Search results for "Dominance"
showing 10 items of 360 documents
Functional ecological patterns and the effect of anthropogenic disturbances on a recently restored Mediterranean coastal lagoon. Needs for a sustaina…
2012
Abstract We present here a detailed case study on the lessons learned after a restoration process of a natural ecosystem, which can be considered as an ecological experiment. Senillar de Moraira is a brackish water small coastal lagoon located in the Spanish Mediterranean coast. It is separated from the sea by a sand bar and a beach, and is regularly fed by groundwater. Mostly due to the strong anthropogenic pressure this lagoon was degraded, and a restoration process, consisting mostly on the rebuilt of hydrogeomorphological features, was accomplished about a decade ago. After the restoration project, ecological monitoring was performed to reveal the recovery of the ecological integrity of…
Interaction Of The Vector-Meson Octet With The Baryon Octet In Effective Field Theory
2015
We analyze the constraint structure of the interaction of vector mesons with baryons using the classical Dirac constraint analysis. We show that the standard interaction in terms of two independent SU(3) structures is consistent at the classical level. We then require the self-consistency condition of the interacting system in terms of perturbative renormalizability to obtain relations for the renormalized coupling constants at the one-loop level. As a result we find a universal interaction with one coupling constant which is the same as in the massive Yang-Mills Lagrangian of the vector-meson sector.
Vector meson exchange in radiative kaon decays and chiral perturbation theory
1990
7 páginas, 4 figuras,1 tabla.
Dominance of the first excitation step for magnetic circular dichroism in near-threshold two-photon photoemission
2012
Magnetic circular dichroism (MCD) in near-threshold photoemission is measured for a perpendicularly magnetized Cs/Co/Pt(111) film with work function adjusted by Cs adsorption. For one-photon photoe ...
Phenomenological applications of rational approximants
2016
We illustrate the powerfulness of Padé approximants (PAs) as a summation method and explore one of their extensions, the so-called quadratic approximant (QAs), to access both space- and (low-energy) time-like (TL) regions. As an introductory and pedagogical exercise, the function [Formula: see text] is approximated by both kind of approximants. Then, PAs are applied to predict pseudoscalar meson Dalitz decays and to extract [Formula: see text] from the semileptonic [Formula: see text] decays. Finally, the [Formula: see text] vector form factor in the TL region is explored using QAs.
Case in favor of theN*(1700)(3/2−)
2013
Using an interaction extracted from the local hidden-gauge Lagrangians, which brings together vector and pseudoscalar mesons, and the coupled channels rho N (s wave), pi N (d wave), pi Delta (s wave), and pi Delta (d wave), we look in the region ofv root s = 1400-1850 MeV and find two resonances dynamically generated by the interaction of these channels, which are naturally associated to N*(1520)(3/2(-)) and N*(1700)(3/2(-)). N*(1700)(3/2(-)) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the pi N (d-wave) data. Both the real and imaginary parts of the pi N amplitude vanish in our approach in the vicinity of this resonance, which is simila…
Effects of aNcc¯*resonance with hidden charm in theπ−p→D−Σc+reaction near threshold
2015
We study the effect of a hidden charm nuclear excited state ${N}_{c\overline{c}}^{*}$ in the ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{D}^{\ensuremath{-}}{\mathrm{\ensuremath{\Sigma}}}_{c}^{+}$ reaction near threshold using an effective Lagrangian approach. We calculate the background contribution of the $t$ and $u$ channels by the ${D}^{*0}$ vector meson exchange and ${\mathrm{\ensuremath{\Sigma}}}_{c}^{++}$ intermediate state, respectively. We show that the consideration of a ${N}_{c\overline{c}}^{*}$ resonance provides an enhancement of the total cross section close to the reaction threshold. We also evaluate the differential cross section for different energies and w…
ρρinteraction in the hidden gauge formalism and thef0(1370)andf2(1270)resonances
2008
We have studied the interaction of vector mesons within the hidden gauge formalism and applied it to the particular case of the $\ensuremath{\rho}\ensuremath{\rho}$ interaction. We find a strong attraction in the isospin, spin channels $I$, $S=0$, 0 and 0, 2, which is enough to bind the $\ensuremath{\rho}\ensuremath{\rho}$ system. We also find that the attraction in the $I$, $S=0$, 2 channel is much stronger than in the 0, 0 case. The states develop a width when the $\ensuremath{\rho}$ mass distribution is considered, and particularly when the $\ensuremath{\pi}\ensuremath{\pi}$ decay channel is turned on. Using a regularization scheme with cutoffs of natural size, we obtain results in fair …
Observation of the Dalitz decayη′→γe+e−
2015
We report the first observation of the Dalitz decay eta' -> gamma e(+)e(-), based on a data sample of 1.31 billion J/psi events collected with the BESIII detector. The eta' mesons are produced via the J/psi -> gamma eta' decay process. The ratio (eta' -> gamma e(+)e(-))/Gamma (eta' -> gamma gamma) is measured to be (2.13 +/- 0.09(stat) +/- 0.07(sys)) x 10(-2). This corresponds to a branching fraction B(eta' -> gamma e(+)e(-)) = (4.69 +/- 0.20(stat) +/- 0.23(sys)) x 10(-4). The transition form factor is extracted and different expressions are compared to the measured dependence on the e(+)e(-) invariant mass. The results are consistent with the prediction of the vector meson dominance model.
Measurement of the branching fractions of the radiative charm decaysD0→K¯*0γandD0→ϕγ
2008
We present a measurement of the branching fractions for the Cabibbo-favored radiative decay D^0→K ^(*0) γ and the Cabibbo-suppressed radiative decay D^0→ϕγ. These measurements are based on a data sample corresponding to an integrated luminosity of 387.1 fb^(-1) and recorded with the BABAR detector at the PEP-II e^+e^- asymmetric-energy collider operating at center-of-mass energies 10.58 and 10.54 GeV. We measure the branching fractions relative to the well-studied decay D^0→K^-π^+ and find B(D^0→K ^(*0) γ)/B(D^0→K^-π^+)=(8.43±0.51±0.70)×10^(-3) and B(D^0→ϕγ)/B(D^0→K^-π^+)=(7.15±0.78±0.69)×10^(-4), where the first error is statistical and the second is systematic. This is the first observat…