1,992 research outputs found
Final state phases in B -> D\pi, \bar{D}\pi decays and CP-asymmetry
Final state phases \delta_f and \delta_f' in B-> D pi, barD pi decays are
shown to be equal i.e. \delta =\delta_f-\delta_f' = 0. Thus CP-violating
asymmetry A(t) is independent of final state phases. The estimate for the
phases \delta_f and \delta_f' is also given.Comment: 6 pages, no figur
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
Governance Issues in the Principal-Agent Framework: Producing Cellulosic Ethanol in Michigan
This article analyzes the incentives and compensation problems faced by cellulosic ethanol producer and logging firms and the consequent impact on the organization of the wood based cellulosic ethanol industry in the US. The success of this relationship is central to setting up the biofuel industry in Michigan and in the US at large. The theoretical results indicate that specification contract under the principal-agent framework is of limited utility due toâ meteringâ problem when the principal contracts with multiple agents for the supply of feedstock.. Alternative arrangements including JVs have the potential to provide close to first best solutions.Principal-Agent, Cellulosic Ethanol, Michigan, Multiple agents, Asymmetric Information, Agribusiness, Institutional and Behavioral Economics, Resource /Energy Economics and Policy, D82, D86, L23, L24, Q42,
CP violation and the CKM angle from angular distributions of untagged decays governed by
We demonstrate that time-dependent studies of angular distributions for
decays caused by quark-level transitions extract
cleanly and model-independently the CKM angle . This CKM angle could be
cleanly determined from untagged decays alone, if the lifetime difference
between the mass eigenstates and is sizable. The
time-dependences for the relevant tagged and untagged observables are given
both in a general notation and in terms of linear polarization states and
should exhibit large CP-violating effects. These observables may furthermore
provide insights into the hadronization dynamics of the corresponding exclusive
decays thereby allowing tests of the factorization hypothesis.Comment: 14 pages, LaTeX, no figure
Determination of the CP Violating Phase by a Sum Over Common Decay Modes to and
To help the difficult determination of the angle of the unitarity
triangle, Aleksan, Dunietz and Kayser have proposed the modes of the type
, common to and . We point out that it is possible
to gain in statistics by a sum over all modes with ground state mesons in the
final state, i.e. , , , .
The delicate point is the relative phase of these different contributions to
the dilution factor of the time-dependent asymmetry. Each contribution to
is proportional to a product where
denotes form factors and decay constants. Within a definite phase
convention, lattice calculations do not show any change in sign when
extrapolating to light quarks the form factors and decay constants. Then, we
can show that all modes contribute constructively to the dilution factor,
except the -wave , which is small. Quark model arguments
based on wave function overlaps also confirm this stability in sign. By summing
over all these modes we find a gain of a factor 6 in statistics relatively to
. The dilution factor for the sum is remarkably stable for
theoretical schemes that are not in very strong conflict with data on or extrapolated from semileptonic charm form factors, giving
, always close to .Comment: 22 pages, LPTHE Orsay 94/03, DAPNIA/SPP/94-2
The Care Accelerator R&D Programme in Europe
CARE, an ambitious and coordinated programme of accelerator research and developments oriented towards high energy physics projects, has been launched in January 2004 by the main European laboratories and the European Commission. This project aims at improving existing infrastructures dedicated to future projects such as linear colliders, upgrades of hadron colliders and high intensity proton drivers. We describe the CARE R&D plans, mostly devoted to advancing the performance of the superconducting technology, both in the fields of RF cavities for electron or proton acceleration and of high field magnets, as well as to developing high intensity electron and proton injectors. We highlight some results and progress obtained so far
b Physics Beyond the Standard Model
I review the signals for New Physics in CP-violating measurements in B and
Lambda_b decays. I also discuss ways of identifying this New Physics, should
such a signal be found.Comment: 10 pages, LaTeX, 1 figure, ps file included. References adde
Phenomenological discussion of decays in QCD improved factorization approach
Trying a global fit of the experimental branching ratios and CP-asymmetries
of the charmless decays according to QCD factorization, we find it
impossible to reach a satisfactory agreement, the confidence level (CL) of the
best fit is smaller than .1 %. This failure reflects the difficulty to
accommodate several large experimental branching ratios of the strange
channels. Furthermore, experiment was not able to exclude a large direct CP
asymmetry in , which is predicted very small by QCD
factorization. Proposing a fit with QCD factorization complemented by a
charming-penguin inspired model we reach a best fit which is not excluded by
experiment (CL of about 8 %) but is not fully convincing.
These negative results must be tempered by the remark that some of the
experimental data used are recent and might still evolve significantly.Comment: 8 pages, 2 figures (requires epsfig, psfrag),talk presented at the
XXXVIIIth Rencontres de Moriond: Electroweak Interactions and Unified
Theories,Les Arcs, France, March 15-22, 2003. To be published in the
Proceeding
- âŠ