Thermodynamics of Chaplygin gas

We clarify thermodynamics of the Chaplygin gas by introducing the integrability condition. All thermal quantities are derived as functions of either volume or temperature. Importantly, we find a new general equation of state, describing the Chaplygin gas completely. We confirm that the Chaplygin gas could show a unified picture of dark matter and energy which cools down through the universe expansion without any critical point (phase transition).Comment: 5 pages, 4 figures, version "Accepted for publication in Astrophysics & Space Science

A More Flavored Higgs boson in Supersymmetric models

A More flavored Higgs boson arises when the flavor structure encoded in SUSY extensions of the SM is transmited to the Higgs sector. The flavor-Higgs transmition mechanism can have a radiative or mixing origin, as it is illustrated with several examples, and can produce interesting Higgs signatures that can be probed at future high-energy colliders. Within the MSSM, the flavor mediation mechanism can be of radiative type, as it is realized trhough gaugino-slepton loops, which transmit the flavor structture of the soft-breaking sector to the Higgs bosons. In particular we focus on evaluating the contributions from the general trilinear terms to the lepton flavor violating Higgs (LFV) vertices. On the other hand, as an example of flavor mediation through mixing, we discuss an E_6 inspired multi-Higgs model, with an abelian flavor symmetry, where LFV as well as lepton flavor conserving Higgs effects are found to arise, though in this case at tree-level. We find that Tevatron and LHC can provide information on the flavor structure of these models through the detection of the LFV higgs mode h-> tau+mu, while NLC can perform high-precision measurements of the LFC mode h-> tau tau.Comment: 17 pages, 5 tables, 3 figures; corrected mistake in last section, results changed but conclusions remmai

History repeats? : the rise of the new middle classes in the developing world

1. Although the ability to detect chemical cues is widespread in many organisms, it is surprising how little is known about the role of chemical communication in avian life histories. Nowadays, growing evidence suggests that birds can use olfaction in several contexts. However, we still do not know the role of bird olfaction in one of the most important determinants of survival, predator detection. 2. Blue tits, Cyanistes caeruleus L., were exposed to chemical cues of: (i) mustelid (predator), (ii) quail (odorous control); or (iii) water (odourless control) inside the nest-box where they were provisioning 8-day-old nestlings. 3. We show that blue tits were able to detect the chemical cues and showed antipredatory behaviours to cope with the risk of predation. Birds delayed their entry to the nest-box, and they perched on the hole of the nest-box and refused to enter more times when they found predator scent than control scents inside the nest-box. In addition, birds decreased the time spent inside the predator-scented nest-box when feeding nestlings. 4. The discovery of the ability of birds to use chemical cues of predators to accurately assess predation may help to understand many aspects of bird life histories that have been neglected until now.Peer reviewe

Testing postcombustion CO2 capture with CaO in a 1.7 MWt pilot facility

AbstractCalcium looping, CaL, is a new and rapidly developing technology that makes use of CaO as a high temperature regenerable sorbent of CO2. Previous theoretical and lab scale studies have shown that this technology could lead to a substantial reduction in the cost of CO2 capture and energy penalties because heat can be effectively recovered from this high temperature solid looping system. We report in this paper on the first results from a pilot plant designed to demonstrate the viability of postcombustion capture of CO2 using CaL under conditions comparable to those expected in a large scale plant. The pilot includes two interconnected circulating fluidized bed reactors of 15 m height: a CO2 absorber (carbonator) able to treat up to 2400kg/h (equivalent to about 1.7 MWth), and an oxy-fired CFB calciner with a firing power between 1-3 MWth. CO2 capture efficiencies over 90% have been experimentally observed, including continuous operation with highly cycled solids in the system (i.e. with modest CO2 carrying capacities). SO2 capture is shown to be extremely high, with concentrations of SO2 well below 10 ppmv at the exit of the carbonator. Closure of carbon and sulfur balances is satisfactory. These results should be valuable base for model validation and scaling up purposes in future stages of the EU FP7 “CaOling” project, under which this investigation has been carried out

Charged lepton Flavor Violation in Supersymmetry with Bilinear R-Parity Violation

The simplest unified extension of the Minimal Supersymmetric Standard Model with bi-linear R-parity violation naturally predicts a hierarchical neutrino mass spectrum, suitable to explain atmospheric and solar neutrino fluxes. We study whether the individual violation of the lepton numbers L_{e,mu,tau} in the charged sector can lead to measurable rates for BR(mu->e gamma)and $BR(tau-> mu gamma). We find that some of the R-parity violating terms that are compatible with the observed atmospheric neutrino oscillations could lead to rates for mu->e gamma measurable in projected experiments. However, the Delta m^2_{12} obtained for those parameters is too high to be compatible with the solar neutrino data, excluding therefore the possibility of having measurable rates for mu->e gamma in the model.Comment: 29 pages, 8 figures. Constraint from solar neutrino data included, conclusions changed respect v

Lepton masses in a supersymmetric 3-3-1 model

We consider the mass generation for both charginos and neutralinos in a 3-3-1 supersymmetric model. We show that R-parity breaking interactions leave the electron and one of the neutrinos massless at the tree level. However the same interactions induce masses for these particles at the 1-loop level. Unlike the similar situation in the MSSM the masses of the neutralinos are related to the masses of the charginos.Comment: RevTex, 11 pages incluing 2 .eps figures. Extended published versio

Solar Neutrino Masses and Mixing from Bilinear R-Parity Broken Supersymmetry: Analytical versus Numerical Results

We give an analytical calculation of solar neutrino masses and mixing at one-loop order within bilinear R-parity breaking supersymmetry, and compare our results to the exact numerical calculation. Our method is based on a systematic perturbative expansion of R-parity violating vertices to leading order. We find in general quite good agreement between approximate and full numerical calculation, but the approximate expressions are much simpler to implement. Our formalism works especially well for the case of the large mixing angle MSW solution (LMA-MSW), now strongly favoured by the recent KamLAND reactor neutrino data.Comment: 34 pages, 14 ps figs, some clarifying comments adde

Reconstructing Neutrino Properties from Collider Experiments in a Higgs Triplet Neutrino Mass Model

We extend the minimal supersymmetric standard model with bilinear R-parity violation to include a pair of Higgs triplet superfields. The neutral components of the Higgs triplets develop small vacuum expectation values (VEVs) quadratic in the bilinear R-parity breaking parameters. In this scheme the atmospheric neutrino mass scale arises from bilinear R-parity breaking while for reasonable values of parameters the solar neutrino mass scale is generated from the small Higgs triplet VEVs. We calculate neutrino masses and mixing angles in this model and show how the model can be tested at future colliders. The branching ratios of the doubly charged triplet decays are related to the solar neutrino angle via a simple formula.Comment: 19 pages, 4 figures; one formula corrected, two author's names corrected; some explanatory comments adde