Higgs-boson production at the Photon Collider at TESLA

We investigate the potential for detecting and studying Higgs bosons in $\gamma\gamma$ and $e\gamma$ collisions at future linear colliders with energies below a TeV. Our study incorporates realistic $\gamma\gamma$ spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with $\sqrt{s_{ee}}\le 200$ GeV; b) the heavy MSSM Higg...

We present a preliminary study of the production of a light Higgs boson with a mass between 120 and 160 GeV in photon-photon collisions at a Compton collider. The event generator for the backgrounds to a Higgs signal due to bbbar and ccbar heavy quark pair production in polarized Gamma-Gamma collisions is based on a complete next-to-leading order (NLO) perturbative QCD calculation. For J_z=0 the large double-logarithmic corrections up to four loops are also included. It is sh...

Assuming a light Higgs boson is discovered, its nature may remain unknown in case that no supersymmetric particles are found. The detection and study of heavier Higgs particles is then of great interest. For this purpose the Compton-collider option of a high energy e+e- linear collider is optimal both to produce Higgs bosons and to reveal their CP-parity. Assuming realistic photon luminosities for various configurations of laser and linac polarizations, we study the heavy, ne...

This study investigates the potential of a photon collider for measuring the two photon partial width times the branching ratio of a light Higgs boson. The analysis is based on the reconstruction of the Higgs events produced in the gamma gamma -> h process, followed by Higgs decay into a b bbar pair. A statistical error of the measurement of the two-photon width times the b bbar branching ratio of the Higgs boson is found to be 1.7% with an integrated luminosity of 80 fb^-1 i...

This report summarizes the progress in the study of Higgs physics at a future linear electron positron collider at center-of-mass energies up to about 1000 GeV and high luminosity. After the publication of the TESLA Technical Design Report, an extended ECFA/DESY study on linear collider physics and detectors was performed. The paper summarizes the status of the studies with main emphasis on recent results obtained in the course of the workshop.

We present a feasibility study of observing $HH\rightarrow b\bar b\gamma\gamma$ at the future hadron colliders with $\sqrt{s}=$14, 33, and 100 TeV. The measured cross section then can be used to constrain the Higgs self-coupling directly in the standard model. Any deviation could be a sign of new physics. The signal and background events are estimated using Delphes 3.0.10 fast Monte Carlo simulation based on the ATLAS detector capabilities. With 3 ab$^{-1}$ data, it would be ...

Observing the production of the Higgs particle in the $\gamma$-$\gamma$ mode of a linear $e^+e^-$ collider allows for the measurement of the $H\gamma\gamma$ coupling. We point out that for the intermediate Higgs mass range this measurement is considerably more challenging than previously believed. The $b \bar b$ signature receives a large background from the production of heavy quark pairs by resolved photons. We quantify the experimental requirements needed to make a meaning...

This thesis concerns the observation of a new particle and the measurements of its properties, from the search of the Higgs boson through its decay into two photons at the CMS experiment at CERN's Large Hadron Collider (LHC), on the full LHC "Run I" data collected by the CMS detector during 2011 and 2012, consisting of proton-proton collision events at $\sqrt{s}$ $=$ $7~\mathrm{TeV}$ with $L$ $=$ $5.1~\mathrm{fb^{-1}}$ and at $\sqrt{s}$ $=$ $8~\mathrm{TeV}$ with $L$ $=$ $19.7...

We examine the prospects for measuring the $H Z \gamma$ coupling of a Standard Model-like Higgs boson with a mass between 120 and 160 GeV at the future TESLA linear \ee collider, assuming an integrated luminosity of 1 ab$^{-1}$ and a center-of-mass energy of 500 GeV. We consider the Higgs boson produced in association with $\nu_e \bar{\nu_e}$ via the $W W$ fusion reaction $e^+e^- \to \nu_e \bar{\nu_e} H$, followed by the rare decay into a $Z$ boson and a photon, $H \to Z \gam...

The level of sensitivity of the processes $\gamma\gamma \to ZZ$, $\gamma\gamma \to W^+W^-$ and $\gamma\gamma \to t\bar t$ to the Higgs sector of the Standard Model Lagrangian in the energy region between 200 GeV and 1 TeV is examined. The elementary Higgs boson is taken to have a mass less than 1 TeV. Sizeable effects are found in the $ZZ$ and $t\bar t$ channels if the incoming photons have the same helicity. Also the possibility that the elementary Higgs boson does not exist...