752 research outputs found
Quark-Hadron Duality, Factorization and Strong Phases in Decay
We consider the hadronic description of the decay, with
the aim to investigate the strong phases generated by the final state
interactions. The derivation of the dispersion relations using the
Lehmann-Symanzik-Zimmermann formalism and the Goldberger-Treiman method to
include inelastic effects in the spectral function are presented. We discuss
the problem of quark-hadron duality and estimate in the hadronic formalism the
corrections to the factorized amplitude in the heavy quark limit.Comment: 16 pages, revised version, introduction of a scale dependenc
The burden of clostridium difficile infection in patients with liver cirrhosis
Clostridium Difficile Infection (CDI) has registered a dramatically increasing incidence in the general population over the past decades. Nowadays, Clostridium Difficile is the leading cause of hospital-acquired diarrhea in Europe and North America. Liver cirrhosis is the final stage of any chronic liver disease (CLD). The most common causes are chronic hepatitis C or B and viral co-infections, alcohol misuse, and nonalcoholic fatty liver disease (NAFLD). CLD and cirrhosis are listed among the ten leading causes of death in the US. Cirrhosis due to any etiology disrupts the homeostatic role of the liver in the body. Cirrhosis-associated immune dysfunction (CAID) leads to alterations in both inherited and acquired systemic and local liver immunity. CAID is caused by increased systemic inflammation and immunodeficiency and it is responsible for 30% of mortality rates all over the world. Clostridium Difficile infection frequently affects patients suffering from liver cirrhosis because of the high number of prolonged hospitalizations, regular use of antibiotics for the prevention or treatment of SBP, proton pump inhibitor (PPI) use, and an overall immunocompromised state. Clostridium Difficile is a Gram-positive bacterium responsible for the high morbidity and mortality rates in patients with cirrhosis, with an essential increase in a 30-day mortality
Dispersion relations and Omn\`es representations for decay amplitudes
We derive dispersion relations for decay, using the
Lehmann-Symanzik-Zimmermann formalism, which allows the analytic continuation
of the amplitudes with respect to the momenta of the external particles. No
off-shell extrapolation of the field operators is assumed. We obtain
generalized Omn\`es representations, which incorporate the and
-wave phase shifts in the elastic region of the direct and crossed channels,
according to Watson theorem. The contribution of the inelastic final-state and
initial-state interactions is parametrized by the technique of conformal
mappings. We compare our results with previous dispersive treatments and
indicate how the formalism can be combined with lattice calculations to yield
physical predictions.Comment: 19 pages, LateX, no figur
One-loop renormalization of general noncommutative Yang-Mills field model coupled to scalar and spinor fields
We study the theory of noncommutative U(N) Yang-Mills field interacting with
scalar and spinor fields in the fundamental and the adjoint representations. We
include in the action both the terms describing interaction between the gauge
and the matter fields and the terms which describe interaction among the matter
fields only. Some of these interaction terms have not been considered
previously in the context of noncommutative field theory. We find all
counterterms for the theory to be finite in the one-loop approximation. It is
shown that these counterterms allow to absorb all the divergencies by
renormalization of the fields and the coupling constants, so the theory turns
out to be multiplicatively renormalizable. In case of 1PI gauge field functions
the result may easily be generalized on an arbitrary number of the matter
fields. To generalize the results for the other 1PI functions it is necessary
for the matter coupling constants to be adapted in the proper way. In some
simple cases this generalization for a part of these 1PI functions is
considered.Comment: 1+26 pages, figures using axodraw, clarifications adde
A q-Deformed Schr\"odinger Equation
We found hermitian realizations of the position vector , the angular
momentum and the linear momentum , all behaving like
vectors under the algebra, generated by and . They are
used to introduce a -deformed Schr\" odinger equation. Its solutions for the
particular cases of the Coulomb and the harmonic oscillator potentials are
given and briefly discussed.Comment: 14 pages, latex, no figure
Theory of unitarity bounds and low energy form factors
We present a general formalism for deriving bounds on the shape parameters of
the weak and electromagnetic form factors using as input correlators calculated
from perturbative QCD, and exploiting analyticity and unitarity. The values
resulting from the symmetries of QCD at low energies or from lattice
calculations at special points inside the analyticity domain can beincluded in
an exact way. We write down the general solution of the corresponding Meiman
problem for an arbitrary number of interior constraints and the integral
equations that allow one to include the phase of the form factor along a part
of the unitarity cut. A formalism that includes the phase and some information
on the modulus along a part of the cut is also given. For illustration we
present constraints on the slope and curvature of the K_l3 scalar form factor
and discuss our findings in some detail. The techniques are useful for checking
the consistency of various inputs and for controlling the parameterizations of
the form factors entering precision predictions in flavor physics.Comment: 11 pages latex using EPJ style files, 5 figures; v2 is version
accepted by EPJA in Tools section; sentences and figures improve
Alcoholic liver cirrhosis, more than a simple hepatic disease – A brief review of the risk factors associated with alcohol abuse
Liver cirrhosis is a significant public health problem, being an important cause of mortality and morbidity, responsible for approximately 1.8% of the total number of deaths in Europe. Chronic alcohol consumption is the most common cause of liver cirrhosis in developed countries. Europe has the highest level of alcohol consumption among all the global World Health Organisation (WHO) regions. In this paper, we briefly review major factors leading to excessive alcohol consumption in order to draw attention to the fact that alcoholic liver cirrhosis is more than a simple liver disease, and if those risk/causal factors can be prevented, the incidence of this disease could be reduced greatly. Although excessive alcohol consumption is regarded as the cause of alcoholic liver cirrhosis, the etiology is complex, involving multiple factors that act in synchrony, and which, if prevented, could greatly reduce the incidence of this disease. Children of addicts are likely to develop an alcohol-related mental disorder; however, there is no “gene for alcoholism”
Hard Non-commutative Loops Resummation
The non-commutative version of the euclidean theory is
considered. By using Wilsonian flow equations the ultraviolet renormalizability
can be proved to all orders in perturbation theory. On the other hand, the
infrared sector cannot be treated perturbatively and requires a resummation of
the leading divergencies in the two-point function. This is analogous to what
is done in the Hard Thermal Loops resummation of finite temperature field
theory. Next-to-leading order corrections to the self-energy are computed,
resulting in contributions in the massless case, and
in the massive one.Comment: 4 pages, 3 figures. The resummation procedure is now discussed also
at finite ultraviolet cut-off. Minor changes in abstract and references.
Final version to be published in Physical Review Letter
The burden of clostridium difficile infection in patients with liver cirrhosis
Clostridium Difficile Infection (CDI) has registered a dramatically increasing incidence in the general population over the past decades. Nowadays, Clostridium Difficile is the leading cause of hospital-acquired diarrhea in Europe and North America. Liver cirrhosis is the final stage of any chronic liver disease (CLD). The most common causes are chronic hepatitis C or B and viral co-infections, alcohol misuse, and nonalcoholic fatty liver disease (NAFLD). CLD and cirrhosis are listed among the ten leading causes of death in the US. Cirrhosis due to any etiology disrupts the homeostatic role of the liver in the body. Cirrhosis-associated immune dysfunction (CAID) leads to alterations in both inherited and acquired systemic and local liver immunity. CAID is caused by increased systemic inflammation and immunodeficiency and it is responsible for 30% of mortality rates all over the world. Clostridium Difficile infection frequently affects patients suffering from liver cirrhosis because of the high number of prolonged hospitalizations, regular use of antibiotics for the prevention or treatment of SBP, proton pump inhibitor (PPI) use, and an overall immunocompromised state. Clostridium Difficile is a Gram-positive bacterium responsible for the high morbidity and mortality rates in patients with cirrhosis, with an essential increase in a 30-day mortality
Nonperturbative mechanisms of strong decays in QCD
Three decay mechanisms are derived systematically from the QCD Lagrangian
using the field correlator method. Resulting operators contain no arbitrary
parameters and depend only on characteristics of field correlators known from
lattice and analytic calculations. When compared to existing phenomenological
models, parameters are in good agreement with the corresponding fitted values.Comment: 12 pages, latex2
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