An Algorithm for Quantum Computation of Particle Decays

TL;DR

This paper introduces a quantum algorithm for calculating particle decay rates and scattering cross sections by computing Green's functions on quantum hardware, demonstrated on IBM's quantum computers for a scalar decay process.

Contribution

It presents a novel quantum algorithm for particle decay calculations that scales polynomially and demonstrates its feasibility on current quantum hardware.

Findings

Successfully computed decay rates on IBM quantum hardware.

Demonstrated polynomial scaling of the quantum algorithm.

Validated the method with a scalar particle decay example.

Abstract

A quantum algorithm is developed to calculate decay rates and cross sections using quantum resources that scale polynomially in the system size assuming similar scaling for state preparation and time evolution. This is done by computing finite-volume one- and two-particle Green's functions on the quantum hardware. Particle decay rates and two particle scattering cross sections are extracted from the imaginary parts of the Green's function. A $0+1$ dimensional implementation of this method is demonstrated on IBM's superconducting quantum hardware for the decay of a heavy scalar particle to a pair of light scalars.