8,401 research outputs found
Combining exclusive semi-leptonic and hadronic B decays to measure |V_ub|
The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the
rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little
theoretical uncertainty, provided the hadronic form factor for the B -> pi
transition can be measured from some other B decay. In here, we suggest using
the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be
properly described within the usual factorization approximation; we use instead
a simple and very general phenomenological model for the b d J\psi vertex. In
order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l
+ antineutrino_l decays, we use form factor relations that hold for
heavy-to-light transitions at large recoil.Comment: Latex, 7 pages, no figure
Brain diffusion-weighted and diffusion tensor imaging findings in an infant with biotinidase deficiency
Knowledge-Driven Intelligent Survey Systems Towards Open Science
Open Access via Springer Compact Agreement. Acknowledgements: We are grateful to all of our survey participants, and to Anne Eschenbruecher, Sally Lamond, and Evelyn Williams for their assistance in participant recruitment. We are also grateful to Patrik Bansky for his work on refinement of the survey system.Peer reviewedPublisher PD
Modeling extreme wave heights from laboratory experiments with the nonlinear Schrödinger equation
Spatial variation of nonlinear wave groups with different initial envelope
shapes is theoretically studied first, confirming that the simplest nonlinear
theoretical model is capable of describing the evolution of propagating wave
packets in deep water. Moreover, three groups of laboratory experiments run
in the wave basin of CEHIPAR (Canal de Experiencias Hidrodinámicas de El
Pardo, known also as El Pardo Model Basin) was founded in 1928 by the Spanish
Navy. are systematically compared with the numerical simulations of the
nonlinear Schrödinger equation. Although a little overestimation is
detected, especially in the set of experiments characterized by higher
initial wave steepness, the numerical simulation still displays a high degree
of agreement with the laboratory experiments. Therefore, the nonlinear
Schrödinger equation catches the essential characteristics of the extreme
waves and provides an important physical insight into their generation. The
modulation instability, resulting from the quasi-resonant four-wave
interaction in a unidirectional sea state, can be indicated by the
coefficient of kurtosis, which shows an appreciable correlation with the
extreme wave height and hence is used in the modified Edgeworth–Rayleigh
distribution. Finally, some statistical properties on the maximum wave
heights in different sea states have been related with the initial
Benjamin–Feir index
Influência da intermitência do tempo de irrigação na cultura da videira festival irrigada por gotejamento, no vale do Submédio são Francisco.
Portando, esse trabalho teve como objetivo adequar manejos de irrigação que possibilite maiores produções da cultura com a mesma quantidade de água requerida
ISO-3D Applications of 3-Dimensional Electromagnetic Induction by Sources in the Oceans: a MAST-3 Project. Final report of ISO-3D Working Group.
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