Abstract
We show in this paper that, in a $U(1)$-symmetric two-Higgs-doublet model (2HDM), the two additional neutral Higgs bosons would become nearly degenerate in the large $\tan\beta$ regime, under the combined constraints from both theoretical arguments and experimental measurements. As a consequence, the excess observed in the anomalous magnetic moment of the muon could not be addressed in the considered framework, following the usual argument where these two neutral scalars are required to manifest a large mass hierarchy. On the other hand, we find that, with an $\mathcal{O}(1)$ top-Yukawa coupling and a relatively light charged Higgs boson, large contributions from the two-loop Barr-Zee type diagrams can account for the muon $g-2$ anomaly at the 1$\sigma$ level, in spite of a large cancellation between the scalar and pseudoscalar contributions. Furthermore, the same scenario can survive the tight constraints from the $B$-physics observables.
Highlights
There is a long-standing deviation between the standard model (SM) prediction and the experimental measurement for aμ ≡ ðg − 2Þ=2, the anomalous magnetic moment of the muon [1,2,3,4,5]
With the particular up-quark flavor-changing neutral current (FCNC) texture specified in Refs. [34,49], we will illustrate in this paper that, in spite of the large cancellation between the scalar and pseudoscalar contributions, the 1σ range of Δaμ can be accommodated through the two-loop Barr-Zee-type diagrams [31,32,50,51,52,53,54,55,56,57,58], in which a sizeable top-quark Yukawa coupling and a relatively light charged Higgs boson are simultaneously presented
Calculations [92,93] of the leading-order hadronic vacuum polarization contribution to the muon g − 2 obtained consistent results that are larger than the previous ones. If these results are confirmed, the discrepancy between the SM prediction and the experimental measurement will be diluted. This in turn indicates that, if new physics (NP) really exists as the one considered here, it will be unnecessary to invoke large εtt and small MHÆ to account for the muon g − 2 excess, making the scenario considered much easier to avoid the tight constraints from the B-physics observables
Summary
There is a long-standing deviation between the standard model (SM) prediction and the experimental measurement for aμ ≡ ðg − 2Þ=2, the anomalous magnetic moment of the muon [1,2,3,4,5]. A reasonable solution to the anomaly can be provided in the aligned 2HDM [30,31,32,33] All these scenarios mentioned require a significant mass splitting between the scalar and pseudoscalar Higgs bosons. [34,49], we will illustrate in this paper that, in spite of the large cancellation between the scalar and pseudoscalar contributions, the 1σ range of Δaμ can be accommodated through the two-loop Barr-Zee-type diagrams [31,32,50,51,52,53,54,55,56,57,58], in which a sizeable top-quark Yukawa coupling and a relatively light charged Higgs boson are simultaneously presented.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
