1,059 research outputs found
Alien Registration- Haines, George W. (Mars Hill, Aroostook County)
https://digitalmaine.com/alien_docs/33914/thumbnail.jp
Nuclear Physics Neutrino PreTown Meeting: Summary and Recommendations
In preparation for the nuclear physics Long Range Plan exercise, a group of
104 neutrino physicists met in Seattle September 21-23 to discuss both the
present state of the field and the new opportunities of the next decade. This
report summarizes the conclusions of that meeting and presents its
recommendations. Further information is available at the workshop's web site.
This report will be further reviewed at the upcoming Oakland Town Meeting.Comment: Latex, 31 pages. This version has been updated to include final
Comments from the working group
Observation of the east-west anisotropy of the atmospheric neutrino flux
The east-west anisotropy, caused by the deflection of primary cosmic rays in
the Earth's magnetic field, is observed for the first time in the flux of
atmospheric neutrinos. Using a 45 kt-year exposure of the
Super-Kamiokande detector, 552 e-like and 633 mu-like horizontally-going
events are selected in the momentum range between 400 and 3000 MeV/c.
The azimuthal distribution of e-like and mu-like events agrees with the
expectation from atmospheric neutrino flux calculations that account for the
geomagnetic field, verifying that the geomagnetic field effects in the
production of atmospheric neutrinos in the GeV energy range are well
understood.Comment: 8 pages,3 figures revtex, submitted to PR
Measurement of the flux and zenith-angle distribution of upward through-going muons by Super-Kamiokande
A total of 614 upward through-going muons of minimum energy 1.6 GeV are
observed by Super-Kamiokande during 537 detector live days. The measured muon
flux is 1.74+/-0.07(stat.)+/-0.02(sys.)x10^{-13}cm^{-2}s^{-1}sr^{-1} compared
to an expected flux of 1.97+/-0.44(theo.)x10^{-13}cm^{-2}s^{-1}sr^{-1}. The
absolute measured flux is in agreement with the prediction within the errors.
However, the zenith angle dependence of the observed upward through-going muon
flux does not agree with no-oscillation predictions. The observed distortion in
shape is consistent with the \nu_\mu \nu_\tau oscillation hypothesis with
\sin^22\theta > 0.4 and 1x10^{-3} < \Delta m^2 < 1x10^{-1} eV^{2} at 90%
confidence level.Comment: 8 pages w/ 3 figures new version contains minor fixes, as it appears
in PR
Constraints on neutrino oscillation parameters from the measurement of day-night solar neutrino fluxes at Super-Kamiokande
A search for day-night variations in the solar neutrino flux resulting from
neutrino oscillations has been carried out using the 504 day sample of solar
neutrino data obtained at Super-Kamiokande. The absence of a significant
day-night variation has set an absolute flux independent exclusion region in
the two neutrino oscillation parameter space.Comment: 11 pages, 3 figures, submitted to PRL, single-spacin
Evidence for oscillation of atmospheric neutrinos
We present an analysis of atmospheric neutrino data from a 33.0 kiloton-year
(535-day) exposure of the Super-Kamiokande detector. The data exhibit a zenith
angle dependent deficit of muon neutrinos which is inconsistent with
expectations based on calculations of the atmospheric neutrino flux.
Experimental biases and uncertainties in the prediction of neutrino fluxes and
cross sections are unable to explain our observation. The data are consistent,
however, with two-flavor nu_mu nu_tau oscillations with sin^2(2theta)>0.82
and 5x10^-4 < delta m^2 < 6x10^-3 eV^2 at 90% confidence level.Comment: 9 pages (two-column) with 4 figures. Small corrections to Eqn.4 and
Fig.3. Final version to appear in PR
Detailed SZ study of 19 LoCuSS galaxy clusters: masses and temperatures out to the virial radius
We present 16-GHz AMI SZ observations of 19 clusters with L_X >7x10^37 W
(h50=1) selected from the LoCuS survey (0.142<z<0.295) and of A1758b, in the
FoV of A1758a. We detect 17 clusters with 5-23sigma peak surface brightnesses.
Cluster parameters are obtained using a Bayesian cluster analysis. We fit
isothermal beta-models to our data and assume the clusters are virialized (with
all the kinetic energy in gas internal energy). Our gas temperature, T_AMI, is
derived from AMI SZ data, not from X-ray spectroscopy. Cluster parameters
internal to r500 are derived assuming HSE. We find: (i) Different gNFW
parameterizations yield significantly different parameter degeneracies. (ii)
For h70 = 1, we find the virial radius r200 to be typically 1.6+/-0.1 Mpc and
the total mass M_T(r200) typically to be 2.0-2.5xM_T(r500).(iii) Where we have
found M_T X-ray (X) and weak-lensing (WL) values in the literature, there is
good agreement between WL and AMI estimates (with M_{T,AMI}/M_{T,WL}
=1.2^{+0.2}_{-0.3} and =1.0+/-0.1 for r500 and r200, respectively). In
comparison, most Suzaku/Chandra estimates are higher than for AMI (with
M_{T,X}/M_{T,AMI}=1.7+/-0.2 within r500), particularly for the stronger
mergers.(iv) Comparison of T_AMI to T_X sheds light on high X-ray masses: even
at large r, T_X can substantially exceed T_AMI in mergers. The use of these
higher T_X values will give higher X-ray masses. We stress that large-r T_SZ
and T_X data are scarce and must be increased. (v) Despite the paucity of data,
there is an indication of a relation between merger activity and SZ
ellipticity. (vi) At small radius (but away from any cooling flow) the SZ
signal (and T_AMI) is less sensitive to ICM disturbance than the X-ray signal
(and T_X) and, even at high r, mergers affect n^2-weighted X-ray data more than
n-weighted SZ, implying significant shocking or clumping or both occur even in
the outer parts of mergers.Comment: 45 pages, 33 figures, 13 tables Accepted for publication in MNRA
Measurement of a small atmospheric ratio
From an exposure of 25.5~kiloton-years of the Super-Kamiokande detector, 900
muon-like and 983 electron-like single-ring atmospheric neutrino interactions
were detected with momentum MeV/, MeV/, and
with visible energy less than 1.33 GeV. Using a detailed Monte Carlo
simulation, the ratio was measured to be , consistent with previous results from the
Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from
theoretical models of atmospheric neutrino production.Comment: 14 pages with 5 figure
Calibration of Super-Kamiokande Using an Electron Linac
In order to calibrate the Super-Kamiokande experiment for solar neutrino
measurements, a linear accelerator (LINAC) for electrons was installed at the
detector. LINAC data were taken at various positions in the detector volume,
tracking the detector response in the variables relevant to solar neutrino
analysis. In particular, the absolute energy scale is now known with less than
1 percent uncertainty.Comment: 24 pages, 16 figures, Submitted to NIM
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