{"title":"Macroscopic neutrinoless double beta decay: Long range quantum coherence","authors":"Gordon Baym, Jen-Chieh Peng","doi":"10.1016/j.nuclphysb.2025.116829","DOIUrl":null,"url":null,"abstract":"<div><div>We re-introduce, in light of our modern understanding of neutrinos, the concept of “macroscopic neutrinoless double beta decay” (MDBD) for Majorana neutrinos. In this process an antineutrino produced by a nucleus undergoing beta decay, <span><math><mi>X</mi><mo>→</mo><mi>Y</mi><mo>+</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>+</mo><msub><mrow><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mi>e</mi></mrow></msub></math></span>, is absorbed as a neutrino by another identical <em>X</em> nucleus via the inverse beta decay reaction, <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>+</mo><mi>X</mi><mo>→</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>+</mo><mi>Y</mi></math></span>. The distinct signature of MDBD is that the total kinetic energy of the two electrons equals twice the endpoint energy of single beta decay. The amplitude for MDBD, a coherent sum over the contribution of different mass states of the intermediate neutrinos, reflects quantum coherence over macroscopic distances, and is a new macroscopic quantum effect. We evaluate the rate of MDBD for a macroscopic sample of “<em>X</em>” material, e.g., tritium, acting both as the source and the target. The accidental background for MDBD originating from two separate single beta decays, which contains two final state neutrinos, can be readily rejected by measuring the energy of the detected two electrons. We discuss the similarities and differences between the MDBD and conventional neutrinoless double beta decay. While MDBD is clearly not a viable replacement for traditional 0<em>ν</em>DBD experiments, analysis of the concept of MDBD offers new perspectives on the physics of neutrinoless double beta decays.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1012 ","pages":"Article 116829"},"PeriodicalIF":2.5000,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Physics B","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0550321325000392","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
引用次数: 0
Abstract
We re-introduce, in light of our modern understanding of neutrinos, the concept of “macroscopic neutrinoless double beta decay” (MDBD) for Majorana neutrinos. In this process an antineutrino produced by a nucleus undergoing beta decay, , is absorbed as a neutrino by another identical X nucleus via the inverse beta decay reaction, . The distinct signature of MDBD is that the total kinetic energy of the two electrons equals twice the endpoint energy of single beta decay. The amplitude for MDBD, a coherent sum over the contribution of different mass states of the intermediate neutrinos, reflects quantum coherence over macroscopic distances, and is a new macroscopic quantum effect. We evaluate the rate of MDBD for a macroscopic sample of “X” material, e.g., tritium, acting both as the source and the target. The accidental background for MDBD originating from two separate single beta decays, which contains two final state neutrinos, can be readily rejected by measuring the energy of the detected two electrons. We discuss the similarities and differences between the MDBD and conventional neutrinoless double beta decay. While MDBD is clearly not a viable replacement for traditional 0νDBD experiments, analysis of the concept of MDBD offers new perspectives on the physics of neutrinoless double beta decays.
期刊介绍:
Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics - phenomenology, high energy physics - theory, high energy physics - experiment, and quantum field theory, statistical systems, and mathematical physics. The emphasis is on original research papers (Frontiers Articles or Full Length Articles), but Review Articles are also welcome.