9,817 research outputs found
Heavy Flavor Measurements in ATLAS and CMS
We present heavy flavor measurements performed by the ATLAS and CMS
Collaborations with data collected at the Large Hadron Collider. The production
mechanism of heavy flavor hadrons is discussed as well as lifetime measurements
and searches for the rare decay Bs->mumu. The large available statistics of
about 5 fb-1 per experiment collected during the year 2011 together with the
excellent detector performance allows to perform competitive heavy flavor
measurements.Comment: 8 pages, 12 figures, proceedings for Moriond EW 201
Reassessing the discovery potential of the B → K*ℓ⁺ℓ⁻ decays in the large-recoil region: SM challenges and BSM opportunities
We critically examine the potential to disentangle Standard Model (SM) and
New Physics (NP) in and decays,
focusing on the LHCb anomaly, the search for right-handed
currents, and lepton-universality violation. Restricting ourselves to
the large-recoil region, we advocate a parameterisation of the hadronic matrix
elements that separates model-independent information about nonperturbative QCD
from the results of model calculations. We clarify how to estimate corrections
to the heavy-quark limit that would generate a right-handed (virtual) photon in
the contribution to the decay. We then apply this approach to
the discussion of various sets of observables of increasing theoretical
cleanness. First, we show that angular observables in the optimized
basis are, in general, not robust against the long-distance
QCD effects. While a fit to data favours a NP contribution to the semileptonic
operators of the type , this comes at a relatively small
statistical significance of , once power corrections are
properly accounted for. Second, two of these observables, and
are particularly clean at very low and sensitive probes of right-handed
quark currents. We discuss their potential to set stringent bounds on the
Wilson coefficient , especially using data of the electronic mode.
Finally, in light of the recent hint of lepton-universality violation in
, we introduce and investigate new lepton-universality
observables involving angular observables of the muonic and electronic modes
and their zero crossings, and show that, if the effect is of the size suggested
by experiment, these can clearly distinguish between different NP explanations
in terms of underlying semileptonic operators.Comment: We recalculated the results with some updated theoretical input
parameters which cause mild changes in some central values and a slight
increase of the significance of tensions with the SM. Included new Table with
full results with errors obtained using Gaussian distributions of the
nuisance parameters. Some parts of the discussions have also been improve
Interactive Space Generation through Play: Exploring Form Creation and the Role of Simulation on the Design Table
The reaction 2H(p,pp)n in three kinematical configurations at E_p = 16 MeV
We measured the cross sections of the H(p,pp)n breakup reaction at
E=16 MeV in three kinematical configurations: the np final-state
interaction (FSI), the co-planar star (CST), and an intermediate-star (IST)
geometry. The cross sections are compared with theoretical predictions based on
the CD Bonn potential alone and combined with the updated 2-exchange
Tucson-Melbourne three-nucleon force (TM99'), calculated without inclusion of
the Coulomb interaction. The resulting excellent agreement between data and
pure CD Bonn predictions in the FSI testifies to the smallness of three-nucleon
force (3NF) effects as well as the insignificance of the Coulomb force for this
particular configuration and energy. The CST also agrees well whereas the IST
results show small deviations between measurements and theory seen before in
the pd breakup space-star geometries which point to possible Coulomb effects.
An additional comparison with EFT predictions (without 3NF) up to order NLO
shows excellent agreement in the FSI case and a rather similar agreement as for
CD Bonn in the CST and IST situations.Comment: 20 pages, 11 figure
Measurement of the Strong Coupling Constant alpha_S from the Four-Jet Rate in e+e- Annihilation using JADE data
Data from e+e- annihilation into hadrons collected by the JADE experiment at
centre-of-mass energies between 14 GeV and 44 GeV were used to study the
four-jet rate as a function of the Durham algorithm's resolution parameter
y_cut. The four-jet rate was compared to a QCD NLO order calculations including
NLLA resummation of large logarithms. The strong coupling constant measured
from the four-jet rate is alpha_S(M_Z) = 0.1169 +/- 0.0004 (stat) +/- 0.0012
(expt) +/- 0.0021 (had) +/- 0.0007 (theo), alpha_S(M_Z) = 0.1169 +/- 0.0026
(total error) in agreement with the world average.Comment: JADE note 146 submitted as contributed paper to ICHEP 200
The -cleus experiment: A gram-scale fiducial-volume cryogenic detector for the first detection of coherent neutrino-nucleus scattering
We discuss a small-scale experiment, called -cleus, for the first
detection of coherent neutrino-nucleus scattering by probing nuclear-recoil
energies down to the 10 eV-regime. The detector consists of low-threshold
CaWO and AlO calorimeter arrays with a total mass of about 10 g and
several cryogenic veto detectors operated at millikelvin temperatures.
Realizing a fiducial volume and a multi-element target, the detector enables
active discrimination of , neutron and surface backgrounds. A first
prototype AlO device, operated above ground in a setup without
shielding, has achieved an energy threshold of eV and further
improvements are in reach. A sensitivity study for the detection of coherent
neutrino scattering at nuclear power plants shows a unique discovery potential
(5) within a measuring time of weeks. Furthermore, a site
at a thermal research reactor and the use of a radioactive neutrino source are
investigated. With this technology, real-time monitoring of nuclear power
plants is feasible.Comment: 14 pages, 19 figure
Study of moments of event shapes in e+e- annihilation using JADE data
Data from e+e- annihilation into hadrons collected by the JADE experiment at
centre-of-mass energies between 14 GeV and 44 GeV were used to study moments of
event shape distributions. The data were compared with Monte Carlo models and
with predictions from QCD NLO order calculations. The strong coupling constant
measured from the moments is alpha_S(M_Z) = 0.1286 +/- 0.0007 (stat) +/- 0.0011
(expt) +/- 0.0022 (had) +/- 0.0068 (theo), alpha_S(M_Z) = 0.1286 +/- 0.0072
(total error), consistent with the world average. However, systematic
deficiencies in the QCD NLO order predictions are visible for some of the
higher moments.Comment: JADE note 147 submitted as contributed paper to ICHEP 2004, corrected
statistical error of 6 observable average and several typo
Symbolic Activities in Virtual Spaces
This paper presents an approach to combine concepts ofsymbolic acting and virtual storytelling with the support ofcooperative processes. We will motivate why symboliclanguages are relevant in the social context of awarenessapplications. We will describe different symbolicpresentations and illustrate their application in three differentprototypes
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