A study of the measurement precision of the Higgs boson decaying into tau pairs at the ILC

Shin-Ichi Kawada,Tohru Takahashi,Keisuke Fujii,Taikan Suehara,Tomohiko Tanabe

doi:10.1140/epjc/s10052-015-3854-2

Abstract

We evaluate the measurement precision of the production cross section times the branching ratio of the Higgs boson decaying into tau lepton pairs at the International Linear Collider (ILC). We analyze various final states associated with the main production mechanisms of the Higgs boson, the Higgs-strahlung and WW-fusion processes. The statistical precision of the production cross section times the branching ratio is estimated to be 2.6% and 6.9% for the Higgs-strahlung andWW-fusion processes, respectively, with the nominal integrated luminosities assumed in the ILC Technical Design Report; the precision improves to 1.0% and 3.4% with the running scenario including possible luminosity upgrades. The study provides a reference performance of the ILC for future phenomenological analyses.

Highlights

After the discovery of the Higgs boson by the ATLAS and the CMS experiments at the LHC [1,2], the investigation of the properties of the Higgs boson has become an important target of study in particle physics
We have evaluated the measurement precision of the Higgs boson production cross section times the branching ratio of decay into tau leptons at the International Linear Collider (ILC)
The dominant Higgs boson production mechanisms were studied at the center-of-mass energies of 250 and 500 GeV, assuming the nominal luminosity scenario presented in the ILC Technical Design Report (TDR)

Summary

Introduction

After the discovery of the Higgs boson by the ATLAS and the CMS experiments at the LHC [1,2], the investigation of the properties of the Higgs boson has become an important target of study in particle physics. The Yukawa couplings can deviate from the SM prediction in the presence of new physics beyond the SM. It is desired to measure the Higgs couplings as precisely as possible in order to probe new physics. 6. For background processes, we use common Monte-Carlo (MC) samples for SM processes previously prepared for the studies presented in the ILC TDR [13]. The event generation of these processes is performed with WHIZARD [16], in which beamstrahlung, initial state radiation, decay of short-lived particles, and hadronization are taken into account in the same way as described in the previous section for the signal process. The background processes from γ γ interactions with hadronic final states, in which photons are produced by beam–beam interactions, are generated on the basis of the cross section model in Ref.

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Conclusion