We study the electroweak phase transition in three scalar extension models beyond the Standard Model.Assuming new scalars are decoupled at some heavy scale, we use the covariant derivative expansion method to derive a...We study the electroweak phase transition in three scalar extension models beyond the Standard Model.Assuming new scalars are decoupled at some heavy scale, we use the covariant derivative expansion method to derive all of the dimension-6 effective operators, whose coefficients are highly correlated in a specific model. We provide bounds to the complete set of dimension-6 operators by including the electroweak precision test and recent Higgs measurements. We find that the parameter space of strong first-order phase transitions（induced by the ｜H｜~6 operator）can be probed extensively in Zh production at future electron-positron colliders.展开更多
The recent NANOGrav evidence of a common-source stochastic background provides a hint to gravitational waves(GW)radiation from the Early Universe.We show that this result can be interpreted as a GW spectrum produced f...The recent NANOGrav evidence of a common-source stochastic background provides a hint to gravitational waves(GW)radiation from the Early Universe.We show that this result can be interpreted as a GW spectrum produced from first order phase transitions(FOPTs)around a temperature in the keV-MeV window.Such a class of FOPTs at temperatures much below the electroweak scale can be naturally envisaged in several warm dark matter models such as Majoron dark matter.展开更多
The relationship between the transverse field Ising model and the Landau phenomenological theory for ferroelectrics is analyzed, and the Landau free energy expression for ferroelectrics having surfaces is derived. It ...The relationship between the transverse field Ising model and the Landau phenomenological theory for ferroelectrics is analyzed, and the Landau free energy expression for ferroelectrics having surfaces is derived. It is pointed out that the traditional expression in which the surface integral has only a term of the square polarization is valid only for special cases, in general a term of the polarization to the four should be included as well. By use of the newly derived free energy expression, the thickness-dependence of the spontaneous polarization and Curie temperature of ferroelectric films is calculated; thereby some experimental results incompatible with the traditional phenomenological theory are successfully explained.展开更多
基金supported in part by the National Science Foundation of China(11175069,11275009,11422545)supported by the NSFC(11121092,11033005,11375202)+1 种基金by the CAS Pilot-B programsupported by the China Postdoctoral Science Foundation(2016M590133,2017T100108)
文摘We study the electroweak phase transition in three scalar extension models beyond the Standard Model.Assuming new scalars are decoupled at some heavy scale, we use the covariant derivative expansion method to derive all of the dimension-6 effective operators, whose coefficients are highly correlated in a specific model. We provide bounds to the complete set of dimension-6 operators by including the electroweak precision test and recent Higgs measurements. We find that the parameter space of strong first-order phase transitions（induced by the ｜H｜~6 operator）can be probed extensively in Zh production at future electron-positron colliders.
基金the Talent Scientific Research Program of College of Physics,Sichuan University(Grant No.1082204112427)Yi-Fu Cai was supported in part by the National Natural Science Foundation of China(NSFC)(Grant Nos.11653002,11961131007,1201101448,11722327,and 11421303)+3 种基金the China Association for Science and Technology-Young Elite Scientist Sponsorship(Grant No.2016QNRC001)the National Youth Talents Program of China,the Fundamental Research Funds for Central Universities,the Chinese Scholarship Council Innovation Talent Funds,and the University of Science and Technology of China(USTC)Fellowship for International Cooperation.Antonino Marciano wishes to acknowledge support by the Shanghai Municipality(Grant No.KBH1512299)the Fudan University(Grant No.JJH151210)NSFC(Grant No.11875113)。
文摘The recent NANOGrav evidence of a common-source stochastic background provides a hint to gravitational waves(GW)radiation from the Early Universe.We show that this result can be interpreted as a GW spectrum produced from first order phase transitions(FOPTs)around a temperature in the keV-MeV window.Such a class of FOPTs at temperatures much below the electroweak scale can be naturally envisaged in several warm dark matter models such as Majoron dark matter.
基金Project partly supported by the Laboratory of Function Inorganic Materials of the Chinese Academy of Sciences.
文摘The relationship between the transverse field Ising model and the Landau phenomenological theory for ferroelectrics is analyzed, and the Landau free energy expression for ferroelectrics having surfaces is derived. It is pointed out that the traditional expression in which the surface integral has only a term of the square polarization is valid only for special cases, in general a term of the polarization to the four should be included as well. By use of the newly derived free energy expression, the thickness-dependence of the spontaneous polarization and Curie temperature of ferroelectric films is calculated; thereby some experimental results incompatible with the traditional phenomenological theory are successfully explained.
