1,276 research outputs found
Scaling ansatz, four zero Yukawa textures and large
We investigate 'Scaling ansatz' in the neutrino sector within the framework
of type I seesaw mechanism with diagonal charged lepton and right handed
Majorana neutrino mass matrices (). We also assume four zero texture of
Dirac neutrino mass matrices () which severely constrain the
phenomenological outcomes of such scheme. Scaling ansatz and the present
neutrino data allow only Six such matrices out of 126 four zero Yukawa
matrices. In this scheme, in order to generate large we break
scaling ansatz in through a perturbation parameter and we also show our
breaking scheme is radiatively stable. We further investigate CP violation and
baryogenesis via leptogenesis in those surviving textures.Comment: 25 pages, 8 figures, Accepted for publication in Phys. Rev.
Heavy Top Quark Searches in the Di-Lepton Mode at the Tevatron
We present the results of a detailed study of the effects of -tagging on
the heavy top-quark signal and backgrounds for the modes of the di-lepton plus
two high transverse energy jets at the Fermilab Tevatron. The general
characteristics of the heavy top-quark signal events are also discussed so that
a comparison can be made between -tagging and imposing stringent kinematical
cuts to eliminate backgrounds.Comment: uses PHYZZX and TABLES macros, 10 pages, four figures not included
(available by request), FERMILAB-Pub-93/105-
Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments
In the overlap region, for the normal and inverted hierarchies, of the
neutrino-antineutrino bi-probability space for appearance,
we derive a simple identity between the solutions in the (, ) plane for the different hierarchies. The
parameter sets the scale of the
appearance probabilities at the atmospheric eV whereas controls the amount of CP
violation in the lepton sector. The identity between the solutions is that the
difference in the values of for the two hierarchies equals twice
the value of divided by the {\it critical} value
of . We apply this identity to the two proposed
long baseline experiments, T2K and NOA, and we show how it can be used to
provide a simple understanding of when and why fake solutions are excluded when
two or more experiments are combined. The identity demonstrates the true
complimentarity of T2K and NOA.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of
Physics, ``Focus on Neutrino Physics'' issu
On the Coupling of Gravitons to Matter
Using relationships between open and closed strings, we present a
construction of tree-level scattering amplitudes for gravitons minimally
coupled to matter in terms of gauge theory partial amplitudes. In particular,
we present examples of amplitudes with gravitons coupled to vectors or to a
single fermion pair. We also present two examples with massive graviton
exchange, as would arise in the presence of large compact dimensions. The gauge
charges are represented by flavors of dynamical scalars or fermions. This also
leads to an unconventional decomposition of color and kinematics in gauge
theories.Comment: RevTex, 4 page
M\"ossbauer Antineutrinos: Recoilless Resonant Emission and Absorption of Electron Antineutrinos
Basic questions concerning phononless resonant capture of monoenergetic
electron antineutrinos (M\"ossbauer antineutrinos) emitted in bound-state
beta-decay in the 3H - 3He system are discussed. It is shown that lattice
expansion and contraction after the transformation of the nucleus will
drastically reduce the probability of phononless transitions and that various
solid-state effects will cause large line broadening. As a possible
alternative, the rare-earth system 163Ho - 163Dy is favoured.
M\"ossbauer-antineutrino experiments could be used to gain new and deep
insights into several basic problems in neutrino physics
Academic Librarianship and the Redefining Scholarship Project: A Report from the Association of College and Research Libraries Task Force on Institutional Priorities and Faculty Rewards
At the July, 1996 Annual Conference of the American Library Association, the Board of Directors of the Association of College and Research Libraries (ACRL) appointed a task force to write a formal statement defining and describing the kind of scholarship performed by academic librarians, using as a framework the taxonomy developed by Eugene Rice and elaborated by Ernest Boyer in his 1990 book Scholarship Reconsidered: Priorities of the Professoriate.(1) The task force\u27s statement, upon approval by the ACRL Board, is intended to become part of a larger movement established by Syracuse University\u27s Center for Instructional Development, entitled the Institutional Priorities and Faculty Rewards project. The project, which is being funded by the Lilly Endowment, with support from the Fund for the Improvement of Postsecondary Education, is providing assistance to academic associations for the development and dissemination of definitions of scholarship for their disciplines. The definitions are intended to extend the range of activities recognized as scholarly for the purposes of tenure, promotion, merit, or reward system guidelines. The following is the report of the ACRL task force
Implications of New Gallex Results for the MSW Solution of the Solar Neutrino Problem
We compare the implications for 7Be and pp neutrinos of the two MSW fits to
the new GALLEX solar neutrino measurements . Small mixing angle solutions tend
to suppress the former as electron-neutrinos, but not the latter, and large
angle solutions tend to reduce both by about a factor of 2. The consequences
for BOREXINO and similar solar neutrino--electron scattering experiments are
discussed.Comment: 7 pages (plus 3 figures available upon request) UTAPHY-HEP-
Parameter Degeneracies in Neutrino Oscillation Measurement of Leptonic CP and T Violation
The measurement of the mixing angle \theta_{13}, sign of \Delta m^2_{13} and
the CP or T violating phase \delta is fraught with ambiguities in neutrino
oscillation. In this paper we give an analytic treatment of the paramater
degeneracies associated with measuring the \nu_\mu -> \nu_e probability and its
CP and/or T conjugates. For CP violation, we give explicit solutions to allow
us to obtain the regions where there exist two-fold and four-fold degeneracies.
We calculate the fractional differences, \Delta \theta / \bar{\theta}, between
the allowed solutions which may be used to compare with the expected
sensitivities of the experiments. For T violation we show that there is always
a complete degeneracy between solutions with positive and negative \Delta
m^2_{13} which arises due to a symmetry and cannot be removed by observing one
neutrino oscillation probability and its T conjugate. Thus, there is always a
four fold parameter degeneracy apart from exceptional points. Explicit
solutions are also given and the fractional differences are computed. The
bi-probability CP/T trajectory diagrams are extensively used to illuminate the
nature of the degeneracies.Comment: 35 pages, Latex, 11 postscript figures, minor correction
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