|
BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Evidence for the decay X(3872) -> J/psi omega. Phys. Rev. D, 82(1), 011101–8pp.
Abstract: We present a study of the decays B-0,B-+ -> J/psi pi(+)pi(-)pi K-0(0,+), using 467 x 106 B (B) over bar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) -> J/psi omega, with product branching fractions B(B+ -> X(3872K(+)) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.2(stat) +/- 0.1(syst)] x 10(-5), and B(B-0 -> X(3872)K-0) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.3(stat) +/- 0.1(syst)] x 10(-5). A detailed study of the pi(+) pi(-) pi(0) mass distribution from X(3872) decay favors a negative-parity assignment.
|
|
|
ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2011). Search for quark contact interactions in dijet angular distributions in pp collisions at sqrt(s)=7 TeV measured with the ATLAS detector. Phys. Lett. B, 694(4-5), 327–345.
Abstract: Dijet angular distributions from the first LHC pp collisions at center-of-mass energy root s = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb(-1). Dijet chi distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the chi distributions excludes quark contact interactions with a compositeness scale Lambda below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits.
|
|
|
Baron, R., Boucaud, P., Carbonell, J., Deuzeman, A., Drach, V., Farchioni, F., et al. (2010). Light hadrons from lattice QCD with light (u, d), strange and charm dynamical quarks. J. High Energy Phys., 06(6), 111–31pp.
|
|
|
Cheng, Y., Csernai, L. P., Magas, V. K., Schlei, B. R., & Strottman, D. (2010). Matching stages of heavy-ion collision models. Phys. Rev. C, 81(6), 064910–8pp.
Abstract: Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications.
|
|
|
Jimenez, R., Kitching, T., Pena-Garay, C., & Verde, L. (2010). Can we measure the neutrino mass hierarchy in the sky? J. Cosmol. Astropart. Phys., 05(5), 035–14pp.
Abstract: Cosmological probes are steadily reducing the total neutrino mass window, resulting in constraints on the neutrino-mass degeneracy as the most significant outcome. In this work we explore the discovery potential of cosmological probes to constrain the neutrino hierarchy, and point out some subtleties that could yield spurious claims of detection. This has an important implication for next generation of double beta decay experiments, that will be able to achieve a positive signal in the case of degenerate or inverted hierarchy of Majorana neutrinos. We find that cosmological experiments that nearly cover the whole sky could in principle distinguish the neutrino hierarchy by yielding 'substantial' evidence for one scenario over the another, via precise measurements of the shape of the matter power spectrum from large scale structure and weak gravitational lensing.
|
|