17,096 research outputs found
Electric Dipole Moments in the Generic Supersymmetric Standard Model
The generic supersymmetric standard model is a model built from a
supersymmetrized standard model field spectrum the gauge symmetries only. The
popular minimal supersymmetric standard model differs from the generic version
in having R-parity imposed by hand. We review an efficient formulation of the
model and some of the recently obtained interesting phenomenological features,
focusing on one-loop contributions to fermion electric dipole moments.Comment: 1+7 pages Revtex 3 figures incoporated; talk at NANP'0
Unusual magnetoresistance in a topological insulator with a single ferromagnetic barrier
Tunneling surface current through a thin ferromagnetic barrier in a
three-dimensional topological insulator is shown to possess an extraordinary
response to the orientation of barrier magnetization. In contrast to
conventional magnetoresistance devices that are sensitive to the relative
alignment of two magnetic layers, a drastic change in the transmission current
is achieved by a single layer when its magnetization rotates by 90 degrees.
Numerical estimations predict a giant magnetoresistance as large as 800 % at
room temperature and the proximate exchange interaction of 40 meV in the
barrier. When coupled with electrical control of magnetization direction, this
phenomenon may be used to enhance the gating function with potentially sharp
turn-on/off for low power applications
Entropy and Its Quantum Thermodynamical Implication for Anomalous Spectral Systems
The state function entropy and its quantum thermodynamical implication for
two typical dissipative systems with anomalous spectral densities are studied
by investigating on their low-temperature quantum behavior. In all cases it is
found that the entropy decays quickly and vanishes as the temperature
approaches zero. This reveals a good conformity with the third law of
thermodynamics and provides another evidence for the validity of fundamental
thermodynamical laws in the quantum dissipative region.Comment: 10 pages, 3 figure
A Detailed Analysis of One-loop Neutrino Masses from the Generic Supersymmetric Standard Model
In the generic supersymmetric standard model which had no global symmetry
enforced by hand, lepton number violation is a natural consequence.
Supersymmetry, hence, can be considered the source of experimentally demanded
beyond standard model properties for the neutrinos. With an efficient
formulation of the model, we perform a comprehensive detailed analysis of all
one-loop contributions to neutrino masses.Comment: 27 pages Revtex, no figur
One-loop Neutron Electric Dipole Moment from Supersymmetry without R-parity
We present a detailed analysis together with exact numerical calculations on
one-loop contributions to neutron electric dipole moment from supersymmetry
without R-parity, focusing on the gluino, chargino, and neutralino
contributions. Apart from the neglected family mixing among quarks, complete
formulae are given for the various contributions, through the quark dipole
operators, to which the present study is restricted. We discuss the structure
and main features of the R-parity violating contributions and the interplay
between the R-parity conserving and violating parameters. In particular, the
parameter combination , under the optimal
parametrization adopted, is shown to be solely responsible for the R-parity
violating contributions in the supersymmetric loop diagrams. While
could bear a complex phase, the latter is not
necessary to have a R-parity violating contribution.Comment: 43 pages Revtex with 15 eps- and 4 ps- figure files incoporated;
proofread version to be published in Phys. Rev.
Heavy metal concentrations in ceiling fan and roadside car park dust collected from residential colleges in Universiti Putra Malaysia, Serdang, Selangor
In this study, dust samples were collected from 4 residential colleges (K2, K5, KOSAS and K10) in UniversitiPutra Malaysia (UPM) Serdang, Selangor. The samples were collected from ceiling fans and car parksroadside dust. Sand dust on top of the car park cover were collected using polyethylene brush, tray and keptin a polyethylene bag. Dust from ceiling fan on the first floor was collected and put into a polyethylene bag.The dust samples collected were analysed for the concentrations of Cd, Cu, Fe, Ni and Zn. It was found thatK5 [Cu (62.94 ± 0.77 µg/g dw), Fe (1802.40 ± 9.81 µg/g dw), and Zn (253.34 ± 22.76 µg/g dw) of car parkdust; Zn (997.20 ± 16.10 µg/g dw) (of ceiling fan dust] and K10 [Ni (26.88 ± 1.84 µg/g dw) and Zn (199.77± 6.64 µg/g dw) of car park dust; Cu (468.55 ± 3.67 µg/g dw), Ni (83.96 ± 0.75 µg/g dw), and Fe (3131.58 ±27.01 µg/g dw) of ceiling fan dust] exhibited elevated concentrations of heavy metals that might be related tovehicular activities as compared to K2 and KOSAS. In general, ceiling fan dust had significantly (P< 0.05)higher concentrations of heavy metals than the car park dust. In comparison to other reported studies in theliterature, the maximum levels of Ni and Cu were comparable or higher than those reported for major cities inthe world. Hence, more monitoring studies should be conducted in the future to check for metal contaminationin the dust, as this can serve as an atmospheric indicator of heavy metal pollution
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