Twisted mass chiral perturbation theory for 2+1+1 quark flavours

We present results for the masses of pseudoscalar mesons in twisted mass lattice QCD with a degenerate doublet of u and d quarks and a non-degenerate doublet of s and c quarks in the framework of next-to-leading order chiral perturbation theory, including lattice effects up to O(a^2). The masses depend on the two twist angles for the light and heavy sectors. For maximal twist in both sectors, O(a)-improvement is explicitly exhibited. The mixing of flavour-neutral mesons is also discussed, and results in the literature for the case of degenerate s and c quarks are corrected.Comment: LaTeX2e, 12 pages, corrected typo

Hadron masses in QCD with one quark flavour

One-flavour QCD - a gauge theory with SU(3) colour gauge group and a fermion in the fundamental representation - is studied by Monte Carlo simulations. The mass spectrum of hadronic bound states is investigated in a volume with extensions of L ~ 4.4r_0 (~2.2fm) at two different lattice spacings: a ~ 0.37r_0 (~0.19fm) and a ~ 0.27r_0 (~0.13fm). The lattice action is Symanzik tree-level-improved Wilson action for the gauge field and (unimproved) Wilson action for the fermion.Comment: 21 pages, 4 figures; further references adde

Collective dynamics in phospholipid bilayers investigated by inelastic neutron scattering: Exploring the dynamics of biological membranes with neutrons

We present the first inelastic neutron scattering study of the short wavelength dynamics in a phospholipid bilayer. We show that inelastic neutron scattering using a triple-axis spectrometer at the high flux reactor of the ILL yields the necessary resolution and signal to determine the dynamics of model membranes. The results can quantitatively be compared to recent Molecular Dynamics simulations. Reflectivity, in-plane correlations and the corresponding dynamics can be measured simultaneously to gain a maximum amount of information. With this method, dispersion relations can be measured with a high energy resolution. Structure and dynamics in phospholipid bilayers, and the relation between them, can be studied on a molecular length scale

Agenda 21 local como herramienta de desarollo sostenible : La situación en Suiza

1999an Suitzak bere konpromisoa bete zuen, garapen iraunkorra Konstituzioan barneratu baitzuen. Herrialde hau Tokiko Agenda 21 delakoaren moduko prozesu zehatzak sustatzeko hainbat estrategia ari da probatzen. 2005eko uztailean, Suitzako udalerrien % 4 baino ez zegoen prozesu honetan sartuta; hau da, biztanleriaren % 29. Suitzako tokiko agintaritzek, sistema federala dela eta, autonomia handia izan dute aspalditik; gainera, biztanleek demokrazia zuzeneko sistema suitzarraren bidez, Europako beste herrialde batzuetan baino zuzenago parte har dezakete erabaki politikoak hartzerakoan. Epe luzera, Garapen Iraunkorreko Estrategia Nazionalaren helburua garapen iraunkorra agintari publikoen jarduera eta politika guztietan barneratzea da.In 1999, Switzerland made good its pledge by writing sustainable development into its Constitution. Different strategies and programs are going on to promote Agenda 21-like processes. In July 2005, just 4% of municipalities were involved in the process, though this does represent 29% of the population. In Switzerland, under the country¿s federal system, local authorities have for a long time enjoyed considerable autonomy and, under the Swiss system of direct democracy, citizens are able to participate more fully in all political decision-making than in other countries. In the longer term, the aim of the National Sustainable development Strategy is to include sustainable development in all the policies and activities of public authorities.En 1999, Suiza cumplió con su compromiso al incluir el desarrollo sostenible en la Constitución. Este país está ensayando diferentes estrategias para fomentar determinados procesos del estilo de la Agenda 21 Local. En julio de 2005, tan sólo un 4% de los municipios suizos se habían involucrado en este proceso, si bien representan un 29% de la población. Las autoridades locales suizas, bajo un sistema federal, han disfrutado durante mucho tiempo de una autonomía considerable. Y los ciudadanos, mediante el sistema suizo de democracia directa, pueden participar de una manera más activa que en otros países europeos en la toma de decisiones políticas. A largo plazo, el objetivo de la Estrategia Nacional de Desarrollo Sostenible es incluir el desarrollo sostenible en todas las actividades y políticas de las autoridades pública

The supersymmetric Ward identities on the lattice

Supersymmetric (SUSY) Ward identities are considered for the N=1 SU(2) SUSY Yang Mills theory discretized on the lattice with Wilson fermions (gluinos). They are used in order to compute non-perturbatively a subtracted gluino mass and the mixing coefficient of the SUSY current. The computations were performed at gauge coupling $\beta$=2.3 and hopping parameter $\kappa$=0.1925, 0.194, 0.1955 using the two-step multi-bosonic dynamical-fermion algorithm. Our results are consistent with a scenario where the Ward identities are satisfied up to O(a) effects. The vanishing of the gluino mass occurs at a value of the hopping parameter which is not fully consistent with the estimate based on the chiral phase transition. This suggests that, although SUSY restoration appears to occur close to the continuum limit of the lattice theory, the results are still affected by significant systematic effects.Comment: 34 pages, 7 figures. Typo corrected, last sentence reformulated, reference added. To appear in Eur. Phys. J.

Mass Spectrum and Bounds on the Couplings in Yukawa Models With Mirror-Fermions

The $\rm SU(2)_L\otimes SU(2)_R$ symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling $\lambda$ is fixed at zero and infinity. The phase structure is explored and the relevant phase transition is found to be consistent with a second order one. The fermionic mass spectrum close to that transition is discussed and a first non-perturbative estimate of the influence of fermions on the upper and lower bounds on the renormalized scalar self-coupling is given. Numerical results are confronted with perturbative predictions.Comment: 7 (Latex) page