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arXiv 0801.4346hep-phhep-ex
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反B--> X(s)伽马在两个普遍的额外维度

Anti-B --> X(s) gamma in two universal extra dimensions

Ayres Freitas, Ulrich Haisch

摘要:

计算了具有两个大的平坦普适额外维的标准模型中反B-> X(s)γ衰变的首阶修正.我们发现物理标量场a^+-_(kl)的Kaluza-Klein模交换的贡献与紫外截止标度λ有数学关系。我们强调,所有的口味改变中性电流过渡遭受这个问题。尽管紫外线敏感性削弱了反B-> X(s)γ导致的逆紧化半径1/R的下限,但该约束仍然比任何其他可用的直接测量更强。在仔细研究了截止效应和高阶效应的潜在影响后,我们发现,如果误差以正交方式合并,则在95%的置信水平下,1/R > 650 GeV。我们的限制是在方差与参数区域1/R <~ 600 GeV首选的暗物质的约束。

英文摘要:

We calculate the leading order corrections to the anti-B --> X(s) gamma 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 cut-off scale Lambda. 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 anti-B --> X(s) gamma, the constraint remains stronger than any other available direct measurement. After performing a careful study of the potential impact of cut-off and higher-order effects, we find 1/R > 650 GeV at 95% confidence level if errors are combined in quadrature. Our limit is at variance with the parameter region 1/R <~ 600 GeV preferred by dark matter constraints.

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