Abstract
The interpretation of measurements of high-energy particle collisions relies heavily on the performance of full event generators. By far the largest amount of time to predict the kinematics of multi-particle final states is dedicated to the calculation of the hard process and the subsequent parton shower step. With the continuous improvement of quantum devices, dedicated algorithms are needed to exploit the potential quantum computers can provide. We propose general and extendable algorithms for quantum gate computers to facilitate calculations of helicity amplitudes and the parton shower process. The helicity amplitude calculation exploits the equivalence between spinors and qubits and the unique features of a quantum computer to compute the helicities of each particle involved simultaneously, thus fully utilising the quantum nature of the computation. This advantage over classical computers is further exploited by the simultaneous computation of s and t-channel amplitudes for a 2$\rightarrow$2 process. The parton shower algorithm simulates collinear emission for a two-step, discrete parton shower. In contrast to classical implementations, the quantum algorithm constructs a wavefunction with a superposition of all shower histories for the whole parton shower process, thus removing the need to explicitly keep track of individual shower histories. Both algorithms utilise the quantum computer's ability to remain in a quantum state throughout the computation and represent a first step towards a quantum computing algorithm to describe the full collision event at the LHC.
Highlights
Modern collider experiments such as the Large Hadron Collider (LHC) at CERN depend heavily on the modeling of particle collisions and simulations of detector response to examine physics processes within the experiments
The helicity amplitude calculation exploits the equivalence between spinors and qubits and the unique features of a quantum computer to compute the helicities of each particle involved simultaneously, fully utilizing the quantum nature of the computation
This modeling is used to construct different possible outcomes from particle collisions, used both for the identification of certain physical processes and for the construction of event backgrounds. Such simulations play a crucial role in modern high energy physics, and are usually carried out by Monte Carlo event generators such as PYTHIA [1], HERWIG [2], and SHERPA [3]
Summary
Modern collider experiments such as the Large Hadron Collider (LHC) at CERN depend heavily on the modeling of particle collisions and simulations of detector response to examine physics processes within the experiments. This paper presents a first step towards a generic implementation of quantum algorithms, applicable to QGC devices, for two key components of the event generation in high-energy collisions: the calculation of the hard process in terms of helicity amplitudes and the simulation of the parton shower.. This paper presents a first step towards a generic implementation of quantum algorithms, applicable to QGC devices, for two key components of the event generation in high-energy collisions: the calculation of the hard process in terms of helicity amplitudes and the simulation of the parton shower.2 These algorithms utilize the unique features of a quantum device and demonstrate distinct advantages over the classical implementations.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
