Higgs Properties and Fourth Generation Leptons
Higgs Properties and Fourth Generation Leptons
复制标题
希格斯性质和第四代轻子
DOI：
10.1103/physrevd.84.055025
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发表时间：
2011
影响因子：
5
通讯作者：
M. Wise
中科院分区：
文献类型：
--
作者：
Koji Ishiwata;M. Wise
有可能存在额外的类矢量代，其中夸克的质量项不是源于弱对称破缺，但轻子只通过弱对称破缺获得质量。我们讨论了新轻子对Higgs玻色子衰变分支比的影响，以及在这样的模型中(只有一个新的类矢量代)允许的Higgs质量范围。我们发现，如果第四代轻子太重而不能在希格斯衰变中产生，那么新的轻子会使h→γγ的分支比减少到其标准模型值的约30%。这个分支比对新的带电轻子质量的依赖性很弱。此外，如果新夸克比弱标度重得多，那么大型强子对撞机的预期希格斯产生率将非常接近其标准模型值。如果新夸克的质量接近理论的截止值，那么对于大于10^(15)GeV的截止值，新的轻子质量不可能比大约100GeV重很多，希格斯质量的值必须在175GeV左右。
It is possible that there are additional vectorlike generations where the quarks have mass terms that do not originate from weak symmetry breaking, but the leptons only get mass through weak symmetry breaking. We discuss the impact that the new leptons have on Higgs boson decay branching ratios and on the range of allowed Higgs masses in such a model (with a single new vectorlike generation). We find that if the fourth generation leptons are too heavy to be produced in Higgs decay, then the new leptons reduce the branching ratio for h→γγ to about 30% of its standard-model value. The dependence of this branching ratio on the new charged lepton masses is weak. Furthermore the expected Higgs production rate at the LHC is very near its standard-model value if the new quarks are much heavier than the weak scale. If the new quarks have masses near the cutoff for the theory, then for cutoffs greater than 10^(15) GeV, the new lepton masses cannot be much heavier than about 100 GeV and the Higgs mass must have a value around 175 GeV.