New Physics Beyond SM: An Introduction

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1 New Physics Beyond SM: An Introduction
标准模型取得了巨大成功， 但它不是一个基本的理论， 有一些理论问题无法解释

2 New physics beyond SM certainly exists
Finetuning

3 问题1：暗物质和暗能量

4 问题2：费米子代和味道之谜 为什么恰好有三代 ？ 为什么有不同的质量? CP 破坏问题

5 问题3：物质和反物质不对称问题

6 问题4：大统一 基本粒子物理的一个主要目标就是把各种作用力统一起来 ---大统一理论 爱因斯坦晚年致力于把电磁力和引力统一起来,但没有成功
至今，人们仍在探索大统一理论

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9 问题5：精细调节问题 黑格斯质量的平方发散：

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12 1015 GeV 大统一 1 TeV 新物理 100 GeV 参数 2 /52 100 GeV 标准模型
If SM valid up to GUT scale, the theory has extreme fine-tuning ! 1015 GeV 大统一 100 GeV 参数 2 /52 在地球上拿枪瞄准月球上的一只兔子 在光滑的镜面上竖立起一根很尖的针 1 TeV 新物理 1693年，牛顿 回答‘引力定律怎样跟静态宇宙自洽’： 100 GeV 标准模型

13 The naturalness problem is that the mass of a fundamental scalar is quadratically sensitive to high energy thresholds This is a statement about renormalized quantities and has nothing to do with the regularization method used. We can see this from a toy model that is a Yukawa type theory with two scalars and a fermion：

14 Using dimensional regularization and the MS renormalization scheme, we obtain at one loop

15 corrections since they are protected by a symmetry.
Thus, scalar masses are unstable, quadratically sensitive to higher energy thresholds whereas fermion masses are stable against radiative corrections since they are protected by a symmetry. To see this, we consider 15/42

16 ‘t Hooft Doctrine of Naturalness
G.'t Hooft: in Recent Developments in Field Theories, ed. G.'t Hooft et al., Plenum Press, New York, 1980, page 135.

17 Gerard ’t Hooft, Beijing Feb 25, 2014

18 Edward Witten Hunter College Mar 4, 2013

19 Savas Dimopoulos Beijing Feb 24, 2014

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22 W and Z contribution to proton and neutron mass
Stuart Samuel hep-ph/

23 三座大山

24 标准模型 新物理

25 to Solve Finetuning Problem
25/42 Possible New Physics to Solve Finetuning Problem Little Higgs !

26 Murayama SUSY-2016 It’s striking that we’ve thought about these things for 30 years and we have not made one correct prediction that they have seen.

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28 实验家 实验家 理论家 实验家

29 Savas Dimopoulos Beijing Feb 24, 2014

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32 The current LHC data

33 LHC 最大的功劳 — 发现了黑格斯粒子 François Englert Peter W. Higgs

34 LHC 最大的玩笑 — 750 双光子超出 The LHC is now providing the opportunity
of a lifetime to break entirely new ground.

35 35/42 Note:

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42 J. Ellis SUSY2013