Toward Complete Leading-Order Predictions for Neutrinoless Double β Decay

Area of Science:

• Nuclear Physics
• Particle Physics
• Quantum Field Theory

Background:

• Neutrinoless double beta decay (0νββ) is a key process for understanding neutrino properties and searching for new physics.
• Accurate nuclear-structure calculations are essential for interpreting 0νββ decay experiments.

Purpose of the Study:

• To develop a method for estimating the numerical value of a required contact operator's coefficient in 0νββ decay.
• To reduce uncertainties in nuclear-structure calculations for 0νββ searches.

Main Methods:

• Systematic analysis in chiral effective field theory.
• Development of a method analogous to the Cottingham formula for estimating the contact operator coefficient.
• Validation using charge-independence-breaking contributions to nucleon-nucleon scattering lengths.

Main Results:

• A method to estimate the contact operator coefficient for 0νββ decay is established.
• The renormalized amplitude A_{ν}(|p|,|p^{'}|) is determined, allowing for contact-term contribution matching.
• A significant reduction in a crucial uncertainty for 0νββ decay interpretation is achieved.

Conclusions:

• The developed method provides a crucial input for nuclear-structure calculations in 0νββ searches.
• This work enhances the precision of interpreting experimental results for neutrinoless double beta decay.
• The findings contribute to advancing the search for physics beyond the Standard Model.