Application of a Quantum Search Algorithm to High- Energy Physics Data
  at the Large Hadron Collider
We demonstrate a novel method for applying a scientific quantum algorithm -
the Grover Algorithm (GA) - to search for rare events in proton-proton
collisions at 13 TeV collision energy using CERN's Large Hadron Collider. The
search is of an unsorted database from the ATLAS detector in the form of ATLAS
Open Data. As indicated by the Higgs boson decay channel $H\rightarrow
ZZ^*\rightarrow 4l$, the detection of four leptons in one event may be used to
reconstruct the Higgs boson and, more importantly, evince Higgs boson decay to
some new phenomena, such as $H\rightarrow ZZ_d \rightarrow 4l$. In searching
the dataset for collisions resulting in the detection of four leptons, the
study demonstrates the effectiveness and potential of applying quantum
computing to high-energy particle physics. Using a Jupyter Notebook, a
classical simulation of GA, and multiple quantum computers, each with several
qubits, it is demonstrated that this application makes the proper selection in
the unsorted dataset. The implementation of the method on several classical
simulators and on several of IBM's quantum computers using the IBM Qiskit Open
Source Software exhibits the promising prospects of quantum computing in
high-energy physics.
Anthony E. Armenakas Oliver K. Baker