Study of the heavy CP-even Higgs with mass 125 GeV in two-Higgs-doublet models at the LHC and ILC

Lei Wang 0 1 Xiao-Fang Han 0 1 Open Access 0 1 c The Authors. 0 1 0 Qingquan Street, Yantai 264005 , P.R. China 1 Department of Physics, Yantai University We assume that the 125 GeV Higgs discovered at the LHC is the heavy CP-even Higgs of the two-Higgs-doublet models, and examine the parameter space in the Type-I, Type-II, Lepton-specific and Flipped models allowed by the latest Higgs signal data, the (LHC-300 fb1) and 3000 fb1 (LHC-3000 fb1) as well as the ILC at relevant experimental and theoretical constraints. Further, we show the projected limits on tan , sin( ), Hf f and HV V couplings from the future measurements of the 125 GeV Higgs at the LHC and ILC, including the LHC with integrated luminosity of 300 fb1 - s = 250 GeV (ILC250 GeV), s = 500 GeV (ILC-500 GeV) and that the future Higgs signal data have no deviation from the SM expectation, the LHCThe future experiments at the LHC and ILC will constrain the Higgs couplings to be very close to SM values, especially for the HV V coupling. 1 Introduction 2 Two-Higgs-doublet models 3 Numerical calculations 4 Results and discussions 5 Conclusion Introduction A 125 GeV Higgs boson has been discovered in the ATLAS and CMS experiments at the LHC [1, 2]. A number of new measurements or updates of existing ones were presented in ICHEP 2014 [3, 4]. Especially the diphoton signal strength is changed from 1.6 0.4 to from ATLAS and CMS, as well as an overall update from the D0 [15] since 2013. The properties of this particle with large experimental uncertainties agree with the Standard Model (SM) predictions. The two-Higgs-doublet model (2HDM) has very rich Higgs phenomenology, including two neutral CP-even Higgs bosons h and H, one neutral pseudoscalar A, and two charged Higgs H. There are four traditional types for 2HDMs, Type-I [16, 17], TypeII [16, 18], Lepton-specific, and Flipped models [1924] according to their different Yukawa couplings, in which the tree-level flavor changing neutral currents (FCNC) are forbidden by a discrete symmetry. In addition, there is no tree-level FCNC in the 2HDM that allows both doublets to couple to the fermions with aligned Yukawa matrices [25]. The recent Higgs data have been used to constrain these 2HDMs over the last few months [2654]. In this paper, we assume that the 125 GeV Higgs discovered at the LHC is respectively the heavy CP-even Higgs of the Type-I, Type-II, Lepton-specific and Flipped 2HDMs, and examine the parameter space allowed by the latest Higgs signal data, the non-observation of additional Higgs at the collider, and the theoretical constraints from vacuum stability, unitarity and perturbativity as well as the experimental constraints from the electroweak precision data and flavor observables. Further, we analyze how well 2HDMs can be distinguished from SM by the future measurements of the 125 GeV Higgs at the LHC and s = 14 TeV and integrated luat s = 250 GeV (ILC-250 GeV), s = 500 GeV (ILC-500 GeV) and s = 1000 GeV (ILC-1000 GeV). For the 125 GeV Higgs is the light CP-even Higgs, the projected limits HV V (W W, ZZ) Higgs boson. u, d and l denote the up-type quarks, down-type quarks and the charged leptons, been studied in [39, 40]. on 2HDMs from the future measurements of the 125 GeV Higgs at the LHC and ILC have Our work is organized as follows. In section II we recapitulate the two-Higgs-doublet models. In section III we introduce the numerical calculations. In section IV, we examine the implications of the latest Higgs signal data on the 2HDMs and projected limits on the 2HDMs from the future measurements of the 125 GeV Higgs at the LHC and ILC after imposing the theoretical and experimental constraints. Finally, we give our conclusion in Two-Higgs-doublet models The Higgs potential with a softly broken Z2 symmetry is written as [55] 1 = 12 (v1 + 01 + ia1) , 2 = 12 (v2 + 02 + ia2) electroweak symmetry breaking, there are five mass eigenstates: two neutral CP-even h and H, one neutral pseudoscalar A, and two charged scalar H. The tree-level couplings of the neutral Higgs bosons can have sizable deviations from those of SM Higgs boson. Table 1 shows the couplings of the heavy CP-even Higgs with respect to those of the SM Higgs boson in the Type-I, Type-II, Lepton-specific and Flipped Numerical calculations Using the method taken in [5663], we perform a global fit to the latest Higgs data of 29 channels (see tables I-V in [64]). The signal strength for the i channel is defined as ij denotes the assumed signal composition of the partonic process j, which are given in ( i iexp)2 nel. The uncertainty asymmetry is retained in our calculations. For the two correlated observables, we use " ( i iexp)2 ( j jexp)2 dimensional plane of the model parameters when explaining the Higgs data (corresponding We employ 2HDMC-1.6.4 [65, 66] to implement the theoretical constraints from the vacuum stability, unitarity and coupling-constant perturbativity, and calculate the oblique cisely (...truncated)