# Electric dipole and magnetic quadrupole moments of the W boson via a CP-violating HWW vertex in effective Lagrangians

## Abstract

The possibility of nonnegligible W electric dipole ({mu}-tilde{sub W}) and magnetic quadrupole (Q-tilde{sub W}) moments induced by the most general HWW vertex is examined via the effective Lagrangian technique. It is assumed that new heavy fermions induce an anomalous CP-odd component of the HWW vertex, which can be parametrized by an SU{sub L}(2)xU{sub Y}(1)-invariant dimension-six operator. This anomalous contribution, when combined with the standard model CP-even contribution, leads to CP-odd electromagnetic properties of the W boson, which are characterized by the form factors {delta}{kappa}-tilde and {delta}Q-tilde. It is found that {delta}{kappa}-tilde is divergent, whereas {delta}Q-tilde is finite, which reflects the fact that the latter cannot be generated at the one-loop level in any renormalizable theory. Assuming reasonable values for the unknown parameters, we found that {mu}-tilde{sub W}{approx}3-6x10{sup -21} e{center_dot}cm, which is 8 orders of magnitude larger than the SM prediction and close to the upper bound derived from the neutron electric dipole moment. The estimated size of the somewhat less-studied Q-tilde{sub W} moment is of the order of -10{sup -36} e{center_dot}cm{sup 2}, which is 15 orders of magnitude above the SM contribution.

- Authors:

- Departamento de Matematicas y Fisica, Universidad Autonoma de Aguascalientes, Avenida Universidad 940, C.P. 20100, Aguascalientes, Aguascalientes (Mexico)
- (Mexico)

- Publication Date:

- OSTI Identifier:
- 20774463

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 72; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevD.72.115009; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CP INVARIANCE; ELECTRIC DIPOLE MOMENTS; ELECTRIC DIPOLES; ELECTROMAGNETIC FORM FACTORS; LAGRANGIAN FIELD THEORY; LAGRANGIAN FUNCTION; MAGNETIC MOMENTS; NEUTRONS; QUADRUPOLE MOMENTS; QUADRUPOLES; RENORMALIZATION; STANDARD MODEL; SU-2 GROUPS; U-1 GROUPS; UNITARY SYMMETRY; W MINUS BOSONS; W PLUS BOSONS

### Citation Formats

```
Montano, J., Ramirez-Zavaleta, F., Tavares-Velasco, G., Toscano, J.J., Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000, Mexico, D.F., and Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Puebla.
```*Electric dipole and magnetic quadrupole moments of the W boson via a CP-violating HWW vertex in effective Lagrangians*. United States: N. p., 2005.
Web. doi:10.1103/PhysRevD.72.115009.

```
Montano, J., Ramirez-Zavaleta, F., Tavares-Velasco, G., Toscano, J.J., Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000, Mexico, D.F., & Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Puebla.
```*Electric dipole and magnetic quadrupole moments of the W boson via a CP-violating HWW vertex in effective Lagrangians*. United States. doi:10.1103/PhysRevD.72.115009.

```
Montano, J., Ramirez-Zavaleta, F., Tavares-Velasco, G., Toscano, J.J., Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000, Mexico, D.F., and Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Puebla. Thu .
"Electric dipole and magnetic quadrupole moments of the W boson via a CP-violating HWW vertex in effective Lagrangians". United States.
doi:10.1103/PhysRevD.72.115009.
```

```
@article{osti_20774463,
```

title = {Electric dipole and magnetic quadrupole moments of the W boson via a CP-violating HWW vertex in effective Lagrangians},

author = {Montano, J. and Ramirez-Zavaleta, F. and Tavares-Velasco, G. and Toscano, J.J. and Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000, Mexico, D.F. and Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Puebla},

abstractNote = {The possibility of nonnegligible W electric dipole ({mu}-tilde{sub W}) and magnetic quadrupole (Q-tilde{sub W}) moments induced by the most general HWW vertex is examined via the effective Lagrangian technique. It is assumed that new heavy fermions induce an anomalous CP-odd component of the HWW vertex, which can be parametrized by an SU{sub L}(2)xU{sub Y}(1)-invariant dimension-six operator. This anomalous contribution, when combined with the standard model CP-even contribution, leads to CP-odd electromagnetic properties of the W boson, which are characterized by the form factors {delta}{kappa}-tilde and {delta}Q-tilde. It is found that {delta}{kappa}-tilde is divergent, whereas {delta}Q-tilde is finite, which reflects the fact that the latter cannot be generated at the one-loop level in any renormalizable theory. Assuming reasonable values for the unknown parameters, we found that {mu}-tilde{sub W}{approx}3-6x10{sup -21} e{center_dot}cm, which is 8 orders of magnitude larger than the SM prediction and close to the upper bound derived from the neutron electric dipole moment. The estimated size of the somewhat less-studied Q-tilde{sub W} moment is of the order of -10{sup -36} e{center_dot}cm{sup 2}, which is 15 orders of magnitude above the SM contribution.},

doi = {10.1103/PhysRevD.72.115009},

journal = {Physical Review. D, Particles Fields},

number = 11,

volume = 72,

place = {United States},

year = {Thu Dec 01 00:00:00 EST 2005},

month = {Thu Dec 01 00:00:00 EST 2005}

}