MCSTHAR++, a Monte Carlo code for the microcanonical hadronization

MCSTHAR++ is a new Monte Carlo code implementing the Statistical Hadronization Model. This model assumes that hadronization proceeds through the microcanonical decay of massive extended clusters. Unlike other hadronization models, in this approach very few free parameters are needed, as has been demonstrated in previous studies. The tuning of the model and the comparison with the data is ongoing.Comment: 3 pages; To appear in the proceedings of the conference IFAE 2010, Roma, Italy, 7-9 April 201

The 2^-+ assignment for the X(3872)

Very recently the BaBar collaboration has put forward a claim that the X(3872) is not a 1^++ resonance, as most of the phenomenological work on the subject was relying on, but rather a 2^-+ one. We examine the consequences of this quantum number assignment for the solution of the X(3872) puzzle. The molecular interpretation appears less likely, and the conventional charmonium interpretation should be reconsidered. There are several well-known difficulties with this interpretation, to which we add a new one: the production cross section at CDF is predicted to be much smaller than that observed. We also confirm, using a relativistic string model, the conclusion from potential models that the mass of the state is not consistent with expectations. In the tetraquark interpretation the 2^-+ assignment implies a rich spectrum of partner states, although the X(3872) may be among the few which are narrow enough to be observable.Comment: 18 pages, 6 figures, 4 tables; minor style corrections. Version to appear in PR

UTOPIAS AND DYSTOPIAS IN LANDSCAPE AND CULTURAL MOSAIC. VISIONS, VALUES, VULNERABILITY: AN INTRODUCTION

How much is it worth for whom? How long will be worth for? We must not be scared off by mythical names such as the City of the Sun, Utopia, New Atlantis, and we must not give in to the chanting of their Mermaids. Let\u2019s start from Friedman and his definition of urban utopia and dystopia: \u201cutopian thinking: the capacity to imagine a future that departs significantly from what we know to be a general condition of the present.\u2026In the peculiar form of dystopias, utopian thinking may alert us to certain tendencies in the present, which, if allowed to continue unchecked and carried to a logical extreme, would result in a world we would find abhorrent\u201d. Emphasis will not be placed on the urban utopias of the perfect city since this field has been widely and finely explored by urban planners and architects. It was, after all, the first topic that was dealt with by many utopians in their description of their little perfect worlds. Rather, we want to explore the abstract spatial forms of utopia and dystopias. The term dystopia is not only used to refer to the extreme consequences of the mistakes of mankind, but also to the conflicts arising from different utopias and particularly between utopias and the real world. Such conflicts will enable us to consider spatial forms in their temporal development, not only as a starting and finishing point but also as a process having intermediate phases that are often concealed by the saying \u201cthe ends justify the means\u201d. The age-old dystopia between city and countryside must be overcome. Border areas have never been well defined and are formed by the combination of numerous tesserae that, at times, are juxtaposed like proper mosaic tesserae, and at times represent mixed areas where the single components become blurred and indistinguishable. One\u2019s desire to classify and separate must give way to the analysis of merging, dissolution and enlargement of borders, just like Gottman did in his much praised (but also criticised) Megalopolis

Status and accuracy of the Monte Carlo generators for luminosity measurements

The status and accuracy of the precision Monte Carlo generators used for luminosity measurements at flavour factories is reviewed. It is shown that, thanks to a considerable, long-term effort in tuned comparisons between the predictions of independent programs, as well as in the validation of the generators against the presently available calculations of the next-to-next-to-leading order QED corrections to Bhabha scattering, the theoretical accuracy reached by the most precise tools is of about one per mille. This error estimate is valid for realistic experimental cuts, appears to be quite robust and is already sufficient for very accurate luminosity measurements. However, recent progress and possible advances to further improve it are also discussed.Comment: 6 pages, 1 table. Proceedings of the PhiPsi09 workshop, Oct. 13-16, 2009, Beijing, Chin

Full one-loop electroweak corrections to e+e- to 3 jets at linear colliders

We describe the impact of the full one-loop electroweak terms of O(alpha_s alpha_EM^3) entering the electron-positron into three-jet cross-section from sqrt(s)=M_Z to TeV scale energies. We include both factorisable and non-factorisable virtual corrections and photon bremsstrahlung. Their importance for the measurement of alpha_S from jet rates and shape variables is explained qualitatively and illustrated quantitatively, also in presence of b-tagging.Comment: 6 pages, to appear in the proceedings of the workshop "LC09 -- e+e- Physics at the TeV scale and the Dark Matter Connection", 21-24 September 2009, Perugia (Italy). Minor corrections, references added