### Abstract

The action for a massless particle in 4D Minkowski space-time has a worldline-time reversing symmetry corresponding to CPT invariance of the quantum theory. The analogous symmetry of the -extended superparticle is shown to be anomalous when is odd; in the supertwistor formalism this is because a CPT-violating worldline-Chern-Simons term is needed to preserve the chiral U(1) gauge invariance. This accords with the fact that no massless = 1 super-Poincaré irrep is CPT-self-conjugate. There is a CPT self-conjugate supermultiplet when is even, but it has 2+1 states when 1 2 is odd (e.g. the = 2 hypermultiplet) in contrast to just 2 when 1 2 is even (e.g. the = 4 Maxwell supermultiplet). This is shown to follow from a Kramers degeneracy of the superparticle state space when 1 2 is odd.

Original language | English (US) |
---|---|

Article number | 1650152 |

Journal | International Journal of Modern Physics A |

Volume | 31 |

Issue number | 27 |

DOIs | |

State | Published - Sep 30 2016 |

### Fingerprint

### Keywords

- Superparticle
- time reversal
- twistors

### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Astronomy and Astrophysics

### Cite this

*International Journal of Modern Physics A*,

*31*(27), [1650152]. https://doi.org/10.1142/S0217751X16501529

**Worldline CPT and massless supermultiplets.** / Arvanitakis, Alex S.; Mezincescu, Alexandru; Townsend, Paul K.

Research output: Contribution to journal › Article

*International Journal of Modern Physics A*, vol. 31, no. 27, 1650152. https://doi.org/10.1142/S0217751X16501529

}

TY - JOUR

T1 - Worldline CPT and massless supermultiplets

AU - Arvanitakis, Alex S.

AU - Mezincescu, Alexandru

AU - Townsend, Paul K.

PY - 2016/9/30

Y1 - 2016/9/30

N2 - The action for a massless particle in 4D Minkowski space-time has a worldline-time reversing symmetry corresponding to CPT invariance of the quantum theory. The analogous symmetry of the -extended superparticle is shown to be anomalous when is odd; in the supertwistor formalism this is because a CPT-violating worldline-Chern-Simons term is needed to preserve the chiral U(1) gauge invariance. This accords with the fact that no massless = 1 super-Poincaré irrep is CPT-self-conjugate. There is a CPT self-conjugate supermultiplet when is even, but it has 2+1 states when 1 2 is odd (e.g. the = 2 hypermultiplet) in contrast to just 2 when 1 2 is even (e.g. the = 4 Maxwell supermultiplet). This is shown to follow from a Kramers degeneracy of the superparticle state space when 1 2 is odd.

AB - The action for a massless particle in 4D Minkowski space-time has a worldline-time reversing symmetry corresponding to CPT invariance of the quantum theory. The analogous symmetry of the -extended superparticle is shown to be anomalous when is odd; in the supertwistor formalism this is because a CPT-violating worldline-Chern-Simons term is needed to preserve the chiral U(1) gauge invariance. This accords with the fact that no massless = 1 super-Poincaré irrep is CPT-self-conjugate. There is a CPT self-conjugate supermultiplet when is even, but it has 2+1 states when 1 2 is odd (e.g. the = 2 hypermultiplet) in contrast to just 2 when 1 2 is even (e.g. the = 4 Maxwell supermultiplet). This is shown to follow from a Kramers degeneracy of the superparticle state space when 1 2 is odd.

KW - Superparticle

KW - time reversal

KW - twistors

UR - http://www.scopus.com/inward/record.url?scp=84989967809&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84989967809&partnerID=8YFLogxK

U2 - 10.1142/S0217751X16501529

DO - 10.1142/S0217751X16501529

M3 - Article

AN - SCOPUS:84989967809

VL - 31

JO - International Journal of Modern Physics A

JF - International Journal of Modern Physics A

SN - 0217-751X

IS - 27

M1 - 1650152

ER -