Renormalization of HQET ΔB=2\Delta B=2 operators: O(aa) improvement and 1/m1/m matching with QCD

We determine a basis of dimension-7 operators which arise at O($a$) in the Symanzik expansion of the $\Delta B=2$ operators with static heavy quarks. We consider both Wilson-like and Ginsparg-Wilson light quarks. Exact chiral symmetry reduces the number of these O($a$) counterterms by a factor of two. Only a subset of these operators has previously appeared in the literature. We then extend the analysis to the O($1/m$) operators contributing beyond the static approximation.Comment: 7 pages, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German

Non-perturbative scale evolution of four-fermion operators in two-flavour QCD

We apply finite-size recursion techniques based on the Schrodinger functional formalism to determine the renormalization group running of four-fermion operators which appear in the Delta S=2 effective weak Hamiltonian of the Standard Model. Our calculations are done using O(a) improved Wilson fermions with N_f=2 dynamical flavours. Preliminary results are presented for the four-fermion operator which determines the B_K parameter in tmQCD.Comment: 7 pages, 2 figures, talk presented at Lattice2006 (Renormalization

Renormalisation of quark bilinears with Nf=2 Wilson fermions and tree-level improved gauge action

We present results for the renormalisation constants of bilinear quark operators, using the Nf=2 twisted mass Wilson action at maximal twist (which guarantees automatic O(a) improvement) and the tree-level Symanzik improved gauge action. The scale-independent renormalisation constants are computed with a new method, which makes use of both standard twisted mass and Osterwalder-Seiler fermions. Moreover, the results from an RI-MOM calculation are presented for both scale independent and scale dependent renormalisation constants.Comment: 7 pages, talk at The XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensbur

Estudo das alterações renais em pacientes submetidos a transplante de medula óssea : microalbuminuria por ensaio imunoturbidimetrico, beta 2-microglobulina (B2-M) e proteina transportadora do retinol (RBP) por ensaios imunoenzimometricos

Orientador: Rogerio A. MulinariDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Medicina InternaResumo: O melhor conhecimento das complicações próprias do transplante e o suporte de novos agentes medicamentosos permitem sobrevida prolongada de uma parcela considerável de pacientes submetidos a transplante de medula óssea (TMO). Todavia, as complicações renais ocorrem em percentagem significativa e têm contribuído na morbidade nestes pacientes. Disfunções renais estão relacionadas às alterações da própria doença, ao uso de drogas, de irradiação e às complicações clínicas no pós-TMO. O objetivo foi detectar a presença de disfunção renal. Foram avaliados 11 pacientes submetidos a TMO admitidos seqüencialmente, independente de sexo e diagnóstico, excluídos os com diagnósticos de doença renal, hepática e doenças metabólicas prévias. Não ocorreu modificações da filtração glomerular. Verificou-se diminuição na excreção urinária de sódio possivelmente relacionada ao aumento da secreção de aldosterona e ao sistema coletor que reabsorveu sódio e volume em atendimento às necessidades do organismo. Houve alteração na excreção urinária de bicarbonato apenas nos pacientes que fizeram uso de anfotericina, sugerindo disfunção tubular secundária a droga. Não foi observada alteração da integridade da barreira de ultrafiltração glomerular avaliada pela microalbuminuria, portanto não se definindo lesão glomerular pós-transplante. A determinação da excreção urinária de proteínas de baixo peso molecular, como proteína transportadora do retinol ( RBP ) e beta 2- microglobulina (p 2-M ), permitiu estudar a integridade fimcional do sistema tubular renal. A avaliação conjunta evidenciou alteração da função dos túbulos renais após a realização do enxerto de medula óssea. Concluiu-se que ocorreu disfunção renal, primariamente tubular, após o TMO.Abstract: A better understanding of specific complications of Bone Marrow Transplantation (BMT) procedures, and the availability of new drugs have increased survival of a considerable amount of BMT patients. Nevertheless, renal dysfunction significantly contributes to the morbidity of those patients. Renal dysfunction may be a consequence of the underlying disease, of drugs, or irradiation as well as to clinical complications of transplantation procedures. The purpose of this study was to detect the ocurrence of renal dysfunction in eleven patients sequentially submitted to BMT, regardless of their sex, age, or diagnosis; the ones who had been previously diagnosed with renal, hepatic, or metabolic disease were excluded beforehand. No changes in glomerular filtration were found. There was a decreased renal sodium excretion, probably related to increased secretion of aldosterone, as well as the greater reabsortion of sodium and water by the collector duct to fulfill the body's requirements during the post-transplantation period. Urinary excretion of bicarbonate was affected only in those patients who had been treated with Amphotericin, suggesting the presence of tubular dysfunction secondary to that drug. No change in the integrity of the albuminuria-evaluated glomerular ultrafiltration barrier was observed, but in glomerular lesion was not detected after transplantation. The determination of urinary excretion of low molecular weigth proteins, such as retinol-binding protein (RBP) and beta 2-microglobulin (p 2-M), enabled us to evaluate functional integrity of renal tubules. BMT significantly affected tubular function. Our observations allow us to conclude that Bone Marrow Transplantation might cause renal dysfunction which is primarily of tubular origen

fB and fBs with maximally twisted Wilson fermions

We present a lattice QCD calculation of the heavy-light decay constants fB and fBs performed with Nf = 2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay constants have been also computed in the static limit and the results are used to interpolate the observables between the charmand the infinite-mass sectors, thus obtaining the value of the decay constants at the physical b quark mass. Our preliminary results are fB = 191(14)MeV, fBs = 243(14)MeV, fBs/ fB = 1.27(5). They are in good agreement with those obtained with a novel approach, recently proposed by our Collaboration (ETMC), based on the use of suitable ratios having an exactly known static limit