Measuring the fermion Yukawa coupling constants is important for understanding the origin of the fermion masses and their relationship with spontaneously electroweak symmetry breaking.In contrast,some new physics(NP)m...Measuring the fermion Yukawa coupling constants is important for understanding the origin of the fermion masses and their relationship with spontaneously electroweak symmetry breaking.In contrast,some new physics(NP)models change the Lorentz structure of the Yukawa interactions between standard model(SM)fermions and the SM-like Higgs boson,even in their decoupling limit.Thus,the precise measurement of the fermion Yukawa interactions is a powerful tool of NP searching in the decoupling limit.In this work,we show the possibility of investigating the Lorentz structure of the bottom-quark Yukawa interaction with the 125 GeV SM-like Higgs boson for future e^+e^- colliders.展开更多
A double-well potential model is proposed for the pionic deuterium that enables to calculate the energy split, the potential barrier height and estimate the pion tetrahedron edge length. We propose that pion tetrahedr...A double-well potential model is proposed for the pionic deuterium that enables to calculate the energy split, the potential barrier height and estimate the pion tetrahedron edge length. We propose that pion tetrahedrons, π<sup>Td</sup> = u<sub>d</sub>~</sup>dũ, play a central role in the Yukawa interaction by enabling quark exchange reactions between protons and neutrons by tunneling through a potential barrier. A vacuum polarization Feynman diagram is proposed for the π<sup>Td</sup> having chains of fermion loops for the two valence quarks and anti-quarks connected by gluons. With a higher order vacuum polarization diagram, the d and u quark loops are interleaved and the chiral symmetry is broken dynamically. The proposed π<sup>Td</sup> vacuum polarization integral does not diverge in both the IR and UV limits and vanishes in the limit of an infinite pion tetrahedron condensate. We propose a new Delbruck scattering Feynman diagram that includes d and u quark and anti-quark interleaved loops. We further propose that conversion of gravitons to photons may occur via quark and anti-quark loops that describe the pion tetrahedrons dynamics in the vacuum and may also transfer gravitational waves.展开更多
We propose a new dihedral angle observable for measuring the CP property of the interaction between the top quark and Higgs boson int\bar{t}Hproduction at the 14 TeV Large Hadron Collider(LHC).We consider two decay mo...We propose a new dihedral angle observable for measuring the CP property of the interaction between the top quark and Higgs boson int\bar{t}Hproduction at the 14 TeV Large Hadron Collider(LHC).We consider two decay modes of the Higgs boson,H→to b\b and H→γγ,and demonstrate that the dihedral angle distribution is able to distinguish between the CP-even and the CP-odd hypothesis at a 95%confidence level,with an integrated luminosity of\sim 180fb^(-1).展开更多
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 pa...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.展开更多
基金The work of JG is sponsored by the National Natural Science Foundation of China(11875189,11835005)and the MOE Key Lab for Particle Physics,Astrophys-ics and Cosmology.The research of QB,KC,YL and HZ is supported by the fiunding from the Institute of High Energy Physics,Chinese Academy of Sciences(Y6515580U1)and the funding from Chinese Academy of Sciences(Y8291120K2).JG and HZ are plesed to reeognize the support and the hosptality of the Center for High Energy Physics at Peking University。
文摘Measuring the fermion Yukawa coupling constants is important for understanding the origin of the fermion masses and their relationship with spontaneously electroweak symmetry breaking.In contrast,some new physics(NP)models change the Lorentz structure of the Yukawa interactions between standard model(SM)fermions and the SM-like Higgs boson,even in their decoupling limit.Thus,the precise measurement of the fermion Yukawa interactions is a powerful tool of NP searching in the decoupling limit.In this work,we show the possibility of investigating the Lorentz structure of the bottom-quark Yukawa interaction with the 125 GeV SM-like Higgs boson for future e^+e^- colliders.
文摘A double-well potential model is proposed for the pionic deuterium that enables to calculate the energy split, the potential barrier height and estimate the pion tetrahedron edge length. We propose that pion tetrahedrons, π<sup>Td</sup> = u<sub>d</sub>~</sup>dũ, play a central role in the Yukawa interaction by enabling quark exchange reactions between protons and neutrons by tunneling through a potential barrier. A vacuum polarization Feynman diagram is proposed for the π<sup>Td</sup> having chains of fermion loops for the two valence quarks and anti-quarks connected by gluons. With a higher order vacuum polarization diagram, the d and u quark loops are interleaved and the chiral symmetry is broken dynamically. The proposed π<sup>Td</sup> vacuum polarization integral does not diverge in both the IR and UV limits and vanishes in the limit of an infinite pion tetrahedron condensate. We propose a new Delbruck scattering Feynman diagram that includes d and u quark and anti-quark interleaved loops. We further propose that conversion of gravitons to photons may occur via quark and anti-quark loops that describe the pion tetrahedrons dynamics in the vacuum and may also transfer gravitational waves.
基金QHC and RZ are supported in part by the National Science Foundation of China(11725520,11675002,11635001)KPX is supported by grant(NRF-2019RICIC1010050)+1 种基金HZ is supported by Institute of High Energy Physics,Chinese Academy of Science(Y6515580U1)Innovation Grant(Y4545171Y2)。
文摘We propose a new dihedral angle observable for measuring the CP property of the interaction between the top quark and Higgs boson int\bar{t}Hproduction at the 14 TeV Large Hadron Collider(LHC).We consider two decay modes of the Higgs boson,H→to b\b and H→γγ,and demonstrate that the dihedral angle distribution is able to distinguish between the CP-even and the CP-odd hypothesis at a 95%confidence level,with an integrated luminosity of\sim 180fb^(-1).
文摘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.
