965 research outputs found
DETERMINATION OF THE SURCHARGE THAT CONSUMERS ARE WILLING TO PAY FOR AN ORGANIC CHEESE IN SPAIN
Consumer requirements for preferably new, quality products with health guarantees are causing competitive adaptation by agro-food businesses. In this sense, cheese-producing enterprises are immersed in restructuring to adapt to the new scene. To assure the greatest possible success in this process it is advisable to determine what the preferences of cheese consumers are. In searching for the answer to this question, 420 surveys were made on regular food shoppers for at-home consumption in the metropolitan area of Madrid (Spain). Treatment of this data consisted in using the Conjoint Analysis technique and maximum willingness to pay. Results show that the main differentiating element for cheese is origin and the maximum willing to pay for an organic cheese with respect a conventional one is 15.42%.Consumer behaviour, Organic, Food Marketing, Demand and Price Analysis,
T and CPT Symmetries in Entangled Neutral Meson Systems
Genuine tests of an asymmetry under T and/or CPT transformations imply the
interchange between in-states and out-states. I explain a methodology to
perform model-indepedent separate measurements of the three CP, T and CPT
symmetry violations for transitions involving the decay of the neutral meson
systems in B- and {\Phi}-factories. It makes use of the quantum-mechanical
entanglement only, for which the individual state of each neutral meson is not
defined before the decay of its orthogonal partner. The final proof of the
independence of the three asymmetries is that no other theoretical ingredient
is involved and that the event sample corresponding to each case is different
from the other two. The experimental analysis for the measurements of these
three asymmetries as function of the time interval {\Delta}t > 0 between the
first and second decays is discussed, as well as the significance of the
expected results. In particular, one may advance a first observation of true,
direct, evidence of Time-Reserval-Violation in B-factories by many standard
deviations from zero, without any reference to, and independent of,
CP-Violation. In some quantum gravity framework the CPT-transformation is
ill-defined, so there is a resulting loss of particle-antiparticle identity.
This mechanism induces a breaking of the EPR correlation in the entanglement
imposed by Bose statistics to the neutral meson system, the so-called
{\omega}-effect. I present results and prospects for the {\omega}-parameter in
the correlated neutral meson-antimeson states.Comment: Proc. DISCRETE 2010, Symposium on Prospects in the Physics of
Discrete Symmetries, December 2010, Rom
Universal extra dimensions and Z->b bar-b
We study, at the one loop level, the dominant contributions from a single
universal extra dimension to the process (Z\to b\bar{b}). By resorting to the
gaugeless limit of the theory we explain why the result is expected to display
a strong dependence on the mass of the top-quark, not identified in the early
literature. A detailed calculation corroborates this expectation, giving rise
to a lower bound for the compactification scale which is comparable to that
obtained from the parameter. An estimate of the subleading corrections
is furnished, together with a qualitative discussion on the difference between
the present results and those derived previously for the non-universal case.Comment: 16 pages, 4 figures, revtex
Probing CPT in transitions with entangled neutral kaons
In this paper we present a novel CPT symmetry test in the neutral kaon system based, for the first time, on the direct comparison of the probabilities of a transition and its CPT reverse. The required interchange of in out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a phi-factory. The observable quantities have been constructed by selecting the two semileptonic decays for flavour tag, the pi and 3 pi(0) decays for CP tag and the time orderings of the decay pairs. The interpretation in terms of the standard Weisskopf-Wigner approach to this system, directly connects CPT violation in these observables to the violating R delta parameter in the mass matrix of K-0 (K) over bar (0), a genuine CPT violating effect independent of Delta Gamma and not requiring the decay as an essential ingredient. Possible spurious effects induced by CP violation in the decay and/or a violation of the Delta S = Delta Q rule have been shown to be well under control. The proposed test is thus fully robust, and might shed light on possible new CPT violating mechanisms, or further improve the precision of the present experimental limits. It could be implemented at the DA Phi NE facility in Frascati, where the KLOE-2 experiment might reach a statistical sensitivity of O (10(-3)) on the newly proposed observable quantities
Spin Physics at e^+e^- Colliders
A large number of measurements with polarized beams and/or spin analysis of
final state particles has been performed at the e^+e^- colliders LEP and SLC,
providing important information on the dynamics of high energy interactions. In
this paper three subjects, for which the role of spin studies was particularly
relevant, will be covered: the measurements of the electroweak couplings, the
study of fragmentation dynamics and the search for physics beyond the Standard
Model.Comment: 11 pages, Invited talk given at the International Workshop on
Symmetry and Spin - Prague, Czech Republic, August 30 - September 5, 199
Electroweak Baryogenesis in the Presence of an Isosinglet Quark
We consider the possibility of electroweak baryogenesis in a simple extension
of the standard model with an extra singlet complex scalar and a vector-like
down quark. We show that in the present model the first-order electroweak phase
transition can be strong enough to avoid the baryon asymmetry washout by
sphalerons and that the CP-violating effects can be sufficient to explain the
observed baryon-to-entropy ratio nB/s ~ 10^(-10). Other appealing features of
the model include the generation of a CKM phase from spontaneous CP breaking at
a high energy scale and a possible solution of the strong CP problem through
the natural suppression of the parameter theta.Comment: LaTeX, 19 pages, 2 EPS figures, uses epsf, amsmath, amsfonts, amssym
Identification of vaginal microbiome associated with IVF pregnancy
The factors that cause a preterm birth (PTB) are not completely understood up to date. Moreover,
PTB is more common in pregnancies achieved by in-vitro fertilization (IVF) than in spontaneous
pregnancies. Our aim was to compare the composition of vaginal microbiome at 12 weeks of gestation
between women who conceived naturally or through IVF in order to study whether IVF PTB-risk could
be related to vaginal microbiome composition. We performed an observational, prospective and
multicentre study among two public hospitals and a fertility private clinic in Spain. Vaginal swabs from
64 pregnant women at 12 weeks of gestation were collected to analyse the microbiome composition
by sequencing the V3–V4 region of the 16S rRNA. Our results showed that the vaginal microbiome
signature at 12 weeks of pregnancy was different from women who conceived naturally or through
IVF. The beta diversity and the genus composition were different between both cohorts. Gardnerella,
Neisseria, Prevotella, and Staphylococcus genus were enriched genus in the vaginal microbiome from
the IVF group, allowing us to create a balance model to predict both cohorts. Moreover, at species
level the L. iners abundance was higher and L. gasseri was lower in the IVF group. As a conclusion, our
findings were consistent with a proposed framework in which IVF pregnancy are related to risk for
preterm birth (PTB) suggesting vaginal microbiome could be the reason to the relation between IVF
pregnancy and risk for PTB
On a Neutrino Electroweak Radius
We study a combination of amplitudes for neutrino scattering that can isolate
a (gauge-invariant) difference of chirality-preserving neutrino electroweak
radii for and . This involves both photon and
exchange contributions. It is shown that the construction singles out the
contributions of the hypercharge gauge field in the standard model.
We comment on how gauge-dependent terms from the charge radii cancel with other
terms in the relative electroweak radii defined.Comment: 16 pages, revtex with embedded figure
Entanglement and Nonunitary Evolution
We consider a collapsing relativistic spherical shell for a free quantum
field. Once the center of the wavefunction of the shell passes a certain radius
R, the degrees of freedom inside R are traced over. We show that an observer
outside this region will determine that the evolution of the system is
nonunitary. We argue that this phenomenon is generic to entangled systems, and
discuss a possible relation to black hole physics.Comment: 14 pages, 1 figure; Added a clarification regarding the relation with
black hole physic
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