0000000000138649
AUTHOR
John N. Bahcall
showing 15 related works from this author
Robust signatures of solar neutrino oscillation solutions
2001
With the goal of identifying signatures that select specific neutrino oscillation parameters, we test the robustness of global oscillation solutions that fit all the available solar and reactor experimental data. We use three global analysis strategies previously applied by different authors and also determine the sensitivity of the oscillation solutions to the critical nuclear fusion cross section, S_{17}(0), for the production of 8B. The favored solutions are LMA, LOW, and VAC in order of g.o.f. The neutral current to charged current ratio for SNO is predicted to be 3.5 +- 0.6 (1 sigma), which is separated from the no-oscillation value of 1.0 by much more than the expected experimental er…
If sterile neutrinos exist, how can one determine the total solar neutrino fluxes?
2002
The 8B solar neutrino flux inferred from a global analysis of solar neutrino experiments is within 11% (1 sigma) of the predicted standard solar model value if only active neutrinos exist, but could be as large as 1.7 times the standard prediction if sterile neutrinos exist. We show that the total 8B neutrino flux (active plus sterile neutrinos) can be determined experimentally to about 10% (1 sigma) by combining charged current measurements made with the KamLAND reactor experiment and with the SNO CC solar neutrino experiment, provided the LMA neutrino oscillation solution is correct and the simulated performance of KamLAND is valid. Including also SNO NC data, the sterile component of the…
NEUTRINO ASTRONOMY AND COSMIC RAYS AT THE SOUTH POLE: LATEST RESULTS FROM AMANDA AND PERSPECTIVES FOR ICECUBE
2005
The AMANDA neutrino telescope has been in operation at the South Pole since 1996. The present final array configuration, operational since 2000, consists of 677 photomultiplier tubes arranged in 19 strings, buried at depths between 1500 and 2000 m in the ice. The most recent results on a multi-year search for point sources of neutrinos will be shown. The study of events triggered in coincidence with the surface array SPASE and AMANDA provided a result on cosmic ray composition. Expected improvements from IceCube/IceTop will also be discussed.
Sensitivity of the IceCube detector to astrophysical sources of high energy muon neutrinos
2003
We present the results of a Monte-Carlo study of the sensitivity of the planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV energies. A complete simulation of the detector and data analysis is used to study the detector's capability to search for muon neutrinos from sources such as active galaxies and gamma-ray bursts. We study the effective area and the angular resolution of the detector as a function of muon energy and angle of incidence. We present detailed calculations of the sensitivity of the detector to both diffuse and pointlike neutrino emissions, including an assessment of the sensitivity to neutrinos detected in coincidence with gamma-ray burst observatio…
IceCube contributions to the XIV International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2006)
2008
IceCube contributions to the XIV International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2006) Weihai, China - August 15-22
A road map to solar neutrino fluxes, neutrino oscillation parameters, and tests for new physics
2003
We analyze all available solar and related reactor neutrino experiments, as well as simulated future 7Be, p-p, pep, and ^8B solar neutrino experiments. We treat all solar neutrino fluxes as free parameters subject to the condition that the total luminosity represented by the neutrinos equals the observed solar luminosity (the `luminosity constraint'). Existing experiments show that the p-p solar neutrino flux is 1.02 +- 0.02 (1 sigma) times the flux predicted by the BP00 standard solar model; the 7Be neutrino flux is 0.93^{+0.25}_{-0.63} the predicted flux; and the ^8B flux is 1.01 +- 0.04 the predicted flux. The neutrino oscillation parameters are: Delta m^2 = 7.3^{+0.4}_{-0.6}\times 10^{-…
Does the Sun Shine byppor CNO Fusion Reactions?
2002
We show that solar neutrino experiments set an upper limit of 7.8% (7.3% including the recent KamLAND measurements) to the fraction of energy that the Sun produces via the CNO fusion cycle, which is an order of magnitude improvement upon the previous limit. New experiments are required to detect CNO neutrinos corresponding to the 1.5% of the solar luminosity that the standard solar model predicts is generated by the CNO cycle.
Solar models and solar neutrino oscillations
2004
We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.
Global Analysis of Solar Neutrino Oscillations Including SNO CC Measurement
2001
For active and sterile neutrinos, we present the globally allowed solutions for two neutrino oscillations. We include the SNO CC measurement and all other relevant solar neutrino and reactor data. Five active neutrino oscillation solutions (LMA, LOW, SMA, VAC, and Just So2) are currently allowed at 3 sigma; three sterile neutrino solutions (Just So2, SMA, and VAC) are allowed at 3 sigma. The goodness of fit is satisfactory for all eight solutions. We also investigate the robustness of the allowed solutions by carrying out global analyses with and without: 1) imposing solar model constraints on the 8B neutrino flux, 2) including the Super-Kamiokande spectral energy distribution and day-night…
Solar Neutrinos Before and After Neutrino 2004
2004
We compare, using a three neutrino analysis, the allowed neutrino oscillation parameters and solar neutrino fluxes determined by the experimental data available Before and After Neutrino 2004. New data available after Neutrino2004 include refined KamLAND and gallium measurements. We use six different approaches to analyzing the KamLAND data. We present detailed results using all the available neutrino and anti-neutrino data for Delta m^2_{12}, tan^2 theta_{12}, sin^2 theta_{13}, and sin^2 eta (sterile fraction). Using the same complete data sets, we also present Before and After determinations of all the solar neutrino fluxes, which are treated as free parameters, an upper limit to the lumi…
Solar Neutrinos Before and After KamLAND
2002
We use the recently reported KamLAND measurements on oscillations of reactor anti-neutrinos, together with the data of previously reported solar neutrino experiments, to show that: (1) the total 8B neutrino flux emitted by the Sun is 1.00(1.0 \pm 0.06) of the standard solar model (BP00) predicted flux, (2) the KamLAND measurements reduce the area of the globally allowed oscillation regions that must be explored in model fitting by six orders of magnitude in the Delta m^2-tan^2 theta plane, (3) LMA is now the unique oscillation solution to a CL of 4.7sigma, (4) maximal mixing is disfavored at 3.1 sigma, (5) active-sterile admixtures are constrained to sin^2 eta<0.13 at 1 sigma, (6) the ob…
Five years of searches for point sources of astrophysical neutrinos with the AMANDA-II neutrino telescope
2007
We report the results of a five-year survey of the northern sky to search for point sources of high energy neutrinos. The search was performed on the data collected with the AMANDA-II neutrino telescope in the years 2000 to 2004, with a live-time of 1001 days. The sample of selected events consists of 4282 upward going muon tracks with high reconstruction quality and an energy larger than about 100 GeV. We found no indication of point sources of neutrinos and set 90% confidence level flux upper limits for an all-sky search and also for a catalog of 32 selected sources. For the all-sky search, our average (over declination and right ascension) experimentally observed upper limit \Phi^{0}=(E/…
What can we learn from neutrinoless double beta decay experiments?
2004
We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but ne…
Status of the IceCube Neutrino Observatory
2004
Abstract The IceCube neutrino telescope, to be constructed near the Antarctic South Pole, represents the next generation of neutrino telescope. Its large 1 km3 size will make it uniquely sensitive to the detection of neutrinos from astrophysical sources. The current design of the detector is presented. The basic performance of the detector and its ability to search for neutrinos from various astrophysical sources has been studied using detailed simulations and is discussed.
Before and after: how has the SNO neutral current measurement changed things?
2002
We present Before and After global oscillation solutions, as well as predicted Before and After values and ranges for ten future solar neutrino observables (for BOREXINO, KamLAND, SNO, and a generic p-p neutrino detector). The 'Before' case includes all solar neutrino data (and some theoretical improvements) available prior to April 20, 2002 and the After case includes, in addition, the new SNO data on the CC, NC, and day-night asymmetry. We have performed global analyses using the full SNO day-night energy spectrum and, alternatively, using just the SNO NC and CC rates and the day-night asymmetry. The LMA solution is the only currently allowed MSW oscillation solution at similar to99% CL. …