10,368 research outputs found
Anomalous resonant production of the fourth family up type quarks at the LHC
Considering the present limits on the masses of fourth family quarks from the
Tevatron experiments, the fourth family quarks are expected to have mass larger
than the top quark. Due to their expected large mass they could have different
dynamics than the quarks of three families of the Standard Model. The resonant
production of the fourth family up type quark t' has been studied via anomalous
production subprocess gq_i-->t' (where q_i=u,c) at the LHC with the center of
mass energy 10 TeV and 14 TeV. The signatures of such process are discussed
within the SM decay modes. The sensitivity to anomalous coupling
\kappa/\Lambda=0.1 TeV^(-1) can be reached at \sqrt{s}=10 TeV and L_int=100
pb^(-1).Comment: 14 pages, 13 figures, 7 table
Fermi level pinning by integer charge transfer at electrode-organic semiconductor interfaces
The atomic structure of interfaces between conducting electrodes and molecular organic materials varies considerably. Yet experiments show that pinning of the Fermi level, which is observed at such interfaces, does not depend upon the structural details. In this letter, we develop a general model to explain Fermi level pinning, and formulate simple expressions for the pinning levels, based upon integer charge transfer between the conductor and the molecular layer. In particular, we show that DFT calculations give good values for the pinning levels
From spin-polarized interfaces to giant magnetoresistance in organic spin valves
We calculate the spin-polarized electronic transport through a molecular bilayer spin valve from first principles, and establish the link between the magnetoresistance and the spin-dependent interactions at the metal-molecule interfaces. The magnetoresistance of a Fe| bilayer-C 70 | Fe spin valve attains a high value of 70% in the linear-response regime, but it drops sharply as a function of the applied bias. The current polarization has a value of 80% in linear response and also decreases as a function of bias. Both these trends can be modeled in terms of prominent spin-dependent Fe| C 70 interface states close to the Fermi level, unfolding the potential of spinterface science to control and optimize spin current
Impact of the relatively light fourth family neutrino on the Higgs boson search
The existence of a fourth fermion generation has mostly been considered as a
source of enhanced Higgs signals with respect to the 3 family Standard Model
predictions. However, a fourth Standard Model family neutrino could cause the
opposite situation. It is shown that relatively light fourth family neutrino
(2m_(nu_(4))<m_(H)) could drastically change the interpretation of the search
results for the Higgs boson, especially if m_(H)<170 GeV.Comment: 5 pages, 9 figure
Down Type Isosinglet Quarks in ATLAS
We evaluate the discovery reach of the ATLAS experiment for down type
isosinglet quarks, , using both their neutral and charged decay channels,
namely the process with subsequent decays resulting in
, and final states.
The integrated luminosity required for observation of a heavy quark is
estimated for a mass range between 600 and 1000 GeV using the combination of
results from different search channels.Comment: 12 page
Anomalous single production of the fourth SM family quarks at Tevatron
Possible single productions of fourth family u_{4} and d_{4} quarks via
anomalous q_{4}qV interactions at Tevatron are studied. Signature of such
processes are discussed and compared with the recent results from Tevatron.Comment: 6 pages, 1 figure, 4 table
Effects of Piperonyl Butoxide and Tetramethrin Combinations on Biological Activities of Selected Synthetic Pyrethroid Insecticides against Different Housefly (Musca domestica L., Diptera: Muscidae) Populations
Piperonyl butoxide (PBO), a methylenedioxyphenyl compound, is primarily used as a synergist in combination with space spray, residual and admixture products for the control of insect pests in or around domestic and commercial premises, especially food preparation areas. Also, tetramethrin is known as a knockdown agent on target organism and it is generally used with piperonyl butoxide. In this study, effects of piperonyl butoxide and tetramethrin combinations on biological activities of synthetic pyrethroids, cypermethrin, deltamethrin, and permethrin against different housefly (Musca domestica Linnaeus, 1758) populations were evaluated. In addition, the biological efficiency of the insecticides used in the study, insecticide + PBO and insecticide + PBO + tetramethrin combinations, against the WHO standard sensitive housefly population and housefly populations collected from different parts of Turkey were compared. Results showed that PBO extensively promoted the ratio of knockdown and killing effect values of the insecticides. The results also indicated that PBO and PBO + tetramethrin combinations moderately reduced the knockdown effect times of all formulation in all housefly populations. The knockdown effect times were more decreased by insecticide + PBO + tetramethrin combinations than insecticides that are used alone and insecticide + PBO combinations
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