A nonperturbative calculation of basic chiral QCD parameters within zero modes enhancement model of the QCD vacuum, 2

Basic chiral QCD parameters (the pion decay constant, quark and gluon condensates, the dynamically generated quark mass, etc) as well as the vacuum energy density have been calculated from first principles within a recently proposed zero modes enhancement (ZME) model of the QCD true vacuum. It is based on the solution to the Schwinger-Dyson (SD) equation for the quark propagator in the infrared (IR) domain. In order to analyze our numerical results we set a scale by the two different ways. First this was done at a scale responsible for dynamical chiral symmetry breaking (DCSB) at the fundamental quark level \Lambda_{CSBq}, defined as the double of the dynamically generated light quark mass m_d. In the second case m_d was reasonably taken to be 300 \le m_d \le 400 \ (MeV) otherwise first remains arbitrary. Our unique input data was chosen to be the pion decay constant in the chiral limt given by the chiral perturbation theory at the hadronic level (CHPTh). With the help of the nonperturbative gluon contributions to the vacuum energy density one can establish realistic lower bounds for the m_d. In both cases we obtain almost the same numerical results for all chiral QCD parameters. Phenomenological estimates of these quantites are in good agreement with our numerical results. Also our numerical result for the vacuum energy density agrees well with the QCD sum rules and random instanton liquid model (RILM) values for this quantity. One of the most important our conclusions is that the above mentioned scale of DCSB at the fundamental quark level \Lambda_{CSBq} and the scale at which confinement occurs \Lambda_c are nearly the same indeed. Nonperturbative vacuum structure, which emerges from the ZME model, appears to be well suited to describe quark confinement, DCSB, the Goldstone nature of th

Renormalization of the mass gap

The full gluon propagator relevant for the description of the truly non-perturbative QCD dynamics, the so-called intrinsically non-perturbative gluon propagator has been derived in our previous work. It explicitly depends on the regularized mass gap, which dominates its structure at small gluon momentum. It is automatically transversal in a gauge invariant way. It is characterized by the presence of severe infrared singularities at small gluon momentum, so the gluons remain massless, and this does not depend on the gauge choice. In this paper we have shown how precisely the renormalization program for the regularized mass gap should be performed. We have also shown how precisely severe infrared singularities should be correctly treated. This allowed to analytically formulate the exact and gauge-invariant criteria of gluon and quark confinement. After the renormalization program is completed, one can derive the gluon propagator applicable for the calculation of physical observables processes, etc., in low-energy QCD from first principles.Comment: 16 pages, no figures, no tables, some minor changes are introduce

Vacuum Energy Density in the Quantum Yang - Mills Theory

Using the effective potential approach for composite operators, we have formulated a general method of calculation of the truly non-perturbative Yang-Mills vacuum energy density (this is, by definition, the Bag constant apart from the sign). It is the main dynamical characteristic of the QCD ground state. Our method allows one to make it free of the perturbative contributions ('contaminations'), by construction. We also perform an actual numerical calculation of the Bag constant for the confining effective charge. Its choice uniquely defines the Bag constant, which becomes free of all the types of the perturbative contributions now, as well as possessing many other desirable properties as colorless, gauge independence, etc. Using further the trace anomaly relation, we develop a general formalism which makes it possible to relate the Bag constant to the gluon condensate not using the weak coupling solution for the corresponding $\beta$ function. Our numerical result for the Bag constant shows a good agreement with other phenomenological estimates of the gluon condensate.Comment: 28 pages and 4 figures, typos corrected, added new appendices and new references in comparison with the published versio

Прогноз результата кожной пластики по параметрам микроциркуляции в ожоговой ране

BACKGROUND Irregularity and mosaicity in the depth of the burn skin lesion limits the possibility of performing precision tangential necrectomy in the early stages after injury. Non-radical necrectomy leads to lysis of transplanted autodermal grafts. This problem is most relevant in the treatment of victims with extensive dermal and deep burns.AIM OF STUDY To study the relationship between microcirculation parameters in the burn wound and the outcomes of autodermal transplantation after tangential necrectomy.MATERIAL AND METHODS 74 patients with extensive skin burns included in the study underwent tangential necrectomy with simultaneous autodermal transplantation. All operations were performed early (up to 10 days) after injury before the formation of the demarcation line. Microcirculation parameters in the burn wound were studied by laser Doppler flowmetry before and after tangential necrectomy and in healthy skin of the same anatomical region.RESULTS Statistically significant differences (p≤0.001) were found between microcirculation parameters in the center of the burn wound after tangential necrectomy and in the control area of intact skin. In this case, the results of autodermal transplantation were characterized by a skin engraftment rate of up to 60–70%. In those areas of the body where there were no differences between microcirculation parameters , the engraftment exceeded 80%.CONCLUSION Assessment of microcirculation by laser Doppler flowmetry can be a reliable method for diagnosing the condition and viability of a burn wound after tangential excision of dead tissues in the early stages of treatment — before the formation of a demarcation line. The diagnostic technique is easy to use, but requires skills in working with a flowmeter, unification of such devices and methods for their use in the practice of surgical treatment of burns.Актуальность Неравномерность и мозаичность по глубине ожогового поражения кожи ограничивает возможности выполнения прецизионной тангенциальной некрэктомии в ранние сроки после травмы. Нерадикальная некрэктомия приводит к лизису пересаженных аутодермотрансплантатов. Наиболее актуальна данная проблема в лечении пострадавших с обширными дермальными и глубокими ожогами.Цель Изучить зависимость между параметрами микроциркуляции в ожоговой ране и результатами аутодермотрансплантации после выполнения тангенциальной некрэктомии.Материал и методы Хирургическое лечение 74 пациентов с обширными ожогами кожи, включенных в исследование, осуществляли путем тангенциальной некрэктомии с одновременной аутодермотрансплантацией. Все операции выполняли в ранние сроки (до 10 суток) после травмы до формирования линии демаркации. Параметры микроциркуляции в ожоговой ране изучали методом лазерной допплеровской флоуметрии до и после тангенциальной некрэктомии и в здоровой коже той же анатомической области.Результаты Выявлены статистически значимые различия (при p≤0,001) между параметрами микроциркуляции непосредственно в ожоговой ране после выполнения тангенциальной некрэктомии и на контрольном участке неповрежденной кожи. В этом случае результаты аутодермотрансплантации характеризовались частотой приживления кожи до 60–70%. В тех областях тела, где различий между показателями микроциркуляции не было, результаты приживления превысили 80%.Выводы Оценка микроциркуляции методом лазерной допплеровской флоуметрии может явиться достоверным методом диагностики состояния и жизнеспособности ожоговой раны после тангенциального иссечения погибших тканей в ранние сроки лечения – до формирования демаркационной линии. Методика диагностики проста в применении, однако требует навыков работы с флуометром, унификации таких приборов и методик их использования в практике хирургического лечения ожогов

A minimal quasiparticle approach for the QGP and its large-NcN_c limits

We propose a quasiparticle approach allowing to compute the equation of state of a generic gauge theory with gauge group SU($N_c$) and quarks in an arbitrary representation. Our formalism relies on the thermal quasiparticle masses (quarks and gluons) computed from Hard-Thermal-Loop techniques, in which the standard two-loop running coupling constant is used. Our model is minimal in the sense that we do not allow any extra ansatz concerning the temperature-dependence of the running coupling. We first show that it is able to reproduce the most recent equations of state computed on the lattice for temperatures higher than 2 $T_c$. In this range of temperatures, an ideal gas framework is indeed expected to be relevant. Then we study the accuracy of various inequivalent large-$N_c$ limits concerning the description of the QCD results, as well as the equivalence between the QCD$_{AS}$ limit and the ${\cal N}=1$ SUSY Yang-Mills theory. Finally, we estimate the dissociation temperature of the $\Upsilon$-meson and comment on the estimations' stability regarding the different considered large-$N_c$ limits.Comment: 19 pages, 6 figure