NLO differential distributions of massive lepton-pair production in longitudinally polarized proton-proton collisions

We present the full next-to-leading order (NLO) corrected inclusive cross section $d^3\Delta \sigma/dQ^2/dy/dp_T$ for massive lepton pair production in longitudinally polarized proton-proton collisions $p + p\to l^+l^- + 'X'$. Here $'X'$ denotes any inclusive hadronic state and Q represents the invariant mass of the lepton pair which has transverse momentum p_T and rapidity y. All QCD partonic subprocesses have been included provided the lepton pair is created by a virtual photon, which is a valid approximation for $Q<50{\rm GeV}$. Like in unpolarized proton-proton scattering the dominant subprocess is given by $q(\bar q) + g \to \gamma^* + 'X'$ so that massive lepton pair production provides us with an excellent method to measure the spin density of the gluon. Our calculations are carried out using the method of n-dimensional regularization by making a special choice for the $\gamma_5$-matrix. Like in the case of many other prescriptions evanescent counter terms appear. They are determined by computing the NLO coefficient functions for $d\Delta\sigma/dQ^2$ and the polarized cross section for Higgs production using both n-dimensional regularization and a four dimensional regularization technique in which the $\gamma_5$-matrix is uniquely defined. Our calculations reveal that the non-singlet polarized coefficient function equals the unpolarized one up to a minus sign. We give predictions for double longitudinal spin asymmetry measurements at the RHIC.Comment: 56 pages, LaTeX, 20 postscript figures. We have changed the discussion of the various regularization schemes in the penultimate paragraph of section 1 and in the text between Eq. (2.17) and Eq. (2.18). Furthermore a more careful comparison between our results and those in refs. [13],[14] for the quark-anti-quark channel reveals that we have full agreement. Further some misprints like the ones occuring in Eq. (2.61) and table 1 in section 4 are correcte

Occupational sex segregation and working time: Regional evidence from Germany

This paper provides descriptive evidence for declining occupational sex segregation on the German labor market, especially concerning the regional differences between the former East and West Germany. I use segregation measures and long-run social security data for the decade of 1992 to 2004. While segregation has declined over time, it remains higher for the eastern part of Germany. Although this finding is observable for full-time and part-time work, segregation is always lower in part-time employment

A note on happiness in Eastern Europe

Recent studies in economics of happiness focusing on the influence of different aspects of subjective well-being in transition countries. Here these countries are located in Eastern Europe. After aggregating a dataset which combines the World Values Survey and the European Values Survey, I use an OLS and ordered probit and ordered logit estimation with marginal effects to perform regressions. The main findings are that individuals in transition countries behave like individuals in western industrialisted countries. This shows the international reliability of approach the happiness research approach.peer-reviewe

Molecular simulations of entangled defect structures around nanoparticles in nematic liquid crystals

We investigate the defect structures forming around two nanoparticles in a Gay-Berne nematic liquid crystal using molecular simulations. For small separations, disclinations entangle both particles forming the figure of eight, the figure of omega and the figure of theta. These defect structures are similar in shape and occur with a comparable frequency to micron-sized particles studied in experiments. The simulations reveal fast transitions from one defect structure to another suggesting that particles of nanometre size cannot be bound together effectively. We identify the 'three-ring' structure observed in previous molecular simulations as a superposition of the different entangled and non-entangled states over time and conclude that it is not itself a stable defect structure.Comment: keywords: molecular-simulation, defects, nematic, disclination, algorithmic classification ; 8 pages, 7 figures, 1 tabl

Gender Differences in Life Satisfaction and Social Participation

The paper deals with the effects of social participation activities on life satisfaction. Using the German General Social Survey (ALLBUS) for 2010, marginal effects of binary probit\ud estimations on life satisfaction are presented. Strong gender differences are observable. While sport, welfare or parental activities affect only female life satisfaction, males are more affected by classical hobbies. As an interesting result that political activities, such as a political party or a union membership, have no or even negative effects. The general results may be interpreted in that way, that activities or memberships with influence in local fields with own responsibility and\ud personal interest in a short of time, may be more satisfying than activities with more idealistic tasks and long run results, such as protecting nature or human rights

Kinder - ein Quell der Freude?!

It is well known, that the presences of children lower parental happiness. That is based on psychological and economical reasons. The effect holds on for micro data of the GSOEP. The number of children affects an inverse u-shaped curve on happiness. Even an enlargement of the dataset with macroeconomic variables offers the same results. The effect disappears only after generating terms of interaction for catching some effects of macroeconomic uncertainty. Children turn to be positive. This result could be interpreted as consumption utility of children. Considering these factors, children might be a source of joy.Happiness, children

Machen Kinder doch glücklich?

In der ökonomischen Zufriedenheitsforschung wird ein negativer Effekt von Kindern auf die elterliche Zufriedenheit ermittelt. Dazu werden oftmals Probitmodelle geschätzt. In diesem Papier wird nun ein fixed effects Modell benutzt. Mittels Daten des Sozioökonomischen Panels (SOEP) werden Personen betrachtet, die im Zeitablauf zu Eltern werden. Es ergibt sich ein signifikant positiver Effekt von Kinder im Haushalt. Weiterhin werden Interaktionsterme gebildet, um Effekte individueller Arbeitslosigkeit einzufangen. Bei arbeitslosen Väter sinkt deutschlandweit die Zufriedenheit. Arbeitslose Mütter erleben in den alten Bundesländern einen positiven Zufriedenheitseffekt, in den neuen einen Negativen. Dies wird als Folge von regional unterschiedlichen weiblichen Erwerbsmustern in Deutschland interpretiert.

Polynomials associated with graph coloring and orientations

We study colorings and orientations of graphs in two related contexts. Firstly, we generalize Stanley's chromatic symmetric function using the k-balanced colorings of Pretzel to create a new graph invariant. We show that in fact this invariant is a quasisymmetric function which has a positive expansion in the fundamental basis. We also define a graph invariant generalizing the chromatic polynomial for which we prove some theorems analogous to well-known theorems about the chromatic polynomial. Secondly, we examine graphs and graph colorings in the context of the combinatorial Hopf algebras of Aguiar, Bergeron and Sottile. By doing so, we are able to obtain a new formula for the antipode of a Hopf algebra on graphs previously studied by Schmitt. We also obtain new interpretations of evaluations of the Tutte polynomial

Measuring Double Parton Distributions in Nucleons at Proton-Nucleus Colliders

We predict a strong enhancement of multijet production in proton-nucleus collisions at collider energies, as compared to a naive expectation of a cross section $\propto A$. The study of the process would allow to measure, for the first time, the double parton distribution functions in a nucleon in a model independent way and hence to study both the longitudinal and the transverse correlations of partons.Comment: 12 pages, 2 figure