Demonstrating the feasibility of testing microscopic acausality at the LHC with CMS open data

Abstract

In this work, we describe the feasibility to reconstruct acausal vertices that could arise from Lee Wick standard model processes. Using open data from the CMS experiment, we identify measurable wrong displaced vertices associated to acausal-like decays predicted by the Lee Wick model. The signal considered is the pair production of Lee Wick electrons due to its favorable cross-section. The study was carried out for mass values of 200, 300, 400, and 500 GeV for the Lee Wick electron, with the 200 GeV sample being the one closest to satisfying detector resolution limitations. The expected final state consists of one electron and a pair of jets emerging from a wrong displaced vertex for each of the Lee Wick electrons. We detail the method used to reconstruct wrong displaced vertices with the given topology. We also define a new quantity, the parallelity, to better distinguish wrong displaced vertices. We test the possibility to identify acausal decays by comparing the signal, simulated background processes and collisions data from CMS Run 1. An asymmetry in the parallelity distribution suggests the capability of distinguishing acausal decays if ever present.

Keywords

• Particle physics
• Standard model renormalization
• Acausality
• CMS Open Data
• Lee Wick standard model
• wrong displaced vertex