Abstract
Axion fields provide the most elegant solution to the strong CP problem. In string compactifications it is difficult to obtain an axion whose decay constant is consistent with current cosmological bounds. We examine this question in theories with accidental U(1) symmetries that appear as low energy remnants of discrete symmetries. We refer to the axion-like particles from the spontaneous breakdown of these symmetries as accions. In such systems, the accion decay constant depends on the vacuum configuration and can be lowered to fit the bounds. Furthermore, we find that such accions with consistent decay constant can be embedded in special vacua of Z6-II orbifold models with realistic features.
| Original language | English |
|---|---|
| Pages (from-to) | 381-386 |
| Number of pages | 6 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 675 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - 18 May 2009 |
Bibliographical note
Funding Information:We would like to thank Jihn E. Kim and Michael Ratz for useful discussions. K.S.C. is supported in part by the Grant-in-Aid for Scientific Research No. 20⋅08326 and 20540266 from the Ministry of Education, Culture, Sports, Science and Technology of Japan. P.V. would like to thank LMU Excellent for support. This research was supported by the DFG cluster of excellence Origin and Structure of the Universe, the European Union 6th framework program MRTN-CT-2006-035863 “UniverseNet” and SFB-Transregio 33 “The Dark Universe” by Deutsche Forschungsgemeinschaft (DFG).