e+ e- -> t anti-t H including decays: on the size of background contributions

We present results for the lowest order cross sections, calculated with the complete set of the standard model Feynman diagrams, of all possible detection channels of the associated production of the top quark pair and the light Higgs boson, which may be used for determination of the top-Higgs Yukawa coupling at the future e+e- linear collider. We show that, for typical particle identification cuts, the background contributions are large. In particular, the QCD background contributions are much bigger than could be expected when taking into account a possibly low virtuality of exchanged gluons. Moreover, we include the initial state radiation effects and discuss the dependence of the cross sections on the Higgs boson and top quark masses.Comment: 13 pages, 1 figure; substantially revised version, accepted for publication in Eur.Phys.J.

An anomalous Wtb coupling at a linear collider

Differential cross sections of secondary particles in a process of top quark pair production and decay into six fermions at a linear collider with an unpolarized and a longitudinally polarized electron beam are computed to the lowest order in the standard model and in the presence of an anomalous Wtb coupling. It is illustrated that the latter has a little impact on the differential cross sections. In particular, it is shown that the angular distribution of a secondary lepton receives practically no contribution from the anomalous Wtb coupling, even if the top quark is produced off shell and the non-double resonance background contributions are taken into account. This finding is in accordance with the decoupling theorem that has been proven in literature in the narrow top quark width approximation.Comment: 11 pages, 9 figures, axodraw.st

A priori estimates for the complex Hessian equations

We prove some $L^{\infty}$ a priori estimates as well as existence and stability theorems for the weak solutions of the complex Hessian equations in domains of $C^n$ and on compact K\"ahler manifolds. We also show optimal $L^p$ integrability for m-subharmonic functions with compact singularities, thus partially confirming a conjecture of Blocki. Finally we obtain a local regularity result for $W^{2,p}$ solutions of the real and complex Hessian equations under suitable regularity assumptions on the right hand side. In the real case the method of this proof improves a result of Urbas.Comment: 18 pages, preliminary versio

On the energy dependence of hadronic BcB_c production

An estimate is presented of the production cross section of $B_c$ mesons between threshold and LHC energies using lowest-order perturbation theory and non-relativistic bound state approximation. It is shown that the ratio of the production cross sections for $B_c$ mesons and for $b$ quarks varies strongly with energy.Comment: 5 pages, 1 figure, Latex; Contribution to the 5th International Workshop on $B$-Physics at Hadron Machines, 1997, Los Angeles, California, US

Maximal subextensions of plurisubharmonic functions

In this paper we are concerned with the problem of local and global subextensions of (quasi-)plurisubharmonic functions from a "regular" subdomain of a compact K\"ahler manifold. We prove that a precise bound on the complex Monge-Amp\`ere mass of the given function implies the existence of a subextension to a bigger regular subdomain or to the whole compact manifold. In some cases we show that the maximal subextension has a well defined complex Monge-Amp\`ere measure and obtain precise estimates on this measure. Finally we give an example of a plurisubharmonic function with a well defined Monge-Amp\`ere measure and the right bound on its Monge-Amp\`ere mass on the unit ball in \C^n for which the maximal subextension to the complex projective space \mb P_n does not have a globally well defined complex Monge-Amp\`ere measure

Liceum, muzeum, mauzoleum… O wskrzeszaniu arcydzieł na lekcjach polskiego

Theodor W. Adorno claimed that ‘‘museum and mausoleum are related not only phonetically. Museums are like family tombs of artwork.” The author of this text comes to the conclusion that this set of sound-alike words can be topped up with another word – high school (Polish: liceum). The ones responsible for completing school curricula and textbooks fill them up with texts of culture for some reasons considered import ant and valuable. They also segregate them according to various order (on high school level it is mainly a chronological order). This ‘‘compulsory collective existence”, which might be understood if we take an academic context into consideration (history of art, history of literature), very often does not make sense to high school students. The author of this text wonders why it is the way it is and what to do so that high school does not change into museum, and even mausoleum. And how to make high school students appreciate the values acknowledged by experts. Looking for the solutions, the author starts with reflections on art, expresses a negative opinion on the new high school curriculum, refers to works of experts on various fields (e.g. history of art, sociology, didactics, philosophy) and – most of all – refers to literary works and paintings.Theodor W. Adorno uważał, że „muzeum i mauzoleum łączy nie tylko skojarzenie fonetyczne. Muzea są jak rodzinne groby dzieł sztuki”. Autor szkicu dochodzi do wniosku, że do tego zestawu podobnie brzmiących słów można dopisać trzecie – liceum. W szkolnych programach i podręcznikach gromadzi się teksty kultury z jakichś powodów uznane za ważne i wartościowe oraz układa w rozmaitych porządkach (na poziomie liceum głównie w porządku chronologicznym). Ta „przymusowa zbiorowa egzystencja”, zrozumiała z perspektywy akademickiej (historia sztuki, historia literatury), z perspektywy ucznia często nie ma sensu. Autor szkicu zastanawia się, dlaczego tak się dzieje i jak spowodować, by liceum nie zamieniało się ani muzeum, ani tym bardziej w mauzoleum. Jak spowodować, by to, co uznane za wartość przez specjalistów, mogło stać się wartościowe również dla niespecjalistów, poddawanych w szkole edukacji ogólnej. Szukając rozwiązań, autor szkicu wychodzi od rozważań na temat fenomenu sztuki, krytycznie ocenia najnowszą podstawę programową dla liceum, odwołuje się do prac specjalistów z różnych dziedzin (m.in. historia sztuki, socjologia, dydaktyka, filozofia) i – przede wszystkim – do samych dzieł literackich i malarskich

Zmiany sytuacji zatrudnienia oraz miejsca zatrudnienia Polaków w świetle badań panelowych POLPAN

Publikacja dofinansowana przez Polskie Towarzystwo Socjologiczne i Wydział Ekonomiczno-Socjologiczny UŁ Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00

The Double Life of a Packet of Sugar. The Noise(lessness) of Communication of the Items of Everyday Use

This review discusses the book by Aleksander W. Mikołajczak and Patryk Borowiak entitled Design saszetki zcukrem. O komunikowaniu się zrzeczami (On the Design of a Packet of Sugar. How WeCommunicate with Objects). The text focuses on theinteractions between people and objects, a phenomenon intrinsic to postmodernity, or the contemporary consumerist culture. The work is a peculiar biography of the packet of sugar and presents a multifaceted exploration thereof. The authors depart from the commonly conducted statistical analysis of the object of interest and instead endeavour to present the full extent of its existence and all the subsequent stages of its life, pointing to the complexity and the volatility of the process; this should be considered an innovative approach at its own right. The packet of sugar is viewed not only in the sociocultural perspective, but also through the lens of linguistics and onomastics

Scleractinian corals of suborders Pachythecaliina and Rhipidogyrina : discussion on similarities and description of species from Štramberk-type limestones, Polish Outer Carpathians

Similarities between scleractinian corals from extinct suborders Pachythecaliina Eliášová 1976 and Rhipidogyrina Roniewicz 1976 are discussed. Corals of the former suborder are considered by some authors as possible descendants of Palaeozoic Rugosa because of their unusual skeletal characters. Some rhipidogyrinans, especially the family Aulastraeoporidae, despite their different septal microstructure, share more common features with pachythecaliinans than with other scleractinians. The following skeletal features are discussed to show similarities between these two suborders: (1) wall microstructure and its relations to septa, (2) corallite bilateral symmetry, (3) marginarium, (4) lonsdaleoid and apophysal septa, and (5) internal septal margin. These similarities can be explained by convergence, although phylogenetic relationships of both suborders can not be excluded. This hypothesis needs to be verified by more studies, especially on early blastogeny of rhipidogyrinans and wall microstructure of pachythecaliinans. The systematic part gives descriptions of the discussed coral suborders occuring in the Štramberk-type limestones, the Polish Outer Carpathians (Tithonian-?Berriasian, ?Valanginian). Similarly as in the Štramberk Limestone (Moravia), pachythecaliinans are highly diversified (17 species, 12 genera, including Pachythecophyllia eliasovae n.gen., n.sp.). Rhipidogyrinans are represented by 4 species of 4 genera, including ?Ogilvinella morycowae n.sp