Search results for "Experiments"

First measurement of the charge asymmetry in beauty-quark pair production.

2014

The difference in the angular distributions between beauty quarks and antiquarks, referred to as the charge asymmetry, is measured for the first time in b[bar over b] pair production at a hadron collider. The data used correspond to an integrated luminosity of 1.0  fb[superscript −1] collected at 7 TeV center-of-mass energy in proton-proton collisions with the LHCb detector. The measurement is performed in three regions of the invariant mass of the b[bar over b] system. The results obtained are A[b[bar over b] over C](40 105  GeV/c[superscript 2]) = 1.6 ± 1.7 ± 0.6%, where A[b[bar over b] over C] is defined as the asymmetry in the difference in rapidity between jets formed from the beauty q…

TIME EVOLUTION OF LOCAL SCOURING DOWNSTREAM OF A RIGID BED:lessons learned from experiments

2018

This present work concerns the phenomenon of local erosion occurring downstream a rigid bed of a structure constructed along a river. In particular, attention is focused on the time evolution of the maximum scour depth. This chapter reports a brief review of findings obtained by author using both data appositely collected in a laboratory channel and literature data.

Analysis of local scour downstream of bed sills: preliminary results of an experimental work

2006

Bed sills are often used to limit bed degradation, to control bed erosion around bridge piers or downstream stilling basins of dams. In this paper, the local scour that takes place downstream of the bed sill, in addition to the general erosion process, is examined. The data collected during experimental work are used to analyse the applicability of the relationship found in the literature and to define the relation between the maximum scour depth and the flow rate.

Studio dell’interazione corrente-vegetazione in un alveo meandriforme di elevata ampiezza in presenza di vegetazione sommersa matura e non ed al vari…

Salvador, F. i Gallifa, J. (1997) Introducció al disseny d'experiments en psicologia. AFUNTAP

2004

Searches for rare or forbidden semileptonic charm decays

2011

We present searches for rare or forbidden charm decays of the form $X_c^+\to h^\pm\ell^\mp\ell^{(\prime)+}$, where $X_c^+$ is a charm hadron ($D^+$, $D^+_s$, or $\Lambda_c^+$), $h^\pm$ is a pion, kaon, or proton, and $\ell^{(\prime)\pm}$ is an electron or muon. The analysis is based on $384 fb^{-1}$ of $e^+e^-$ annihilation data collected at or close to the $\Upsilon(4S)$ resonance with the BaBar detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the 35 decay modes that are investigated. We establish 90% confidence-level upper limits on the branching fractions between $1 \times 10^{-6}$ and $44 \times 10^{-6}$ depending on the channel. In most…

Measurement of Semileptonic B Decays into Orbitally Excited Charmed Mesons

2009

We present a study of B decays into semileptonic final states containing charged and neutral D-1(2420) and D-2*(2460). The analysis is based on a data sample of 208 fb(-1) collected at the Y(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference Delta m = m(D**) - m(D) distribution. Product branching fractions are determined to be B(B+ -> D(1)(0)l(+)nu(l)) x B(D-1(0) -> D*+pi(-)) = (2.97 +/- 0.17 +/- 0.17) x 10(-3), B(B+ -> D-2*l(+)nu(e)) x B(D-2*(0) -> D(*)+pi(-)) = (2.29 +/- 0.23 +/- 0.21) x 10(-3), B(B-0 -> D…

Measurement and interpretation of moments in inclusive semileptonic decays ¯¯¯B→Xcℓ−¯ν

2010

We present results for the moments of observed spectra in inclusive semileptonic B-meson decays to charm hadrons (B) over bar -> X(c)l(-)(nu) over bar. Moments of the hadronic-mass and the combined mass-and-energy spectra for different minimum electron or muon momenta between 0.8 and 1: 9 GeV/c are obtained from a sample of 232 X 10(6) Gamma(4S) -> B (B) over bar events, collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. We also present a reevaluation of the moments of electron-energy spectra and partial decay fractions B((B) over bar -> X(c)e(-)(nu) over bar) for minimum electron momenta between 0.6 and 1: 5 GeV/c based on a sample of 51 X 10(6) Gamm…

Un’indagine sperimentale sul ruolo della temperatura am- biente nel processo di riscaldamento/raffreddamento per ir- raggiamento

2012

The process of heating / cooling of an object in vacuum can be studied by the known Stefan's law. Many studies have investigated this phenomenon without inquire the role of the environment and of its temperature. In this paper the author proposes an experimental method through which to study the above process, by monitoring the ambient temperature on the assumption that this can vary with an exponential law. Under this hypothesis, in defined conditions, the temporal evolution of cooling of the object is similar to the case where the con- vection and / or the conduction are the principale phenomenon of energy exchange.

Electrochemical metallization ReRAMs (ECM) - Experiments and modelling: general discussion

2019

Electrochemical metallization ReRAMs (ECM) - Experiments and modelling: General discussion