0ν2β0\nu2\beta Nuclear Matrix Elements and Neutrino Magnetic Moments

We compare different methods of obtaining the neutrinoless double beta decay nuclear matrix elements (NME). On the example of 76Ge we use the NME to calculate the Majorana neutrino transition magnetic moments, generated through particle-sparticle R-parity violating loop diagrams whithin the minimal supersymmetric standard model.Comment: I've decided to move the collection of my papers to arXiv for easier access. Proceedings of the Nuclear Physics Workshop in Kazimierz Dolny, Poland, 200

Space-time directional Lyapunov exponents for cellular automata

Space-time directional Lyapunov exponents are introduced. They describe the maximal velocity of propagation to the right or to the left of fronts of perturbations in a frame moving with a given velocity. The continuity of these exponents as function of the velocity and an inequality relating them to the directional entropy is proved

Constraining Bilinear R-Parity Violation from Neutrino Masses

We confront the R-parity violating MSSM model with the neutrino oscillation data. Investigating the 1-loop particle-sparticle diagrams with additional bilinear insertions on the external neutrino lines we construct the relevant contributions to the neutrino mass matrix. A comparison of the so-obtained matrices with the experimental ones assuming normal or inverted hierarchy and taking into account possible CP violating phases, allows to set constraints on the values of the bilinear coupling constants. A similar calculation is presented with the input from the Heidelberg-Moscow neutrinoless double beta decay experiment. We base our analysis on the renormalization group evolution of the MSSM parameters which are unified at the GUT scale. Using the obtained bounds we calculate the contributions to the Majorana neutrino transition magnetic moments.Comment: I've decided to move the collection of my papers to arXiv for easier acces

SL(2,C) Chern-Simons Theory, a non-Planar Graph Operator, and 4D Loop Quantum Gravity with a Cosmological Constant: Semiclassical Geometry

We study the expectation value of a nonplanar Wilson graph operator in SL(2,C) Chern-Simons theory on $S^3$. In particular we analyze its asymptotic behaviour in the double-scaling limit in which both the representation labels and the Chern-Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat connection on the graph complement manifold. We find that flat connections in this class are in correspondence with the geometries of constant curvature 4-simplices. The result is fully non-perturbative from the perspective of the reconstructed geometry. We also show that the asymptotic behavior of the amplitude contains at the leading order an oscillatory part proportional to the Regge action for the single 4-simplex in the presence of a cosmological constant. In particular, the cosmological term contains the full-fledged curved volume of the 4-simplex. Interestingly, the volume term stems from the asymptotics of the Chern-Simons action. This can be understood as arising from the relation between Chern-Simons theory on the boundary of a region, and a theory defined by an $F^2$ action in the bulk. Another peculiarity of our approach is that the sign of the curvature of the reconstructed geometry, and hence of the cosmological constant in the Regge action, is not fixed a priori, but rather emerges semiclassically and dynamically from the solution of the equations of motion. In other words, this work suggests a relation between 4-dimensional loop quantum gravity with a cosmological constant and SL(2,C) Chern-Simons theory in 3-dimensions with knotted graph defects.Comment: 54+11 pages, 9 figure

Four-dimensional Quantum Gravity with a Cosmological Constant from Three-dimensional Holomorphic Blocks

Prominent approaches to quantum gravity struggle when it comes to incorporating a positive cosmological constant in their models. Using quantization of a complex $\mathrm{SL}(2,\mathbb{C})$ Chern-Simons theory we include a cosmological constant, of either sign, into a model of quantum gravity.Comment: 5 pages and 2 figure

Widespread HCN maser emission in carbon-rich evolved stars

Context. HCN is a major constituent of the circumstellar envelopes of carbon-rich evolved stars, and rotational lines from within its vibrationally excited states probe parts of these regions closest to the stellar surface. A number of such lines are known to show maser action. Historically, in one of them, the 177 GHz $J=2\rightarrow1$ line in the $l$-doubled bending mode has been found to show relatively strong maser action, with results only published for a single object, the archetypical high-mass loss asymptotic giant branch (AGB) star IRC+10216. Aims. To examine how common 177 GHz HCN maser emission is, we conducted an exploratory survey for this line toward a select sample of carbon-rich asymptotic giant branch stars that are observable from the southern hemisphere. Methods. We used the Atacama Pathfinder Experiment 12 meter submillimeter Telescope (APEX) equipped with a new receiver to simultaneously observe three $J=2\rightarrow1$ HCN rotational transitions, the $(0,1^{{1}_{\rm c}},0)$ and $(0,1^{{1}_{\rm d}},0)$ $l$-doublet components, and the line from the (0,0,0) ground state. Results. The $(0,1^{{1}_{\rm c}},0)$ maser line is detected toward 11 of 13 observed sources, which all show emission in the (0,0,0) transition. In most of the sources, the peak intensity of the $(0,1^{{1}_{\rm c}},0)$ line rivals that of the (0,0,0) line; in two sources, it is even stronger. Except for the object with the highest mass-loss rate, IRC+10216, the $(0,1^{{1}_{\rm c}},0)$ line covers a smaller velocity range than the (0,0,0) line. Conclusions. Maser emission in the 177 GHz $J=2\rightarrow1$ $(0,1^{{1}_{\rm c}},0)$ line of HCN appears to be common in carbon-rich AGB stars. (Abbreviated)Comment: 12 pages (including appendix), 3 figures / Astronomy & Astrophysics (in press

Extra Dimensions and Neutrinoless Double Beta Decay Experiments

The neutrinoless double beta decay is one of the few phenomena, belonging to the non-standard physics, which is extensively being sought for in experiments. In the present paper the link between the half-life of the neutrinoless double beta decay and theories with large extra dimensions is explored. The use of the sensitivities of currently planned $0\nu2\beta$ experiments: DAMA, CANDLES, COBRA, DCBA, CAMEO, GENIUS, GEM, MAJORANA, MOON, CUORE, EXO, and XMASS, gives the possibility for a non-direct `experimental' verification of various extra dimensional scenarios. We discuss also the results of the Heidelberg--Moscow Collaboration. The calculations are based on the Majorana neutrino mass generation mechanism in the Arkani-Hamed--Dimopoulos--Dvali model.Comment: I've decided to move the collection of my papers to arXiv for easier acces