308 research outputs found
The specificity of searches for , and coming from extra dimensions
We discuss the specificity of searches for hypothetical ,
and bosons at hadron colliders in single top
quark and production and Drell-Yan processes assuming these
particles to be the Kaluza-Klein excitations of the gauge bosons of the
Standard Model. In this case any process mediated by is also mediated by
the whole KK tower of its excitations, whereas to the processes mediated by
and there is not only a contribution from their KK towers, but also
from that of the graviton. The contributions of the towers above ,
and and above the first excitation of the
graviton are included with the help of effective four-fermion Lagrangians. We
compute the cross-sections of these processes taking into account the
contributions of the Standard Model gauge bosons, of their first KK modes and
of the corresponding KK towers and discuss the impact of the interference
between them. For pp-collisions at the LHC with the center of mass energy 14
TeV we found specific changes of the distribution tails due to the interference
effects. Such a modification of distribution tails is characteristic for the
processes mediated by particles coming from extra dimensions and should always
be taken into account when looking for them.Comment: 14 pages, 12 figures, LaTeX. References added, figures added, text
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A non-standard matter distribution in the RS1 model and the coupling constant of the radion
In the zero mode approximation we solve exactly the equations of motion for
linearized gravity in the Randall-Sundrum model with a non-standard
distribution of matter in the neighbourhood of the negative tension brane. It
is shown that the form of this distribution can strongly affect the coupling of
the radion to matter. We believe that such a situation can arise in models with
a realistic mechanisms of matter localization.Comment: 12 pages, LaTe
Population and Mutagenesis or About Hardy and Weinberg One Methodical Mistake
The existing discrete form of the Hardy-Weinberg genetic law is applicable for a family tree. For population it is necessary to use a continuous time scale. The differential form of the Hardy-Weinberg law is offered. On the basis of this form of the law the demographic problem is considered where oncological diseases connected with the action of the stochastic mutagen factor. Genetic-mathematical aspects of hemophilia are considered in the assumption of the equivalent constant mutagen factor action
Some Genetic Features of Population Migration
The differential equation for moving genome of panmictic and inbred populations is found. These equations have allowed find the dependence of the population movement speed on various parameters: average time of a generation alternation, the area of the territory developed by the population for certain time, length of a wave of the moving population and inbreeding factor. The nonlinear differential equation of the third order reflecting natural selection in a population is found. Research of the migrating inbred population at present of natural selection has allowed to fined a condition of the allele frequency preservation at women in Х-chromosomes
Inter-brane distance stabilization by bulk Higgs field in RS model
An extension of the Standard Model based on the Randall-Sundrum model with two branes is considered. The size of the extra dimension is stabilized by a fivedimensional two-component complex scalar field, the bulk Higgs field. All the matter fields, which are supposed to be localized on the brane with negative tension, acquire their masses due to the interaction with the boundary value of this field. The gauge invariance of the theory demands that the electroweak gauge fields also propagate in the bulk. The equations of motion for the background fields and their fluctuations against a background solution are found. The second variation Lagrangian is derived. The interactions of the bulk Higgs field with the multidimensional gauge and fermion fields are studied and a possible background solution is obtained
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