1、王 磊,Dark matter in the LHT under current experimental constraints from LHC, Planck, Xenon,烟台大学 2013. 8. 21-24于大连,L. Wang, Jin Min Yang, Jingya Zhu, arXiv:1307.7780,Outline：, Introduction, Conclusions, The LHT confronted with the LHC Higgs data, Planck relic density and XENON100 limit,Lagrangian (Kin
2、etic term),SM gauges : A, W, Z Heavy gauges : AH, WH, ZHSM Higgs : HTriplet Higgs : ,14 Goldsone boson fields,N. Arkani-Hamed, A. G. Cohen, E. Katz, A.E. Nelson, JHEP 0207, 034 (2002),Littlest Higgs model,10 & 30 are eaten by heavy gauge bosons (AH, WH, and ZH),T. Han, H. E. Logan, B. McElrath, L.-T
3、. Wang, PRD67, 095004 (2003),Littlest Higgs model with T-parity (LHT),Under T-parity:,H. C. Cheng, I. Low, JHEP 0309, 051 (2003),(A, W, Z, h, ) are T-even (AH, WH, ZH, F, ) are T-odd,AH is the lightest T-odd particle, and could be a dark matter !,Top-quark Yukawa interaction,T-parity eigenstate:,whe
4、re i, j, k summed over 1, 2, 3 whereas x, y summed over 4, 5.,where,Physical states:,top quark t,top partner T (T-even),The top quark mixes with the top even partner. The mixing can be parameterized by,top partner,(T-odd),Mirror quark:,The couplings of mirror lepton is similar to those of mirror qua
5、rk.,The Higgs couplings are generally suppressed by a factor of,1. From the field,2. The mixing of several fields, such as top quark and the T-even partner.,Some typical Higgs and heavy photon couplings:,For the down-type quark and lepton, there are two cases:,C. R. Chen, K. Tobe, C.-P. Yuan, PLB640
6、, 263 (2006),The parameter space,For , the only decay mode of mirror quark is the two-body decay into the heavy photon and a SM quark. The ATLAS and CMS have analyzed the jets plus missing transverse momentum signal, and not yet found any hints of new physics.,1.,2.,from the LEP limits on the mass o
7、f charged lepton.,3.,J. Hubisz et al., JHEP01, 135 (2006).,Higgs decays:,LHC Higgs data,is kinematically forbidden for f 500 GeV,For,is not sensitive to the mass of particle in the loop as long as they are much larger than half of the Higgs mass.,The r dependence of top quark loop and T quark loop c
8、an cancel to a large extent.,The Higgs signal rates in many channels are only sensitive to the scale,is enhanced while is suppressed more sizably.,LHC diphoton Higgs rate,ATLAS Collaboration, ATLAS-CONF-2013-034,CMS Collaboration, CMS-PAS-HIG-13-005,A global fit to the CMS Higgs data,CMS Collaborati
9、on, CMS-PAS-HIG-13-005,The values for ATLAS data are much larger than those for CMS data,A global fit to the 2012 LHC and Tevatron Higgs data,X.-F. Han, L. Wang, J. M. Yang, J. Zhu, PRD87, 055004 (2013),X.-F. Han, L. Wang, J. M. Yang, J. Zhu, PRD87, 055004 (2013),Dark matter relic density,The heavy
10、photon pair-annihilation processes:,The mirror leptons can give the additional important effects on the relic density via the coannihilation processes for their masses close to the heavy photon. MicrOMEGAs is used to calculate the relic density and the cross section between heavy photon and nucleon.
11、,The heavy photon scattering with nucleon,Planck Collaboration, arXiv:1303.5076,LHT-A,XENON100, PRL109, 181301 (2012),XENON1T, arXiv:1206.6288,2. At , a fit using the CMS Higgs data give the lowest chi-square of 2.63, and also the relic density can be the closest to the measured central value relic
12、density. For the best point and its nearby favored region, the spin-independent cross section between the heavy photon and nucleon is below the bound of XENON100, and can be covered by the future XENON1T (2017) experiment.,Conclusions,Thanks！,1. The LHT can provide the better fit to CMS data than SM
13、, but be disfavored by the ATLAS observation of diphoton enhancement.,玻色子的质量本征态,T-宇称变换下:,top夸克、规范玻色子以及标量粒子圈图能够产生适当的H场势能和质量项，电弱自发对称破缺, 新引进的粒子通过 场的真空期望值获得f标度的质量, SM中的粒子通过H场的真空期望值获得电弱标度的质量,引入以下的场,费米子部分,T-宇称变换下：,是 二重态， 单态； 与此相反。,T-宇称的本征态:,T-odd费米子（mirror费米子）获得质量,定义T-宇称变换：,mirror费米子的质量：,具有T-宇称不变的Yukawa相互
14、作用,top夸克Yukawa耦合为例,T-宇称的本征态：,T-even费米子获得质量,top夸克和 夸克的质量本征态：,引入单态 以及,新引进的top 夸克partner：,质量TeV,费米子规范相互作用,含有,top夸克部分引入的单态场,的运动学项,右手费米子场 的运动学项形式与上面类似,右手mirror费米子场规范相互作用,定义质量本征态的右手场 ，得到,其中,C. G. Callan, S. R. Coleman, J. Wess, B. Zumino, Phys. ReV. 177 (1969) 2247;,T. Goto, Y.Okada, Y. Yamamoto, PLB 670 (2009) 378,mirror夸克的弱混合,mirror 夸克与SM夸克存在类似CKM矩阵的混合矩阵,T-宇称本征态下,质量本征态下,定义转动矩阵,混合矩阵满足,质量混合矩阵,费曼规范下，Goldstone粒子 分别对应,夸克部分的 描述了SM上型（下型）夸克与mirror夸克之间的相互作用，,参数：,M. Blanke etal, Phys.Lett.B646:253-257,2007,C. S. Chen et al., arXiv:0605314,
