The treatment of hypertrophy of the masseter and temporal muscles has to date been dominated by conservative and surgical measures. Local therapy with type A botulinum toxin permits an alternative method of treatment. After targeted, sometimes electromyographically controlled, intramuscular injection of the affected muscles, marked inactivity atrophy occurred in the muscles of seven patients over the course of 3 to 8 weeks. This atrophy remained constant over a follow-up period of up to 25 months, and no side effects were observed. Because of its minimal invasiveness, this technique seems to have an advantage over conventional surgical therapy. Consequently, treatment with type A botulinum toxin can be regarded as a sensible alternative to surgery in cases of hypertrophy of the masseter and/or temporal muscles.

We investigate a method for determining the CP nature of a neutral Higgs boson or spin-zero resonance Φ at a future linear e + e − collider (ILC) in its Φ → τ − τ + decay channel. Our procedure is applicable if the production vertex of the Higgs boson can be measured. This will be the case, for example, for the Higgs-strahlung process e + e − → Z + Φ. We show that the method is feasible for both the leptonic and the hadronic 1-prong tau decay modes, τ Recently, the ATLAS and CMS experiments reported the discovery of a neutral boson of mass ∼ 126 GeV at the LHC [1,2]. The experimental findings disfavor the option of a spin J = 1 resonance. The experimental results [1,2] are compatible with the hypothesis of identifying this resonance with the Standard Model (SM) Higgs boson; however, much more detailed investigations will be necessary to establish this conjecture. The investigations of the properties of this resonance will probably be possible at the LHC to a large extent. A high-energy linear e + e − collider would be an ideal machine to investigate the properties of this resonance, i.e., its couplings, decay modes, spin, and CP parity, in great detail (and, of course, also of other, not too heavy resonances of similar type if they exist). As it is likely that the ATLAS and CMS resonance is a spin-zero (Higgs) boson, one may revert, for assessing the prospects of exploring this particle at a future linear collider, to the many existing phenomenological investigations, within the SM and many of its extensions, of Higgs-boson production and decay in e + e − collisions. As to the prospects of exploring the spin and CP properties of a Higgs boson, there have been a number of proposals and studies, including that are relevant for Higgs-boson production and decay at a linear collider. In this workshop contribution we apply a method [26,27] for the determination of the CP properties of a neutral spin-zero (Higgs) boson Φ in its τ + τ − decays to the production of Φ at a future e + e − linear collider (ILC). For definiteness, we consider e + e − → ZΦ, but the analysis outlined below is applicable to any other Φ production mode. In our analysis all major 1-prong τ decays are taken into account. We demonstrate that the CP properties of Φ can be determined with our method in an unambiguous way.

We investigate how the CP quantum numbers of a neutral Higgs boson or spin-zero resonance Φ, produced at the CERN Large Hadron Collider, can be determined in its τ-pair decay mode Φ → τ − τ + . We use a method [1] based on the distributions of two angles and apply it to the major 1-prong τ decays. We show for the resulting dilepton, lepton-pion, and two-pion final states that appropriate selection cuts significantly enhance the discriminating power of these observables. From our analysis we conclude that, provided a Higgs boson will be found at the LHC, it appears feasible to collect the event numbers needed to discriminate between a CP-even and CP-odd Higgs boson and/or between Higgs boson(s) with CP-conserving and CP-violating couplings after several years of high-luminosity runs.

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We investigate how precisely the CP nature of the 125 GeV Higgs boson h, parametrized by a scalar-pseudoscalar Higgs mixing angle φ τ , can be determined in h → τ − τ + decay with subsequent τ-lepton decays to charged prongs at the Large Hadron Collider (LHC). We combine two methods in order to define an observable ϕ * CP which is sensitive to φ τ : We use the ρ-decay plane method for τ ∓ → ρ ∓ and the impact parameter method for all other major τ decays. For estimating the precision with which φ τ can be measured at the LHC (13 TeV) we take into account the τ − τ + background from Drell-Yan production and perform a Monte Carlo simulation of measurement uncertainties on the ϕ * CP signal and background distributions. We obtain that the mixing angle φ τ can be determined with an uncertainty of