3,715 research outputs found
Anomalously interacting extra neutral bosons
We study phenomenological consequences of the Standard Model extension by the
new spin-1 chiral fields with the internal quantum numbers of the electroweak
Higgs doublets. There are at least three different classes of theories, all
motivated by the hierarchy problem, which predict new vector weak-doublets with
masses not far from the electro-weak scale. We discuss resonance production of
these neutral chiral Z* bosons at hadron colliders. The bosons can be observed
as a Breit-Wigner resonance peak in the invariant dilepton mass distributions
in the same way as the well-known extra gauge Z' bosons. This includes them
into a list of very interesting objects for early searches with the first LHC
data. Moreover, the Z* bosons have unique signatures in transverse momentum,
angular and pseudorapidity distributions of the final leptons, which allow to
distinguish them from the other heavy neutral resonances.Comment: 8 pages, 9 figures, uses cimento.cls: for Proceedings of the 2010
Rencontres de Physique de la Vallee d'Aoste, La Thuil
Vibron transport in macromolecular chains
We study the hopping mechanism of the vibron excitation transport in the
simple 1D model of biological macromolecular chains. We supposed that the
vibron interaction with thermal oscillations of the macromolecular structural
elements will result in vibron self -trapping, and the formation of the partial
dressed vibron state. With use of the modified Holstein polaron model, we
calculate vibron diffusivity in dependence of the basic system parameters and
temperature. We obtain that the vibron diffusivity smoothly decreases in non
adiabatic limit when the strength of the vibron-phonon coupling grows. However
this dependence becomes by discontinuous one in case of growth of the
adiabaticity of the system. The value of the critical point depends of the
system temperature, and at room temperatures it belongs to the low or
intermediate coupling regime. We discuss an application of these results to
study of vibron transport to 3D bundles of such macromolecules chains
considering it as polymer nanorods and to 2D polymer films organized from such
macromolecules.Comment: 4 pages, 6 figures, contribution to the Proceedings of the Conference
"Physical mesomechanics of multi-level systems`2014", September 3-5 2014,
Tomsk, Russi
Charged-Lepton-Flavour Violation in Kaon Decays in Supersymmetric Theories
We discuss rare kaon decays that violate charged-lepton flavour conservation
in supersymmetric theories with and without R parity, in view of possible
experiments using an intense proton source as envisaged for a neutrino factory.
In the Minimal Supersymmetric Standard Model, such decays are generated by box
diagrams involving charginos and neutralinos, but the limits from \mu -> e
\gamma, \mu-e conversion and \Delta m_K constrain the branching ratios to
challengingly small values. However, this is no longer the case in R-violating
theories, where such decays may occur at tree level at rates close to the
present experimental limits. Within this framework, we obtain bounds on
products of LL\bar{E} and LQ\bar{D} operators from the experimental upper
limits on K^0 -> \mu^\pm e^\mp and K^{\pm,0} -> \pi^{\pm,0} \mu^\pm e^\mp
decays. We also note the possibility of like-sign lepton decays K^\pm ->
\pi^\mp \ell^\pm \ell^\pm in the presence of non-zero \tilde{b}_L-\tilde{b}_R
mixing. We conclude that rare kaon decays violating charged-lepton flavour
conservation could be an interesting signature of R violation.Comment: 25 pages, 6 figures, Prepared for the Kaon Physics Working Group as
part of the ECFA/CERN study of Neutrino Factory & Muon Storage Rings At CERN.
Referencies added, constraints update
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