arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1805.09795hep-phastro-ph.COhep-ex
收藏

再论WIMP暗物质散射中的非对称性

Uncertainties in WIMP Dark Matter Scattering Revisited

John Ellis, Natsumi Nagata, Keith A. Olive

摘要:

我们重新讨论了WIMP暗物质粒子在核物质上散射的自旋无关散射矩阵元计算中的不确定性。除了讨论由于我们对轻夸克标量密度< N的核子矩阵元的认识有限而引起的不确定性外,|{ \bar u} u,{ \bar d} d,{ \bar s} s| N>的情况下,我们还讨论了重夸克标量密度< N| { \bar c} c、{ \bar b} b、{ \bar t} t| N >,并评论夸克质量比的不确定性。我们分析了在过去十年中使用晶格计算和/或唯象输入的光夸克密度的估计。我们发现组合中的不确定性|{ \bar u} u + { \bar d} d| N >的范围大于某些唯象分析中所假设的范围,|{ \bar s} s| N >,这是较小的,但与早期的估计兼容。我们还分析了重夸克矩阵元的{ \cal O}(α_s^3)计算的重要性,它为自旋无关散射截面的计算提供了重要的改进。我们使用一个基准CMSSM点的焦点区域,这是兼容的LHC和其他搜索的限制。

英文摘要:

We revisit the uncertainties in the calculation of spin-independent scattering matrix elements for the scattering of WIMP dark matter particles on nuclear matter. In addition to discussing the uncertainties due to limitations in our knowledge of the nucleonic matrix elements of the light quark scalar densities < N |{\bar u} u, {\bar d} d, {\bar s} s| N>, we also discuss the importances of heavy quark scalar densities < N |{\bar c} c, {\bar b} b, {\bar t} t| N >, and comment on uncertainties in quark mass ratios. We analyze estimates of the light-quark densities made over the past decade using lattice calculations and/or phenomenological inputs. We find an uncertainty in the combination < N |{\bar u} u + {\bar d} d | N > that is larger than has been assumed in some phenomenological analyses, and a range of < N |{\bar s} s| N > that is smaller but compatible with earlier estimates. We also analyze the importance of the {\cal O}(α_s^3) calculations of the heavy-quark matrix elements that are now available, which provide an important refinement of the calculation of the spin-independent scattering cross section. We use for illustration a benchmark CMSSM point in the focus-point region that is compatible with the limits from LHC and other searches.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑