Monoidal categorifications of cluster algebras of type A and D

In this note, we introduce monoidal subcategories of the tensor category of finite-dimensional representations of a simply-laced quantum affine algebra, parametrized by arbitrary Dynkin quivers. For linearly oriented quivers of types A and D, we show that these categories provide monoidal categorifications of cluster algebras of the same type. The proof is purely representation-theoretical, in the spirit of [arXiv:0903.1452].Comment: 15 pages ; to appear in the proceedings of the Conference Symmetries, Integrable systems and Representation

Perturbation Theory for Fat-link Fermion Actions

We discuss weak coupling perturbation theory for lattice actions in which the fermions couple to smeared gauge links. The normally large integrals that appear in lattice perturbation theory are drastically reduced. Even without detailed calculation, it is easy to determine to good accuracy the scale of the logarithms that appear in cases where an anomalous dimension is present. We describe several 1-loop examples for fat-link Wilson and clover fermions. including the additive mass shift, the relation between the lattice and MSbar quark masses, and the axial current renormalization factor ($Z_A$) for light-light and static-light currents.Comment: LATTICE99(Improvement and Renormalization); 3 pages, no figure

Cluster algebras and quantum affine algebras

Let C be the category of finite-dimensional representations of a quantum affine algebra of simply-laced type. We introduce certain monoidal subcategories C_l (l integer) of C and we study their Grothendieck rings using cluster algebras.Comment: 55 pages, accepted for publication in Duke Mathematical Journa

Kaon B-parameter using Overlap Fermions

I present first results from an in-progress calculation of B_K in quenched approximation using overlap fermions. My particular implementation of the overlap uses a kernel with nearest and next-nearest neighbor interactions and HYP-blocked gauge connections. Matching to the continuum NDR regularization is done perturbatively. I present preliminary results at beta=5.9 and 6.1 (lattice spacings 0.125 and 0.09 fm) for quark masses, pseudoscalar decay constants, and B-parameter -- B_K(NDR(mu=2 GeV) is 0.66(3-4).Comment: 3 pages, Latex, 3 postscript figures. COLO-HEP-483; Lattice2002(matrixel

A global assessment of piezoelectric actuated micro-pumps

LGEP 2010 ID = 632International audienceThis article provides an extensive outlook of different types of piezoelectric actuated micro-pumps published in the literature recently. We start by reminding the reader about the conventional operating parameters used to quantify the capabilities of these devices. After this introductory stage, we describe and classify the most prominent micro-pump's geometries found with piezoelectric actuation. At this point we identify the parameters given previously for each pump in order to establish a subsequent discussion in which the trends of different families are compared. Specific attention is given to the particularities of each case namely: flow rates and backpressures

Heavy-light and light-light weak matrix elements on the lattice

I review recent developments in lattice weak matrix element calculations. I focus on on $f_B$ (both with propagating quarks and in the static limit for the $b$ quark), semi-leptonic form factors for $D$ meson decay, form factors for $B \to K^* \gamma$, and $B_K$. [Review presented at Lattice '93]Comment: 16 pages. (latex; 7 postscript figures included; 7 other figures are reproduced from work by others and are not available here. Some hardcopies of the talk will be available; send e-mail to [email protected].

Student-tutor for a PBL module: making the experience relevant for a future engineer

During their first week of engineering studies at the Institut National des Sciences Appliquées Toulouse, France, 300 first year students are introduced to Project/problem Based Learning thanks to an introductory module (PBL0) which is designed to be both technical and fun. In order to recognise and valorise this involvement, INSA has created a “Pedagogy module” which is validated by 3 credits as part of their engineering course. The module adopts an active learning approach. During the module, the student-tutors engage in activities which contribute to the development of transversal competencies required in the engineering profession but also the ability to reflect on one’s actions in order to progress in one’s learning.Peer Reviewe

f_B for Various Actions : Approaching the Continuum Limit with Dynamical Fermions

We present results for pseudoscalar decay constants of heavy-light mesons using both quenched and N_f = 2 dynamical fermion configurations. A variety of fermion actions is investigated : Wilson, nonperturbative clover, and fat-link clover. For heavy quarks the Fermilab formalism is applied. In the quenched approximation, results with the nonperturbatively improved clover action of the Alpha collaboration allow us to study the systematic error of the continuum extrapolation from the Wilson action. In addition, we use quenched configurations to explore the effects of fattening. The lessons from the quenched analyses are then applied to data with dynamical fermions, where both Wilson and fat-link clover actions have been used. This allows us to attempt a continuum extrapolation of the dynamical results.Comment: Lattice 2000 (Heavy Quark Physics). 4 pages, 2 figure

Light quark masses in quenched QCD with exact chiral symmetry

The parameters in the pseudoscalar meson mass formula in quenched chiral perturbation theory to one-loop order are determined by quenched lattice QCD with overlap Dirac operator, and from which the light quark masses are determined with the experimental inputs of pion and kaon masses, and the pion decay constant. Our results are $m_{u,d} = 5.3 \pm 0.3$ MeV, and $m_s = 115\pm 8$ MeV, in the $\bar{MS}$ scheme at scale $\mu = 2$ GeV.Comment: 5 pages, LaTeX, in v2: the missing numerical factor in (13) is restored, and the physical quark masses (16)-(17) are in good agreement with the current lattice world averag

Lattice results for the decay constant of heavy-light vector mesons

We compute the leptonic decay constants of heavy-light vector mesons in the quenched approximation. The reliability of lattice computations for heavy quarks is checked by comparing the ratio of vector to pseudoscalar decay constant with the prediction of Heavy Quark Effective Theory in the limit of infinitely heavy quark mass. Good agreement is found. We then calculate the decay constant ratio for B mesons: $f_{B^*}/f_B= 1.01(0.01)(^{+0.04}_{-0.01})$. We also quote quenched $f_{B^*}=177(6)(17)$ MeV.Comment: 11 pages, 3 postscript figs., revtex; two references adde