Higgs And Extra Scalar Particles

Whether an extra light scalar particle exists outside the standard model(SM)is an interesting problem.Because the results of ATLAS and CMS collaborations looking for the optical resonance state at about 95 GeV in the diphoton channel are inconsistent,we do not know the physical properties outside the standard model(SM)in the low mass region.We study a light scalar particle in the minimal dilaton model(MDM).Compared with the standard model,this model has a new scalar particle,dilaton particle.The minimal dilaton model can be seen as the linear realization of other common dilaton fields.Under the theoretical and latest experimental constraints,according to the diphoton rate of light scalar particles,the selected data samples are divided into two cases:the large-diphoton scenario(with ???/SM(?)0.2)and the small-diphoton scenario(with???/SM(?)0.2),which are favored by CMS and Atlas results respectively.We compare the two cases,test the model parameters,scalar coupling,generation and attenuation characteristics,and consider how to further identify them on the collider.Finally,we reach the following conclusions:(i)The formal usually has small Higgs-dilaton mixing angle(|sin?S|(?)0.2)and small dilaton vacuum expectation value(VEV)f(0.5(?)??v/f(?)1),and the later usually has large mixing(|sin?S|(?)0.4)or large VEV(??v/f(?)0.3).(ii)The former usually predicts small s?? coupling(|Cs??/SM|(?)0.3)and large sgg coupling(0.6(?)|Csgg/SM|(?)1.2),while the later usually predicts small sgg coupling(|Csgg/SM|(?)0.5).(?)The former can interpret the small diphoton excess by CMS at its central value,when ms(?)95GeV,?(?)0.6 and |sin?S|(?)0.(iv)The former usually predicts a negative correlation between Higgs couplings |Ch??/SM|and |Chgg/SM|,while the later usually predicts the two couplings both smaller than 1,or |Chyy/SM|(?)0.9(?)|Chgg/SM|.