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Flavour changing neutral currents in intersecting brane models

Abel, Steven; Jose, Santiago; Manuel, Masip


Santiago Jose

Masip Manuel


Intersecting D-brane models provide an attractive explanation of family replication in the context of string theory. We show, however, that the localization of fermion families at different brane intersections in the extra dimensions introduces flavour changing neutral currents mediated by the Kaluza-Klein excitations of the gauge fields. This is a generic feature in these models, and it implies stringent bounds on the mass of the lightest Kaluza-Klein modes (becoming severe when the compactification radii are larger than the string length). We present the full string calculation of four-fermion interactions in models with intersecting D-branes, recovering the field theory result. This reveals other stringy sources of flavour violation, which give bounds that are complementary to the KK bounds (i.e. they become severe when the compactification radii are comparable to the string length). Taken together these bounds imply that the string scale is larger than Msgtrsim102 TeV, implying that non-supersymmetric cases are phenomenologically disfavoured.


Abel, S., Jose, S., & Manuel, M. (2003). Flavour changing neutral currents in intersecting brane models. Journal of High Energy Physics, 2003(04),

Journal Article Type Article
Publication Date Apr 1, 2003
Deposit Date Sep 10, 2007
Journal Journal of High Energy Physics
Print ISSN 1126-6708
Electronic ISSN 1029-8479
Publisher Scuola Internazionale Superiore di Studi Avanzati (SISSA)
Peer Reviewed Peer Reviewed
Volume 2003
Issue 04
Keywords Field theories in higher dimensions, D-branes, Compactification, String models.
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