11,344 research outputs found
New ways to explore factorization in b decays
We propose to study factorization breaking effects in exclusive b decays
where they are strongly enhanced over the factorizing contributions. This can
be done by selecting final-state mesons with a small decay constant or with
spin greater than one. We find a variety of decay modes which could help
understand the dynamical origin of factorization and the mechanisms responsible
for its breaking.Comment: 30 pages, 5 figures, references added, signs corrected in eqs.
10-13,19,2
Assessing Financial Stability of Suppliers: Avoiding Potential Distress
OEM and Tier One suppliers must move to employ a comprehensive financial and operational review of their supply chain.supply chain, financial stability, automotive manufacturing, BBK ratings, supply base
The Al Gamma-ray Line from Massive-Star Regions
The measurement of gamma rays from the diffuse afterglow of radioactivity
originating in massive-star nucleosynthesis is considered a laboratory for
testing models, when specific stellar groups are investigated, at known
distance and with well-constrained stellar population. Regions which have been
exploited for such studies include Cygnus, Carina, Orion, and
Scorpius-Centaurus. The Orion region hosts the Orion OB1 association and its
subgroups at about 450~pc distance. We report the detection of Al gamma
rays from this region with INTEGRAL/SPI.Comment: Contribution to Symposium "Nuclei in the Cosmos XIV", Niigata, Japan,
Jun 2016; 3 pages, 2 figures; accepted for publication in JPS (Japan Physical
Society) Conference Proceedings http://jpscp.jps.jp
Boundary critical behavior at m-axial Lifshitz points for a boundary plane parallel to the modulation axes
The critical behavior of semi-infinite -dimensional systems with
-component order parameter and short-range interactions is
investigated at an -axial bulk Lifshitz point whose wave-vector instability
is isotropic in an -dimensional subspace of . The associated
modulation axes are presumed to be parallel to the surface, where . An appropriate semi-infinite model representing the
corresponding universality classes of surface critical behavior is introduced.
It is shown that the usual O(n) symmetric boundary term
of the Hamiltonian must be supplemented by one of the form involving a
dimensionless (renormalized) coupling constant . The implied boundary
conditions are given, and the general form of the field-theoretic
renormalization of the model below the upper critical dimension
is clarified. Fixed points describing the ordinary, special,
and extraordinary transitions are identified and shown to be located at a
nontrivial value if . The surface
critical exponents of the ordinary transition are determined to second order in
. Extrapolations of these expansions yield values of these
exponents for in good agreement with recent Monte Carlo results for the
case of a uniaxial () Lifshitz point. The scaling dimension of the surface
energy density is shown to be given exactly by , where
is the anisotropy exponent.Comment: revtex4, 31 pages with eps-files for figures, uses texdraw to
generate some graphs; to appear in PRB; v2: some references and additional
remarks added, labeling in figure 1 and some typos correcte
Crossover from Attractive to Repulsive Casimir Forces and Vice Versa
Systems described by an O(n) symmetrical Hamiltonian are considered
in a -dimensional film geometry at their bulk critical points. The critical
Casimir forces between the film's boundary planes , are
investigated as functions of film thickness for generic symmetry-preserving
boundary conditions . The
-dependent part of the reduced excess free energy per cross-sectional area
takes the scaling form when , where are scaling
fields associated with the variables , and is a surface
crossover exponent. Explicit two-loop renormalization group results for the
function at dimensions are
presented. These show that (i) the Casimir force can have either sign,
depending on and , and (ii) for appropriate
choices of the enhancements , crossovers from attraction to
repulsion and vice versa occur as increases.Comment: 4 RevTeX pages, 2 eps figures; minor misprints corrected and 3
references adde
Yet another way to measure
We show that the CKM phase can be extracted from measurement
of the time dependent rates in the decays and
, where , , , , ,
. These channels have a large asymmetry between decays of
and into the same final state. Even though the branching ratios are
small, their sensitivity to can be competitive with decays into
and .Comment: 5 pages, some clarifications and references adde
Generalized parton distributions and transversity from full lattice QCD
We present here the latest results from the QCDSF collaboration for moments
of generalized parton distributions and transversity in two-flavour QCD,
including a preliminary analysis of the pion mass dependence.Comment: Talks presented by Ph.Hagler and J.Zanotti at BARYONS 2004, Paris,
Oct. 25-29, 2004, 8 pages, 5 figure
Boundary critical behaviour at -axial Lifshitz points: the special transition for the case of a surface plane parallel to the modulation axes
The critical behaviour of -dimensional semi-infinite systems with
-component order parameter is studied at an -axial bulk
Lifshitz point whose wave-vector instability is isotropic in an -dimensional
subspace of . Field-theoretic renormalization group methods are
utilised to examine the special surface transition in the case where the
potential modulation axes, with , are parallel to the surface.
The resulting scaling laws for the surface critical indices are given. The
surface critical exponent , the surface crossover exponent
and related ones are determined to first order in
\epsilon=4+\case{m}{2}-d. Unlike the bulk critical exponents and the surface
critical exponents of the ordinary transition, is -dependent already
at first order in . The \Or(\epsilon) term of is
found to vanish, which implies that the difference of and
the bulk exponent is of order .Comment: 21 pages, one figure included as eps file, uses IOP style file
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