1,705 research outputs found
Study of a Long Baseline nu_tau Appearance Neutrino Oscillation Experiment in the Quasi-Elastic Regime
We present a study for a design of a long baseline nu_mu to nu_tau appearance
experiment to probe the high sin^2(2theta) and low Delta m^2 region relevant to
explain the atmospheric neutrino anomaly. The experiment relies on a good
identification of quasi-elastic interactions, which is a clean topology that
has an important contribution in the lowest Delta m^2 part of the region
probed. The detector we studied is a fine grained liquid scintillator detector
of 15 kilotons, optimized to detect electrons from tau -> e bar(nu_e) nu_tau
decays, while rejecting backgrounds from pi^0 in nu_mu interactions and
electrons from the nu_e beam contamination. As a reference, the proposed nu_mu
neutrino beam from CERN to Gran Sasso was used.Comment: 17 page
Een kunstwerk onder de Nieuwe Maas
The tunnel below the river the Nieuwe Maas not only is a civil-technical achievement. Connecting both banks of the Maas the tunnel is an element to improve the coherence in Rotterdam's urban conglomerate of centre, harbours and housing areas. As Holland's first tunnel below water-level (1937-'42) this tunnel moreover has to be seen as a technical object of prestige.
To improve contact between the town- and harbour developments on the left bank with the mother town on the right side ir. L. W. H. van Dijk , director of Municipal Works in 1929 proposed to lay out a tunnel in the line Park-Charlois. Joining the network of thoroughfares this tracé would ameliorate interlocal connection to the south as well. This solution at first being furnished in 1854 the idea of a tunnel had continually been rejected because of doubts on technical realizableness.
The tunnel also was subject of discussion among municipality and the State Department of Buildings and Roads, which had planned a bridge to the east of the town at Stormpolder. In 1933 the Department however accepted the Burgomaster and Aldermen's proposal to lay out a junction in the line Park-Charlois serving urban and interlocal traffic, the bridge at Stormpolder being mainly of regional importance.
Still in 1935 Minister dr. H.Colijn demanded the institution of a committee to explore the design, costs and usefulness of both plans which had to be worked out in detail. After many sessions of the town council and requests to the Government with respect to financing in 1937 the State finally agreed with the tunnel-plan which had been extended with space to traffic by pedestrians and cyclists.
Knowledge had to be acquired before one could start building. Representatives of Municipal Works undertook study tours to the United States, Great Britain and Germany. Because of the condition of the soil, the sink-method of sinking concrete tubes next to one another into a firm dry-dock proved to be the most suitable. The Municipal Technical Service advised the construction of a four-laned tunnel with bugger-squares to separate in- and out-coming traffic. In many ways, the first car-tunnel, the Holland-tunnel in New York, served as an example.
The Maas-tunnel consists of three parts: one river-part and two instalments on land, which parts have been connected by the foundations of the ventilation-buildings on caissons. Next to these buildings an entrance building destined for pedestrians and cyclists and a garage are built on each side of the river. The traverse of the Maas-tunnel meets local as well as interlocal traffic.
During the period of the Rebuilding the metro project was presented (1960-'68). This metro-line also contains a tunnel below the Nieuwe Maas. Within the framework of the new network of thoroughfares surrounding Rotterdam the Beneluxtunnel (1967) has been constructed to the west of the Maas-tunnel. Local and interlocal junctions of the banks are being adapted. Nevertheless, the Maas-tunnel still is an important link in the urban network as well as an example of how to construct these sort of tunnels like this was the case at the Y-tunnel of Amsterdam
Een kunstwerk onder de Nieuwe Maas
The tunnel below the river the Nieuwe Maas not only is a civil-technical achievement. Connecting both banks of the Maas the tunnel is an element to improve the coherence in Rotterdam\u27s urban conglomerate of centre, harbours and housing areas. As Holland\u27s first tunnel below water-level (1937-\u2742) this tunnel moreover has to be seen as a technical object of prestige.
To improve contact between the town- and harbour developments on the left bank with the mother town on the right side ir. L. W. H. van Dijk , director of Municipal Works in 1929 proposed to lay out a tunnel in the line Park-Charlois. Joining the network of thoroughfares this tracé would ameliorate interlocal connection to the south as well. This solution at first being furnished in 1854 the idea of a tunnel had continually been rejected because of doubts on technical realizableness.
The tunnel also was subject of discussion among municipality and the State Department of Buildings and Roads, which had planned a bridge to the east of the town at Stormpolder. In 1933 the Department however accepted the Burgomaster and Aldermen\u27s proposal to lay out a junction in the line Park-Charlois serving urban and interlocal traffic, the bridge at Stormpolder being mainly of regional importance.
Still in 1935 Minister dr. H.Colijn demanded the institution of a committee to explore the design, costs and usefulness of both plans which had to be worked out in detail. After many sessions of the town council and requests to the Government with respect to financing in 1937 the State finally agreed with the tunnel-plan which had been extended with space to traffic by pedestrians and cyclists.
Knowledge had to be acquired before one could start building. Representatives of Municipal Works undertook study tours to the United States, Great Britain and Germany. Because of the condition of the soil, the sink-method of sinking concrete tubes next to one another into a firm dry-dock proved to be the most suitable. The Municipal Technical Service advised the construction of a four-laned tunnel with bugger-squares to separate in- and out-coming traffic. In many ways, the first car-tunnel, the Holland-tunnel in New York, served as an example.
The Maas-tunnel consists of three parts: one river-part and two instalments on land, which parts have been connected by the foundations of the ventilation-buildings on caissons. Next to these buildings an entrance building destined for pedestrians and cyclists and a garage are built on each side of the river. The traverse of the Maas-tunnel meets local as well as interlocal traffic.
During the period of the Rebuilding the metro project was presented (1960-\u2768). This metro-line also contains a tunnel below the Nieuwe Maas. Within the framework of the new network of thoroughfares surrounding Rotterdam the Beneluxtunnel (1967) has been constructed to the west of the Maas-tunnel. Local and interlocal junctions of the banks are being adapted. Nevertheless, the Maas-tunnel still is an important link in the urban network as well as an example of how to construct these sort of tunnels like this was the case at the Y-tunnel of Amsterdam
Proposal to Search for Heavy Neutral Leptons at the SPS
A new fixed-target experiment at the CERN SPS accelerator is proposed that
will use decays of charm mesons to search for Heavy Neutral Leptons (HNLs),
which are right-handed partners of the Standard Model neutrinos. The existence
of such particles is strongly motivated by theory, as they can simultaneously
explain the baryon asymmetry of the Universe, account for the pattern of
neutrino masses and oscillations and provide a Dark Matter candidate.
Cosmological constraints on the properties of HNLs now indicate that the
majority of the interesting parameter space for such particles was beyond the
reach of the previous searches at the PS191, BEBC, CHARM, CCFR and NuTeV
experiments. For HNLs with mass below 2 GeV, the proposed experiment will
improve on the sensitivity of previous searches by four orders of magnitude and
will cover a major fraction of the parameter space favoured by theoretical
models.
The experiment requires a 400 GeV proton beam from the SPS with a total of
2x10^20 protons on target, achievable within five years of data taking. The
proposed detector will reconstruct exclusive HNL decays and measure the HNL
mass. The apparatus is based on existing technologies and consists of a target,
a hadron absorber, a muon shield, a decay volume and two magnetic
spectrometers, each of which has a 0.5 Tm magnet, a calorimeter and a muon
detector. The detector has a total length of about 100 m with a 5 m diameter.
The complete experimental set-up could be accommodated in CERN's North Area.
The discovery of a HNL would have a great impact on our understanding of
nature and open a new area for future research
Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering
Neutrino-electron scatterings () are purely leptonic processes with
robust Standard Model (SM) predictions. Their measurements can therefore
provide constraints to physics beyond SM. Non-commutative (NC) field theories
modify space-time commutation relations, and allow neutrino electromagnetic
couplings at the tree level. Their contribution to neutrino-electron scattering
cross-section was derived. Constraints were placed on the NC scale parameter
from experiments with reactor and accelerator
neutrinos. The most stringent limit of at 95%
confidence level improves over the direct bounds from collider experiments.Comment: 6 pages, 2 figures, 2 tables, V2: minor revisions to match published
versio
Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets
The HARP collaboration has presented measurements of the double-differential
pi+/pi- production cross-section in the range of momentum 100 MeV/c <= p 800
MeV/c and angle 0.35 rad <= theta <= 2.15 rad with proton beams hitting thin
nuclear targets. In many applications the extrapolation to long targets is
necessary. In this paper the analysis of data taken with long (one interaction
length) solid cylindrical targets made of carbon, tantalum and lead is
presented. The data were taken with the large acceptance HARP detector in the
T9 beam line of the CERN PS. The secondary pions were produced by beams of
protons with momenta 5 GeV/c, 8 GeV/c and 12 GeV/c. The tracking and
identification of the produced particles were performed using a small-radius
cylindrical time projection chamber (TPC) placed inside a solenoidal magnet.
Incident protons were identified by an elaborate system of beam detectors.
Results are obtained for the double-differential yields per target nucleon d2
sigma / dp dtheta. The measurements are compared with predictions of the MARS
and GEANT4 Monte Carlo simulations.Comment: 43 pages, 20 figure
Measurement of Neutrino-Electron Scattering Cross-Section with a CsI(Tl) Scintillating Crystal Array at the Kuo-Sheng Nuclear Power Reactor
The elastic scattering cross-section was measured with
a CsI(Tl) scintillating crystal array having a total mass of 187kg. The
detector was exposed to an average reactor flux of
at the Kuo-Sheng Nuclear Power
Station. The experimental design, conceptual merits, detector hardware, data
analysis and background understanding of the experiment are presented. Using
29882/7369 kg-days of Reactor ON/OFF data, the Standard Model(SM) electroweak
interaction was probed at the squared 4-momentum transfer range of . The ratio of experimental to SM cross-sections
of was measured. Constraints on
the electroweak parameters were placed, corresponding to a weak
mixing angle measurement of \s2tw = 0.251 \pm 0.031({\it stat}) \pm
0.024({\it sys}) . Destructive interference in the SM \nuebar -e process was
verified. Bounds on anomalous neutrino electromagnetic properties were placed:
neutrino magnetic moment at \mu_{\nuebar}< 2.2 \times 10^{-10} \mu_{\rm B}
and the neutrino charge radius at -2.1 \times 10^{-32} ~{\rm cm^{2}} <
\nuchrad < 3.3 \times 10^{-32} ~{\rm cm^{2}}, both at 90% confidence level.Comment: 18 Figures, 7 Tables; published version as V2 with minor revision
from V
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