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arXiv 0903.3385astro-ph.HE
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皮埃尔俄歇天文台表面探测器对超高能τ中微子扩散通量的限制

Limit on the diffuse flux of ultra-high energy tau neutrinos with the surface detector of the Pierre Auger Observatory

The Pierre Auger Collaboration

摘要:

在皮埃尔·俄歇天文台收集的数据被用来建立宇宙辐射中τ中微子扩散通量的上限。掠过地球的$ν_τ$可能在地壳中相互作用,并通过带电电流相互作用产生$τ$轻子。$τ$轻子可能从地球中出现,并在大气中衰变,产生一个具有典型特征的几乎水平的簇射,即使在非常大的大气深度也是一个持续的电磁分量。本文描述了在宇宙线引起的正常簇射背景下,选择由$τ$衰变引起的事件的搜索过程。详细介绍了计算随时间连续增长的探测器曝光量的方法。系统的不确定性,从探测器的曝光,分析和所涉及的物理进行了讨论。对于能量范围为$τ$ eV $< E_ν$ $<$ $2\times10^{19}$ eV的中微子,假设扩散谱的形式为$E_ν^{-2}$,2004年1月1日至2008年4月30日收集的数据产生了90%的置信度上限为$E_ν^{2} \mathrm{d}N_{ν_τ}/\mathrm{d}E_ν < 9 \times 10^{-8}$ GeV cm $^{-2}$ s $^{-1}$ sr $^{-1}$。

英文摘要:

Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse flux of tau neutrinos in the cosmic radiation. Earth-skimming $ν_τ$ may interact in the Earth's crust and produce a $τ$ lepton by means of charged-current interactions. The $τ$ lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower with a typical signature, a persistent electromagnetic component even at very large atmospheric depths. The search procedure to select events induced by $τ$ decays against the background of normal showers induced by cosmic rays is described. The method used to compute the exposure for a detector continuously growing with time is detailed. Systematic uncertainties in the exposure from the detector, the analysis and the involved physics are discussed. No $τ$ neutrino candidates have been found. For neutrinos in the energy range $2\times10^{17}$ eV $< E_ν$ $<$ $2\times10^{19}$ eV, assuming a diffuse spectrum of the form $E_ν^{-2}$, data collected between 1 January 2004 and 30 April 2008 yield a 90% confidence-level upper limit of $E_ν^{2} \mathrm{d}N_{ν_τ}/\mathrm{d}E_ν < 9 \times 10^{-8}$ GeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$.

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。

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