Search results for "normal"
showing 10 items of 2571 documents
Higher-order effects for the coupling constant in asymptotically free theories
1977
It is shown that the two-loop contribution to the Callan-Symanzik $\ensuremath{\beta}$ function leads to an effective coupling constant which may be quite different from the value obtained from the standard one-loop calculation. This correction is larger than that due to finite quark masses. Possible implications for the comparison between asymptotically free theories and experiment are discussed.
Renormalization of the effective theory for heavy quarks at small velocity
1995
The slope of the Isgur-Wise function at the normalization point, $\xi^{(1)}(1)$,is one of the basic parameters for the extraction of the $CKM$ matrix element $V_{cb}$ from exclusive semileptonic decay data. A method for measuring this parameter on the lattice is the effective theory for heavy quarks at small velocity $v$. This theory is a variant of the heavy quark effective theory in which the motion of the quark is treated as a perturbation. In this work we study the lattice renormalization of the slow heavy quark effective theory. We show that the renormalization of $\xi^{(1)}(1)$ is not affected by ultraviolet power divergences, implying no need of difficult non-perturbative subtraction…
Kaon mixing beyond the SM from N-f=2 tmQCD and model independent constraints from the UTA
2013
We present the first unquenched, continuum limit, lattice QCD results for the matrix elements of the operators describing neutral kaon oscillations in extensions of the Standard Model. Owing to the accuracy of our calculation on Delta S = 2 weak Hamiltonian matrix elements, we are able to provide a refined Unitarity Triangle analysis improving the bounds coming from model independent constraints on New Physics. In our non-perturbative computation we use a combination of N-f = 2 maximally twisted sea quarks and Osterwalder-Seiler valence quarks in order to achieve both O(a)-improvement and continuum-like renormalization properties for the relevant four-fermion operators. The calculation of t…
Observing myoglobin proteinquake with an X-ray free-electron laser
2015
The events following the photodissociation of the bond be- tween myoglobin and its ligand have been extensively studied with a variety of experimental, theoretical and computational methods [1]. The results of these investigations have been rationalized in terms of a model that implies a protein quake- like motion [2], i.e. the propagation of the strain released upon photoexcitation through the protein similar to the prop- agation of acoustic waves during an earthquake. The exper- imental investigations performed so far have been based on spectroscopic measurements or did not have sufficient time- resolution to measure the timescale of such “proteinquake”. We have obtained direct experiment…
BMI-BFMNU: A structural index linked to fat mass
2021
Abstract Introduction: Body mass index (BMI) provides little information on body composition. For example, two people with the same BMI might have different body compositions. In this sense, the development of a new BMI able to provide body composition information is of clinical and scientific interest. The aim of the study was to suggest a new modified BMI formula. Material and Methods: A total of 108 subject, females 56 and males 52, 0-73 years old, in various physiopathological conditions were evaluated. Data were collected and processed by a program that through anthropometric measurements calculates classic BMI, volume, surface, V/S (that we can defined like a body-thickness “pse…
A combined molecular dynamics and Monte Carlo study of the approach towards phase separation in colloid-polymer mixtures.
2011
A coarse-grained model for colloid-polymer mixtures is investigated where both colloids and polymer coils are represented as point-like particles interacting with spherically symmetric effective potentials. Colloid-colloid and colloid-polymer interactions are described by Weeks-Chandler-Andersen potentials, while the polymer-polymer interaction is very soft, of strength k(B)T/2 for maximum polymer-polymer overlap. This model can be efficiently simulated both by Monte Carlo and molecular dynamics methods, and its phase diagram closely resembles that of the well-known Asakura-Oosawa model. The static and dynamic properties of the model are presented for systems at critical colloid density, va…
Up, down, strange and charm quark masses with N-f=2+1+1 twisted mass lattice QCD
2014
We present a lattice QCD calculation of the up, down, strange and charm quark masses performed using the gauge configurations produced by the European Twisted Mass Collaboration with N-f = 2 + 1 + 1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their physical values. The simulations are based on a unitary setup for the two light quarks and on a mixed action approach for the strange and charm quarks. The analysis uses data at three values of the lattice spacing and pion masses in the range 210-450 MeV, allowing for accurate continuum limit and controlled chiral extrapolation. The quark mass renorma…
Pervasive body sensing: Implanted RFID tags for vascular monitoring
2010
Beside the common logistic usages of the Radio Frequency Identification (RFID) technology, one of the most innovative and promising applications is the possibility to process the backscattering signals to detect additional information about the target, such as its state and its evolution, without any specific embedded sensor or local power supply. The rationale of this idea lies in the clear dependence of the tag's input impedance and reflectivity on the physical and geometrical features of a real target. When the object where the tag is attached on undergoes some changes along with the time, the tag's electrical features also change and these variations can be remotely detected by the read…
Analysis of inhomogeneously filled waveguides using a bi-orthonormal-basis method
2000
A general theoretical formulation to analyze inhomogeneously filled waveguides with lossy dielectrics is presented in this paper. The wave equations for the tranverse-field components are written in terms of a nonself-adjoint linear operator and its adjoint. The eigenvectors of this pair of linear operators define a biorthonormal-basis, allowing for a matrix representation of the wave equations in the basis of an auxiliary waveguide. Thus, the problem of solving a system of differential equations is transformed into a linear matrix eigenvalue problem. This formulation is applied to rectangular waveguides loaded with an arbitrary number of dielectric slabs centered at arbitrary points. The c…
Naturally occurring137Cs,90Sr and226Ra radionuclides in raw milk in the Sibiu province of Romania
2012
Milk is a sensitive indicator of the levels of contamination existing in the environment following nuclear incidents, for example at Chernobyl 1986 (Ukraine) and the most recent one in 2011 in Fukushima (Japan). The levels of three radionuclides, caesium 137Cs, strontium 90Sr and radium 226Ra, were determined in cow’s milk from various locations of Sibiu county from 2010 to 2011. The results were compared with the results taken after the explosion at Chernobyl in 1986. The values were within normal limits with insignificant increases of the milk that was collected in the area of Copsa-Mica and Sibiu.