5,802 research outputs found
The Fine-Tuning Problem of the Electroweak Symmetry Breaking Mechanism in Minimal SUSY Models
We calculate the region of the MSSM parameter space (i.e. , ,
, \ldots) compatible with a correct electroweak breaking and a realistic
top-quark mass. To do so we have included {\em all} the one-loop corrections to
the effective potential and checked their importance in order to obtain
consistent results. We also consider the fine-tuning problem due to the
enormous dependence of on (the top Yukawa coupling), which is
substantially reduced when the one-loop effects are taken into account. We also
explore the reliability of the so-called "standard" criterion to estimate the
degree of fine-tuning. As a consequence, we obtain a new set of upper bounds on
the MSSM parameters or, equivalently, on the supersymmetric masses perfectly
consistent with the present experimental bounds.Comment: talk given at the XVI Kazimierz Meeting on Elementary Particle
Physics, Kazimierz (Poland) 24-28 May 1993, 4 pages in standard LATEX + 2
figures (not included but available upon request), CERN-TH.7024/9
The Probabilistic Representative Values
In this paper we define a new family of solutions for the class of cooperative games with transferable utility, in which the set of players exhibits a structure of a priori unions.This family is deeply connected with the Shapley value for games with transferable utility but, moreover, we assume a solidarity strong connection among all the components of each union.As a consequence of this, they are disposed to delegate one coalition of members of the union to negotiate with the other unions, and, therefore, each union will have a representative coalition.Furthermore, three interesting solutions that belong to this family of values are studied, as well as the non cooperative selection of the best representative coalition for each union.TU-games with unions;Shapley value;representative coalition
SUSY Soft Breaking Terms from String Scenarios
The general SUSY soft breaking terms for a large class of phenomenologically
relevant string scenarios (symmetric orbifolds) are given. They show a certain
lack of universality, but not dangerous for flavor changing neutral currents.
To get more quantitative results a specific SUSY breaking mechanism has to be
considered, namely gaugino condensation in the hidden sector. Then, it turns
out that squark and slepton masses tend to be much larger than scalar masses
(), which probably is a quite general fact. Experimental
bounds and the requirement of a successful electroweak breaking without fine
tuning impose further restrictions on the soft breaking terms. As a consequence
the gluino and chargino masses should be quite close to their present
experimental limits, whereas squark and slepton masses should be much higher (>
1 TeV).Comment: (Talk presented at the SUSY-93 Conference, Boston, March 29 - April
2, 1993), 11 pages, CERN--TH.6922/9
The Two-stage Constrained Equal Awards and Losses Rules for Multi-Issue Allocation Situation
This paper considers two-stage solutions for multi-issue allocation situations.Characterisations are provided for the two-stage constrained equal awards and constrained equal losses rules, based on the properties of composition and path independence.multi-issue allocation situations;constrained equal awards;constrained equal losses;two-stage solutions
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