Colorless States in Perturbative QCD: Charmonium and Rapidity Gaps

We point out that an unorthodox way to describe the production of rapidity gaps in deep inelastic scattering, recently proposed by Buchm\"uller and Hebecker, suggests a description of the production of heavy quark bound states which is in agreement with data. The approach questions the conventional treatment of the color quantum number in perturbative QCD.Comment: 14 pages, plain Latex, 9 postscript figures included. Uses epsf.sty. Postscript file of paper with figures also available at http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-919.ps.Z or at ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-919.ps.

Low-latitude boundary layer clouds as seen by CALIPSO

The distribution of low-level cloud in the tropical belt is investigated using 6 months of Level 2 retrievals from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) at 333 m and 1 km horizontal resolutions. Regional patterns of tropical clouds emerge from the data, matching expectations from existing observations. The advantage of the lidar is highlighted by the distribution of cloud-top height, revealing the preponderance of low-level clouds over the tropical oceans. Over land, cloud top is more uniformly distributed under the influence of diurnal variation. The integrated cloud-top distribution suggests tropical, marine low-cloud amount around 25-30%; a merged CALIPSO-CloudSat product has a similar cloud-top distribution and includes a complementary estimate of cloud fraction based on the lidar detections. The low-cloud distribution is similar to that found in fields of shallow cumulus observed during the Rain in Cumulus Over the Ocean (RICO) field study. The similarity is enhanced by sampling near the RICO site or sampling large-scale conditions similar to those during RICO. This finding shows how satellite observations can help to generalize findings from detailed field observations

An update on χc\chi_c Decays: Perturbative QCD versus Data

We present a global fit of current available experimental results on $\chi_c$ decays within next-to-leading-order perturbative QCD. The quality and reduced errors of recent data improve the agreement between theory and experiment.Comment: 10 pages, Late

Tradition or revolution? The difficult "turning point" in Italian Children\u2019s Literature

The 1960s and 1970s in Italy was a complex period, full of often contrasting stimuli from different directions. The imaginary worlds of children participated in what was happening at a social and cultural level, albeit in a more muted way. By analysing sources from the publishing world, TV programmes for children and other mass media, it is possible to identify a profound ambiguity and ambivalence in the material proposed. On the one hand there was an abundance of writers, artists and thinkers ready to place childhood at the very centre of educational processes, attributing to it a heretofore unthinkable autonomy and dignity. On the other, it is possible to sense in many narrators a firm retreat into tradition, conservatism and the maintenance of a status quo based on stories of \u201cfine sentiments\u201d, filial love and containment of emotions\u2026Even though there was much distance between these contradictory visions, their incongruity was able to spark new curiosities in (perhaps not only) children, to suggest new existential questions and open up new interpretive perspectives

Born to win. Children\u2019s literature and male models

Rispetto alla complessit\ue0 che ha accompagnato la trasformazione dei modelli femminili nel corso degli ultimi secoli della nostra storia, quelli maschili, fino a tempi molto recenti, si sono perlopi\uf9 limitati a due, speculari e imprescindibili l\u2019uno dall\u2019altro: i vincitori e le vittime; tenendo conto, per\uf2, come quest\u2019ultima tipologia non rappresenti, quasi mai, un punto di riferimento attivo, ma denoti lo spettro di situazioni esistenziali dalle quali gli uomini di qualunque et\ue0 sarebbe bene si tenessero lontani. Ancora oggi i modelli maschili proposti dalla narrazione contemporanea si ostinano a veicolare, pi\uf9 di quelli femminili, stereotipi e prassi educativo-comportamentali legati ad una inossidabile cultura di tipo patriarcale

How psychological distance affects consumer behavior towards sustainable product features and attributes

Consumers are constantly confronted with decision making processes on a daily basis and the number of different offers and the vast amount of opportunities can be challenging. But also, for marketeers creating the right amount of attention and desire to promote and place their products at the right time and right way is challenging. An important factor and variable plays the construal level theory, that states that people can be either in a more concrete (low) or in a more abstract (high) state of mind. This theory of psychological distance is an important key factor for understanding consumer behavior and to understand what effects this can cause and what are the different dimensions that influence psychological distance. With sustainable consumption on the rise and the offer for more sustainable product alternatives constantly rising, this dissertation aims to explore the connections and the effects psychological distance manipulation has on how consumers evaluate and rate products with sustainable product features and attributes. Previous research has stated that sustainable attributes gain importance when consumers are in a more abstract state of mind with the construal level theory examining, that people that are in a more concrete state of mind are more detailed orientated in their decision- making process. And the combination of those two theories are the baseline of this dissertation. It hypothesizes that psychological distance is a mechanism that affects consumer behavior towards sustainable product attributes. Two studies were conducted for testing these hypotheses.Os consumidores são constantemente confrontados com processos de tomada de decisão numa base diária e o número de diferentes ofertas e a vasta quantidade de oportunidades pode ser um desafio. Um factor importante e variável desempenha a teoria do nível constual, que afirma que as pessoas podem estar ou num estado de espírito mais concreto (baixo) ou num estado de espírito mais abstracto (alto). Esta teoria da distância psicológica é um factor chave importante para compreender o comportamento do consumidor e para compreender os efeitos que isto pode causar, quais são as diferentes dimensões que influenciam a distância psicológica. Com o consumo sustentável em ascensão e a oferta de alternativas de produtos mais sustentáveis a aumentar constantemente, esta dissertação visa explorar as ligações e os efeitos que a manipulação psicológica da distância tem sobre a forma como os consumidores avaliam e classificam produtos com características e atributos de produtos sustentáveis. Pesquisas anteriores afirmaram que os atributos sustentáveis ganham importância quando os consumidores estão num estado de espírito mais abstracto com a teoria do nível constual examinando que as pessoas que estão num estado de espírito mais concreto se orientam mais detalhadamente no seu processo de tomada de decisões. E a combinação destas duas teorias é a base desta dissertação. A tese pressupõe que a distância psicológica é um mecanismo que afecta o comportamento do consumidor em relação aos atributos do produto sustentável

Stabilizing the intensity of a wave amplified by a beam of particles

The intensity of an electromagnetic wave interacting self-consistently with a beam of charged particles as in a free electron laser, displays large oscillations due to an aggregate of particles, called the macro-particle. In this article, we propose a strategy to stabilize the intensity by re-shaping the macro-particle. This strategy involves the study of the linear stability (using the residue method) of selected periodic orbits of a mean-field model. As parameters of an additional perturbation are varied, bifurcations occur in the system which have drastic effect on the modification of the self-consistent dynamics, and in particular, of the macro-particle. We show how to obtain an appropriate tuning of the parameters which is able to strongly decrease the oscillations of the intensity without reducing its mean-value

Enhancement of particle trapping in the wave-particle interaction

The saturated dynamics of a Single-Pass Free Electron Laser is considered within a simplified mean-field approach. A method is proposed to increase the size of the macro-particle, which is responsible for the oscillations of the intensity of the wave. This approach is based on the reconstruction of invariant tori of the dynamics of test particles. To this aim a dedicated control term is derived, the latter acting as a small apt perturbation of the system dynamics. Implications of these findings are discussed in relation to the optimization of the laser source