B̄→Xsγ in two universal extra dimensions

Journal article

We calculate the leading order corrections to the B̄→Xsγ decay in the standard model with two large flat universal extra dimensions. We find that the contributions involving the exchange of Kaluza-Klein modes of the physical scalar field a(kl)± depend logarithmically on the ultraviolet cutoff scale Λ. We emphasize that all flavor-changing neutral current transitions suffer from this problem. Although the ultraviolet sensitivity weakens the lower bound on the inverse compactification radius 1/R that follows from B̄→Xsγ, the constraint remains stronger than any other available direct measurement. After performing a careful study of the potential impact of cutoff and higher-order effects, we find 1/R>650GeV at 95% confidence level if errors are combined in quadrature. Our limit is at variance with the parameter region 1/R 600GeV preferred by dark matter constraints. © 2008 The American Physical Society.

Authors: Freitas, A; Haisch, U

• Journal: Physical Review D
• Volume: 77
• Issue: 9
• Publication date: 2008-05-20
• DOI: 10.1103/PhysRevD.77.093008
• EISSN: 1550-2368
• ISSN: 1550-7998
• Language: English