论文标题

关于CDF的W-MAS测量的猜测

Speculations on the W-Mass Measurement at CDF

论文作者

Gu, Jiayin, Liu, Zhen, Ma, Teng, Shu, Jing

论文摘要

Tevatron CDF实验的W质量测定报告偏离了SM期望值为7 $σ$级别。我们讨论一些可能的解释及其对撞机的影响。我们在各种框架和假设下执行Electroweak全球拟合。我们考虑三种类型的Electroweak Global适合有效的视野理论框架:$ S $ - $ T $,$ S $ - $ T $ - $ t $ - $ΔG_F$和八参数味道通风。我们讨论了这些拟合中反映的不同$ m_w $测量与这些参数中心值的相应变化之间的紧张局势的数量。借助了这些Electroweak Fit图片,我们提供了一些不同类别的模型,并讨论了它们与这些结果的兼容性。我们发现,在解释$ M_W $差异的同时,单量规玻色扩展将面临强大的LHC直接搜索约束,除非$ z'$是Fermiophopic(Leptophobic),如果额外的矢量费(Leptons(Leptons))与Sm fermions(Leptons)混合(Leptons),则可以实现。类似矢量的顶级合作伙伴可以部分生成所需的转移到Electroweak可观察物。还详细研究了与Top Squark的兼容性。我们发现非分类的顶部蹲力软质量可以增强所需的操作员系数,从而使允许的解释与当前的LHC测量兼容。总体而言,更多的理论和实验发展需要揭示这种差异背后的物理学。

The W Mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at 7$σ$ level. We discuss a few possible interpretations and their collider implications. We perform electroweak global fits under various frameworks and assumptions. We consider three types of electroweak global fits in the effective-field-theory framework: the $S$-$T$, the $S$-$T$-$δG_F$, and the eight-parameter flavor-universal one. We discuss the amounts of tensions between different $m_W$ measurements reflected in these fits and the corresponding shifts in central values of these parameters. With these electroweak fit pictures in hand, we present a few different classes of models and discuss their compatibility with these results. We find that while explaining the $m_W$ discrepancy, the single gauge boson extensions face strong LHC direct search constraints unless the $Z'$ is fermiophobic (leptophobic) which can be realized if extra vector fermions (leptons) mix with the SM fermions (leptons). Vector-like top partners can partially generate the needed shift to the electroweak observables. The compatibility with top squark is also studied in detail. We find non-degenerate top squark soft masses enhance the needed operator coefficients, enabling an allowed explanation compatible with current LHC measurements. Overall, more theory and experimental developments are highly in demand to reveal the physics behind this discrepancy.

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