Higgsless electroweak symmetry breaking at the LHC

While the Higgs model is the best studied scenario of electroweak symmetry breaking, a number strongly-coupled models exist, predicting new signatures. Recent studies of WW and WZ final states at the ATLAS and CMS experiments are summarized and expected sensitivities are presented within the frameworks of the technicolor straw-man model and the electroweak chiral Lagrangian.Comment: Proceedings for the EPS HEP 2007 conference, Manchester, U.K., on behalf of the ATLAS and CMS Collaboration

Will Jets Identify the Progenitors of Type Ia Supernovae?

We use the fact that a Type Ia supernova has been serendipitously discovered near the jet of the active galaxy 3C 78 to examine the question of whether jets can enhance accretion onto white dwarfs. One interesting outcome of such a jet-induced accretion process is an enhanced rate of novae in the vicinity of jets. We present results of observations of the jet in M87 which appear to have indeed discovered 11 novae in close proximity to the jet. We show that a confirmation of the relation between jets and novae and Type Ia supernovae can finally identify the elusive progenitors of Type Ia supernovae.Comment: 10 pages, 3 figure

SURVEY OF THE DEPENDENCE ON TEMPERATURE OF THE COERCIVITY OF GARNET-FILMS

The temperature dependence of the domain-wall coercive field of epitaxial magnetic garnets films has been investigated in the entire temperature range of the ferrimagnetic phase, and has been found to be described by a set of parametric exponents. In subsequent temperature regions different slopes were observed, with breaking points whose position was found to be sample dependent. A survey ba.ed on literature Data as well as on a large number of our own samples shows the general existence of this piecewise exponential dependence and the presence of the breaking points. This type of domain-wall coercive field temperature dependence was found in all samples in the large family of the epitaxial garnets (about 30 specimens of more than ten chemical compositionsj and also in another strongly anisotropic material (TbFeCo)

Lattice study of vacuum polarization function and determination of strong coupling constant

We calculate the vacuum polarization functions on the lattice using the overlap fermion formulation.By matching the lattice data at large momentum scales with the perturbative expansion supplemented by Operator Product Expansion (OPE), we extract the strong coupling constant $\alpha_s(\mu)$ in two-flavor QCD as $\Lambda^{(2)}_{\overline{MS}}$ = $0.234(9)(^{+16}_{- 0})$ GeV, where the errors are statistical and systematic, respectively. In addition, from the analysis of the difference between the vector and axial-vector channels, we obtain some of the four-quark condensates.Comment: 24 pages, 9 figures, enlarged version published in Phys. Rev.

Determinação do número de fêmeas virgens por armadilha e periodicidade de captura de machos de Helicoverpa zea (Boddie) (Lepidoptera: noctuidae).

Avaliou-se em lavouras de milho em fase de liberacao de estilo-estigmas, na EMBRAPA/CNPMS, em Sete Lagoas, MG, a atratividade de diferentes numeros de femeas virgens de Helicoverpa zea (Boddie) em armadilha adesiva, alem de uma formulacao comercial do feromonio sintetico, proveniente dos E.E.U.U. A maior atividade de procura por acasalamento teve inicio nas primeiras horas da noite. Nao houve diferenca significativa ente medias de insetos capturados com uma, tres ou cinco femeas. Cinco femeas por armadilha tornam o monitoramento pouco pratico: uma apenas pode comprometer a captura por disfuncao fisiologica ou mesmo morte. Nao houve captura nas armadilhas contendo feromonio sintetico, que, ao inves, capturou machos de Mythimna, outro Noctuidae. A maior frequencia de captura nas armadilhas ocorreu apos a meia noite, diminuindo proximo do alvorecer. O horario de inicio de chamamento e captura esteve estreitamente relacionado com a temperatura ambiente

Combination Forecasts of Bond and Stock Returns: An Asset Allocation Perspective

We investigate the out-of-sample forecasting ability of the HML, SMB, momentum, short-term and long-term reversal factors along with their size and value decompositions on U.S. bond and stock returns for a variety of horizons ranging from the short run (1 month) to the long run (2 years). Our findings suggest that these factors contain significantly more information for future bond and stock market returns than the typically employed financial variables. Combination of forecasts of the empirical factors turns out to be particularly successful, especially from an an asset allocation perspective. Similar findings pertain to the European and Japanese markets

The Rate and Spatial Distribution of Novae in M101 (NGC 5457)

A new multi-epoch H-alpha imaging study of M101 (NGC 5457) has been carried out as part of a larger campaign to study the rate and stellar population of extragalactic novae. The survey yielded a total of 13 nova detections from 10 epochs of M101 observations spanning a three year period. After correcting for the temporal coverage and survey completeness, a global nova rate of 11.7^{+1.9}_{-1.5} per year is found. This value corresponds to a luminosity-specific nova rate of 1.23\pm0.27 novae per year per 10^{10} L_{\sun,K} when the K luminosity is derived from the B-K color, or 1.94\pm0.42 novae per year per 10^{10} L_{\sun,K} when the K magnitude from the Two Micron All Sky Survey is used. These values are consistent with previous estimates by Shafter et al. that were based on more limited data. The spatial distribution of the combined nova sample from the present survey and from the earlier Shafter et al. survey shows that the specific frequency of novae closely follows the integrated background light of the galaxy.Comment: 22 pages; 4 figures; accepted for publication in the Astrophysical Journa

Limits on Low Energy Photon-Photon Scattering from an Experiment on Magnetic Vacuum Birefringence

Experimental bounds on induced vacuum magnetic birefringence can be used to improve present photon-photon scattering limits in the electronvolt energy range. Measurements with the PVLAS apparatus (E. Zavattini {\it et al.}, Phys. Rev. D {\bf77} (2008) 032006) at both $\lambda = 1064$ nm and 532 nm lead to bounds on the parameter {\it A$_{e}$}, describing non linear effects in QED, of $A_{e}^{(1064)} < 6.6\cdot10^{-21}$ T$^{-2}$ @ 1064 nm and $A_{e}^{(532)} < 6.3\cdot10^{-21}$ T$^{-2}$ @ 532 nm, respectively, at 95% confidence level, compared to the predicted value of $A_{e}=1.32\cdot10^{-24}$ T$^{-2}$. The total photon-photon scattering cross section may also be expressed in terms of $A_e$, setting bounds for unpolarized light of $\sigma_{\gamma\gamma}^{(1064)} < 4.6\cdot10^{-62}$ m$^{2}$ and $\sigma_{\gamma\gamma}^{(532)} < 2.7\cdot10^{-60}$ m$^{2}$. Compared to the expected QED scattering cross section these results are a factor of $\simeq2\cdot10^{7}$ higher and represent an improvement of a factor about 500 on previous bounds based on ellipticity measurements and of a factor of about $10^{10}$ on bounds based on direct stimulated scattering measurements