Search for scalar top and scalar bottom quarks at LEP OPAL Collaboration
Search for scalar top and scalar bottom quarks at LEP OPAL Collaboration
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在 LEP OPAL Collaboration 中搜索标量顶夸克和标量底夸克
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
S. Dallison
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文献类型：
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作者：
G. Abbiendi;G. Alexander;G. Anagnostou;G. Azuelos;I. Bailey;P. Bechtle;T. Behnke;D. Bonacorsi;L. Brigliadori;S. Campana;Á. Csilling;S. Dallison
用LEP的蛋白石探测器收集的438PB−1，质心能量为√S=192-209GeV的数据样本，对标量顶夸克和标量底夸克进行了研究。没有找到信号的证据。当顶夸克左右态的超对称配对的混合角为零时，标量顶夸克质量的95%置信度下限为97.6GeV。当标量顶夸克与Z0玻色子解耦时，下限为95.7GeV。假设标量顶夸克衰变为魅力夸克和最轻的中性子，并且标量顶夸克和最轻的中性子之间的质量差大于10GeV，得到了这些极限。还研究了标量顶夸克衰变为底夸克、带电轻子和标量中微子的互补衰变模式。当标量顶夸克与标量中微子的质量差大于10GeV且标量顶夸克的混合角为零时，标量顶夸克质量的下限为96.0GeV。通过对标量底夸克的研究，如果标量底夸克与最轻的中性微子之间的质量差大于10GeV，则其质量极限为96.9GeV。2002Elsevier Science B.V.版权所有。
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 438 pb −1 at centreof-mass energies of √ s = 192–209 GeV collected with the OPAL detector at LEP. No evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 97 .6 GeV if the mixing angle between the supersymmetric partners of the leftand right-handed states of the top quark is zero. When the scalar top quark decouples from the Z 0 boson, the lower limit is 95.7 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. The lower limit on the scalar top quark mass is 96 .0 GeV for this decay mode, if the mass difference between the scalar top quark and the scalar neutrino is greater than 10 GeV and if the mixing angle of the scalar top quark is zero. From a search for the scalar bottom quark, a mass limit of 96 .9 GeV was obtained if the mass difference between the scalar bottom quark and the lightest neutralino is larger than 10 GeV. 2002 Elsevier Science B.V. All rights reserved.