and vertex charge reconstruction with an ILC vertex detector

Abstract

The precision measurements envisaged at the International Linear Collider (ILC) depend on excellent instrumentation and reconstruction software. The correct identification of heavy flavour jets, placing unprecedented requirements on the quality of the vertex detector, will be central for the ILC programme. This paper describes the LCFIVertex software, which provides tools for vertex finding and for identification of the flavour and charge of the leading hadron in heavy flavour jets. These tools are essential for the ongoing optimisation of the vertex detector design for linear colliders such as the ILC. The paper describes the algorithms implemented in the LCFIVertex package, as well as the scope of the code and its performance for a typical vertex detector design.

CP-violating top quark couplings at future linear $$e^+e^-$$ e + e - colliders

“…Particle-flow objects are clustered into exactly four jets. Heavy-flavour jets are identified using the LCFI algorithm [65,66].…”

The International Linear Collider Technical Design Report - Volume 4: Detectors

“…LCFIVertex [374] is a package for vertex finding, based on the ZVTop algorithm and for jet flavour tagging using Artificial Neural Networks (ANNs). LCFIPlus is a new package that provides improved flavour tagging, introducing additional input variables and replacing the ANNs with Mutli Variate Analysis techniques, as well as a new jet clustering algorithm [375].…”

Tau lepton reconstruction at collider experiments using impact parameters

“…2 for both prompt µ tracks and π tracks from τ decay. The two µ tracks were fitted to a common vertex to measure the event IP using the lcfivertex [18] package, achieving a typical precision on the IP position of better than 3µm in all three dimensions.…”