2,255 research outputs found
Heavy-meson physics and flavour violation with a single generation
We study flavour-violating processes which involve heavy B- and D-mesons and
are mediated by Kaluza-Klein modes of gauge bosons in a previously suggested
model where three generations of the Standard Model fermions originate from a
single generation in six dimensions. We find the bound on the size R of the
extra spatial dimensions 1/R>3.3 TeV, which arises from the three-body decay
B_s to K mu e. Due to the still too low statistics this bound is much less
stringent than the constraint arising from K to mu e, 1/R>64 TeV, which was
found in a previous work (Frere et al., JHEP, 2003). Nevertheless, we argue
that a clear signature of the model would be an observation of K to mu e and
B_s to K mu e decays without observations of other flavour and lepton number
changing processes at the same precision level.Comment: 15 page
Central pseudoscalar production in pp scattering and the gluon contribution to the proton spin
Central pseudoscalar production in scattering is suppressed at small
values of , where is defined as the difference between the momenta
transferred from the two protons. Such a behaviour is expected if the
production occurs through the fusion of two vectors. Photon exchange could
provide the dominant contribution at low transferred momenta, but we argue that
an extension of the experiment could probe the gluon contribution to the proton
spin.Comment: 12 pages, 2 figures and 3 tables, uses epsf.sty. Added references and
tables. Minor changes include
Neutrino Mass Patterns within the See-saw Model from Multi-localization along Extra Dimensions
We study a multi-localization model for charged leptons and neutrinos,
including the possibility of a see-saw mechanism. This framework offers the
opportunity to allow for realistic solutions in a consistent model without
fine-tuning of parameters, even if quarks are also considered. Those solutions
predict that the large Majorana mass eigenvalues for right-handed neutrinos are
of the same order of magnitude, although this almost common mass can span a
large range (bounded from above by ). The model also
predicts Majorana masses between and $\sim 5 \
10^{-2}{\rm eV}\beta\theta_{13}10^{-2} \lesssim
\sin \theta_{13} \lesssim 10^{-1}$, but smaller values are not totally excluded
by the model.Comment: 36 pages, 8 figure
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Robustness of Supply Chain Synchronization Strategies
Modern manufacturing systems dealing with complex assemblies with large numbers of parts present particular challenges in the realm of supply chain management. Complex assemblies, such as those found in aerospace and automobile manufacturing, require thousands of parts to come together at the right time for final assembly. The large number of parts, often coming from hundreds of suppliers, combined with unreliable delivery times and high cost of many of these components can lead to incredibly high inventory costs and assembly delays. Typically, variable delays in part delivery are compensated for by either keeping a buffer of safety stock or a time buffer on the planned lead time of a component. In this thesis, we study the performance of various buffering strategies across a large range of practical scenarios in an effort to identify dominant, robust strategies and how their performance is impacted by the various parameters that define the system. The major conclusion is that aggressive part buffering consistently results in not only better delivery performance but also significant inventory reduction across all settings for assemblies with more than 500 parts
Neutrino masses with a single generation in the bulk
In a class of multidimensional models, topology of the thick brane provides
three chiral fermionic families with hierarchical masses and mixings in the
effective four-dimensional theory, while the full model contains a single
vector-like generation. We discuss how to incorporate three non-degenerate
neutrino masses in these models with the help of only one singlet bulk fermion.Comment: 16 pages, 1 EPS figur
On the production of a lepton pair in the collision of ultrarelativistic neutral particle with nonzero magnetic moment with nuclei
Explicit formulas which describe muon pair production in reaction through neutrino magnetic moment are obtained and used to
derive in the leading approximation cross section of muon pair production in
-scattering due to neutrino magnetic moment. This cross section appears
to be proportional to . Comparison with experimental data on
tridents production provides an upper bound , which is approximately two orders of magnitude weaker than that from
elastic scattering data.Comment: 9 pages, 4 figures, numerical estimates are improve
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