One-loop effective lagrangians after matching

We discuss the limitations of the covariant derivative expansion prescription advocated to compute the one-loop Standard Model (SM) effective lagrangian when the heavy fields couple linearly to the SM. In particular, one-loop contributions resulting from the exchange of both heavy and light fields must be explicitly taken into account through matching because the proposed functional approach alone does not account for them. We review a simple case with a heavy scalar singlet of charge $-1$ to illustrate the argument. As two other examples where this matching is needed and this functional method gives a vanishing result, up to renormalization of the heavy sector parameters, we re-evaluate the one-loop corrections to the T--parameter due to a heavy scalar triplet with vanishing hypercharge coupling to the Brout-Englert-Higgs boson and to a heavy vector-like quark singlet of charged $2/3$ mixing with the top quark, respectively. In all cases we make use of a new code for matching fundamental and effective theories in models with arbitrary heavy field additions.Comment: 22 pages; v2: comments and references added; v3: published version, typos correcte

Tau Custodian searches at the LHC

The tau lepton can be more composite than naively expected in models of strong electroweak symmetry breaking with tri-bimaximal lepton mixing. New leptonic resonances required by custodial symmetry, the tau custodians, can then be the first signal of this lepton flavor realization. Tau custodians can be very light, decaying almost exclusively into taus. The LHC reach for these new leptons is up to masses of 240, 480 and 720 GeV for sqrt{s}=14 TeV and an integrated luminosity of 30, 300 and 3000 fb^{-1}, respectively. Our analysis can be extended to any pair produced particles decaying mostly into taus and Standard Model bosons.Comment: 12 pages, 2 figure

Four and two-lepton signals of leptophilic gauge interactions at large colliders

Many Standard Model extensions can contribute to four-lepton signals at large colliders. We review the particular case of leptophilic interactions eventually observable at the LHC and the ILC, paying special attention to the addition of a new vector boson coupled to muon minus tau lepton number, $Z'_{\mu - \tau}$, and emphasizing the prospects at a very large hadron collider with $\sqrt s =$ 100 TeV. We also discuss in this case the new contribution to two-lepton (Drell-Yan) production when the new leptophilic interaction has a non-vanishing kinetic mixing with the SM.Comment: 12 pages, 5 figures, Contribution to the Proceedings of the Corfu Summer Institute 201

Light neutrino propagation in matter without heavy neutrino decoupling

We review the propagation of light neutrinos in matter assuming that their mixing with heavy neutrinos is close to present experimental limits. The phenomenological implications of the non-unitarity of the light neutrino mixing matrix for neutrino oscillations are discussed. In particular we show that the resonance effect in neutrino propagation in matter persists, but for slightly modified values of the parameters and with the maximum reduced by a small amount proportional to the mixing between light and heavy neutrinos squared

Effective description of brane terms in extra dimensions

We study how theories defined in (extra-dimensional) spaces with localized defects can be described perturbatively by effective field theories in which the width of the defects vanishes. These effective theories must incorporate a ``classical'' renormalization, and we propose a renormalization prescription a la dimensional regularization for codimension 1, which can be easily used in phenomenological applications. As a check of the validity of this setting, we compare some general predictions of the renormalized effective theory with those obtained in a particular ultraviolet completion based on deconstruction.Comment: 28 page

Heavy neutrino signals at large hadron colliders

We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp -> W+ -> l+ N -> l+ l+ jj (l=e,mu) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign charged leptons are not negligible and, moreover, they cannot be eliminated with simple sequential kinematical cuts. Using a likelihood analysis it is shown that, for heavy neutrinos coupling only to the muon, LHC has 5 sigma sensitivity for masses up to 200 GeV in the final state mu+- mu+- jj. This reduction in sensitivity, compared to previous parton-level estimates, is driven by the ~ 10^2-10^3 times larger background. Limits are also provided for e+- e+- jj and e+- mu+- jj final states, as well as for Tevatron. For heavy Dirac neutrinos the prospects are worse because backgrounds involving two opposite charge leptons are much larger. For this case, we study the observability of the lepton flavour violating signal e+- mu-+ jj. As a by-product of our analysis, heavy neutrino production has been implemented within the ALPGEN framework.Comment: Latex 36 pages, 49 PS figures. Major extension incorporating analysis for e+- e+-, e+- mu+- and e+- mu-+ final states. Final version to appear in JHE

Bulk fields with general brane kinetic terms

We analyse the effect of general brane kinetic terms for bulk scalars, fermions and gauge bosons in theories with extra dimensions, with and without supersymmetry. We find in particular a singular behaviour when these terms contain derivatives orthogonal to the brane. This is brought about by $\delta(0)$ divergences arising at second and higher order in perturbation theory. We argue that this behaviour can be smoothed down by classical renormalization.Comment: 31 pages, v2 few typos correcte

Similarity of sediment transport by water and air currents.

Massachusetts Institute of Technology. Dept. of Civil Engineering. Thesis. 1970. Civ.E.MICROFICHE COPY ALSO AVAILABLE IN BARKER ENGINEERING LIBRARY.Bibliography: leaves 98-104.Civ.E

Lepton number violation and scalar searches at the LHC

We review the SM extensions with scalar multiplets including doubly-charged components eventually observable as di-leptonic resonances at the LHC. Special emphasis is paid to the limits on LNV implied by doubly-charged scalar searches at the LHC, and to the characterization of the multiplet doubly-charged scalars belong to if they are observed to decay into same-sign charged lepton pairs

Diseño de adoquines de arcilla, con adición de fibras de bambú para mejorar la resistencia a la compresión, Lamas 2020

Esta investigación “Diseño de adoquines de arcilla, con adición de fibras de bambú para mejorar la resistencia a la compresión, Lamas 2020” tiene como objeto utilizar proporciones de fibra de bambú, para tener como resultado un diseño óptimo con mejor resistencia a compresión, se utilizó material de la ciudad de Tarapoto, con arcilla de la cantera “Lagartococha”, los bambús se utilizaron de las zonas aledañas a la ciudad de Tarapoto. Para poder obtener el diseño del adoquín de arcilla, se diseñó un molde de acero, de 20x10x6 cm, establecidas por la norma para tránsito peatonal y vehicular liviano, con la fibra de bambú se cortó y seco, pasando por procesos de molido hasta obtener fibra vegetal; como muestra patrón se hicieron 10 adoquines con 0% de adición de fibra de bambú y 40 adoquines con adición de fibra de bambú al 0.5%,1%, 1.5% y 2%, haciendo los estudios y análisis de estas muestras a los 7 y 14 días. Para el proceso de elaboración del diseño del adoquín de arcilla se mezcló de forma homogénea la arcilla con el agua para luego agregar la fibra de bambú, colocarlo en el molde y por último pasar por el proceso de cocción