The CKM matrix from anti-SU(7) unification of GUT families
PHYSICS LETTERS B
Authors: Kim, Jihn E.; Mo, Doh Young; Seo, Min-Seok
Abstract
We estimate the CKM matrix elements in the recently proposed minimal model, anti-SU(7) GUT for the family unification, [3] + 2 [2] + 8 [(1) over bar] + (singlets). It is shown that the real angles of the right-handed unitary matrix diagonalizing the mass matrix can be determined to fit the Particle Data Group data. However, the phase in the right-handed unitary matrix is not constrained very much. At present, there are three classes of possible CKM parametrizations, delta(CKM) = alpha, beta, or gamma of the unitarity triangle. For the choice of delta(CKM) = alpha, it is easy to show that the phase is close to a maximal one, which has a parametrization-independent meaning. (C) 2015 The Authors. Published by Elsevier B.V.
Reconstructing lava flow emplacement histories with rheological and morphological analyses: the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
BULLETIN OF VOLCANOLOGY
Authors: Dietterich, Hannah R.; Downs, Drew T.; Stelten, Mark E.; Zahran, Hani
Abstract
Mafic volcanic fields are widespread, but few have erupted in historic times, providing limited observations of the magnitudes, dynamics, and timescales of lava flow emplacement in these settings. To expand our knowledge of effusive mafic eruptions, we must evaluate solidified flows to discern syn-eruptive conditions. The Harrat Rahat volcanic field in western Saudi Arabia offers a good opportunity for this, with a historical eruption in 1256CE and many well-preserved prehistoric flows. We combine historical observations and rheological and morphological analyses of the youngest flows with analytical models to reconstruct eruptive histories and lava flow emplacement conditions in Harrat Rahat. Petrologic analysis of samples for emplacement temperatures and crystallinities shows cooling trends from vent to toe of 1140 to 1090 degrees C at rates of 2-7 degrees Ckm(-1), crystallinities increasing from 0.5 to 60%, and apparent viscosities increasing from 10(2) to 10(9)Pas. High-resolution topographic data facilitates quantitative analysis of morphology and interpolation of pre-eruptive surfaces to measure flow thicknesses, channels, and levees, and enables calculation of eruptive volumes. Analytical models relating flow morphology to emplacement conditions are applied to estimate effusion rates. Within the suite of studied flows, volume estimates range from 0.07 to 0.42km(3) dense rock equivalent, with effusion rates on the order of 10 to 100s of m(3)s(-1) and durations from 1 to 15weeks. These integrated analyses quantify past lava flow emplacement conditions and dynamics in Harrat Rahat, improving our understanding and observations of fundamental parameters and controls of effusive eruptions in mafic volcanic fields.