Search results for "Charm"
showing 10 items of 390 documents
Heavy-Flavor Contribution to Bhabha Scattering
2008
We evaluate the last missing piece of the two-loop QED corrections to the high-energy electron-positron scattering cross section originating from the vacuum polarization by heavy fermions. The calculation is performed within a new approach applicable to a wide class of perturbative problems with mass hierarchy. The result is crucial for the high-precision physics program at existing and future e(+) e(-) colliders.
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…
Search forD0−D¯0mixing using doubly flavor tagged semileptonic decay modes
2007
We have searched for D0-D0 mixing in D*+→π+D0 decays with D0→K(*)eν in a sample of e+e-→cc events produced near 10.58 GeV. The charge of the slow pion from charged D* decay tags the charm flavor at production, and it is required to be consistent with the flavor of a fully reconstructed second charm decay in the same event. We observe 3 mixed candidates compared to 2.85 background events expected from simulation. We ascribe a 50% systematic uncertainty to this expected background rate. We find a central value for the mixing rate of 0.4×10-4. Using a frequentist method, we set corresponding 68% and 90% confidence intervals at (-5.6,7.4)×10-4 and (-13,12)×10-4, respectively. © 2007 The America…
Evidence for b baryons in Z decays
1992
Abstract In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of Λl− and Λl+ combinations have been measured. The observed excess of Λl− over Λl+ of 53±13 is interpreted as evidence for b baryons and their semileptonic decay. Assuming that three body decay processes such as Λ b →Λ c + l − v dominate the semileptonic decay of b baryons, this ex cess corresponds to a product branching ratio BR ( b →Λ b )· BR (Λ b →Λ c + l − v )· BR (Λ c + →ΛX) = (0.95±0.22 ( stat. )±0.21( syst. ))% , where Λb and Λc+ denote the bottom and charm baryons respectively.
Incantesimi e rituali magici nelle tradizioni germaniche medievali: una introduzione
2021
The approach to charms and magical formulas of the Germanic world has developed on an evolutionary path that has from time to time favoured perspectives of different scientific categories, and has been faced on philological, linguistic, semantic-pragmatic, semiotic and historical-literary basis. Starting from different types of criteria and parameters, research has proposed in the past various classifications of charms, intended as specific textual forms, which are identified by the presence of characteristic contents and structural elements. Given the fluidity of matter, the phenomenon of charms and magical formulas of the Germanic area should be seen in a dynamic key, applying different i…
L'esotismo surrealista in Martinique charmeuse de serpents
2007
"Table 38" of "Tuning and test of fragmentation models based on identified particles and precision event shape data."
1996
Compilation of multiplicities of vector mesons from current LEP I data.
"Table 36" of "Tuning and test of fragmentation models based on identified particles and precision event shape data."
1996
Compilation of multiplicities of pseudoscalar mesons from current LEP I data.
"Table 1" of "D_s meson production at central rapidity in proton--proton collisions at sqrt(s) = 7 TeV"
2014
pT-differential inclusive cross section in |y| < 0.5 for prompt D_s^+ meson production in pp collisions at sqrt(s) = 7 TeV.
"Table 2" of "D_s meson production at central rapidity in proton--proton collisions at sqrt(s) = 7 TeV"
2014
pT-integrated inclusive cross section in |y| < 0.5 for prompt D_s^+ meson production in pp collisions at sqrt(s) = 7 TeV. The latter three systematic uncertainties arise from extrapolating the visible cross section to the full pT range, luminosity, and the branching ratio, respectively.