J.A. Grifols

Specifically Supersymmetric Contribution to Electric Dipole Moments

Abstract We discuss a source of CP violation which is specific to supersymmetric theories. CP violating phases appear in the mass matrix of the gauge and Higgs fermions. We estimate its effect on the electric dipole moment of the electron and the neutron. Their magnitude is found to be close to the experimental upper bounds.

Effects of anomalous magnetic dipole and electric quadrupole moments of the charged weak boson on (g−2)μ☆

Abstract We calculate the effect on the muon anomaly of anomalous magnetic dipole and electric quadrupole moments of the charged weak boson and discuss the constraints on those quantities derived from the experimental data.

Radiative Corrections to Weak Boson Masses From Supersymmetry

Abstract We consider the radiative corrections to the masses of the gauge bosons W ± and Z 0 due to supersymmetric particles. In the limit of some fermionic superpartners not heavier than the weak boson masses, an upper bound of at most a few hundred MeV for the weak boson mass shifts obtains which is independent of unknown mixing parameters.

Low energy CP violation in broken supersymmetry

Abstract We investigate the CP violation effects in supersymmetry broken models, due to the exchange of new fermions (gauginos and higgsinos). When the real part of the K 0 − K 0 amplitude is compatible with the experimental value, the possible imaginary part is too small to account for the ϵ parameter. In contrast, the experimental bounds on the ϵ′ parameter and the electric dipole moments, and especially the θ parameter, impose in general severe constraints on the possible CP violating phases. However, in some specific models there are extra suppression factors, leaving those phases essentially unconstrained except perhaps for the θ parameter.

Radiative signal for light neutral supersymmetric particle production in e+e− annihilation

Abstract The process e + e − → γ + neutrals is analyzed as a means for the detection of light supersymmetric neutral particles.

Squarkonium production through Z0 decay

Abstract We discuss the Z decay as a source of production of the 1S0 (JPC=0++) squarkonium state. Although the signal lies above the detectability limits, separation from background will require the positive experimental identification of gluon jets.

Mass shifts of intermediate vector bosons induced by new interactions

Abstract Departures of the vector boson masses from the predictions of the standard model are studied as a possible window to new physics. An estimate of the mass shifts is presented in two different models recently proposed to explain the anomalous l+l−γ events seen at the collider. In both cases there is a cancellation of the leading term and the mass shifts are of the same order of magnitude as the standard radiative corrections in one of the models (scalar particle) while they are too small to be detectable in the other case (excited lepton).

Test of compositeness in pp̄ → γγX processes☆

Abstract If composite spin-zero states are introduced in order to explain the measured abundance of Z → e + e − γ events, it is shown that these states should be observed in the two-photon energy spectrum of pp → γγX. The possible choices for the coupling constants involved are discussed.

Radiative decays of the (composite) charged weak boson

Abstract Assuming the charged weak boson to be endowed with anomalous magnetic dipole and electric quadrupole moments we study the emission of (hard) photons in leptonic W decays.

Technicolour in γγ processes

Abstract We estimate the production rates in γγ annihilation processes of the lightest pseudo-Goldstone bosons in technicolour theories. The charged colour singlet bosons P ± give rates well within experimentally feasible limits and the neutral colour singlet P 3 might be detected in a long and dedicated experiment.