97 research outputs found
Robust Coin Flipping
Alice seeks an information-theoretically secure source of private random
data. Unfortunately, she lacks a personal source and must use remote sources
controlled by other parties. Alice wants to simulate a coin flip of specified
bias , as a function of data she receives from sources; she seeks
privacy from any coalition of of them. We show: If , the
bias can be any rational number and nothing else; if , the bias
can be any algebraic number and nothing else. The proof uses projective
varieties, convex geometry, and the probabilistic method. Our results improve
on those laid out by Yao, who asserts one direction of the case in his
seminal paper [Yao82]. We also provide an application to secure multiparty
computation.Comment: 22 pages, 1 figur
Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model
Focusing on gauge degrees of freedom specified by a 1+3 dimensions model
hosting a Maxwell term plus a Lorentz and CPT non-invariant Chern-Simons-like
contribution, we obtain a minimal extension of such a system to a
supersymmetric environment. We comment on resulting peculiar self-couplings for
the gauge sector, as well as on background contribution for gaugino masses.
Furthermore, a non-polynomial generalization is presented.Comment: revtex4, 4 pages, no figure
Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis
The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.484363369CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçã
Towards Higgs boson production in gluon fusion to NNLO in the MSSM
We consider the Higgs boson production in the gluon-fusion channel to
next-to-next-to-leading order within the Minimal Supersymmetric Standard Model.
In particular, we present analytical results for the matching coefficient of
the effective theory and study its influence on the total production cross
section in the limit where the masses of all MSSM particles coincide. For
supersymmetric masses below 500 GeV it is possible to find parameters leading
to a significant enhancement of the Standard Model cross section, the
-factors, however, change only marginally.Comment: 20 pages; v2: modification of discussion of numerical effect, version
to appear in EPJC; v3: eq.(18) corrected, minor correction
Two-Loop Helicity Amplitudes for Quark-Gluon Scattering in QCD and Gluino-Gluon Scattering in Supersymmetric Yang-Mills Theory
We present the two-loop QCD helicity amplitudes for quark-gluon scattering,
and for quark-antiquark annihilation into two gluons. These amplitudes are
relevant for next-to-next-to-leading order corrections to (polarized) jet
production at hadron colliders. We give the results in the `t Hooft-Veltman and
four-dimensional helicity (FDH) variants of dimensional regularization. The
transition rules for converting the amplitudes between the different variants
are much more intricate than for the previously discussed case of gluon-gluon
scattering. Summing our two-loop expressions over helicities and colors, and
converting to conventional dimensional regularization, gives results in
complete agreement with those of Anastasiou, Glover, Oleari and Tejeda-Yeomans.
We describe the amplitudes for 2 to 2 scattering in pure N=1 supersymmetric
Yang-Mills theory, obtained from the QCD amplitudes by modifying the color
representation and multiplicities, and verify supersymmetry Ward identities in
the FDH scheme.Comment: 77 pages. v2: corrected errors in eqs. (3.7) and (3.8) for one-loop
assembly; remaining results unaffecte
The SUSY-QCD beta function to three loops
A number of DR-bar renormalization constants in softly broken SUSY-QCD are
evaluated to three-loop level: the wave function renormalization constants for
quarks, squarks, gluons, gluinos, ghosts, and epsilon-scalars, and the
renormalization constants for the quark and gluino mass as well as for all
cubic vertices. The latter allow us to derive the corresponding beta functions
through three loops, all of which we find to be identical to the expression for
the gauge beta function obtained by Jack, Jones, and North [Jack:1996vg] (see
also Ref. [Pickering:2001aq]). This explicitely demonstrates the consistency of
DRED with SUSY and gauge invariance, an important pre-requisite for precision
calculations in supersymmetric theories.Comment: Latex, 16 pages, reference added; v2: matches published version in
Eur.Phys.J.
Top-Quark Mediated Effects in Hadronic Higgs-Strahlung
Novel contributions to the total inclusive cross section for Higgs-Strahlung
in the Standard Model at hadron colliders are evaluated. Although formally of
order , they have not been taken into account in previous NNLO
predictions. The terms under consideration are induced by Higgs radiation off
top-quark loops and thus proportional to the top-quark Yukawa coupling. At the
Tevatron, their effects to HW production are below 1% in the relevant Higgs
mass range, while for HZ production, we find corrections between about 1% and
2%. At the LHC, the contribution of the newly evaluated terms to the cross
section is typically of the order of 1%-3%. Based on these results, we provide
updated predictions for the total inclusive Higgs-Strahlung cross section at
the Tevatron and the LHC.Comment: 21 pages, 9 figures, 3 table
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