1,417 research outputs found
Copper‐Catalyzed Enantio‐ and Diastereoselective Addition of Silicon Nucleophiles to 3,3‐Disubstituted Cyclopropenes
A highly stereocontrolled syn‐addition of silicon nucleophiles across cyclopropenes with two different geminal substituents at C3 is reported. Diastereomeric ratios are excellent throughout (d.r.≥98:2) and enantiomeric excesses usually higher than 90 %, even reaching 99 %. This copper‐catalyzed C−Si bond formation closes the gap of the direct synthesis of α‐chiral cyclopropylsilanes.TU Berlin, Open-Access-Mittel - 201
Essays on numerical solutions to forward-backward stochastic differential equations and their applications in finance
In this thesis, we provide convergent numerical solutions to non-linear forward-BSDEs (Backward Stochastic Differential Equations). Applications in mathematical finance, financial economics and financial econometrics are discussed. Numerical examples show the effectiveness of our methods
Pair production of 125 GeV Higgs boson in the SM extension with color-octet scalars at the LHC
Although the Higgs boson mass and single production rate have been determined
more or less precisely, its other properties may deviate significantly from its
predictions in the standard model (SM) due to the uncertainty of Higgs data. In
this work we study the Higgs pair production at the LHC in the Manohar-Wise
model, which extends the SM by one family of color-octet and isospin-doublet
scalars. We first scanned over the parameter space of the Manohar-Wise model
considering exprimental constraints and performed fits in the model to the
latest Higgs data by using the ATLAS and CMS data separately. Then we
calculated the Higgs pair production rate and investigated the potential of its
discovery at the LHC14. We conclude that: (i) Under current constrains
including Higgs data after Run I of the LHC, the cross section of Higgs pair
production in the Manohar-Wise model can be enhanced up to even times
prediction in the SM. (ii) Moreover, the sizable enhancement comes from the
contributions of the CP-odd color-octet scalar . For lighter scalar
and larger values of , the cross section of Higgs pair
production can be much larger. (iii) After running again of LHC at 14 TeV, most
of the parameter spaces in the Manohar-Wise model can be test. For an
integrated luminosity of 100 fb at the LHC14, when the normalized ratio
, the process of Higgs pair production can be detected.Comment: 13 pages, 4 figure
Explanation of the ATLAS Z-peaked excess by squark pair production in the NMSSM
The ATLAS collaboration recently reported a excess in the
leptonic- channel. We intend to interpret this excess by
squark pair production in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM). The decay chain we employ is , where and denote the
lightest and the next-to-lightest neutralinos with singlino and bino as their
dominant components respectively. Our simulations indicate that after
considering the constraints from the ATLAS searches for
signal the central value of the excess can be obtained for , and if the constraint from the CMS on- search is
further considered, more than 10 signal events are still attainable for
. Compared with the interpretation by
gluino pair production, the squark explanation allows for a significantly wider
range of as well as a less compressed SUSY mass spectrum. We
also show that the squark explanation will be readily tested at the initial
stage of the 14 TeV LHC.Comment: 19 pages, 4 figure
Explanation of the ATLAS Z-peaked excess in the NMSSM
Recently the ATLAS collaboration reported a excess in the
leptonic- channel. This may be interpreted in the
Next-to-Minimal Supersymmetric Standard Model (NMSSM) by gluino pair production
with the decay chain , where and denote the
lightest and the next-to-lightest neutralinos with singlino and bino as their
dominant components respectively. After exploring the relevant parameter space
of the NMSSM by considering the constraints from the ATLAS searches for signals, we conclude that the NMSSM is able to explain the excess
at level with the number of the signal events reaching its measured
central value in optimal cases, and the best explanation comes from a
compressed spectrum such as ,
and . We also check the consistency of the ATLAS results with the
null result of the CMS on- search. We find that under the CMS limits at
C.L., the event number of the ATLAS on- signal can still reach 11 in
our scenario, which is about away from the measured central value.Comment: 18 pages, 2 figure
Interpreting The 750 GeV Diphoton Excess Within Topflavor Seesaw Model
We propose to interpret the 750 GeV diphoton excess in a typical topflavor
seesaw model. The new resonance X can be identified as a CP-even scalar
emerging from a certain bi-doublet Higgs field. Such a scalar can couple to
charged scalars, fermions as well as heavy gauge bosons predicted by the model,
and consequently all of the particles contribute to the diphoton decay mode of
the X. Numerical analysis indicates that the model can predict the central
value of the diphoton excess without contradicting any constraints from 8 TeV
LHC, and among the constraints, the tightest one comes from the Z \gamma
channel, \sigma_{8 {\rm TeV}}^{Z \gamma} \lesssim 3.6 {\rm fb}, which requires
\sigma_{13 {\rm TeV}}^{\gamma \gamma} \lesssim 6 {\rm fb} in most of the
favored parameter space.Comment: Major changes, 17 pages, 4 figure, typos corrected, calculation
details adde
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