1,300 research outputs found
Neutrino-nucleon cross sections at energies of Megaton-scale detectors
An updated set of (anti)neutrino-nucleon charged and neutral current cross
sections at is presented.
These cross sections are of particular interest for the detector optimization
and data processing and interpretation in the future Megaton-scale experiments
like PINGU, ORCA, and Hyper-Kamiokande. Finite masses of charged leptons and
target mass corrections in exclusive and deep inelastic
interactions are taken into account. A new set of QCD NNLO parton density
functions, the ABMP15, is used for calculation of the DIS cross sections. The
sensitivity of the cross sections to phenomenological parameters and to
extrapolations of the nucleon structure functions to small and is
studied. An agreement within the uncertainties of our calculations with
experimental data is demonstrated.Comment: 4 pages, 4 figures, accepted for the VLVnT-2015 Conference
proceedings, will be published on EPJ Web of Conference
From Discrete-Time Models to Continuous-Time, Asynchronous Models of Financial Markets
Most agent-based simulation models of financial markets are discrete-time in nature. In this paper, we investigate to what degree such models are extensible to continuous-time, asynchronous modelling of financial markets. We study the behaviour of a learning market maker in a market with information asymmetry, and investigate the difference caused in the market dynamics between the discrete-time simulation and continuous-time, asynchronous simulation. We show that the characteristics of the market prices are different in the two cases, and observe that additional information is being revealed in the continuous-time, asynchronous models, which can be acted upon by the agents in such models. Si
Neutrino Astrophysics in the cold: Amanda, Baikal and IceCube
This talk review status and results from the two presently operating
underwater/ice neutrino telescopes, NT-200 in Lake Baikal and Amanda-II at the
South Pole. It also gives a description of the design and the expected
performance of Icecube, the next-generation neutrino telescope at South Pole.Comment: Talk given at the Nobel Symposium on Neutrino Physics, Haga Slott,
Sweden, 2004, 14 pages, 10 figure
The Indirect Search for Dark Matter with IceCube
We revisit the prospects for IceCube and similar kilometer-scale telescopes
to detect neutrinos produced by the annihilation of weakly interacting massive
dark matter particles (WIMPs) in the Sun. We emphasize that the astrophysics of
the problem is understood; models can be observed or, alternatively, ruled out.
In searching for a WIMP with spin-independent interactions with ordinary
matter, IceCube is only competitive with direct detection experiments if the
WIMP mass is sufficiently large. For spin-dependent interactions IceCube
already has improved the best limits on spin-dependent WIMP cross sections by
two orders of magnitude. This is largely due to the fact that models with
significant spin-dependent couplings to protons are the least constrained and,
at the same time, the most promising because of the efficient capture of WIMPs
in the Sun. We identify models where dark matter particles are beyond the reach
of any planned direct detection experiments while being within reach of
neutrino telescopes. In summary, we find that, even when contemplating recent
direct detection results, neutrino telescopes have the opportunity to play an
important as well as complementary role in the search for particle dark matter.Comment: 17 pages, 10 figures, published in the New Journal of Physics 11
105019 http://www.iop.org/EJ/abstract/1367-2630/11/10/105019, new version
submitted to correct Abstract in origina
Sex differences in risk factor management of coronary heart disease across three regions
Objective To investigate whether there are sex differences in risk factor management of patients with established coronary heart disease (CHD), and to assess demographic variations of any potential sex differences. Methods Patients with CHD were recruited from Europe, Asia, and the Middle East between 2012-2013. Adherence to guideline-recommended treatment and lifestyle targets was assessed and summarised as a Cardiovascular Health Index Score (CHIS). Age-adjusted regression models were used to estimate odds ratios for women versus men in risk factor management. Results 10 112 patients (29% women) were included. Compared with men, women were less likely to achieve targets for total cholesterol (OR 0.50, 95% CI 0.43 to 0.59), low-density lipoprotein cholesterol (OR 0.57, 95% CI 0.51 to 0.64), and glucose (OR 0.78, 95% CI 0.70 to 0.87), or to be physically active (OR 0.74, 95% CI 0.68 to 0.81) or non-obese (OR 0.82, 95% CI 0.74 to 0.90). In contrast, women had better control of blood pressure (OR 1.31, 95% CI 1.20 to 1.44) and were more likely to be a non-smoker (OR 1.93, 95% CI 1.67 to 2.22) than men. Overall, women were less likely than men to achieve all treatment targets (OR 0.75, 95% CI 0.60 to 0.93) or obtain an adequate CHIS (OR 0.81, 95% CI 0.73 to 0.91), but no significant differences were found for all lifestyle targets (OR 0.93, 95% CI 0.84 to 1.02). Sex disparities in reaching treatment targets were smaller in Europe than in Asia and the Middle East. Women in Asia were more likely than men to reach lifestyle targets, with opposing results in Europe and the Middle East. Conclusions Risk factor management for the secondary prevention of CHD was generally worse in women than in men. The magnitude and direction of the sex differences varied by region
Endovascular baroreflex amplification and the effect on sympathetic nerve activity in patients with resistant hypertension: A proof-of-principle study
Background: First in human studies suggest that endovascular baroreflex amplification (EVBA) lowers blood pressure (BP). To explore potential mechanisms for BP reduction, this study examines the effects of EVBA on muscle sympathetic nerve activity (MSNA) and baroreceptor sensitivity (BRS). // Methods: In a single-center sub-study of the CALM-DIEM study (Controlling And Lowering blood pressure with the MobiusHD—Defining Efficacy Markers), 14 patients with resistant hypertension were treated with EVBA. Microneurography and non-invasive continuous BP measurements were performed at baseline and three months after MobiusHD implantation. The primary outcome was change in MSNA. Secondary outcomes were change in baroreflex sensitivity (BRS), cardiovascular responses to a sympathetic stimulus, BP, heart rate (HR) and heart rate variability (HRV). // Results: The primary endpoint was obtained in 10 of 14 patients enrolled in the sub-study. MSNA burst frequency and burst incidence decreased in 6 of 10 patients: mean change -4.1 bursts/min (95% confidence interval -12.2 to 4.0) and -3.8 bursts/100 heartbeats (-15.2 to 7.7). MSNA spike frequency and spike count decreased in 8 of 10 patients: mean change -2.8 spikes/sec (-7.3 to 1.8) and -3.0 spikes/heartbeat (-6.1 to 0.1). Change in MSNA and BP were not correlated. Office BP decreased by -14/-6 mmHg (-27 to -2/-15 to 3). We observed a trend towards decreased HR (-5 bpm, -10 to 1) and increased total power HRV (623 msec2, 78 to 1168). In contrast, BRS and cardiovascular responses remained unchanged after EVBA. // Conclusions: In this proof-of-principle study, EVBA did not significantly decrease MSNA in patients with resistant hypertension. EVBA did not impair baroreflex function
Dilute ferrimagnetic semiconductors in Fe-substituted spinel ZnGaO
Solid solutions of nominal composition
[ZnGaO][FeO], of the semiconducting spinel
ZnGaO with the ferrimagnetic spinel FeO have been prepared with
= 0.05, 0.10, and 0.15. All samples show evidence for long-range magnetic
ordering with ferromagnetic hysteresis at low temperatures. Magnetization as a
function of field for the = 0.15 sample is S-shaped at temperatures as high
as 200 K. M\"ossbauer spectroscopy on the = 0.15 sample confirms the
presence of Fe, and spontaneous magnetization at 4.2 K. The magnetic
behavior is obtained without greatly affecting the semiconducting properties of
the host; diffuse reflectance optical spectroscopy indicates that Fe
substitution up to = 0.15 does not affect the position of the band edge
absorption. These promising results motivate the possibility of dilute
ferrimagnetic semiconductors which do not require carrier mediation of the
magnetic moment.Comment: 9 pages and 6 figure
On High-Energy Behavior of Cross Sections in Theories with Large Extra Dimensions
We discuss the high-energy behavior of cross sections in theories with large
extra dimensions and low-scale quantum gravity, addressing two particular
issues: (i) the tension of the D-branes, and (ii) bounds on the cross section
and their relation to approximations in the mode sum over Kaluza-Klein-graviton
exchanges.Comment: 6 pages, late
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