Rotation-invariant observables in polarization measurements

Abstract

Polarization measurements provide a detailed method to test the Standard Model and to search for new physics. Most previous studies depend on pre-selected coordinates, which blurs the significance of the results. The construction of two rotation-invariant observables in vector boson decay into a fermion pair has been proved to be a big success. In this work, we show that there are more rotation-invariant observables and provide a general recipe to find all of them in an arbitrary decay process. Taking spin-1/2 and spin-1 particle decay processes as examples, we calculate the explicit expressions of all rotation-invariant observables, which can serve as a robust test of the detector acceptance and help the analysis of experimental data.

arXiv comment11 pages

Cited by in corpus (5)

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• Quantum tomography for collider physics: Illustrations with lepton pair production
• Rotation-invariant observables as Density Matrix invariants
• On the Rotational Invariance and Non-Invariance of Lepton Angular Distributions in Drell-Yan and Quarkonium Production
• Polarization and cross section of midrapidity J/$\psi$ production in proton-proton collisions at $\sqrt{s}=510$ GeV