Psychological effects of substantial and appetizing menus for submarine personnel

Psychological effects of food service on submarine personne

Causality in Time-Neutral Cosmologies

Gell-Mann and Hartle (GMH) have recently considered time-neutral cosmological models in which the initial and final conditions are independently specified, and several authors have investigated experimental tests of such models. We point out here that GMH time-neutral models can allow superluminal signalling, in the sense that it can be possible for observers in those cosmologies, by detecting and exploiting regularities in the final state, to construct devices which send and receive signals between space-like separated points. In suitable cosmologies, any single superluminal message can be transmitted with probability arbitrarily close to one by the use of redundant signals. However, the outcome probabilities of quantum measurements generally depend on precisely which past {\it and future} measurements take place. As the transmission of any signal relies on quantum measurements, its transmission probability is similarly context-dependent. As a result, the standard superluminal signalling paradoxes do not apply. Despite their unusual features, the models are internally consistent. These results illustrate an interesting conceptual point. The standard view of Minkowski causality is not an absolutely indispensable part of the mathematical formalism of relativistic quantum theory. It is contingent on the empirical observation that naturally occurring ensembles can be naturally pre-selected but not post-selected.Comment: 5 pages, RevTeX. Published version -- minor typos correcte

Almost Certain Escape from Black Holes

This paper examines how black holes might compute in light of recent models of the black-hole final state. These models suggest that quantum information can escape from the black hole by a process akin to teleportation. They require a specific final state and restrictions on the interaction between the collapsing matter and the incoming Hawking radiation for quantum information to escape. This paper shows that for an arbitrary final state and for generic interactions between matter and Hawking radiation, the quantum information about how the hole was formed and the results of any computation performed by the matter inside the hole escapes with fidelity exponentially close to 1.Comment: 9 Pages, Te

N K and Delta K states in the chiral SU(3) quark model

The isospin I=0 and I=1 kaon-nucleon $S$, $P$, $D$, $F$ wave phase shifts are studied in the chiral SU(3) quark model by solving the resonating group method (RGM) equation. The calculated phase shifts for different partial waves are in agreement with the experimental data. Furthermore, the structures of the $\Delta K$ states with L=0, I=1 and I=2 are investigated. We find that the interaction between $\Delta$ and $K$ in the case of L=0, I=1 is attractive, which is not like the situation of the $NK$ system, where the $S$-wave interactions between $N$ and $K$ for both I=0 and I=1 are repulsive. Our numerical results also show that when the model parameters are taken to be the same as in our previous $NN$ and $YN$ scattering calculations, the $\Delta K$ state with L=0 and I=1 is a weakly bound state with about 2 MeV binding energy, while the one with I=2 is unbound in the present one-channel calculation.Comment: 14 pages, 6 figures. PRC70,064004(2004

Fermion Mass Hierarchy in Lifshitz Type Gauge Theory

We study the origin of fermion mass hierarchy and flavor mixing in a Lifshitz type extension of the standard model including an extra scalar field. We show that the hierarchical structure can originate from renormalizable interactions. In contrast to the Froggatt-Nielsen mechanism, the higher the dimension of associated operators, the heavier the fermion masses. Tiny masses for left-handed neutrinos are obtained without introducing right-handed neutrinos.Comment: 13 pages; clarifications of some point

Probing minimal supergravity in the type-I seesaw mechanism with lepton flavour violation at the CERN LHC

The most general supersymmetric seesaw mechanism has too many parameters to be predictive and thus can not be excluded by any measurements of lepton flavour violating (LFV) processes. We focus on the simplest version of the type-I seesaw mechanism assuming minimal supergravity boundary conditions. We compute branching ratios for the LFV scalar tau decays, ${\tilde \tau}_2 \to (e,\mu) + \chi^0_1$, as well as loop-induced LFV decays at low energy, such as $l_i \to l_j + \gamma$ and $l_i \to 3 l_j$, exploring their sensitivity to the unknown seesaw parameters. We find some simple, extreme scenarios for the unknown right-handed parameters, where ratios of LFV branching ratios correlate with neutrino oscillation parameters. If the overall mass scale of the left neutrinos and the value of the reactor angle were known, the study of LFV allows, in principle, to extract information about the so far unknown right-handed neutrino parameters.Comment: 29 pages, 27 figures; added explanatory comments, corrected typos, final version for publicatio

Alternative Large Nc Schemes and Chiral Dynamics

We compare the dependences on the number of colors of the leading pion pion scattering amplitudes using the single index quark field and two index quark fields. These are seen to have different relationships to the scattering amplitudes suggested by chiral dynamics which can explain the long puzzling pion pion s wave scattering up to about 1 GeV. This may be interesting for getting a better understanding of the large Nc approach as well as for application to recently proposed technicolor models.Comment: RevTex, two-columns, 6 page

String-Inspired Triplet See-Saw from Diagonal Embedding of SU(2)_L in SU(2)_A x SU(2)_B

Motivated by string constructions, we consider a variant on the Type II see-saw mechanism involving the exchange of triplet representations of SU(2)_L in which this group arises from a diagonal embedding into SU(2)_A x SU(2)_B. A natural assignment of Standard Model lepton doublets to the two underlying gauge groups results in a bimaximal pattern of neutrino mixings and an inverted hierarchy in masses. Simple perturbations around this leading-order structure can accommodate the observed pattern of neutrino masses and mixings.Comment: 8 pages; uses RevTe

Dirac neutrino mass from the beta decay end-point modified by the dynamics of a Lorentz-violating equation of motion

Using a generalized procedure for obtaining the equation of motion of a propagating fermionic particle, we examine previous claims for a lightlike preferred axis embedded in the framework of Lorentz-invariance violation with preserved algebra. In a high energy scale, the corresponding equation of motion is reduced to a conserving lepton number chiral (VSR) equation, and in a low energy scale, the Dirac equation for a free is recovered. The new dynamics introduces some novel ingredients (modified cross section) to the phenomenology of the tritium beta decay end-point.Comment: 11 pages, 4 figure