On the Interpretation of the Atmospheric Neutrino Data in Terms of Flavor Changing Neutrino Interactions

Flavour changing (FC) neutrino-matter interactions have been proposed as a solution to the atmospheric neutrino anomaly. Here we perform the analysis of the full set of the recent 52 kTy Super-Kamiokande atmospheric neutrino data, including the zenith angle distribution of the contained events as well as the higher energy upward-going stopping and through-going muon events. Our results show that the FC mechanism can describe the full data sample with a chi^2_{min}=44/(33 d.o.f) which is acceptable at the 90% confidence level. The combined analysis confines the amount of FC to be either close to maximal or to the level of about (10-50)%.Comment: 15 pages, 4 Postscript figures, uses ReVTeX. Updated analysis to 52 kTy Super-Kamiokande data. A new figure for the up-down asymmetry is included. Some comments and references are adde

Global three-neutrino oscillation analysis of neutrino data

A global analysis of the solar, atmospheric and reactor neutrino data is presented in terms of three-neutrino oscillations. We include the most recent solar neutrino rates of Homestake, SAGE, GALLEX and GNO, as well as the recent 1117 day Super-Kamiokande data sample, including the recoil electron energy spectrum both for day and night periods and we treat in a unified way the full parameter space for oscillations, correctly accounting for the transition from the matter enhanced (MSW) to the vacuum oscillations regime. Likewise, we include in our description conversions with $\theta_{12} > \pi/4$. For the atmospheric data we perform our analysis of the contained events and the upward-going $\nu$-induced muon fluxes, including the previous data samples of Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton-yr (1144 days) Super-Kamiokande data set, the recent 5.1 kton-yr contained events of Soudan2 and the results on upgoing muons from the MACRO detector. We first present the allowed regions of solar and atmospheric oscillation parameters $\theta_{12}$, $\Delta m^2_{21}$ and $\theta_{23}$, $\Delta m^2_{32}$, respectively, as a function of $\theta_{13}$ and determine the constraints from atmospheric and solar data on the mixing angle $\theta_{13}$, common to solar and atmospheric analyses. We also obtain the allowed ranges of parameters from the full five-dimensional combined analysis of the solar, atmospheric and reactor data.Comment: 56 pages, 21 postscript figures. Some misprints corrected and new references added. Chooz limit included in Fig.21. Final version to appear in Phys. Rev.

Seasonal Dependence in the Solar Neutrino Flux

MSW solutions of the solar neutrino problem predict a seasonal dependence of the zenith angle distribution of the event rates, due to the non-zero latitude at the Super-Kamiokande site. We calculate this seasonal dependence and compare it with the expectations in the no-oscillation case as well as just-so scenario, in the light of the latest Super-Kamiokande 708-day data. The seasonal dependence can be sizeable in the large mixing angle MSW solution and would be correlated with the day-night effect. This may be used to discriminate between MSW and just-so scenarios and should be taken into account in refined fits of the data.Comment: 4 pages, latex, RevTeX, two postscript figure

Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon

The CENNS-10 experiment of the COHERENT collaboration has recently reported the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in liquid Argon with more than $3 \sigma$ significance. In this work, we exploit the new data in order to probe various interesting parameters which are of key importance to CEvNS within and beyond the Standard Model. A dedicated statistical analysis of these data shows that the current constraints are significantly improved in most cases. We derive a first measurement of the neutron rms charge radius of Argon, and also an improved determination of the weak mixing angle in the low energy regime. We also update the constraints on neutrino non-standard interactions, electromagnetic properties and light mediators with respect to those derived from the first COHERENT-CsI data.Comment: discussion expanded including light mediators and nuclear uncertainties, figures added, references added. V3: Fig. 7 corrected, conclusions unchange

Characterisation of Technological Innovation Management Journals

This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have

Reconciling neutrino anomalies in a simple four-neutrino scheme with R-parity violation

We propose a simple extension of the MSSM based on extra compact dimensions which includes an $SU(2) \otimes U(1)$ singlet superfield. The fermion present in this superfield is the sterile neutrino, which combines with one linear combination of $\nu_e-\nu_{\mu}-\nu_{\tau}$ to form a Dirac pair whose mass accounts for the LSND anomaly. Its small mass can be ascribed to a volume suppression factor associated with extra compact dimensions. On the other hand the sterile neutrino scalar partner can trigger the spontaneous violation of R-parity, thereby inducing the necessary mass splittings to fit also the solar and atmospheric neutrino data. Thus the model can explain all neutrino oscillation data. It leads to four predictions for the neutrino oscillation parameters and implies that the atmospheric neutrino problem must include at least some $\nu_{\mu} \to \nu_s$ oscillations, which will be testable in the near future. Moreover it also predicts that the lightest supersymmetric particle (LSP) decays visibly via lepton number violating modes, which could be searched for at present and future accelerators.Comment: 15 pages, requires axodraw.sty and elsart.cl

Some constraints on neutral heavy leptons from flavor-conserving decays of the Z boson

Small neutrino masses can arise in some grand unified models or superstring theories. We consider a model with an enhanced fermion sector containing Dirac neutral heavy leptons. The dependence on the mass and mixing parameters of these new fermions is investigated for several measurable quantities. We study the flavor-conserving leptonic decays of the Z boson and universality breaking in these decays. We also consider the W boson mass dependence on neutral heavy lepton parameters.Comment: 20 pages, Revtex 3.0, 6 uuencoded and compressed postscript figures included. Compressed postscript file of paper, including figures, also available by anonymous ftp at ftp://ftp.physics.carleton.ca/pub/theory/gour/ocipc9411.ps.Z . Accepted for publication in Phys. Rev. D

Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions to Neutrino Anomalies

We propose a four-neutrino model which can reconcile the existing data coming from underground experiments in terms of neutrino oscillations, together with the hint from the LSND experiment and a possible neutrino contribution to the hot dark matter of the Universe. It applies the idea that extra compact dimensions, probed only by gravity and possibly gauge-singlet fields, can lower the fundamental scales such as the Planck, string or unification scales. Our fourth light neutrino $\nu_s$ ($s$ for sterile) is identified with the zero mode of the Kaluza-Klein states. To first approximation \nu_sterile combines with the nu_mu in order to form a Dirac neutrino with mass in the eV range leaving the other two neutrinos massless. The smallness of this mass scale (suitable for LSND and Hot Dark Matter) arises without appealing neither to a see-saw mechanism nor to a radiative mechanism, but from the volume factor associated with the canonical normalization of the wave-function of the bulk field in the compactified dimensions. % On the other hand the splitting between \nm and \nu_sterile (atmospheric scale) as well as the mass of the two other neutrinos (solar mass scale) arise from the violation of the fermion number on distant branes. We also discuss alternative scenarios involving flavour-changing interactions. In one of them \ne can be in the electron-volt range and therefore be probed in beta decay studies.Comment: 12 pages, latex, no figures, title changed, final version to be published in Phys Rev

Water Use Efficiency in Chilean and Argentine Humid Temperate Grass-Legume Pastures

At two sites in Argentina and Chile five levels of water input were applied to four sown pastures of varying ages during spring and summer. The pastures consisted principally of C3 grasses and legumes, some of which were sown such as Lolium perenne, Trifolium repens, Dactylis glomerata. Dry matter (DM) production was measured and related to the estimated total evapotranspiration (ET): responses were both highly linear. Both responses to ET and absolute yields were higher at the Argentinian than at the Chilean site: respectively 10.7 and 15.2 kg DM/mm water evapotranspired. Nevertheless the calculated indices of sensitivity (Ky) of Doorenbos and Kassam (1979) were similar for the two sites, indicating a similar priority for irrigation in terms of expected responses