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Perez-Ramos, R., Mathieu, V., & Sanchis-Lozano, M. A. (2010). Heavy quark flavour dependence of multiparticle production in QCD jets. J. High Energy Phys., 08(8), 047–24pp.
Abstract: After inserting the heavy quark mass dependence into QCD partonic evolution equations, we determine the mean charged hadron multiplicity and second multiplicity correlators of jets produced in high energy collisions. We thereby extend the so-called dead cone effect to the phenomenology of multiparticle production in QCD jets and find that the average multiplicity of heavy-quark initiated jets decreases significantly as compared to the massless case, even taking into account the weak decay products of the leading primary quark. We emphasize the relevance of our study as a complementary check of b-tagging techniques at hadron colliders like the Tevatron and the LHC.
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Ferrario, P., & Rodrigo, G. (2010). Heavy colored resonances in t(t)over-bar + jet at the LHC. J. High Energy Phys., 02(2), 051–13pp.
Abstract: The LHC is the perfect environment for the study of new physics in the top quark sector. We study the possibility of detecting signals of heavy color-octet vector resonances, through the charge asymmetry, in t (t) over bar + jet events. Besides contributions with the t (t) over bar pair in a color-singlet state, the asymmetry gets also contributions which are proportional to the color factor f(abc)(2). This process is particularly interesting for extra-dimensional models, where the inclusive charge asymmetry generated by Kaluza-Klein excitations of the gluon vanishes at the tree level. We find that the statistical significance for the measurement of such an asymmetry is sizable for different values of the coupling constants and already at low energies.
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Agullo, I., Navarro-Salas, J., Olmo, G. J., & Parker, L. (2010). Hawking Radiation by Kerr Black Holes and Conformal Symmetry. Phys. Rev. Lett., 105(21), 211305–4pp.
Abstract: The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.
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Pandolfi, S., Cooray, A., Giusarma, E., Kolb, E. W., Melchiorri, A., Mena, O., et al. (2010). Harrison-Zel'dovich primordial spectrum is consistent with observations. Phys. Rev. D, 81(12), 123509–6pp.
Abstract: Inflation predicts primordial scalar perturbations with a nearly scale-invariant spectrum and a spectral index approximately unity [the Harrison-Zel'dovich (HZ) spectrum]. The first important step for inflationary cosmology is to check the consistency of the HZ primordial spectrum with current observations. Recent analyses have claimed that a HZ primordial spectrum is excluded at more than 99% c. l. Here we show that the HZ spectrum is only marginally disfavored if one considers a more general reionization scenario. Data from the Planck mission will settle the issue.
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de Putter, R., & Takada, M. (2010). Halo-galaxy lensing: A full sky approach. Phys. Rev. D, 82(10), 103522–9pp.
Abstract: The halo-galaxy lensing correlation function or the average tangential shear profile over sampled halos is a very powerful means of measuring the halo masses, the mass profile, and the halo-mass correlation function of very large separations in the linear regime. We reformulate the halo-galaxy lensing correlation in harmonic space. We find that, counterintuitively, errors in the conventionally used flat-sky approximation remain at a percent level even at very small angles. The errors increase at larger angles and for lensing halos at lower redshifts: the effect is at a few percent level at the baryonic acoustic oscillation scales for lensing halos of z similar to 0.2, and comparable with the effect of primordial non-Gaussianity with f(NL) similar to 10 at large separations. Our results allow one to readily estimate/correct for the full-sky effect on a high-precision measurement of the average shear profile available from upcoming wide-area lensing surveys.
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