7,312 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
Measurement of alpha_S in e+e- collisions at LEP and JADE
Data from e+e- annihilation into hadrons collected by the JADE, the L3 and
the OPAL experiment at centre-of-mass energies between 14 GeV and 209 GeV are
used to determine the strong coupling alpha_S. Observables in leading order
sensitive to alpha_S as well as alpha_S**2 are used. The evolution of alpha_S
with respect to the centre-of-mass energy as predicted by QCD is studied and
confirmed with high precision. All measurements of alpha_S are consistent with
the current world average.Comment: 4 pages, 3 figures, contributed to the Proceedings of ICHEP200
Reassessing the discovery potential of the B â K*ââșââ» 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
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
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
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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