Search results for "Charm"
showing 10 items of 390 documents
s-wave charmed baryon resonances from a coupled-channel approach with heavy quark symmetry
2009
We study charmed baryon resonances which are generated dynamically within a unitary meson-baryon coupled channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with t-channel vector meson exchanges to a SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-w…
Properties of D and D-* mesons in the nuclear medium
2009
We study the properties of D and D-* mesons in nuclear matter within a simultaneous self-consistent coupled-channel unitary approach that implements heavy-quark symmetry. The in-medium solution accounts for Pauli blocking effects and for the D and D-* self-energies in a self-consistent manner. We pay special attention to renormalization of the intermediate propagators in the medium beyond the usual cutoff scheme. We analyze the behavior in the nuclear medium of the rich spectrum of dynamically generated baryonic resonances in the C=1 and S=0 sector and their influence on the self-energy and, hence, the spectral function of D and D-* mesons. The D meson quasiparticle peak mixes with Sigma(c)…
Observation of ψ(3686)→η′e+e−
2018
Abstract Using a data sample of 448.1 × 10 6 ψ ( 3686 ) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay ψ ( 3686 ) → η ′ e + e − , with significances of 7.0σ and 6.3σ when reconstructing the η ′ meson via its decay modes η ′ → γ π + π − and η ′ → π + π − η ( η → γ γ ), respectively. The weighted average branching fraction is determined to be B ( ψ ( 3686 ) → η ′ e + e − ) = ( 1.90 ± 0.25 ± 0.11 ) × 10 − 6 , where the first uncertainty is statistical and the second systematic.
"Table 4" of "Measurement of dielectron production in central Pb-Pb collisions at $\sqrt{{\textit{s}}_{\mathrm{NN}}}$ = 2.76 TeV"
2018
Data-to-cocktail ratio as a function of the invariant-mass. In the hadronic cocktail, random correlations of dielectrons from charm decays are assumed to simulate the effects of the interaction between charm quarks and the medium. The statistical and systematic uncertainties of data are represented by vertical bars and boxes.
Evidence for eta(c) -> gamma gamma and measurement of J/psi -> 3 gamma
2013
The decay of J/psi to three photons is studied using psi (3686) -> pi(+) pi(-) J/psi in a sample of 1.0641 X 10(8) psi (3686) events collected with the BESIII detector. Evidence of the direct decay of eta(c) to two photons, eta(c) -> gamma gamma, is reported, and the product branching fraction is determined to be B(J/psi -> gamma eta(c,) eta(c) -> gamma gamma = (4.5 +/- 1.2 +/- 0.6) X 10(-6), where the first error is statistical and the second is systematic. The branching fraction for J/psi -> 3 gamma is measured to be (11.3 +/- 1.8 +/- 2.0) X 10(-6) with improved precision.
"Table 3" of "Heavy flavour decay muon production at forward rapidity in proton--proton collisions at \sqrt(s) = 7 TeV"
2012
pT-differential production cross section of muons from heavy flavour decays, in the rapidity range 2.5
"Table 1" of "Heavy flavour decay muon production at forward rapidity in proton--proton collisions at \sqrt(s) = 7 TeV"
2012
pT-differential production cross section of muons from heavy flavour decays, in the rapidity range 2.5
"Table 6" of "Heavy flavour decay muon production at forward rapidity in proton--proton collisions at \sqrt(s) = 7 TeV"
2012
pT-differential production cross section of muons from heavy flavour decays, in the rapidity range 3.4
"Table 5" of "Heavy flavour decay muon production at forward rapidity in proton--proton collisions at \sqrt(s) = 7 TeV"
2012
pT-differential production cross section of muons from heavy flavour decays, in the rapidity range 3.1
"Table 4" of "Heavy flavour decay muon production at forward rapidity in proton--proton collisions at \sqrt(s) = 7 TeV"
2012
pT-differential production cross section of muons from heavy flavour decays, in the rapidity range 2.8