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R. Rueckl

Publications and source records attributed to R. Rueckl.

12 recordsLinked to original sources

Flavour physics of leptons and dipole moments

This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

hep-ph

Leptoquarks and the HERA High-Q2 Events

The excess of high-Q2 events recently observed in deep-inelastic positron-proton scattering at HERA has refuelled speculations on physics beyond the standard model, in particular on low-mass leptoquark-type particles. We review the theoretical framework for leptoquark interactions, and their production and decay at HERA. Bounds on leptoquark masses and couplings, and implications on other experiments are also discussed.

hep-ph

Theoretical Interpretations of the HERA High-Q2 Events

Theoretical interpretations of the high-Q^2 events recently observed in deep-inelastic positron-proton scattering at HERA are reviewed. We discuss leptoquarks, squarks with R-parity violating couplings, and contact interactions. Bounds from and implications on other experiments are taken into consideration.

hep-ph

Leptoquark Pair Production at e+e- Linear Colliders: Signals and Background

We study pair production of leptoquarks in e+e- annihilation at linear colliders. A detailed simulation including beamstrahlung and initial state radiation, leptoquark decay and hadronization, as well as detector smearing, is performed. Discovery limits are estimated for center-of-mass energies of 500 and 800 GeV. The prospects for determining masses and couplings of leptoquarks are also investigated.

hep-ph

R-Parity Violating SUSY Signals in Lepton-Pair Production at the Tevatron

In supersymmetric theories with R-parity breaking, sleptons can be produced in quark-antiquark annihilation at the Tevatron through interactions in which two quark fields are coupled to a slepton field. If at the same time trilinear slepton-lepton-lepton couplings are present, the sleptons can be searched for as resonances in $p\bar{p}\to \tildeν \to l^+l^-$ and $\tildeτ\to lν$ final states. Existing Tevatron data can be exploited to derive bounds on the Yukawa couplings of sleptons to quark and lepton pairs. Similar bounds can also be obtained from $e^+e^-$ annihilation to hadrons at LEP2.

hep-ph

Supersymmetry with R-Parity Breaking: Contact Interactions and Resonance Formation in Leptonic Processes at LEP2

In supersymmetric theories with R-parity breaking, trilinear couplings of two leptons to scalar sleptons are possible. In electron-positron collisions such interactions would manifest themselves through contact terms in Bhabha scattering and in annihilation to mu or tau pair Interpreting the high x, high Q2 DIS HERA events as charm squark production with squark masses of order 200 GeV, the formation of tau sneutrinos with a mass in the range close to the LEP2 energy or even in reach, is an exciting speculation which can be investigated in the coming LEP2 runs with energies close to 200 GeV.

hep-ph

Leptoquark/Squark Interpretation of HERA Events: Virtual Effects in e+e- Annihilation to Hadrons

In reference to the recently observed high Q^2, large x events in deep-inelastic positron-proton scattering at HERA, various leptoquark and supersymmetric scenarios are discussed. We study the impact of virtual leptoquark or R-parity breaking squark exchange as well as generic contact interaction on the production of quark-antiquark pairs in $e^+e^-$ annihilation, in particular at LEP2.

hep-ph

Searches For New Physics

Review of prospects for discovery of new physics signals at LEP2. The areas covered include SUSY, exotic fermions, BESS models, leptoquarks, virtual effects and CP violating observables.

hep-ph

Production of Heavy Bound States at LEP and Beyond

We describe some characteristic properties of $B_c$ mesons and discuss the production and the prospects of detection in $e^+ e^-$, $γγ$, and $\bar pp/pp$ collisions. The production mechanisms considered here also play an important role in charmonium and bottomonium production.

hep-ph

Search for New Physics in e-e- Scattering

Considering the physics potential of an e-e- collider in the TeV energy range, we indicate a few interesting examples for exotic processes and discuss the standard model backgrounds. Focussing on pair production of weak gauge bosons, we report some illustrative predictions.

hep-ph

Light Gluinos and the Parton Structure of the Nucleon

We study the effects of light gluinos with mass below about 1 GeV on the nucleon parton densities and the running of alpha_(S). It is shown that from the available high-statistics DIS data no lower bound on the gluino mass can be derived. Also in the new kinematical region accessible at HERA the influence of such light gluinos on structure f unctions is found to be very small and difficult to detect. For use in more direct searches involving final state signatures we present a radiative estimate of the gluino distribution in the nucleon.

hep-ph