Local Realistic Theories and Quantum Mechanics for the two-neutral-kaon system

The predictions of local realistic theories for the observables concerning the evolution of a $K^0\bar{K}^0$ quantum entangled pair (created in the decay of the $\phi$-meson) are discussed. It is shown, in agreement with Bell's theorem, that the most general local hidden-variable model fails in reproducing the whole set of quantum-mechanical joint probabilities. We achieve these conclusion by employing two different approaches. In a first one the local realistic observables are deduced from the most general premises concerning locality and realism, and Bell-like inequalities are not employed. The other approach makes use of Bell's inequalities. Within the former scheme, under particular conditions for the detection times, the discrepancy between quantum mechanics and local realism for the time-dependent asymmetry turns out to be not less than 20%. The same incompatibility can be made evident by means of a Bell-type test by employing both Wigner's and (once properly normalized probabilities are used) Clauser-Holt-Shimony-Holt's inequalities. Because of the relatively low experimental accuracy, the data obtained by the CPLEAR collaboration for the asymmetry parameter do not allow for a decisive test of local realism. Such a test, both with and without the use of Bell's inequalities, should be feasible in the future at the Frascati $\Phi$-factory.Comment: 36 pages, 4 figure

Etude de la thermogravitation dans une couche fluide horizontale

Nous présentons une étude analytique et numérique de l’action conjuguée de la thermodiffusion et de la convection, dite diffusion thermogravitationnelle, dans les mélanges binaires. Il s’agit de quantifier l’importance de la séparation dans le cas d’une cavité parallélépipédique horizontale remplie d’un mélange binaire et soumise à des gradients horizontaux de température constants sur les deux parois horizontales, les autres parois sont imperméables à la matière et thermiquement isolées. Cette nouvelle procédure diffère de celle habituellement utilisée et qui consiste à obtenir la séparation thermogravitationnelle dans une cellule verticale dont deux parois verticales sont maintenues à des températures constantes et différentes

Neutrino oscillations and neutrinoless double beta decay

The relation between neutrino oscillation parameters and neutrinoless double beta decay is studied, assuming normal and inverse hierarchies for Majorana neutrino masses. For normal hierarchy the crucial dependence on U_{e3} is explored. The link with tritium beta decay is also briefly discussed.Comment: RevTex, 9 pages with 3 figures. Few comments and references adde

One-Loop Amplitudes for e^+ e^- to Four Partons

We present the first explicit formulae for the complete set of one-loop helicity amplitudes necessary for computing next-to-leading order corrections for e^+ e^- annihilation into four jets, for W, Z or Drell-Yan production in association with two jets at hadron colliders, and for three-jet production in deeply inelastic scattering experiments. We include a simpler form of the previously published amplitudes for e^+ e^- to four quarks. We obtain the amplitudes using their analytic properties to constrain their form. Systematically eliminating spurious poles from the amplitudes leads to relatively compact results.Comment: Tex, 82 pages, Maple and Mathematica files containing the amplitudes are available from the author

A Cryogenic Underground Observatory for Rare Events: Cuore, an Update

CUORE is a proposed tightly packed array of 1000 TeO_{2} bolometers, each being a cube 5 cm on a side with a mass of 750 gms. The array consists of 25 vertical towers, arranged in a square, of 5 towers by 5 towers, each containing 10 layers of 4 crystals. The design of the detector is optimized for ultralow- background searches for neutrinoless double beta decay of ^{130}Te (33.8% abundance), cold dark matter, solar axions, and rare nuclear decays. A preliminary experiment involving 20 crystals of various sizes (MIBETA) has been completed, and a single CUORE tower is being constructed as a smaller scale experiment called CUORICINO. The expected performance and sensitivity, based on Monte Carlo simulations and extrapolations of present results, are reported.Comment: in press: Nucl. Phys. of Russian Academy of Sc

Double Beta Decay: Historical Review of 75 Years of Research

Main achievements during 75 years of research on double beta decay have been reviewed. The existing experimental data have been presented and the capabilities of the next-generation detectors have been demonstrated.Comment: 25 pages, typos adde

Recent advances in neutrinoless double beta decay search

Even after the discovery of neutrino flavour oscillations, based on data from atmospheric, solar, reactor, and accelerator experiments, many characteristics of the neutrino remain unknown. Only the neutrino square-mass differences and the mixing angle values have been estimated, while the value of each mass eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is still escaping. Neutrinoless double beta decay ($0\nu$-DBD) experimental discovery could be the ultimate answer to some delicate questions of elementary particle and nuclear physics. The Majorana description of neutrinos allows the $0\nu$-DBD process, and consequently either a mass value could be measured or the existence of physics beyond the standard should be confirmed without any doubt. As expected, the $0\nu$-DBD measurement is a very difficult field of application for experimentalists. In this paper, after a short summary of the latest results in neutrino physics, the experimental status, the R&D projects, and perspectives in $0\nu$-DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic

CUORE: A Cryogenic Underground Observatory for Rare Events

CUORE is a proposed tightly packed array of 1000 TeO2 bolometers, each being a cube 5 cm on a side with a mass of 760 g. The array consists of 25 vertical towers, arranged in a square of 5 towers by 5 towers, each containing 10 layers of 4 crystals. The design of the detector is optimized for ultralow-background searches: for neutrinoless double beta decay of 130Te (33.8% abundance), cold dark matter, solar axions, and rare nuclear decays. A preliminary experiment involving 20 crystals 3x3x6 cm3 of 340 g has been completed, and a single CUORE tower is being constructed as a smaller scale experiment called CUORICINO. The expected performance and sensitivity, based on Monte Carlo simulations and extrapolations of present results, are reported.Comment: 39 pages, 12 figures, submitted to NI

Neutrinoless Double Beta Decay in Gauge Theories

Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. Its observation will severely constrain the existing models and signal that the neutrinos are massive Majorana particles. From the elementary particle point of view it pops up in almost every model. In addition to the traditional mechanisms, like the neutrino mass, the admixture of right handed currents etc, it may occur due to the R-parity violating supersymmetric (SUSY) interactions. From the nuclear physics point of view it is challenging, because: 1) The relevant nuclei have complicated nuclear structure. 2) The energetically allowed transitions are exhaust a small part of all the strength. 3) One must cope with the short distance behavior of the transition operators, especially when the intermediate particles are heavy (eg in SUSY models). Thus novel effects, like the double beta decay of pions in flight between nucleons, have to be considered. 4) The intermediate momenta involved are about 100 MeV. Thus one has to take into account possible momentum dependent terms in the nucleon current. We find that, for the mass mechanism, such modifications of the nucleon current for light neutrinos reduce the nuclear matrix elements by about 25 per cent, almost regardless of the nuclear model. In the case of heavy neutrinos the effect is much larger and model dependent. Taking the above effects into account, the available nuclear matrix elements for the experimentally interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 and the experimental limits on the life times we have extracted new stringent limits on the average neutrino mass and on the R-parity violating coupling for various SUSY models.Comment: Latex, 24 pages, 1 postscript figure, uses iopconf.st

In Quest of Neutrino Masses at O{\cal{O}}(eV) Scale

Neutrino oscillation and tritium beta decay experiments taken simultaneously into account are able to access the so far imperceptible absolute neutrino masses at the electronvolt level. The neutrino mass spectrum derived in this way is independent of the nature of neutrinos (Dirac or Majorana). Furthermore, the lack of neutrinoless double beta decay gives additional constraints on the Majorana neutrino mass spectrum. A case of three neutrinos is examined. Influence of different solutions to the solar neutrino deficit problem on the results is discussed. Apart from the present situation, four qualitatively distinct experimental situations which are possible in the future are investigated: when the two decay experiments give only upper bounds on effective neutrino masses, when either one of them gives a positive result, and when both give positive results. The discussion is carried out by taking into account the present experimental errors of relevant neutrino parameters as well as their much more precise expected estimations (e.g. by $\nu$ factories). It is shown in which cases the upgraded decay experiments simultaneously with neutrino oscillation data may be able to fix the absolute scale of the neutrino mass spectrum, answer the question of the neutrino nature and put some light on CP phases in the lepton sector.Comment: 30 pages, 6 figs, to appear in PR