932 research outputs found
Automated Correctness Proof of Algorithm Variants in Elliptic Curve Cryptography
The Elliptic Curve Cryptography (ECC) is widely known as secure and reliable
cryptographic scheme. In many situations the original cryptographic algorithm is
modified to improve its efficiency in terms like power consumption or memory
consumption which were not in the focus of the original algorithm. For all this
modification it is crucial that the functionality and correctness of the original
algorithm is preserved. In particular, various projective coordinate systems are
applied in order to reduce the computational complexity of elliptic curve encryption
by avoiding division in finite fields. This work investigates the possibilities of
automated proofs on the correctness of different algorithmic variants. We introduce
the theorems which are required to prove the correctness of a modified algorithm
variant and the lemmas and definitions which are necessary to prove these goals.
The correctness proof of the projective coordinate system transformation has practically
been performed with the help of the an interactive formal verification system
XeriFun
Secondary Beam Monitors for the NuMI Facility at FNAL
The Neutrinos at the Main Injector (NuMI) facility is a conventional neutrino
beam which produces muon neutrinos by focusing a beam of mesons into a long
evacuated decay volume. We have built four arrays of ionization chambers to
monitor the position and intensity of the hadron and muon beams associated with
neutrino production at locations downstream of the decay volume. This article
describes the chambers' construction, calibration, and commissioning in the
beam.Comment: Accepted for publication in Nucl. Instr. Meth.
The CKM Matrix and The Unitarity Triangle: Another Look
The unitarity triangle can be determined by means of two measurements of its
sides or angles. Assuming the same relative errors on the angles
and the sides , we find that the pairs
and are most efficient in determining
that describe the apex of the unitarity triangle. They
are followed by , , ,
and . As the set \vus, \vcb, and appears to be
the best candidate for the fundamental set of flavour violating parameters in
the coming years, we show various constraints on the CKM matrix in the
plane. Using the best available input we determine the universal
unitarity triangle for models with minimal flavour violation (MFV) and compare
it with the one in the Standard Model. We present allowed ranges for , , , , and within the
Standard Model and MFV models. We also update the allowed range for the
function that parametrizes various MFV-models.Comment: "published version. few typos corrected, results unchanged
Remark on the Theoretical Uncertainty in - Mixing
We re-examine the theoretical uncertainty in the Standard Model expression
for - mixing. We focus on lattice calculations of the ratio
, needed to relate the oscillation frequency of -
mixing to . We replace the usual linear chiral extrapolation with one
that includes the logarithm that appears in chiral perturbation theory. We find
a significant shift in the ratio , from the conventional to
.Comment: Lattice2002(heavyquark), 3 pages, 3 figure
Probing Yukawa Unification with K and B Mixing
We consider corrections to the unification of down-quark and charged-lepton
Yukawa couplings in supersymmetric GUTs, which links the large nu_tau-nu_mu
mixing angle to b -> s transitions. These corrections generically occur in
simple grand-unified models with small Higgs representations and affect s -> d
and b -> d transitions via the mixing of the corresponding right-handed
superpartners. On the basis of a specific SUSY-SO(10) model, we analyze the
constraints from K-Kbar and B-Bbar mixing on the additional
\tilde{d}_R-\tilde{s}_R rotation angle theta. We find that epsilon_K already
sets a stringent bound on theta, theta^{max}=O(1 degree), indicating a very
specific flavor structure of the correction operators. The impact of the large
neutrino mixings on the unitarity triangle analysis is also briefly discussed,
as well as their ability to account for the sizeable CP-violating phase
observed recently in B_s -> psi phi decays.Comment: 19 pages. Discussion in Sec. 5.2 slightly extended; minor numerical
modifications in Secs. 5.1 to 5.4, conclusions unchanged. Version to appear
in JHE
Unitarity Triangles and the Search for New Physics
Assuming that the Kobayashi-Maskawa mechanism gives the dominant contribution
to CP violation at low energies, we propose a novel way of testing the flavour
sector of the Standard Model which has the potencial for discovering New
Physics. Using 3 x 3 unitarity of the V_{CKM} matrix and choosing a complete
set of rephasing invariant phases, we derive a set of exact relations in terms
of measurable quantities, namely moduli of V_{CKM} and arguments of rephasing
invariant quartets. These tests complement the usual analysis in the \rho, \eta
plane and, if there is New Physics, may reveal its source.Comment: 20 pages, 7 figures, uses tcilate
Experimental study of direct photon emission in K- --> pi- pi0 gamma decay using ISTRA+ detector
The branching ratio in the charged-pion kinetic energy region of 55 to 90 MeV
for the direct photon emission in the K- --> pi- pi0 gamma decay has been
measured using in-flight decays detected with the ISTRA+ setup operating in the
25 GeV/c negative secondary beam of the U-70 PS. The value
Br(DE)=[0.37+-0.39(stat)+-0.10(syst)]*10^(-5) obtained from the analysis of 930
completely reconstructed events is consistent with the average value of two
stopped-kaon experiments, but it differs by 2.5 standard deviations from the
average value of three in-flight-kaon experiments. The result is also compared
with recent theoretical predictions.Comment: 13 pages, 8 figure
Strength and Plastic Properties of TiNiMoFeCu Alloys
В работе исследованы пористые сплавы TiNi49,9-xMo0,1Fe0,1Cux(где x = 0, 1, 3, 6, 10 ат.%), полученные методом (СВС). Показано, что существенное влияние на формирование поверхностей разрушения оказывает сформированная структура сплавов. Установлено, что многообразие проявления свойств сплавов с увеличением легирующей добавки от 1 до 10 ат.% Cu определяется как составом материала, так и температурой деформации.In this work, porous alloys TiNi49,9-xMo0.1Fe0.1Cux (where x = 0, 1, 3, 6, 10 at.%) Obtained by the (SHS) method are investigated. It is shown that the formed structure of the alloys has a significant effect on the formation of fracture surfaces. It was found that, the variety of properties of properties of alloys with the alloying additive formula from 1 to 10 at.% Cu is determined by both the composition of the material and the temperature of deformation.Исследование выполнено за счет гранта Российского научного фонда (проект № 19-79-10045).The research was carried out at the expense of a grant from the Russian science foundation (project No. 19-79-10045)
Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low Method
We investigate the "low-" method (developed by the CCFR/NUTEV
collaborations) to determine the neutrino flux in a wide band neutrino beam at
very low energies, a region of interest to neutrino oscillations experiments.
Events with low hadronic final state energy (of 1, 2 and 5 GeV)
were used by the MINOS collaboration to determine the neutrino flux in their
measurements of neutrino () and antineutrino (\nub_\mu) total cross
sections. The lowest energy for which the method was used in MINOS is
3.5 GeV, and the lowest \nub_\mu energy is 6 GeV. At these energies, the
cross sections are dominated by inelastic processes. We investigate the
application of the method to determine the neutrino flux for ,
\nub_\mu energies as low as 0.7 GeV where the cross sections are dominated by
quasielastic scattering and (1232) resonance production. We find that
the method can be extended to low energies by using values of 0.25
and 0.50 GeV, which is feasible in fully active neutrino detectors such as
MINERvA.Comment: 25 pages, 32 figures, to be published in European Physics Journal
Development and validation of a quantitative HPLC/MS/MS method for the determination of piperacillin in blood plasma
Reduced mortality in patients with sepsis taking piperacillin is possible when they receive a long-term infusion, which improves the effect of antimicrobials. However, such piperacillin therapy requires therapeutic drug monitoring, the use of the latest analytical equipment and developed methods for the quantitative determination of piperacilli
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