Calculation of the heavy-hadron axial couplings g_1, g_2, and g_3 using lattice QCD

In a recent letter [Phys. Rev. Lett. 108, 172003 (2012), arXiv:1109.2480] we have reported on a lattice QCD calculation of the heavy-hadron axial couplings $g_1$, $g_2$, and $g_3$. These quantities are low-energy constants of heavy-hadron chiral perturbation theory (HH$\chi$PT) and are related to the $B^*B\pi$, $\Sigma_b^*\Sigma_b\pi$, and $\Sigma_b^{(*)}\Lambda_b\pi$ couplings. In the following, we discuss important details of the calculation and give further results. To determine the axial couplings, we explicitly match the matrix elements of the axial current in QCD with the corresponding matrix elements in HH$\chi$PT. We construct the ratios of correlation functions used to calculate the matrix elements in lattice QCD, and study the contributions from excited states. We present the complete numerical results and discuss the data analysis in depth. In particular, we demonstrate the convergence of $SU(4|2)$ HH$\chi$PT for the axial-current matrix elements at pion masses up to about 400 MeV and show the impact of the nonanalytic loop contributions. Finally, we present additional predictions for strong and radiative decay widths of charm and bottom baryons.Comment: 42 pages, 20 figures, updated calculation of Xi_b^{*0} width using mass measurement from CMS, published versio

The excited hadron spectrum in lattice QCD using a new method of estimating quark propagation

Progress in determining the spectrum of excited baryons and mesons in lattice QCD is described. Large sets of carefully-designed hadron operators have been studied and their effectiveness in facilitating the extraction of excited-state energies is demonstrated. A new method of stochastically estimating the low-lying effects of quark propagation is proposed which will allow reliable determinations of temporal correlations of single-hadron and multi-hadron operators.Comment: 5 pages, 4 figures, talk given at Hadron 2009, Tallahassee, Florida, December 1, 200

B-physics with Nf=2N_f=2 Wilson fermions

We report the final results of the ALPHA collaboration for some B-physics observables: $f_B$, $f_{B_s}$ and $m_b$. We employ CLS configurations with 2 flavors of $O(a)$ improved Wilson fermions in the sea and pion masses ranging down to 190 MeV. The b-quark is treated in HQET to order $1/m_b$. The renormalization, the matching and the improvement were performed non-perturbatively, and three lattice spacings reaching $a=0.048$ fm are used in the continuum extrapolation

Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks

We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included non-perturbatively. Based on Nf=2 gauge field ensembles, covering three lattice spacings a (0.08-0.05)fm and pion masses down to 190MeV, a variational method for extracting hadronic matrix elements is used to keep systematic errors under control. In addition we perform a careful autocorrelation analysis in the extrapolation to the continuum and to the physical pion mass limits. Our final results read fB=186(13)MeV, fBs=224(14)MeV and fBs/fB=1.203(65). A comparison with other results in the literature does not reveal a dependence on the number of dynamical quarks, and effects from truncating HQET appear to be negligible.Comment: 16 pages including figures and table

The b-quark mass from non-perturbative Nf=2N_f=2 Heavy Quark Effective Theory at O(1/mh)O(1/m_h)

We report our final estimate of the b-quark mass from $N_f=2$ lattice QCD simulations using Heavy Quark Effective Theory non-perturbatively matched to QCD at $O(1/m_h)$. Treating systematic and statistical errors in a conservative manner, we obtain $\overline{m}_{\rm b}^{\overline{\rm MS}}(2 {\rm GeV})=4.88(15)$ GeV after an extrapolation to the physical point.Comment: 15 pages including figures and tables; as published in Phys.Lett.B / typo in table 4 corrected / footnote 1 expande

Spatial distributions in static heavy-light mesons: a comparison of quark models with lattice QCD

Lattice measurements of spatial distributions of the light quark bilinear densities in static mesons allow to test directly and in detail the wave functions of quark models. These distributions are gauge invariant quantities directly related to the spatial distribution of wave functions. We make a detailed comparison of the recent lattice QCD results with our own quark models, formulated previously for quite different purposes. We find a striking agreement not only between our two quark models, but also with the lattice QCD data for the ground state in an important range of distances up to about 4/GeV. Moreover the agreement extends to the L=1 states [j^P=(1/2)^+]. An explanation of several particular features completely at odds with the non-relativistic approximation is provided. A rather direct, somewhat unexpected and of course approximate relation between wave functions of certain quark models and QCD has been established.Comment: 40 pages, 5 figures (version published in PRD

First results from 2+1 dynamical quark flavors on an anisotropic lattice: light-hadron spectroscopy and setting the strange-quark mass

We present the first light-hadron spectroscopy on a set of $N_f=2+1$ dynamical, anisotropic lattices. A convenient set of coordinates that parameterize the two-dimensional plane of light and strange-quark masses is introduced. These coordinates are used to extrapolate data obtained at the simulated values of the quark masses to the physical light and strange-quark point. A measurement of the Sommer scale on these ensembles is made, and the performance of the hybrid Monte Carlo algorithm used for generating the ensembles is estimated.Comment: 24 pages. Hadron Spectrum Collaboratio

Isgur-Wise Function for Heavy Light Mesons in D dimensional Potential Model

We report results of a potential model for mesons in D space-time dimension developed by considering the quark-antiquark potential of Nambu-Goto strings. With this wave function, we have studied Isgur-Wise function for heavy-light mesons and its derivatives like slope and curvature. The dimensional dependence of our results and a comparative study with the results of 3+1 dimensional QCD are also reported.Comment: 11 pages, 4 figure

ЛАБОРАТОРИЯ КЛИНИЧЕСКОЙ ИММУНОЛОГИИ НИИ СКОРОЙ ПОМОЩИ ИМ. Н.В. СКЛИФОСОВСКОГО (ИСТОРИЯ И НАСТОЯЩЕЕ)

ABSTRACT. Assessment of the immune status of patients with urgent types of pathology in the Institute for Emergency Medicine is performed according to three main objects of research: humoral , phagocytic and lymphocytic components of immune system . This complex allows to fully and adequately evaluate the condition of the immune system of patients at different stages of traumatic disease and after transplantation of organs and tissues , to forecast the probability of septic complications developing, adjust the therapy . During 45 years of work of immunological service formed the algorithm of the adequate immunological screening was formed, number of innovative methods of diagnosis was developed, the ideology of post-test counseling of patients by immunologists was created, mathematical methods of storage, modeling and processing of research results was introduced. Laboratory staff identified a number of medical and social factors in the spread of blood-borne viral infections (HIV, hepatitis B and C). New organizational and economic methods of management team were introduced in the laboratory. The basis of the work is equal integration of scientific and clinical staff of the laboratory. РЕЗЮМЕ. Оценку иммунного статуса пациентов с ургентными видами патологии в НИИ скорой помощи проводят по трем основным объектам исследований: гуморальное, фагоцитарное и лимфоцитарное звенья иммунитета. Такой комплекс позволяет полноценно и адекватно оценить состояние иммунной системы пациентов на различных стадиях травматической болезни и после трансплантации органов и тканей, дать прогноз вероятности развития гнойно-септических осложнений и скорректировать проводимую терапию. За 45 лет работы иммунологической службы сформирован алгоритм адекватного иммунологического скрининга, разработан ряд инновационных методов диагностики, создана идеология послетестового консультирования больных специалистами-иммунологами, внедрены методы математического хранения, моделирования и обработки результатов исследований. Сотрудниками лаборатории выявлен ряд медико-социальных факторов распространения гемоконтактных вирусных инфекций (ВИЧ-инфекции, гепатитов В и С). В лаборатории внедрены новые организационные и экономические методы управления коллективом. Основой работы является паритетное комплексирование научных и клинических сотрудников лаборатории.