78,329 research outputs found
Profiles of the Unitarity Triangle and CP-Violating Phases in the Standard Model and Supersymmetric Theories
We report on a comparative study of the profile of the CKM unitarity
triangle, and the resulting CP asymmetries in B decays, in the standard model
and in several variants of the minimal supersymmetric standard model (MSSM),
characterized by a single phase in the quark flavour mixing matrix. The
supersymmetric contributions to the mass differences \Delta M_d, \Delta M_s and
to the CP-violating quantity |\epsilon| are, to an excellent approximation,
equal to each other in these theories, allowing for a particularly simple way
of implementing the resulting constraints on the elements of V_{CKM} from the
present knowledge of these quantities. Incorporating the next-to-leading-order
corrections and applying the current direct and indirect constraints on the
supersymmetric parameters, we find that the predicted ranges of \sin 2 \beta in
the standard model and in MSSM models are very similar. However, precise
measurements at B-factories and hadron machines may be able to distinguish
these theories in terms of the other two CP-violating phases \alpha and \gamma.
This is illustrated for some representative values of the supersymmetric
contributions in \Delta M_d, \Delta M_s and |\epsilon|.Comment: 30 pages, 9 figures; typos corrected, minor notation change; matches
version to appear in the European Physical Journal
Attainable lengths for circular binary words avoiding k-powers
We show that binary circular words of length n avoiding 7/3+ powers exist
for every sufficiently large n. This is not the case for binary circular words
avoiding k+ powers with k < 7/3https://projecteuclid.org/download/pdf_1/euclid.bbms/113379334
A system-on-chip digital pH meter for use in a wireless diagnostic capsule
This paper describes the design and implementation of a system-on-chip digital pH meter, for use in a wireless capsule application. The system is organized around an 8-bit microcontroller, designed to be functionally identical to the Motorola 6805. The analog subsystem contains a floating-electrode ISFET, which is fully compatible with a commercial CMOS process. On-chip programmable voltage references and multiplexors permit flexibility with the minimum of external connections. The chip is designed in a modular fashion to facilitate verification and component re-use. The single-chip pH meter can be directly connected to a personal computer, and gives a response of 37 bits/pH, within an operating range of 7 pH units
Design of a single-chip pH sensor using a conventional 0.6-μm CMOS process
A pH sensor fabricated on a single chip by an unmodified, commercial 0.6-/spl μm CMOS process is presented. The sensor comprises a circuit for making differential measurements between an ion-sensitive field-effect transistor (ISFET) and a reference FET (REFET). The ISFET has a floating-gate structure and uses the silicon nitride passivation layer as a pH-sensitive insulator. As fabricated, it has a large threshold voltage that is postulated to be caused by a trapped charge on the floating gate. Ultraviolet radiation and bulk-substrate biasing is used to permanently modify the threshold voltage so that the ISFET can be used in a battery-operated circuit. A novel post-processing method using a single layer of photoresist is used to define the sensing areas and to provide robust encapsulation for the chip. The complete circuit, operating from a single 3-V supply, provides an output voltage proportional to pH and can be powered down when not required
Energy of Stable Half-Quantum Vortex in Equal-Spin-Pairing
In the triplet equal-spin-pairing states of both 3He-A phase and Sr2RuO4
superconductor, existence of Half-Quantum Vortices HQVs are possible. The
vortices carry half-integer multiples of magnetic quantum flux (hc/2e). To
obtain equilibrium condition for such systems, one has to take into account not
only weak interaction energy but also effects of Landau Fermi liquid. Our
method is based on the explanation of the HQV in terms of a BCS-like wave
function with a spin-dependent boots. We have considered l=2 order effects of
the Landau Fermi liquid. We have shown that the effects of Landau Fermi liquid
interaction with l=2 are negligible. In stable HQV, an effective Zeeman field
exists. In the thermodynamic stability state, the effective Zeeman field
produces a non-zero spin polarization in addition to the polarization of
external magnetic field
Effects of heavy Majorana neutrinos at lepton-proton colliders
We discuss the prospects of detecting the processes
and
() under the conditions of the present collider
HERA and of future colliders. These high-energy processes are assumed to be
mediated by the exchange of heavy Majorana neutrinos (HMN). We consider two
simple scenarios for the HMN mass spectrum: the effective singlet () and the effective doublet (). For the latter
case, the cross section includes information about CP-violating phases.Comment: 5pages, 2 figures; published in conference proceedings: Particle
Physics in Laboratory, Space and Universe, 11th. Lomonosov Conf. on
Elementary Particle Physics (Moscow, 21-27 August 2003) (Singapore, World
Scientific, 2005
Electron angular correlation in neutrinoless double beta decay and new physics
The angular correlation of the electrons in the neutrinoless double beta
decay () is calculated taking into account the nucleon recoil, the
and -waves for the electrons and the electron mass using a general
Lorentz invariant effective Lagrangian. We show that the angular coefficient is
essentially independent of the nuclear matrix element models. We work out the
angular coefficient in several scenarios for new physics, in particular, in the
left-right symmetric models.Comment: 5 pages, 1 figure; to appear in the Proceedings of the 13th Lomonosov
Conference on Elementary Particle Physics, 23 --29 August 2007, Moscow,
Russi
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