New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation

We compute the electromagnetic radiative corrections to all leading annihilation processes which may occur in the Galactic dark matter halo, for dark matter in the framework of supersymmetric extensions of the Standard Model (MSSM and mSUGRA), and present the results of scans over the parameter space that is consistent with present observational bounds on the dark matter density of the Universe. Although these processes have previously been considered in some special cases by various authors, our new general analysis shows novel interesting results with large corrections that may be of importance, e.g., for searches at the soon to be launched GLAST gamma-ray space telescope. In particular, it is pointed out that regions of parameter space where there is a near degeneracy between the dark matter neutralino and the tau sleptons, radiative corrections may boost the gamma-ray yield by up to three or four orders of magnitude, even for neutralino masses considerably below the TeV scale, and will enhance the very characteristic signature of dark matter annihilations, namely a sharp step at the mass of the dark matter particle. Since this is a particularly interesting region for more constrained mSUGRA models of supersymmetry, we use an extensive scan over this parameter space to verify the significance of our findings. We also re-visit the direct annihilation of neutralinos into photons and point out that, for a considerable part of the parameter space, internal bremsstrahlung is more important for indirect dark matter searches than line signals.Comment: Replaced Fig. 2c which by mistake displayed the same spectrum as Fig. 2d; the radiative corrections reported here are now implemented in DarkSUSY which is available at http://www.physto.se/~edsjo/darksusy

Renormalization group running of neutrino parameters in the inverse seesaw model

We perform a detailed study of the renormalization group equations in the inverse seesaw model. Especially, we derive compact analytical formulas for the running of the neutrino parameters in the standard model and the minimal supersymmetric standard model, and illustrate that, due to large Yukawa coupling corrections, significant running effects on the leptonic mixing angles can be naturally obtained in the proximity of the electroweak scale, perhaps even within the reach of the LHC. In general, if the mass spectrum of the light neutrinos is nearly degenerate, the running effects are enhanced to experimentally accessible levels, well suitable for the investigation of the underlying dynamics behind the neutrino mass generation and the lepton flavor structure. In addition, the effects of the seesaw thresholds are discussed, and a brief comparison to other seesaw models is carried out.Comment: 30 pages, 7 figures. Final version published in Phys. Rev. D. v3: Typo in Eq. (33) correcte

Antimatter and Gamma-rays from Dark Matter Annihilation

A brief review of the indirect detection signatures of dark matter is given. In particular, detection methods of dark matter particle annihilation to antimatter and gamma-rays are reviewed. With the GLAST satellite soon to be launched, a crucial window in the energy range of a few GeV up to 300 GeV will open. The good angular and energy resolution of the instrument means that structures predicted by cold dark matter models can be searched for. Large, currently planned ground-based imaging Cherenkov telescope arrays, may further improve the limits, or discover a signal, if the current understanding of halo dark matter structure is correct.Comment: 7p, one fig., invited talk at TAUP 2007, Sendai, Japan, to appear in the Proceeding

Paclitaxel, Epirubicin and Capecitabine (TEX) as First-Line Treatment for Metastatic Breast Cancer: a Pilot Phase I/II Feasibility Study

Thirteen patients with untreated metastatic breast cancer received epirubicin 60 mg/m2, paclitaxel 155 mg/m2 (both day 1) and capecitabine 665 mg/m2 twice daily (days 1–14) every 21 days, with intra-patient dose escalation/reduction. Grade 3/4 events were infrequent. Nine patients (69%) achieved an objective response. Median time to progression and overall survival were 6.6 and 23.5 months, respectively

The Color-Octet intrinsic charm in η′\eta^\prime and B→η′XB\to \eta^\prime X decays

Color-octet mechanism for the decay B\to \eta^\prime X is proposed to explain the large branching ratio of Br(B\to \eta^\prime X)\sim 1\times 10^{-3} recently announced by CLEO. We argue that the inclusive \eta^\prime production in B decays may dominantly come from the Cabbibo favored b\to (\bar c c)_8s process where \bar c c pair is in a color-octet configuration, and followed by the nonperturbative transition (\bar c c)_8\to \eta^\prime X. The color-octet intrinsic charm component in the higher Fock states of \eta^\prime is crucial and is induced by the strong coupling of \eta^\prime to gluons via QCD axial anomaly.Comment: 9 pages, RevTex, 1 PS figur

The Fate of Firms: Explaining Mergers and Bankruptcies

Using a uniquely complete data set of more than 50,000 observations of approximately 16,000 corporations, we test theories that seek to explain which firms become merger targets and which firms go bankrupt. We find that merger activity is much greater during prosperous periods than during recessions. In bad economic times, firms in industries with high bankruptcy rates are less likely to file for bankruptcy than they are in better years, supporting the market illiquidity arguments made by Shleifer and Vishny (1992). At the firm level, we find that, among poorly performing firms, the likelihood of merger increases with poorer performance, but among better performing firms, the relation is reversed and chances of merger increase with better performance. Such a changing relation has not been detected in prior merger studies. We also find that low-growth, resource-rich firms are prime acquisition targets and that firms’ debt capacity relates negatively to the likelihood of a merger. Debt-related variables, leverage and secured debt, play an especially prominent role in distinguishing between which firms merge and which firms go bankrupt

Rapid speciation in a newly opened postglacial marine environment, the Baltic Sea

<p>Abstract</p> <p>Background</p> <p>Theory predicts that speciation can be quite rapid. Previous examples comprise a wide range of organisms such as sockeye salmon, polyploid hybrid plants, fruit flies and cichlid fishes. However, few studies have shown natural examples of rapid evolution giving rise to new species in marine environments.</p> <p>Results</p> <p>Using microsatellite markers, we show the evolution of a new species of brown macroalga (<it>Fucus radicans</it>) in the Baltic Sea in the last 400 years, well after the formation of this brackish water body ~8–10 thousand years ago. Sympatric individuals of <it>F. radicans </it>and <it>F. vesiculosus </it>(bladder wrack) show significant reproductive isolation. <it>Fucus radicans</it>, which is endemic to the Baltic, is most closely related to Baltic Sea <it>F. vesiculosus </it>among north Atlantic populations, supporting the hypothesis of a recent divergence. <it>Fucus radicans </it>exhibits considerable clonal reproduction, probably induced by the extreme conditions of the Baltic. This reproductive mode is likely to have facilitated the rapid foundation of the new taxon.</p> <p>Conclusion</p> <p>This study represents an unparalleled example of rapid speciation in a species-poor open marine ecosystem and highlights the importance of increasing our understanding on the role of these habitats in species formation. This observation also challenges presumptions that rapid speciation takes place only in hybrid plants or in relatively confined geographical places such as postglacial or crater lakes, oceanic islands or rivers.</p