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Main Authors: Detwiler, Jason, Han, Ke, Li, Tao
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2605.21315
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author Detwiler, Jason
Han, Ke
Li, Tao
author_facet Detwiler, Jason
Han, Ke
Li, Tao
contents Reconstruction of the individual energies and the opening angle between the electrons emitted in neutrinoless double-beta decay can probe the nature of the beyond-the-Standard-Model exchange mechanism that underlies the process. Although it is often stated that discrimination of the mechanism would require such measurements to be performed with high statistics, we show that this is not the case. If a single mechanism dominates the process, its discrimination at the 1$σ$ level is already achieved with just a few well-reconstructed events; only $\sim$10 such events are required to reach 3$σ$-level discovery sensitivity. In the presence of realistic reconstruction uncertainties, this requirement increases to $\sim$25 events, indicating that substantial discrimination power is retained as long as backgrounds remain small. We conclude that the pursuit of tracking detectors for exchange-mechanism discrimination remains valuable even for ``discovery-class'' experiments in which only a few signal counts are expected.
format Preprint
id arxiv_https___arxiv_org_abs_2605_21315
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Statistical sensitivity of neutrinoless double-beta decay exchange mechanism discrimination by tracking experiments
Detwiler, Jason
Han, Ke
Li, Tao
High Energy Physics - Phenomenology
High Energy Physics - Experiment
Reconstruction of the individual energies and the opening angle between the electrons emitted in neutrinoless double-beta decay can probe the nature of the beyond-the-Standard-Model exchange mechanism that underlies the process. Although it is often stated that discrimination of the mechanism would require such measurements to be performed with high statistics, we show that this is not the case. If a single mechanism dominates the process, its discrimination at the 1$σ$ level is already achieved with just a few well-reconstructed events; only $\sim$10 such events are required to reach 3$σ$-level discovery sensitivity. In the presence of realistic reconstruction uncertainties, this requirement increases to $\sim$25 events, indicating that substantial discrimination power is retained as long as backgrounds remain small. We conclude that the pursuit of tracking detectors for exchange-mechanism discrimination remains valuable even for ``discovery-class'' experiments in which only a few signal counts are expected.
title Statistical sensitivity of neutrinoless double-beta decay exchange mechanism discrimination by tracking experiments
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
url https://arxiv.org/abs/2605.21315