# Ruling out the Weinberg Model of Spontaneous CP Violation

## Abstract

There have been many declarations of the death of the Weinberg model of spontaneous CP violation. Previous studies, before the recent measurements of {epsilon}'/{epsilon}, indicated that the model could not accommodate the experimental values on {epsilon} in K{sup 0} - {bar K}{sup 0} mixing, the neutron electric dipole moment (EDM), the branching ratio of b {yields} s{gamma} and the upper limit on {epsilon}'/{epsilon}. The authors point out that these studies were based on optimistic estimates of the uncertainties in the calculations and that when more realistic estimates of these errors are used the Weinberg model cannot be conclusively ruled out from these considerations alone. Here we use these realistic error estimates to analyze the present situation of the Weinberg model. The latest results from Belle and BaBar on sin 2{beta} allow the small values of this parameter which occur naturally in the Weinberg model. However, in this model, the recently measured value of Re({epsilon}'/{epsilon}) = (1.92 {+-} 0.25) x 10{sup -3} cannot be made compatible with the branching ratio B(b {yields} s{gamma}) = (3.15 {+-} 0.54) x 10{sup -4}. As a result they conclude that the Weinburg model is now confidently and conservatively ruled out.

- Authors:

- Publication Date:

- Research Org.:
- Stanford Linear Accelerator Center, Menlo Park, CA (US)

- Sponsoring Org.:
- USDOE Office of Energy Research (ER) (US)

- OSTI Identifier:
- 784778

- Report Number(s):
- SLAC-PUB-8588

TRN: US0108593

- DOE Contract Number:
- AC03-76SF00515

- Resource Type:
- Technical Report

- Resource Relation:
- Other Information: PBD: 30 Nov 2000

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BRANCHING RATIO; DATA; ELECTRIC DIPOLE MOMENTS; NEUTRONS; WEINBERG-SALAM GAUGE MODEL; CP INVARIANCE; KAONS NEUTRAL; ANTIKAONS NEUTRAL

### Citation Formats

```
Chang, Darwin.
```*Ruling out the Weinberg Model of Spontaneous CP Violation*. United States: N. p., 2000.
Web. doi:10.2172/784778.

```
Chang, Darwin.
```*Ruling out the Weinberg Model of Spontaneous CP Violation*. United States. doi:10.2172/784778.

```
Chang, Darwin. Thu .
"Ruling out the Weinberg Model of Spontaneous CP Violation". United States. doi:10.2172/784778. https://www.osti.gov/servlets/purl/784778.
```

```
@article{osti_784778,
```

title = {Ruling out the Weinberg Model of Spontaneous CP Violation},

author = {Chang, Darwin},

abstractNote = {There have been many declarations of the death of the Weinberg model of spontaneous CP violation. Previous studies, before the recent measurements of {epsilon}'/{epsilon}, indicated that the model could not accommodate the experimental values on {epsilon} in K{sup 0} - {bar K}{sup 0} mixing, the neutron electric dipole moment (EDM), the branching ratio of b {yields} s{gamma} and the upper limit on {epsilon}'/{epsilon}. The authors point out that these studies were based on optimistic estimates of the uncertainties in the calculations and that when more realistic estimates of these errors are used the Weinberg model cannot be conclusively ruled out from these considerations alone. Here we use these realistic error estimates to analyze the present situation of the Weinberg model. The latest results from Belle and BaBar on sin 2{beta} allow the small values of this parameter which occur naturally in the Weinberg model. However, in this model, the recently measured value of Re({epsilon}'/{epsilon}) = (1.92 {+-} 0.25) x 10{sup -3} cannot be made compatible with the branching ratio B(b {yields} s{gamma}) = (3.15 {+-} 0.54) x 10{sup -4}. As a result they conclude that the Weinburg model is now confidently and conservatively ruled out.},

doi = {10.2172/784778},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2000},

month = {11}

}