669 research outputs found
Theoretical models for Dark Matter
A brief review, focused on classes of models in which an interplay between Direct and Indirect searches of Dark Matter and searches of New Physics at the LHC can be established, is presented. Some simplified scenarios, featuring weakly as well as feebly/superweakly interacting dark matter, which can be embedded in many theoretically motivated particle physics frameworks, will be discussed
Aspects of production and kinetic decoupling of non-thermal dark matter
We reconsider non-thermal production of WIMP dark matter in a systematic way
and using a numerical code for accurate computations of dark matter relic
densities. Candidates with large pair annihilation rates are favored,
suggesting a connection with the anomalies in the lepton cosmic-ray flux
detected by Pamela and Fermi. Focussing on supersymmetric models we will
consider the impact of non-thermal production on the preferred mass scale for
dark matter neutralinos. We have also developed a new formalism to solve the
Boltzmann's equation for a system of coannihilating species without assuming
kinetic equilibrium and applied it to the case of pure Winos.Comment: Proceedings for the conference TAUP 201
B anomalies and muon g - 2 from Dark Matter
Motivated by the result of the Muon g-2 experiment and the long-standing anomalies in semileptonic 퐵 meson decays, we systematically build a class of minimal models that can address both experimental results thanks to the contributions of a set of new fields that include a thermal Dark Matter candidate. This talk is mainly based on Refs
Thermal effects in freeze-in neutrino dark matter production
We present a detailed study of the production of dark matter in the form of a
sterile neutrino via freeze-in from decays of heavy right-handed neutrinos. Our
treatment accounts for thermal effects in the effective couplings, generated
via neutrino mixing, of the new heavy neutrinos with the Standard Model gauge
and Higgs bosons and can be applied to several low-energy fermion seesaw
scenarios featuring heavy neutrinos in thermal equilibrium with the primordial
plasma. We find that the production of dark matter is not as suppressed as to
what is found when considering only Standard Model gauge interactions. Our
study shows that the freeze-in dark matter production could be efficient
Right-handed Neutrino Dark Matter, Neutrino Masses, and non-Standard Cosmology in a 2HDM
We explore the dark matter phenomenology of a weak-scale right-handed
neutrino in the context of a Two Higgs Doublet Model. The expected signal at
direct detection experiments is different from the usual spin-independent and
spin-dependent classification since the scattering with quarks depends on the
dark matter spin. The dark matter relic density is set by thermal freeze-out
and in the presence of non-standard cosmology, where an Abelian gauge symmetry
is key for the dark matter production mechanism. We show that such symmetry
allows us to simultaneously address neutrino masses and the flavor problem
present in general Two Higgs Doublet Model constructions. Lastly, we outline
the region of parameter space that obeys collider, perturbative unitarity and
direct detection constraints.Comment: 27 pages, 3 figures. Matches the version accepted for publication in
JCA
Indole Synthesis Using Silver Catalysis
Indoles are amongst the most important class of heteroaromatics in organic chemistry, being commonly found in biologically active natural products and therapeutically useful compounds. The synthesis of indoles is therefore important and several methods for their synthesis that make use of silver(I) catalysts and reagents have been developed in recent years. This Focus Review contains, to the best of our knowledge, a comprehensive coverage of silver-mediated indole forming reactions since the first reaction of this type was reported in 2004
Gravitino Dark Matter in Tree Level Gauge Mediation with and without R-parity
We investigate the cosmological aspects of Tree Level Gauge Mediation, a
recently proposed mechanism in which the breaking of supersymmetry is
communicated to the soft scalar masses by extra gauge interactions at the tree
level. Embedding the mechanism in a Grand Unified Theory and requiring the
observability of sfermion masses at the Large Hadron Collider, it follows that
the Lightest Supersymmetric Particle is a gravitino with a mass of the order of
10 GeV. The analysis in the presence of R-parity shows that a typical Tree
Level Gauge Mediation spectrum leads to an overabundance of the Dark Matter
relic density and a tension with the constraints from Big Bang Nucleosynthesis.
This suggests to relax the exact conservation of the R-parity. The underlying
SO(10) Grand Unified Theory together with the bounds from proton decay provide
a rationale for considering only bilinear R-parity violating operators. We
finally analyze the cosmological implications of this setup by identifying the
phenomenologically viable regions of the parameter space.Comment: 28 pages, 5 figures. References added. To appear in JHE
Synthesis of 4-substituted-1,2-dihydroquinolines by means of gold-catalyzed intramolecular hydroarylation reaction of n-ethoxycarbonyl-n-propargylanilines
An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-Npropargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-metasubstituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning
Dimensionally regularized box and phase-space integrals involving gluons and massive quarks
The basic box and phase space integrals needed to compute at second order the three-jet decay rate of the Z-boson into massive quarks are presented in this paper. Dimensional Regularization is used to regularize the infrared divergences that appear in intermediate steps. Finally, the cancellation of these divergences among the virtual and the real contributions is showed explicitly
Synthesis of 3-benzylisoquinolines by domino imination/cycloisomerisation of 2-propargylbenzaldehydes
An easy entry to uncommon 2-propargylbenzaldehydes was developed. 2-propargylbenzaldehydes
demonstrated to be suitable building blocks for the synthesis of 3-benzyl isoquinolines by
microwave promoted domino imination/cycloisomerisation in the presence of ammonium acetate. A
small library of 3-benzyl isoquinolines was obtained in good yields under mild reaction conditions.
Two alternative plausible reaction mechanisms are proposed
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