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arXiv · 2409.12236

Quantum integration of decay rates at second order in perturbation theory

Jorge J. Martínez de Lejarza·David F. Rentería-Estrada·Michele Grossi·Germán Rodrigo
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Abstract

We present the first quantum computation of a total decay rate in high-energy physics at second order in perturbative quantum field theory. This work underscores the confluence of two recent cutting-edge advances. On the one hand, the quantum integration algorithm Quantum Fourier Iterative Amplitude Estimation (QFIAE), which efficiently decomposes the target function into its Fourier series through a quantum neural network before quantumly integrating the corresponding Fourier components. On the other hand, causal unitary in the loop-tree duality (LTD), which exploits the causal properties of vacuum amplitudes in LTD to coherently generate all contributions with different numbers of final-state particles to a scattering or decay process, leading to singularity-free integrands that are well suited for Fourier decomposition. We test the performance of the quantum algorithm with benchmark decay rates in a quantum simulator and in quantum hardware, and find accurate theoretical predictions in both settings.

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Jorge J. Martínez de Lejarza, David F. Rentería-Estrada, Michele Grossi, Germán Rodrigo. 2024-09-18. Quantum integration of decay rates at second order in perturbation theory. https://doi.org/10.1088/2058-9565%2Fada9c5

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