| The Higgs-like scalar observed at LHC with mass 125 GeV seems to be the Higgs boson predicted by the standard model(SM).For the current and future high-energy experiments,one of main goals is to measure the processes which give information on the couplings of Higgs bo-son with fermions,gauge bosons and its self-couplings and to compare the measurements with the most accurate SM predictions.Any deviation from the SM predictions could be valuable information about new physics beyond the SM.Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles,which is singlet under the SM gauge group,and appears in many extensions of the SM in so-lutions to the strong CP problem or as a mediator between the SM and hidden sector and as a pseudo Nambu-Goldstone boson of spontaneously broken global Abelian symmetry.The inter-actions between ALPs and SM fermions or interactions between ALPs and SM gauge bosons at leading order could be described by the general effective Lagrangian including operators of dimension up to 5.At tree level,there is no dimension-5 operator contributing to the hZa cou-pling,while the fermion-loop graphs arising at dimension-5 and the tree-level contributions of dimension-7 operators can naturally induce this coupling.Only the effective operators of di-mension 6 or higher can induce the haa coupling.The experimental bounds on these couplings and phenomenological analyses have been extensively studied.Taking into account constraints on the free parameters from existing searches and explain-ing the g-2 deviation,we consider the contributions of ALP with mass in the range of 1.5 GeV?ma<mh-mz to the exclusive Higgs decays h?PZ and h?Pl+l-with P being the pseudoscalar mesons ?0,?,?',?c and ?b in a model-independent approach.We find that,in most range of the parameter space,the contributions of ALP to these decay processes are very small,while in the case of the ALP mass ma approximately equaling the meson mass mp,the contributions are significant large. |
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