First Constraints on General Neutrino Interactions Based on KATRIN Data

Area of Science:

• Particle Physics
• Cosmology
• Nuclear Physics

Background:

• The KATRIN experiment conducts high-precision measurements of the tritium beta-decay spectrum.
• General Neutrino Interactions (GNIs) are theoretical extensions to the Standard Model involving neutrinos.
• Searching for GNIs offers a pathway to discover new physics phenomena.

Purpose of the Study:

• To formulate an effective description of GNIs' impact on the tritium beta spectrum.
• To derive the first constraints on effective GNI parameters using KATRIN data.
• To explore KATRIN's potential for discovering specific new physics scenarios.

Main Methods:

• Incorporating all theoretically allowed dimension-6 GNI terms into a low-energy effective field theory.
• Analyzing the tritium beta spectrum measured by the KATRIN experiment.
• Developing an effective description of GNI effects on the beta spectrum.

Main Results:

• The study derived the first constraints on effective GNI parameters.
• Analysis was based on 4x10^6 electrons collected during KATRIN's 2019 campaign.
• Constraints were investigated for specific interactions, including those involving right-handed W bosons, charged Higgs bosons, and leptoquarks.

Conclusions:

• The KATRIN experiment's precision measurements are valuable for searching for general neutrino interactions.
• The derived constraints advance the search for new physics beyond the Standard Model.
• KATRIN demonstrates potential for probing specific new physics models.