Showing papers on "CHOOZ published in 2005"
TL;DR: It is found that the survival probability of solar MaVaNs is independent of how the suppression of neutrino mass caused by the acceleron-matter couplings varies with density.
Abstract: We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data and with reactor antineutrino data at short and long baselines (from CHOOZ and KamLAND). We find that the survival probability of solar MaVaNs is independent of how the suppression of neutrino mass caused by the acceleron-matter couplings varies with density. Measurements of MeV and lower energy solar neutrinos will provide a rigorous test of the idea.
90 citations
TL;DR: The Angra Project as discussed by the authors is a neutrino oscillation experiment proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex, which is aimed to measure theta_13, the last unknown of the three neutrinos mixing angles.
Abstract: We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex. This experiment is aimed to measure theta_13, the last unknown of the three neutrino mixing angles. Combining a high luminosity design, very low background from cosmic rays and careful control of systematic errors at the 1% level, we propose a high sensitivity multi-detector experiment, able to reach a sensitivity to antineutrino disappearance down to sin^2(2*theta_13) = 0.006 in a three years running period, improving present limits constrained by the CHOOZ experiment by more than an order of magnitude.
28 citations
01 Apr 2005
TL;DR: In this paper, the authors review different coordinate choices on the 21-dimensional parameter space of the seesaw and which of these 21 quantities are observable, and speculate on possible resolutions of the puzzle.
Abstract: This proceedings contains a review, followed by a more speculative discussion. I review different coordinate choices on the 21-dimensional parameter space of the seesaw, and which of these 21 quantities are observable. In MSUGRA, there is a 1-1 correspondance between the parameters, and the interactions of light (s)particles. However, not all of the 21 can be extracted from data, so the answer to the title question is “no”. How to parametrise the remaining unknowns is confusingdifferent choices seem to give contradictory results (for instance, to the question “does the Baryon Asymmetry depend on the CHOOZ angle?”). I speculate on possible resolutions of the puzzle.
8 citations
TL;DR: In this paper, the authors consider the Cabibboob effects in lepton mixings (MNS) and discuss possible Wolfenstein parametrizations of the MNS matrix, assuming various types of "Cabibboop Flops".
Abstract: The wealth of new data on neutrinos is easily incorporated in the Electroweak Theory. In this "ν-Standard Model", lepton mixings are distinguished from quark mixings by a unitary matrix coming from the Seesaw. We catalog models in terms of the number of large angles (one or two) in that matrix. Pati-Salam unification implies Cabibbo effects in lepton mixings (MNS). Without such small mixings, the Solar and Atmospheric angles may well be the same, and the CHOOZ angle could vanish: in a wide class of flavor-symmetric models, it is of (λ/√2). We discuss a new approximate chiral family symmetry that preserves Froggat-Nielsen, and relates the 5-bar of the second and third families, but not the particles in the 10's. If exact, the electron and down quark are both massless and the atmospheric angle is maximal. We conclude by discussing possible Wolfenstein parametrizations of the MNS matrix, assuming various types of "Cabibbo Flops".
4 citations
01 Jun 2005
TL;DR: In this article, the prospectives of future nuclear experiments in this field are shown and the main idea is to use two detectors at the same time, with a close one which is monitoring the reactor neutrino flux and spectrum.
Abstract: The actual best limits on the missing mixing angle θ 13 are coming from the reactor experiment at Chooz, France. In this paper the prospectives of future reactor experiments in this field are shown. The main idea is to use two detectors at the same time, with a close one which is monitoring the reactor neutrino flux and spectrum. Hence, most of the systematic errors cancel and the sensitivity on θ 13 may be enhanced significantly.
3 citations
01 Aug 2005
TL;DR: The Double-Chooz experiment as mentioned in this paper is the state-of-the-art neutrino detector with two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores.
Abstract: The Double-Chooz experiment goal is to search for a non-vanishing value of the θ 13 neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin 2 ( 2 θ 13 ) Δ m atm 2 = 2.0 – 2.4 10 −3 eV 2 ). Double-Chooz will explore the range of sin 2 ( 2 θ 13 ) from 0.2 to 0.03–0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a “state of the art” prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sin 2 ( 2 θ 13 ) sensitivity of 0.05 in 2009, and 0.03–0.02 in 2011.
3 citations
01 Aug 2005
TL;DR: In this paper, the current plans for Angra, Braidwood, Daya Bay, KASKA, and KR2DET are reviewed and a case is made that, together with Double-CHOOZ, a future world program should include at least three such experiments.
Abstract: Several new reactor neutrino experiments are being considered to measure the parameter θ 13 . The current plans for Angra, Braidwood, Daya Bay, KASKA and KR2DET are reviewed. A case is made that, together with Double-CHOOZ, a future world program should include at least three such experiments.
2 citations
TL;DR: In this article, the authors demonstrate that ''Bimaximal + Democratic'' type neutrino mass matrix can accommodate the deviation of the maximal value of the quark-lepton complementarity from its maximal value.
Abstract: We demonstrate that `Bimaximal + Democratic' type neutrino mass matrix can accommodate the deviation of $\theta_\odot$ from its maximal value which referred in the literature as `quark-lepton complementarity' along with the other present day neutrino experimental results, namely, atmospheric, CHOOZ, neutrinoless double beta decay ($\beta\beta_{0
u}$) and result obtained from WMAP experiment. We define a function $\chi_p$ in terms of solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle (obtained from different experiments and our proposed texture). The masses and mixing angles are expressed in terms of three parameters in our proposed texture. The allowed region of the texture parameters is obtained through minimization of the above function. The proposed texture crucially depends on the value of the experimental results of $\beta\beta_{0
u}$ experiment among all other above mentioned experiments. If, in future, $\beta\beta_{0
u}$ experiments, namely, MOON, EXO, GENIUS shift the lower bound on $ $ at the higher side by one order, the present texture will be ruled out.
2 citations
KEK1
TL;DR: Yuichi et al. as discussed by the authors reported the results from the K2K experiment and status of the T2k experiment, which is the first long-baseline neutrino oscillation experiment with a distance of several hundred kilometers and using an accelerator-based Neutrino beam.
Abstract: Results from the K2K experiment and status of the T2K experiment are reported. 1. Results from the K2K experiment The K2K experiment[1] is the first long-baseline neutrino oscillation experimentwith a distance of hundred kilometers andusing an acceleratorbased neutrino beam. It started in 1999 and ended in November, 2004. The main purpose of K2K is to confirm muon neutrino oscillation claimed by the Super-Kamiokande experiment[2] using an artificial neutrino beam. Because the details of the experiment are already described in other articles[1, 3], only updated numbers and figures are presented in Table 1. Some comments that were not covered in my previous articles[3] are itemized below: − After the accident of Super-Kamiokande in November, 2001, the total number of PMTs in Super-Kamiokande was reduced to be about one half. The K2K experiment of this period was named K2K-II. In this period, the lead-glass counters of the front detector were replaced by a SciBar detector[1], a fully active fine-grained detector made of 14848 strips of extruded scintillator read out by wavelength-shifting fibers. There is no essential change in the oscillation analysis. − A possible νe appearance signal from νe ↔ νμ oscillation was also searched[4]. From tight e-like event selection, only one candidate remains, where the expected background is 1.63. The expected signal is 1 ∼ 2 events if the parameter region around the CHOOZ limit[5] is assumed. The 90% C.L. upper limit on sin 2θeμ (=12 sin 2 2θ13) is 0.18 for ∆m2 = 2.8× 10−3eV2. This limit has no impact on our present knowledge on the oscillation parameters because of the poor statistics (see Section 3.1). ‡ E-mail address: yuichi.oyama@kek.jp; URL: http://www-nu.kek.jp/ oyama ∗ Talk at International Conference on New Trends in High-Energy Physics (Crimea2005), Yalta, Ukraine, September 10-17, 2005
1 citations
TL;DR: In this paper, the current plans for Angra, Braidwood, Daya Bay, KASKA, and KR2DET are reviewed and a case is made that, together with Double-CHOOZ, a future world program should include at least three such experiments.
Abstract: Several new reactor neutrino experiments are being considered to measure the parameter theta-13. The current plans for Angra, Braidwood, Daya Bay, KASKA and KR2DET are reviewed. A case is made that, together with Double-CHOOZ, a future world program should include at least three such experiments.
1 citations
DSM1
TL;DR: The Double-Chooz experiment as discussed by the authors is the state-of-the-art neutrino detector, which has two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores.
Abstract: The Double-Chooz experiment goal is to search for a non-vanishing value of the θ13 neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin 2 ( 2 θ 13 ) 0.2 (90% C.L., Δ m atm 2 = 2.0 eV 2 ). Double-Chooz will explore the range of sin 2 ( 2 θ 13 ) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a “state of the art” prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sensitivity sin 2 ( 2 θ 13 ) of 0.05 in 2009, and 0.03-0.02 in 2011.
DSM1
TL;DR: The current best constraint on the third mixing angle comes from the Chooz reactor neutrino experiment sin 2 ( 2 θ 13 ) 0.2 (90 % C.L., Δ m atm 2 = 2.0 10 −3 ǫV 2 ) as discussed by the authors.
Abstract: It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the θ 13 mixing angle, free from any parameter degeneracies and correlations induced by matter effect and the unknown leptonic Dirac CP phase. The current best constraint on the third mixing angle comes from the Chooz reactor neutrino experiment sin 2 ( 2 θ 13 ) 0.2 (90 % C.L., Δ m atm 2 = 2.0 10 −3 eV 2 ). Several projects of experiment, with different timescales, have been proposed over the last two years all around the world. Their sensitivities range from sin 2 ( 2 θ 13 ) 0.01 to 0.03, having thus an excellent discovery potential of the ν e fraction of ν 3 .
01 Jun 2005
Posted Content•
TL;DR: In this paper, a non-zero Ue3 close to the CHOOZ bound was shown to change the geo-neutrino flux by 12% in Kamland with a exposure of $3 \times 10^{32} proton years.
Abstract: We show that a non-zero Ue3 close to the CHOOZ bound ($Sin^2 2 \theta_{13} \simeq 0.16$ 90% CL) can change the geo-neutrino flux by 12%. Geo-neutrino detection in Kamland with a exposure of $3 \times 10^{32} proton-years$ is sensitive to $Sin^2 2 \theta_{13}$ to the level of $0.2 (1 \sigma)$. For the same exposure a detector close to Himalayas can probe $Sin^2 2 \theta_{13}$ down to $0.15 (1 \sigma)$ due to higher geo-neutrino flux from the Tibetan plate.