338 research outputs found
Prompt neutrinos and intrinsic charm at SHiP
We present a new evaluation of the far-forward neutrino plus antineutrino
flux and number of events from charm hadron decays in a 400 GeV proton beam
dump experiment like the Search for Hidden Particles (SHiP). Using
next-to-leading order perturbative QCD and a model for intrinsic charm, we
include intrinsic transverse momentum effects and other kinematic angular
corrections. We compare this flux to a far-forward flux evaluated with
next-to-leading order perturbative QCD, without intrinsic transverse momentum,
that used the angular distribution of charm quarks rather than the neutrinos
from their decays. The tau neutrino plus antineutrino number of events in the
perturbative QCD evaluation is reduced by a factor of about three when
intrinsic transverse momentum and the full decay kinematics are included. We
show that intrinsic charm contributions can significantly enhance the number of
events from neutrinos from charm hadron decays. Measurements of the number of
events from tau neutrino plus antineutrino interactions and of the muon charge
asymmetry as a function of energy can be used to constrain intrinsic charm
models.Comment: 39 pages, 18 figures; v2 with revisions of text for clarity, version
to be published in JHE
Soft error in FPGA-implemented asynchronous circuits
In this paper, we investigate the mechanism of soft error generation and propagation in asynchronous circuits which are implemented on FPGAs. The effects of the soft errors on Quasi-delay-insensitive (QDI) asynchronous circuits are analyzed. The results show that it is much easier to detect the soft error in asynchronous circuits implemented on FPGAs so that FPGAs can be reprogrammed, compared with traditional synchronous circuits
Forward production of prompt neutrinos from charm in the atmosphere and at high energy colliders
The high-energy atmospheric neutrino flux is dominated by neutrinos from the
decays of charmed hadrons produced in the forward direction by cosmic ray
interactions with air nuclei. We evaluate the charm contributions to the prompt
atmospheric neutrino flux as a function of the center-of-mass energy
of the hadronic collision and of the center-of-mass rapidity of the
produced charm hadron. Uncertainties associated with parton distribution
functions are also evaluated as a function of . We find that the
coverage of LHCb for forward heavy-flavour production, complemented by the
angular coverage of present and future forward neutrino experiments at the LHC,
bracket the most interesting regions for the prompt atmospheric neutrino
flux. At TeV foreseen for the HL-LHC phase, nucleon collisions in
air contribute to the prompt neutrino flux prominently below ~GeV. Measurements of forward charm and/or forward neutrinos produced in
hadron collisions up to TeV, which might become possible at the
FCC, are relevant for the prompt atmospheric neutrino flux up to
GeV and beyond.Comment: 29 pages, 11 figure
1-(2,3,4,6-Tetra-O-acetyl-β-d-glucoÂpyranosÂyl)-3-thioÂureidothioÂurea monohydrate
In the title compound, C16H24N4O9S2·H2O, the hexopyranosyl ring adopts a chair conformation (4
C
1), and the five substituents are in equatorial positions. In the crystal structure, extensive O—H⋯O, N—H⋯S and N—H⋯O hydrogen bonding leads to the formation of a three-dimensional network
Obstacle Avoidance of Semi-Trailers Based on Nonlinear Model Predictive Control
Obstacle avoidance is a core part of the autonomous driving of off-road vehicles, such as semi-trailers. Due to the long length of semi-trailers, the traditional obstacle avoidance controller based on the circumcircle model can ensure that there is no collision between the semi-trailer and the obstacle, but it also greatly reduces the passable area. To solve this problem, we propose a new obstacle avoidance model. In this model, the distance between the obstacle and the middle line of semi-trailers is used as the indicator of obstacle avoidance. Based on this model, we design a new obstacle avoidance controller for semi-trailers. The simulation results show that the proposed controller can ensure that no collision occurs between the semi-trailer and the obstacle. The minimum distance between the obstacle center and the semi-trailer body trajectory is greater than the sum of the obstacle radius and the safety margin. Compared with the traditional obstacle avoidance controller based on the circumcircle model, the proposed controller greatly reduces the error between the semi-trailer and the reference path during obstacle avoidance.
Document type: Articl
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