Abstract: We present a new Little Higgs model, motivated by the deconstruction of a five-dimensional gauge-Higgs model. The approximate global symmetry is SO(5)0×SO(5)1, breaking to SO(5), with a gauged subgroup of [SU(2)0L × U(1)0R] × O(4)1, breaking to SU(2)L×U(1)Y . Radiative corrections produce an additional small vacuum misalignment, breaking the electroweak symmetry down to U(1)EM. Novel ...

We have calculated the width of the rare decay H → γγZ at one-loop level in the standard model for Higgs boson masses in the range 115GeV ≤ mH ≤ 160GeV . For this range of Higgs boson masses we find that Z boson is predominantly longitudinally polarized, and the photons have the same helicity. A comparison of the decay width Γ(H → γγZ) to those of H → γγ and H → γZ shows that, for the Higgs bos...

Bottom quark–induced processes are responsible for a large fraction of the LHC discovery potential, in particular for supersymmetric Higgs bosons. Recently, the discrepancy between exclusive and inclusive Higgs boson production rates has been linked to the choice of an appropriate bottom factorization scale. We investigate the process kinematics at hadron colliders and show that it leads to a c...

The dominant electroweak corrections to the production cross sections and partial decay widths of a light Standard-Model Higgs boson, with mass MH ≪ 2mt, are due to top-quark loops. By means of a low-energy theorem, we study at the twoloop level the leading shifts in the Higgs-boson couplings to pairs of light fermions and gauge bosons induced by a sequential isodoublet of high-mass fermions. F...

If a global chiral symmetry is explicitly broken by anomalies in nonabelian gauge theories, a pseudo Nambu-Goldstone boson (axion) associated with a spontaneous breakdown of such a global symmetry acquires a mass through nonperturbative instanton effects. We calculate the axion mass assuming a supersymmetric SU(2) gauge theory and show that the axion obtains an extremely small mass when the SU(...

This work describes the results of the searches for a Higgs boson decaying into gauge bosons carried out by the four LEP collaborations: ALEPH, DELPHI, L3 and OPAL. A lower bound of 109.7 GeV is set at 95% confidence level on the mass of a fermiophobic Higgs boson decaying into photons. This mass limit can be extended by considering the Higgs decay mode into weak bosons. Such a combination has ...

Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139 Abstract We study classical dynamics in the spherical ansatz for the SU(2) gauge and Higgs fields of the electroweak Standard Model in the absence of fermions and the photon. With the Higgs boson mass equal to twice the gauge boson mass, we numerically demonstrate the existence of oscillons, extremely long-liv...

The one-loop radiative corrections to the Higgs boson potential in the MSSM, originating from the top quark and squark loops, are summed in the leading log approximation using the renormalization group. The RG improved effective potential is minimized and the corrections to the CP-odd and CP-even Higgs boson masses are calculated. The resulting masses exhibit smoother top mass dependence than t...

This paper is an updated version of the lectures given at the XXIX International Meeting on Fundamental Physics in Sitges, Barcelona (February 2001). The measurements performed at LEP and SLC have substantially improved the precision of the test of the Minimal Standard Model. The precision is such that there is sensitivity to pure weak radiative corrections. This allows to indirectly determine ...