Abelian 3-form gauge theory: superfield approach

We discuss a D-dimensional Abelian 3-form gauge theory within the framework of Bonora-Tonin's superfield formalism and derive the off-shell nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for this theory. To pay our homage to Victor I. Ogievetsky (1928-1996), who was one of the inventors of Abelian 2-form (antisymmetric tensor) gauge field, we go a step further and discuss the above D-dimensional Abelian 3-form gauge theory within the framework of BRST formalism and establish that the existence of the (anti-)BRST invariant Curci-Ferrari (CF) type of restrictions is the hallmark of any arbitrary p-form gauge theory (discussed within the framework of BRST formalism).Comment: LaTeX file, 8 pages, Talk delivered at BLTP, JINR, Dubna, Moscow Region, Russi

Minimal subtraction and the Callan-Symanzik equation

The usual proof of renormalizability using the Callan-Symanzik equation makes explicit use of normalization conditions. It is shown that demanding that the renormalization group functions take the form required for minimal subtraction allows one to prove renormalizability using the Callan-Symanzik equation, without imposing normalization conditions. Scalar field theory and quantum electrodynamics are treated.Comment: 6 pages, plain Te

Two loop effective potential for < A^2_\mu > in the Landau gauge in quantum chromodynamics

We construct the effective potential for the dimension two composite operator 1/2 A^{a 2}_\mu in QCD with massless quarks in the Landau gauge for an arbitrary colour group at two loops. For SU(3) we show that an estimate for the effective gluon mass decreases as N_f increases.Comment: 17 latex page

Pré-compostagem de cadáveres de bovinos acometidos pelo botulismo.

Foram pré-compostados, em células individuais e isoladas, cinco cadáveres de bovinos acometidos pelo botulismo com a finalidade de monitorar a presença de esporos de Clostridium botulinum e de toxina botulínica antes e após o processo de decomposição em leira estática com fonte de carbono. O diagnóstico da intoxicação nos animais foi baseado nas características clínico-patológicas, epidemiológicas ou laboratoriais. Dos cinco bovinos com evolução clínica crônica de botulismo, cujos cadáveres foram pré-compostados, três foram acometidos pela toxina tipo D, um pelo complexo CD e um dos animais foi negativo na tentativa de detecção da toxina e de esporos da bactéria nas vísceras pelo bioensaio e neutralização em camundongo. O processo de pré-compostagem foi realizado em leira estática, com o uso de material carbonáceo umidificado como substrato e esquartejamento do animal, vedado individualmente com lona plástica e sem aeração por um período de 50 dias. A temperatura das leiras foi monitorada durante o período e oscilou de 40,5-52,4ºC. Após a abertura das leiras, pôde-se constatar a completa decomposição de todo material mole, com redução significativa do seu peso (de 26,5-44,5%), restando apenas os ossos. Não foi detectado esporo ou toxina botulínica no interior dos ossos (n=5 para cada cadáver). Nas 200 amostras examinadas do homogeneizado restante (n=40 para cada cadáver), em apenas duas amostras de uma leira foram detectados esporos de C. botulinum tipo C, enquanto que todas foram negativas para a tentativa de detecção da toxina botulínica pelo bioensaio em camundongo. Da forma como foi avaliado o processo de pré-compostagem de bovinos mortos pela intoxicação botulínica não contribuiu para a proliferação de C. botulinum. Five carcasses of cattle that died from botulism were composted in individual isolated beds with the purpose of monitoring the effect on spores of Clostridium botulinum and of botulinum toxin. The diagnosis of botulinum poisoning was based on clinical and pathological, epidemic and/or laboratorial characteristics. Of the five bovines with clinical signs of chronic botulism, three were affected by the type D toxin, one by the CD complex, and one was negative for toxin and spores of C. botulinum in the viscera using a mouse bioassay. The composting process was carried out in beds with carcasses cut up and mixed with sawdust as a carbon source. They were kept anaerobic under a plastic sheet for 50 days. The temperature of the beds was monitored during the period and oscillated from 40.5 to 52.4ºC. After this time, soft tissue had complete decomposed with a significant loss of weight (26.5-44.5%). The remaining bones no longer contained spores or botulinum toxin in the 5 samples taken from each carcass. Only 2 of the 200 samples of homogenized remaining (40 for each carcass) contained spores of C. botulinum type C. All samples were negative for botulinum toxin using the mouse bioassay. Composting carcasses of cattle that died from botulism eliminated botulinum spores and toxin from the remains

Gluon Fragmentation into Heavy Quarkonium

The dominant production mechanism for heavy quark-antiquark bound states in very high energy processes is fragmentation, the splitting of a high energy parton into a quarkonium state and other partons. We show that the fragmentation functions $D(z,\mu)$ describing these processes can be calculated using perturbative QCD. We calculate the fragmentation functions for a gluon to split into S-wave quarkonium states to leading order in the QCD coupling constant. The leading logarithms of $\mu/m_Q$, where $\mu$ is the factorization scale and $m_Q$ is the heavy quark mass, are summed up using Altarelli-Parisi evolution equations.Comment: LateX 11 pages (3 figures available upon request). NUHEP-TH-92-2

Quantum properties of a non-Abelian gauge invariant action with a mass parameter

We continue the study of a local, gauge invariant Yang-Mills action containing a mass parameter, which we constructed in a previous paper starting from the nonlocal gauge invariant mass dimension two operator F_{\mu\nu} (D^2)^{-1} F_{\mu\nu}. We return briefly to the renormalizability of the model, which can be proven to all orders of perturbation theory by embedding it in a more general model with a larger symmetry content. We point out the existence of a nilpotent BRST symmetry. Although our action contains extra (anti)commuting tensor fields and coupling constants, we prove that our model in the limit of vanishing mass is equivalent with ordinary massless Yang-Mills theories. The full theory is renormalized explicitly at two loops in the MSbar scheme and all the renormalization group functions are presented. We end with some comments on the potential relevance of this gauge model for the issue of a dynamical gluon mass generation.Comment: 17 pages. v2: version accepted for publication in Phys.Rev.

Renormalizing a BRST-invariant composite operator of mass dimension 2 in Yang-Mills theory

We discuss the renormalization of a BRST and anti-BRST invariant composite operator of mass dimension 2 in Yang-Mills theory with the general BRST and anti-BRST invariant gauge fixing term of the Lorentz type. The interest of this study stems from a recent claim that the non-vanishing vacuum condensate of the composite operator in question can be an origin of mass gap and quark confinement in any manifestly covariant gauge, as proposed by one of the authors. First, we obtain the renormalization group flow of the Yang-Mills theory. Next, we show the multiplicative renormalizability of the composite operator and that the BRST and anti-BRST invariance of the bare composite operator is preserved under the renormalization. Third, we perform the operator product expansion of the gluon and ghost propagators and obtain the Wilson coefficient corresponding to the vacuum condensate of mass dimension 2. Finally, we discuss the connection of this work with the previous works and argue the physical implications of the obtained results.Comment: 49 pages, 35 eps-files, A number of typographic errors are corrected. A paragraph is added in the beginning of section 5.3. Two equations (7.1) and (7.2) are added. A version to be published in Phys. Rev.

Q2-evolution of parton densities at small-x values

In the leading twist approximation of the Wilson operator product expansion with "frozen" and analytic strong coupling constants we show that Bessel-inspired behavior of the structure function F2 at small x, obtained for a flat initial condition in the DGLAP evolution equations, leads to good agreement with the deep inelastic scattering experimental data from HERA.Comment: 19 pages, 5 figures, published in the Proceedings of Workshop on Physics of Fundamental Interactions, Institute of High Energy Physics, Protvino, Russia, 22--25 December 2008 (Phys.Atom.Nucl. in press

Zur Personenwahrnehmung im Attributionsgeschehen: Eine Replikation der klassischen Arbeit von Heider und Simmel (1944)

Als zentraler Befund der einflussreichen Arbeit von Heider und Simmel [American Journal of Psychology, 57, 243-259 (1944)]zeigte sich, dass bewegte geometrische Objekte ganz überwiegend als intentional handelnde Lebewesen wahrgenommen werden und diese wiederum mehrheitlich als Personen. Da die Originaluntersuchung ausschließlich Frauen miteinbezog und die Darstellung der Ergebnisse mitunter keine genauen Angaben zur Häufigkeit personaler Kausalität erlaubt, wird eine Replikation durchgeführt, um die Befunde auf eine breiter generalisierbare Basis zu stellen. Unter Verwendung des Originalversuchsmaterials zeigt sich auch bei konservativer Analyse der Ergebnisse, dass geschlechtsunabhängig weniger als 35 % der Teilnehmenden die geometrischen Objekte als Lebewesen beschrieben. Von denjenigen, die die Objekte als beseelt wahrnahmen, wurden diese in etwa 80 % der Fälle als Menschen bezeichnet. Mögliche Erklärungen dieser Abweichungen von den Originalbefunden werden diskutiert

Interacting Vector-Spinor and Nilpotent Supersymmetry

We formulate an interacting theory of a vector-spinor field that gauges anticommuting spinor charges \{Q_\alpha{}^I, Q_\beta{}^J \} = 0 in arbitrary space-time dimensions. The field content of the system is (\psi_\mu{}^{\alpha I}, \chi^{\alpha I J}, A_\mu{}^I), where \psi_\mu{}^{\alpha I} is a vector-spinor in the adjoint representation of an arbitrary gauge group, and A_\mu{}^I is its gauge field, while \chi^{\alpha I J} is an extra spinor with antisymmetric adjoint indices I J. Amazingly, the consistency of the vector-spinor field equation is maintained, despite its non-trivial interactions.Comment: 10 pages, no figure