Di-Higgs production as a probe of flavor changing neutral Yukawa couplings  

作　　者：Shi-Ping He 和世平(Center for Future High Energy Physics and Theoretical Physics Division,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Center for Future High Energy Physics and Theoretical Physics Division,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics C》2021年第7期91-110,共20页中国物理C（英文版）

摘　　要：Top partners are well motivated in many new physics models.Usually,vector like quarks,T_(L,R),are introduced to circumvent the quantum anomaly.Therefore,it is crucial to probe their interactions with standard model particles.However,flavor changing neutral couplings are always difficult to detect directly in current and future experiments.In this paper,we demonstrate how to constrain the flavor changing neutral Yukawa coupling Tth indirectly,via the di-Higgs production.We consider the simplified model,including a pair of gauge singletT_(L,R).Under the perturbative unitarity and experimental constraints,we selectm_(T)=400 GeV,s_(L)=0.2,andm_(T)=800 GeV,s_(L)=0.1as benchmark points.After the analysis on the amplitude and evaluation of the numerical cross sections,we infer that the present constraints from di-Higgs production have already surpassed the unitarity bound because of the (y_(L,R)^(tT)^4behavior.For the case ofm_(T)=400 GeV and s_(L)=0.2,Rey_(L,R)^(tT) and Imy_(L,R)^(tT)can be bounded optimally in the range (-0.4,0.4) at the HL-LHC wit2σCL.For the case ofm_(T)=800GeV and s_(L)=0.1,Rey_(L,R)^(tT) and Imy_(L,R)^(tT)can be bounded optimally in the range (-0.5,0.5) at the HL-LHC wit 2σCL.The anomalous triple Higgs coupling delta_(hhh) can also affect the constraints ony_(L,R)^(tT).Finally,we determine that the top quark electric dipole moment can provide strongery_(L,R)^(tT)bounds in the off-axis regions for some scenarios.

关 键 词：double Higgs vector like quarks flavour changing neutral Yukawa interactions 

分 类 号：O572.2[理学—粒子物理与原子核物理]