# Neutrinoless double beta decay and chiral SU (3)

## Abstract

TeV-scale lepton number violation can affect neutrinoless double beta decay through dimension-9 ΔL=ΔI=2 operators involving two electrons and four quarks. Since the dominant effects within a nucleus are expected to arise from pion exchange, the π ^{-}→π ^{+}ee matrix elements of the dimension-9 operators are a key hadronic input. Here in this letter we provide estimates for the π ^{-}→π ^{+} matrix elements of all Lorentz scalar ΔI=2 four-quark operators relevant to the study of TeV-scale lepton number violation. The analysis is based on chiral SU(3) symmetry, which relates the π ^{-}→π ^{+} matrix elements of the ΔI=2 operators to the $K$ ^{0}→$$\bar{K}$$ ^{0} and K→ππ matrix elements of their ΔS=2 and ΔS=1 chiral partners, for which lattice QCD input is available. The inclusion of next-to-leading order chiral loop corrections to all symmetry relations used in the analysis makes our results robust at the 30% level or better, depending on the operator.

- Authors:

- Publication Date:

- Research Org.:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

- Sponsoring Org.:
- USDOE Laboratory Directed Research and Development (LDRD) Program

- OSTI Identifier:
- 1351662

- Alternate Identifier(s):
- OSTI ID: 1352442

- Report Number(s):
- LA-UR-17-20043

Journal ID: ISSN 0370-2693; S0370269317302940; PII: S0370269317302940

- Grant/Contract Number:
- AC52-06NA25396

- Resource Type:
- Published Article

- Journal Name:
- Physics Letters B

- Additional Journal Information:
- Journal Name: Physics Letters B Journal Volume: 769 Journal Issue: C; Journal ID: ISSN 0370-2693

- Publisher:
- Elsevier

- Country of Publication:
- Netherlands

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Atomic and Nuclear Physics

### Citation Formats

```
Cirigliano, V., Dekens, W., Graesser, M., and Mereghetti, E. Neutrinoless double beta decay and chiral SU (3). Netherlands: N. p., 2017.
Web. doi:10.1016/j.physletb.2017.04.020.
```

```
Cirigliano, V., Dekens, W., Graesser, M., & Mereghetti, E. Neutrinoless double beta decay and chiral SU (3). Netherlands. doi:10.1016/j.physletb.2017.04.020.
```

```
Cirigliano, V., Dekens, W., Graesser, M., and Mereghetti, E. Thu .
"Neutrinoless double beta decay and chiral SU (3)". Netherlands. doi:10.1016/j.physletb.2017.04.020.
```

```
@article{osti_1351662,
```

title = {Neutrinoless double beta decay and chiral SU (3)},

author = {Cirigliano, V. and Dekens, W. and Graesser, M. and Mereghetti, E.},

abstractNote = {TeV-scale lepton number violation can affect neutrinoless double beta decay through dimension-9 ΔL=ΔI=2 operators involving two electrons and four quarks. Since the dominant effects within a nucleus are expected to arise from pion exchange, the π-→π+ee matrix elements of the dimension-9 operators are a key hadronic input. Here in this letter we provide estimates for the π-→π+ matrix elements of all Lorentz scalar ΔI=2 four-quark operators relevant to the study of TeV-scale lepton number violation. The analysis is based on chiral SU(3) symmetry, which relates the π-→π+ matrix elements of the ΔI=2 operators to the $K$0→$\bar{K}$0 and K→ππ matrix elements of their ΔS=2 and ΔS=1 chiral partners, for which lattice QCD input is available. The inclusion of next-to-leading order chiral loop corrections to all symmetry relations used in the analysis makes our results robust at the 30% level or better, depending on the operator.},

doi = {10.1016/j.physletb.2017.04.020},

journal = {Physics Letters B},

number = C,

volume = 769,

place = {Netherlands},

year = {2017},

month = {6}

}

DOI: 10.1016/j.physletb.2017.04.020

*Citation information provided by*

Web of Science

Web of Science