Spectrum of CHL dyons from genustwo partition function
Abstract
We compute the genustwo chiral partition function of the leftmoving heterotic string for a Bbb Z_{2} CHL orbifold. The required twisted determinants can be evaluated explicitly in terms of the untwisted determinants and theta functions using orbifold techniques. The dependence on Prym periods cancels neatly once summation over odd charges is properly taken into account. The resulting partition function is a Siegel modular form of level two and precisely equals recently proposed dyon partition function for this model. This result provides an independent weak coupling derivation of the dyon partition function using the Mtheory lift of string webs representing the dyons. We discuss generalization of this technique to general Bbb Z_{N} orbifolds.
 Publication:

Journal of High Energy Physics
 Pub Date:
 December 2007
 DOI:
 10.1088/11266708/2007/12/087
 arXiv:
 arXiv:hepth/0612011
 Bibcode:
 2007JHEP...12..087D
 Keywords:

 High Energy Physics  Theory
 EPrint:
 25 pages, 2 figures, minor typos corrected