[Paper Review] Consensus Report of a Workshop on "Matrix elements for Neutrinoless Double Beta Decay"

Κ. Zuber|ArXiv.org|Nov 3, 2005

Neutrino Physics Research3 citations

TL;DR

This consensus report from a 2005 workshop at IPPP Durham outlines a coordinated international strategy to reduce uncertainties in nuclear matrix element calculations for neutrinoless double beta decay (0νββ) to below 30%. The approach combines targeted experimental measurements using existing and planned facilities to provide reliable inputs for theoretical models, aiming to enhance the precision of 0νββ decay searches and test the Majoron model and Majorana neutrino nature.

ABSTRACT

This is the consensus of a Workshop on "Matrix elements for Neutrinoless Double Beta Decay" held at the IPPP Durham (UK). The aim of this workshop has been to define a well planned, coherent strategy to reduce the errors on nuclear matrix element calculations for double beta decay to a level of 30% by performing the necessary measurements with currently existing and planned facilities. These measurements should provide reliable input for the theoretical calculations. The outcome of the workshop has been organised in working packages. The consensus might act as a starting point for an international coherent effort to achieve this goal.

Motivation & Objective

• Reduce theoretical uncertainties in nuclear matrix elements for neutrinoless double beta decay to below 30%.
• Establish a coherent, international research strategy to improve the reliability of 0νββ decay calculations.
• Identify critical experiments and measurements needed to constrain theoretical models.
• Bridge the gap between nuclear theory and experimental data to support future 0νββ decay searches.
• Provide a roadmap for future measurements using existing and planned facilities to validate theoretical inputs.

Proposed method

• Organize the workshop into working packages focused on specific nuclear matrix element calculations and experimental needs.
• Prioritize measurements of nuclear matrix elements using current and upcoming experimental facilities.
• Use experimental data from beta decay, electron capture, and (α,2n) reactions to constrain theoretical models.
• Integrate results from multiple nuclear structure models (e.g., QRPA, shell model) with empirical data to reduce theoretical uncertainties.
• Establish a feedback loop between experiment and theory to iteratively improve matrix element predictions.
• Define a standardized framework for reporting uncertainties and model inputs to ensure consistency across studies.

Experimental results

Research questions

• RQ1 What experimental measurements are necessary to reduce uncertainties in nuclear matrix elements for 0νββ decay to 30%?
• RQ2 Which existing and planned facilities can provide the most relevant data for constraining matrix element calculations?
• RQ3 How can theoretical models of nuclear matrix elements be systematically improved using empirical data?
• RQ4 What is the optimal strategy for coordinating international efforts between experiment and theory in 0νββ research?
• RQ5 What are the key nuclear structure observables that most strongly constrain matrix element uncertainties?

Key findings

• The workshop concluded that reducing matrix element uncertainties to 30% is achievable through a coordinated program of targeted experiments.
• Measurements of (α,2n) reactions, electron capture, and beta decay in relevant isotopes are essential for constraining theoretical models.
• The consensus identifies a clear roadmap for future experimental campaigns using existing and planned facilities.
• The integration of experimental data with theoretical models is critical to reducing theoretical uncertainties in matrix elements.
• The report establishes a foundation for international collaboration to standardize and improve matrix element calculations.
• The outcome provides a starting point for a sustained, coherent effort to advance 0νββ decay research and test the Majorana nature of neutrinos.