Search results for "Mass hierarchy"
showing 10 items of 12 documents
Neutrino mass hierarchy extraction using atmospheric neutrinos in ice
2008
We show that the measurements of 10 GeV atmospheric neutrinos by an upcoming array of densely packed phototubes buried deep inside the IceCube detector at the South Pole can be used to determine the neutrino mass hierarchy for values of sin^2(2theta13) close to the present bound, if the hierarchy is normal. These results are obtained for an exposure of 100 Mton years and systematic uncertainties up to 10%.
From transition magnetic moments to majorana neutrino masses
2005
It is well known that a majorana mass induces a (small) transition magnetic moment. The converse is also true; in this paper we estimate the loop contribution of transition magnetic moments $[\mu]_{\alpha \beta}$ to the neutrino mass matrix $[m]_{\alpha \beta}$. We show that for hierarchical neutrino masses, the contribution of $[\mu]_{e \tau}$ to $[m]_{e \tau}$ can exceed the experimental value of $[m]_{e \tau}$.
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…
Neutrino Physics with JUNO
2016
The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plan…
Untangling CP violation and the mass hierarchy in long baseline experiments
2004
In the overlap region, for the normal and inverted hierarchies, of the neutrino-antineutrino bi-probability space for $\nu_\mu \to \nu_e$ appearance, we derive a simple identity between the solutions in the ($\sin^2 2\theta_{13}$, $\sin \delta$) plane for the different hierarchies. The parameter $\sin^2 2\theta_{13}$ sets the scale of the $\nu_\mu \to \nu_e$ appearance probabilities at the atmospheric $\delta m^2_{atm} \approx 2.4 \times 10^{-3}$ eV$^2$ whereas $\sin \delta $ controls the amount of CP violation in the lepton sector. The identity between the solutions is that the difference in the values of $\sin \delta$ for the two hierarchies equals twice the value of $\sqrt{\sin^2 2\theta…
Atmospheric neutrino oscillations, theta (13) and neutrino mass hierarchy
2003
We derive predictions for the Nadir angle (theta(n)) dependence of the ratio N(mu)/N(e) of the rates of the mu-like and e-like multi-GeV events measured in water-Cerenkov detectors in the case of 3-neutrino oscillations of the atmospheric nu(e) (antinu(e)) and nu(mu) (antinu(mu)), driven by one neutrino mass squared difference, |Delta m2(31)| ~ (2.5 - 3.0) x 10^(-3) eV^2 >> Delta m2(21). This ratio is particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta(13)) and sin^2(theta(23)), theta(13) and theta(23) being the neutrino mixing angle limited by the CHOOZ and Palo Verde experiments and that responsible for t…
Atmospheric neutrinos and nu mass hierarchy
2003
We discuss the possibility for matter effects in the three-neutrino oscillations of the atmospheric nu_e (bar{nu}_e) and nu_mu (bar{nu}_mu), driven by one neutrino mass squared difference, |Delta m2_{31}| >> Delta m2_{21}, to be observable under appropriate conditions. We derive predictions for the Nadir angle (theta_n) dependence of the ratio N_mu/N_e of the rates of the mu-like and e-like multi-GeV events which is particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin2{theta_{13}} and sin2{theta_{23}}, and also to the type of neutrino mass spectrum.
Probing the neutrino mass hierarchy with Super-Kamiokande
2012
We show that for recently discovered large values of theta(13), a superbeam with an average neutrino energy of ~ 5 GeV, such as those being proposed at CERN, if pointing to Super-Kamiokande (L = 8770 km), could reveal the neutrino mass hierarchy at 5 sigma in less than two years irrespective of the true hierarchy and CP phase. The measurement relies on the near resonant matter effect in the numu to nue oscillation channel, and can be done counting the total number of appearance events with just a neutrino beam.
Updates to the Dualized Standard Model on Fermion Masses and Mixings
2003
The Dualized Standard Model has scored a number of successes in explaining the fermion mass hierarchy and mixing pattern. This note contains updates to those results including (a) an improved treatment of neutrino oscillation free from previous assumptions on neutrino masses, and hence admitting now the preferred LMA solution to solar neutrinos, (b) an understanding of the limitation of the 1-loop calculation so far performed, thus explaining the two previous discrepancies with data, and (c) an analytic derivation and confirmation of the numerical results previously obtained.
Heavy-Flavor Contribution to Bhabha Scattering
2008
We evaluate the last missing piece of the two-loop QED corrections to the high-energy electron-positron scattering cross section originating from the vacuum polarization by heavy fermions. The calculation is performed within a new approach applicable to a wide class of perturbative problems with mass hierarchy. The result is crucial for the high-precision physics program at existing and future e(+) e(-) colliders.