Ref HAL: hal-00453634_v1
Ref Arxiv: 1001.5350
DOI: 10.1002/prop.201000016
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
2 citations
Résumé:

We summarize the extensive work started in ref.1, according to which total helicity is conserved for any two-to-two process, at sqrt{s} larger than M_{SUSY} and fixed angles, in any SUSY extension of SM. Asymptotically the theorem is exact. But it may also have important implications at lower energies sqrt{s} close to M_{SUSY}. Up to now, these have been investigated to 1loop electroweak (EW) order for the processes ug to d W+, sd_L chi+; as well as the 17 gg to HH', and the 9 gg to VH processes, where H,H' denote Higgs or Goldstone bosons, and V=Z, W.

Commentaires: Talk presented by GJG at the meeting on the "Standard Model and beyond and the Standard Cosmology", held at Corfu (Greece), during August 30 - September 6, 2009

Ref HAL: hal-00430281_v1
Ref Arxiv: 0911.1120
DOI: 10.1007/JHEP03(2010)080
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
429 citations
Résumé:

We propose an alternate, calculable mechanism of dark matter genesis,"thermal freeze-in," involving a Feebly Interacting Massive Particle (FIMP)interacting so feebly with the thermal bath that it never attains thermalequilibrium. As with the conventional "thermal freeze-out" productionmechanism, the relic abundance reflects a combination of initial thermaldistributions together with particle masses and couplings that can be measuredin the laboratory or astrophysically. The freeze-in yield is IR dominated bylow temperatures near the FIMP mass and is independent of unknown UV physics,such as the reheat temperature after inflation. Moduli and modulinos of stringtheory compactifications that receive mass from weak-scale supersymmetrybreaking provide implementations of the freeze-in mechanism, as do models thatemploy Dirac neutrino masses or GUT-scale-suppressed interactions. Experimentalsignals of freeze-in and FIMPs can be spectacular, including the production ofnew metastable coloured or charged particles at the LHC as well as thealteration of big bang nucleosynthesis.

Ref HAL: hal-00420854_v1
Ref Arxiv: 0909.5574
DOI: 10.1088/1751-8113/43/8/085207
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
1 citation
Résumé:

We study the Kowalevski expansions near singularities of the swinging Atwood's machine. We show that there is a infinite number of mass ratios $M/m$ where such expansions exist with the maximal number of arbitrary constants. These expansions are of the so--called weak Painlevé type. However, in view of these expansions, it is not possible to distinguish between integrable and non integrable cases.

Ref HAL: hal-00425545_v1
Ref Arxiv: 0910.1785
DOI: 10.1016/j.physrep.2010.07.001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
679 citations
Résumé:

We review the theoretical and phenomenological aspects of the Next-to-Minimal Supersymmetric Standard Model: the Higgs sector including radiative corrections and the 2-loop beta-functions for all parameters of the general NMSSM; the tadpole and domain wall problems, baryogenesis; NMSSM phenomenology at colliders, B physics and dark matter; specific scenarios as the constrained NMSSM, Gauge Mediated Supersymmetry Breaking, U(1)'-extensions, CP and R-parity violation.

Commentaires: 142 pages, 11 figures

Ref HAL: hal-00409798_v1
Ref Arxiv: 0908.1332
DOI: 10.1103/PhysRevD.80.053011
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
17 citations
Résumé:

The process of charged Higgs production in association with a top quark atthe LHC has been calculated at the complete NLO electroweak level both in a TwoHiggs Doublets Model and in the Minimal Supersymmetric Standard Model, assuminga mSUGRA breaking scheme. We have numerically explored the size of the one-loopcorrections in two typical supersymmetric scenarios, with particular attentionto the tan beta dependence, and we have found that they remain perturbativelysmall but possibly sizable, reaching a 20% limit for extreme values of tanbeta, when the complete set of Feynman diagrams is taken into account.

Commentaires: 8 pages

Ref HAL: hal-00398342_v1
Ref Arxiv: 0906.4312
DOI: 10.1016/j.physletb.2009.07.060
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
69 citations
Résumé:

We elaborate on the relation between perturbative and power-like correctionsto short-distance sensitive QCD observables. We confront theoreticalexpectations with explicit perturbative calculations existing in literature. Asis expected, the quadratic correction is dual to a long perturbative series andone should use one of them but not both. However, this might be true only forvery long perturbative series, with number of terms needed in most casesexceeding by far the number of terms available. What has not been foreseen isthat the quartic corrections might also be dual to the perturbative series. Wereview possible reasons for this emerging duality. We also observe anapproximate geometric growth of the perturbative series for differentobservables evaluated in the euclidean region, signaling a simple structure ofthe series in large orders. Some phenomenological applications are discussed.The emerging values of the running light quark masses at 2 GeV, frompseudoscalar, e+e- to hadrons and tau-decay sum rules and including thequadratic corrections are: (m_u+m_d)(2)=8.7(1.3) MeV and m_s(2) = 106.2(15.4)MeV, while the one of the QCD coupling from tau-decay is: alpha_s(M_Z)=0.1192(10). These results are comparable with existing estimates.

Ref HAL: hal-00398313_v1
Ref Arxiv: 0906.2087
DOI: 10.1088/1367-2630/11/10/105028
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
119 citations
Résumé:

We review how our current understanding of the light element synthesis duringthe Big Bang Nucleosynthesis era may help shed light on the identity ofparticle dark matter.

Commentaires: Part of Focus on Dark Matter and Particle Physics. 20 pp.