Search results for "mass [rho(770)]"
showing 10 items of 416 documents
Density-dependent body growth reduces the potential of marine reserves to enhance yields
2005
1. Some models of marine no-take reserves predict that reserves can enhance fishery yield. However, empirical evidence of this remains inconclusive. One reason for this may be the disregard for density-dependent body growth in most models. Density-dependent body growth links the number and size of individuals, and thus could influence the biomass of fishery yield. 2. We developed an age- and size-structured model of an exploited population and analysed the effect of implementing a no-take reserve of varying size. 3. Protecting part of a population from exploitation in a no-take reserve results in a rapid build-up of biomass inside the reserve because of increased survival. However, when bod…
Vertical structure of bi-layered microbial mats from Byers Peninsula, Maritime Antarctica
2013
AbstractA summer study of the vertical structure of bi-layered microbial mats was carried out on Byers Peninsula (Livingston Island, South Shetland Islands). These benthic communities had a common basic structure that consisted of two distinct layers differing in composition, morphology and colour. Our sampling focused on mats showing more layering, which thrived over moist soils and at the bottom of ponds. The photosynthetic pigments analysis performed by high-performance liquid chromatography demonstrated a major occurrence of cyanobacteria and diatoms on these mats, the former being more abundant in relative terms on the surface and composed by morphospecies grouping into orders Oscillat…
Physics at CERN's Antiproton Decelerator
2013
The Antiproton Decelerator of CERN began operation in 1999 to serve experiments for studies of CPT invariance by precision laser and microwave spectroscopy of antihydrogen ($\bar{\rm H}$) and antiprotonic helium ($\bar{p}{\rm He}^+$). The first 12 years of operation saw cold $\bar{\rm H}$ synthesized by overlapping clouds of positrons ($e^+$) and antiprotons ($\bar{p}$) confined in magnetic Penning traps. Cold $\bar{\rm H}$ was also produced in collisions between Rydberg positronium atoms and $\bar{p}$. Ground-state $\bar{\rm H}$ was later trapped for up to $\sim 1000$ s in a magnetic bottle trap, and microwave transitions excited between its hyperfine levels. In the $\bar{p}{\rm He}^+$ ato…
Combining data from high-energy p p -reactions and neutrinoless double-beta decay: Limits on the mass of the right-handed boson
2016
From the recently established lower-limits on the nonobservability of the neutrinoless double-beta decay of 76Ge (GERDA collaboration) and 136Xe (EXO-200 and KamLAND-Zen collaborations), combined with the ATLAS and CMS data, we extract limits for the left-right (LR) mixing angle, of the SU(2)L ×SU(2)R electroweak Hamiltonian. For the theoretical analysis, which is a model dependent, we have adopted a minimal extension of the Standard Model (SM) of Electroweak Interactions belonging to the SU(2)L ×SU(2)R representation. The nuclear-structure input of the analysis consists of a set of matrix elements and phase-space factors, and the experimental lower-limits for the half-lives. The other inpu…
Nonlocal energy density functionals for pairing and beyond-mean-field calculations
2017
We propose to use two-body regularized finite-range pseudopotential to generate nuclear energy density functional (EDF) in both particle-hole and particle-particle channels, which makes it free from self-interaction and self-pairing, and also free from singularities when used beyond mean field. We derive a sequence of pseudopotentials regularized up to next-to-leading order (NLO) and next-to-next-to-leading order (N2LO), which fairly well describe infinite-nuclear-matter properties and finite open-shell paired and/or deformed nuclei. Since pure two-body pseudopotentials cannot generate sufficiently large effective mass, the obtained solutions constitute a preliminary step towards future imp…
From transition magnetic moments to majorana neutrino masses
2005
It is well known that a majorana mass induces a (small) transition magnetic moment. The converse is also true; in this paper we estimate the loop contribution of transition magnetic moments $[\mu]_{\alpha \beta}$ to the neutrino mass matrix $[m]_{\alpha \beta}$. We show that for hierarchical neutrino masses, the contribution of $[\mu]_{e \tau}$ to $[m]_{e \tau}$ can exceed the experimental value of $[m]_{e \tau}$.
Neutrino phenomenology and stable dark matter with A4
2011
We present a model based on the A4 non-abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta_23 ~ pi/4 for very small reactor angle and deviation from maximal atmospheric mixing for large theta_13. Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be |m_ee| > 4 10^{-4} eV.
What can we learn from neutrinoless double beta decay experiments?
2004
We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but ne…
The new neutron-rich isotope228Rn
1989
2 pages, 1 table, 2 figures.-- PACS nrs.: 23.90.+w; 27.90.+b.-- Section: Short Notes.
On the ecology of littoral Oligochaeta of an oligotrophic Finnish lake
1982
In material sampled from 0.5–6 m on two sampling dates and three subareas the dominant Oligochaeta were Limnodrilus hoffmeisteri Claparede and Peloscolex ferox (Eisen), both composing more than 30% of the abundances of oligochaetes present. The numbers of Oligochaeta were mostly higher in August than in May. Regional differences could be found although the lake seems to be very homogenous. Temporal and vertical variations were detectable in separate subareas. The oligochaete biomass was maximal at 2 m depth. In soft bottom sediments the oligochaetes composed 15.9% of macrobenthos biomass and 12.2% of numbers, but on the stony bottom only 1.9% of numbers. The ratio of Oligochaeta/Chironomida…