202 research outputs found
Semibiotic Persistence
From observation, we find four different strategies to successfully enable structures to persist over extended periods of time. If functionally relevant features are very large compared to the changes that can be effectuated by entropy, the functional structure itself has a high enough probability to erode only slowly over time. If the functionally relevant features are protected from environmental influence by sacrificial layers that absorb the impinging of the environment,deterioration can be avoided or slowed. Loss of functionality can be delayed, even for complex systems, by keeping alternate options for all required components available. Biological systems also apply information processing to actively counter the impact of entropy. The latter strategy increases the overall persistence of living systems and enables them to maintain a highly complex functional organisation during their lifetime and over generations. In contrast to the other strategies, information processing has only low material overhead. While at present engineered technology is far from achieving the self-repair of evolved systems, the semibiotic combination of biological components with conventionally engineered systems may open a path to long-term persistence of functional devices in harsh environments. We review nature’s strategies for persistence, and consider early steps taken in the laboratory to import such capabilities into engineered architectures.<br/
Observation of and Evidence for
We report the first observation of and first
evidence for , which are CP eigenstate decay modes.
These results are obtained from of data collected at
the resonance with the Belle detector at the KEKB
collider. We measure the branching fractions with a significance of , and
with a significance of . The last error
listed is due to uncertainty in the number of produced pairs.Comment: 5 pages, 2 figures, 2 tables, published in PR
Angular analysis of
We present a measurement of angular observables, , , ,
, in the decay , where
is either or . The analysis is performed on
a data sample corresponding to an integrated luminosity of
containing pairs, collected
at the resonance with the Belle detector at the
asymmetric-energy collider KEKB. Four angular observables,
are extracted in five bins of the invariant mass squared of the
lepton system, . We compare our results for with Standard
Model predictions including the region in which the LHCb collaboration
reported the so-called anomaly.Comment: Conference paper for LHC Ski 2016. SM prediction for
corrected and reference for arXiv:1207.2753 adde
Belle II Technical Design Report
The Belle detector at the KEKB electron-positron collider has collected
almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an
upgrade of KEKB is under construction, to increase the luminosity by two orders
of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2
/s luminosity. To exploit the increased luminosity, an upgrade of the Belle
detector has been proposed. A new international collaboration Belle-II, is
being formed. The Technical Design Report presents physics motivation, basic
methods of the accelerator upgrade, as well as key improvements of the
detector.Comment: Edited by: Z. Dole\v{z}al and S. Un
Evidence for the Suppressed Decay B- -> DK-, D -> K+pi-
The suppressed decay chain B- -> DK-, D -> K+pi-, where D indicates a anti-D0
or D0 state, provides important information on the CP-violating angle phi_3. We
measure the ratio R_{DK} of the decay rates to the favored mode B- -> DK-, D ->
K-pi+ to be R_{DK} = [1.63^{+0.44}_{-0.41}(stat)^{+0.07}_{-0.13}(syst)] x
10^{-2}, which indicates the first evidence of the signal with a significance
of 4.1sigma. We also measure the asymmetry A_{DK} between the charge-conjugate
decays to be A_{DK} = -0.39^{+0.26}_{-0.28}(stat)^{+0.04}_{-0.03}(syst). The
results are based on the full 772 x 10^6 B anti-B pair data sample collected at
the Upsilon(4S) resonance with the Belle detector.Comment: 6 pages, 2 figures, 2 tables, accepted by Physical Review Letter
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