帶新阿貝爾規範對稱的變形雙希格斯二重態模型研究

The study on a variant two-Higgs doublet model with a new Abelian gauge symmetry

林郭彥(Kuo-Yen Lin)

指導教授 ： 蔣正偉

國立臺灣大學/理學院/物理學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201901867

摘要

本研究受V. Barger 和H.S. Lee 在2012 發表的論文所啟發，他們的概念是建構在規範群SU(3)C X SU(2)L X U(1)Y X U(1)B 下，額外添加四代費米子及一純量波色子，來實現新加入的規範波色子Z′ 衰變至四個帶電輕子的過程(Four Leptons Resonance)。在本論文中，我們試圖建構一個能夠實現Four Leptons Resonance 的理論模型。但因為當今希格斯粒子的實驗數據不容許標準模型中第四代費米子的存在，因此我們的模型採用Dipankar Das 等人的想法，並將模型置入Type-II 2HDM 的架構中才得以實現。

在這篇論文中，我們考慮了數個Flavor violating processes 及暗物質直接探測的實驗結果，探討了此模型用於解釋Muon g-2 anomaly 和暗物質的可能性。我們發現此模型能以很小的耦和常數對Muon g-2 給出足夠的貢獻，同時也擁有足夠多的自由參數，使得此模型能滿足其他實驗結果的限制。在暗物質的部分，我們發現暗物質直接探測對於新加入的規範玻色子Z′ 有著相當大的限制，因此此模型可望在未來的暗物質實驗中能被檢驗。

關鍵字

緲子g-2 ； 暗物質 ； 四代費米子

並列摘要

This research is inspiring by the paper published by V. Barger and H.S Lee in 2012. Their idea is based on the gauge group SU(3)C X SU(2)L X U(1)Y X U(1)B and add fourth generation fermions and a complex scalar boson to realize the process that one gauge boson Z′ decays into four charged leptons. In this paper, we try to establish a theoretical model to realize Four leptons resonance. Unfortunately, the standard model + fourth generation fermions is basically ruled out by current Higgs boson experimental data. Therefore, we adopt the idea from the paper by Dipankar Das et al and embed our model into the framework of type-II two Higgs doublet model (type-II 2HDM).

In this paper, we consider experimental constraints from several flavour violating processes and dark matter direct detection and see if this model can explain muon g-2 anomaly and dark matter. We found even for small coupling
constant, it can still give an adequate contribution to muon g-2. This model has enough free parameters which can be fine tuned to satisfy the constraints from other experiments. In dark matter part, we found dark matter
direct detection is a strong constraint for new added gauge boson Z′. This makes the model testable in the future dark matter search.

並列關鍵字

Muon g-2 ； Dark matter ； Fourth generation fermion

參考文獻

[1] Dipankar Das, Anirban Kundu, and Ipsita Saha. Higgs data does not rule out a sequential fourth generation with an extended scalar sector. Phys. Rev.,

D97(1):011701, 2018.

[2] Extended rotation curves of high-luminosity spiral galaxies. IV - Systematic dynamical properties, SA through SC.

[3] E. Aprile et al. First Dark Matter Search Results from the XENON1T Experiment. Phys. Rev. Lett., 119(18):181301, 2017.

[4] The ATLAS collaboration. Combined measurements of Higgs boson production and decay using up to 80 fb^{-1} of proton–proton collision data at p s = 13 TeV collected with the ATLAS experiment. 2019.