7,018 research outputs found
Robust And Optimal Opportunistic Scheduling For Downlink 2-Flow Network Coding With Varying Channel Quality and Rate Adaptation
This paper considers the downlink traffic from a base station to two
different clients. When assuming infinite backlog, it is known that
inter-session network coding (INC) can significantly increase the throughput of
each flow. However, the corresponding scheduling solution (when assuming
dynamic arrivals instead and requiring bounded delay) is still nascent.
For the 2-flow downlink scenario, we propose the first opportunistic INC +
scheduling solution that is provably optimal for time-varying channels, i.e.,
the corresponding stability region matches the optimal Shannon capacity.
Specifically, we first introduce a new binary INC operation, which is
distinctly different from the traditional wisdom of XORing two overheard
packets. We then develop a queue-length-based scheduling scheme, which, with
the help of the new INC operation, can robustly and optimally adapt to
time-varying channel quality. We then show that the proposed algorithm can be
easily extended for rate adaptation and it again robustly achieves the optimal
throughput. A byproduct of our results is a scheduling scheme for stochastic
processing networks (SPNs) with random departure, which relaxes the assumption
of deterministic departure in the existing results. The new SPN scheduler could
thus further broaden the applications of SPN scheduling to other real-world
scenarios
Can the 750-GeV diphoton resonance be the singlet Higgs boson of custodial Higgs triplet model?
The observation of diphoton excess around the mass of 750 GeV in LHC Run-II
motivates us to consider whether the singlet Higgs boson in the custodial Higgs
triplet model can serve as a good candidate because an earlier study of
comprehensive parameter scan shows that it can have the right mass in the
viable mass spectra. By assuming the singlet Higgs mass at 750 GeV, its total
width less than 50 GeV and imposing constraints from the LHC 8-TeV data, we
identify an approximately linear region on the plane along
which the exotic Higgs boson masses satisfy a specific hierarchy and have lower
possible spectra, where denotes the triplet vacuum expectation value
and is the mixing angle between the singlet Higgs boson and the
standard model-like Higgs boson. Although the diphoton decay rate can be
enhanced by charged Higgs bosons running in the loop in this region, it is
mostly orders of magnitude smaller than that required for the observed
production rate, except for the small region when the diphoton
fusion production mechanism becomes dominant. Nonetheless, this part of
parameter space suffers from the problems of breakdown of perturbativity and
large uncertainties in the photon parton distribution function of proton.Comment: 14 pages, 2 figures, and 2 tables; bugs in numerical calculations
fixed, and discussions and conclusions changed; typo corrected; 16 pages,
expanded with more detailed discussions, updated figures and tables, version
to appear in the journa
Radiative corrections to Higgs couplings with weak gauge bosons in custodial multi-Higgs models
We calculate 1-loop radiative corrections to the and couplings in
models with next--to--simplest Higgs sectors satisfying the electroweak
parameter equal to 1 at tree level: the Higgs singlet model, the two-Higgs
doublet models, and the Georgi-Machacek model. Under theoretical and current
experimental constraints, the three models have different correlations between
the deviations in the and couplings from the standard model
predictions. In particular, we find for each model predictions with no overlap
with the other two models.Comment: 5 pages, 1 figur
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