208 research outputs found
b -> d Penguins: CP Violation, General Lower Bounds on the Branching Ratios and Standard Model Tests
With the wealth of new data from the B-factories, b -> d penguin decays
become available for study, in addition to their b -> s counterparts that have
proven an indespensable tool for the exploration of new-physics effects in
flavour physics. A prominent example of the b -> d penguin transitions is . We show that this decay can be charaterized in the
Standard Model by a surface in the observable space of the direct and
mixing-induced CP asymmetries and the branching ratio. The form of this
surface, which is theoretically clean, implies a lower bound for the branching
ratio that has recently been confirmed experimentally. If future measurements
of the CP asymmetries yield a point away from the SM surface, this would be an
interesting signal of new physics. We point out that the hadronic parameters in
that parameterize the position on the SM surface
are related to hadronic parameters in the B -> pi K system. The fact that the
branching ratio of is very close to its lower
bound yields interesting implications for B -> pi K even without knowledge of
the CP asymmetries of . The mechanism that
produces the lower bound for is actually much
more general; we derive lower bounds for various other b -> d penguin-induced
processes, including B -> rho gamma and .
Some of these theoretical lower bounds are very close to the current
experimental upper bounds.Comment: 4 pages, 2 figures. Contribution to the proceedings of EPS-HEP200
B -> pi pi, New Physics in B -> pi K and Implications for Rare K and B Decays
The measured B -> pi pi, pi K branching ratios exhibit puzzling patterns. We
point out that the B -> pi pi hierarchy can be nicely accommodated in the
Standard Model (SM) through non-factorizable hadronic interference effects,
whereas the B -> pi K system may indicate new physics (NP) in the electroweak
(EW) penguin sector. Using the B -> pi pi data and the SU(3) flavour symmetry,
we may fix the hadronic B -> pi K parameters, which allows us to show that any
currently observed feature of the B -> pi K system can be easily explained
through enhanced EW penguins with a large CP-violating NP phase. Restricting
ourselves to a specific scenario, where NP enters only through Z^0 penguins, we
derive links to rare K and B decays, where an enhancement of the K_L-> pi^0 nu
nu_bar rate by one order of magnitude, with BR(K_L -> pi^0 nu nu_bar) > BR(K^+
-> pi^+ nu nu_bar), BR(K_L -> pi^0 e^+ e^-)=O(10^{-10}), (\sin2\beta)_{pi nu
nu_bar} K* mu^+ mu^-,
are the most spectacular effects. We address also other rare K and B decays,
epsilon'/epsilon and B_d -> phi K_S.Comment: 6 pages, LaTeX, reference added and a few typos correced, to appear
in Physical Review Letter
General Lower Bounds for b -> d Penguin Processes
For the exploration of flavour physics, b -> d penguin processes are an
important aspect, with the prominent example of \bar B^0_d -> K^0 \bar K^0. We
recently derived lower bounds for the CP-averaged branching ratio of this
channel in the Standard Model; they were found to be very close to the
corresponding experimental upper limits, thereby suggesting that \bar B^0_d ->
K^0 \bar K^0 should soon be observed. In fact, the BaBar collaboration
subsequently announced the first signals of this transition. Here we point out
that it is also possible to derive lower bounds for \bar B -> \rho \gamma
decays, which are again surprisingly close to the current experimental upper
limits. We show that these bounds are realizations of a general bound that
holds within the Standard Model for b -> d penguin processes, allowing further
applications to decays of the kind B^\pm -> K^{(\ast)\pm} K^{(\ast)} and B^\pm
-> \pi^\pm \ell^+ \ell^-, \rho^\pm \ell^+ \ell^-.Comment: Minor changes, to appear as rapid communication in Phys. Rev
A conceptual modeling approach for supply chain event management (SCEM)
The management of supply chains is a very comprehensive task. Predictability and response to incidents in process executions are challenging. With Supply Chain Event Management (SCEM), researchers propose an approach for overcoming these problems through proactive monitoring and notification of crucial process activities across the supply chain. The identification and definition of such crucial activities and information needs are necessary to handle possible abnormalities although they are challenging task which have not been solved in SCEM research so far. Hence, we propose a modeling approach which allows the conceptual specification of an adequate information exchange along the supply chain. With our approach we focus on the specification of relevant logistical objects, the definition of possible events, and the design of notifications for decision makers in the supply chain
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