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Rinaldi, M., Scopetta, S., Traini, M., & Vento, V. (2018). A model calculation of double parton distribution functions of the pion. Eur. Phys. J. C, 78(9), 781–9pp.
Abstract: Two-parton correlations in the pion are investigated in terms of double parton distribution functions. A Poincare covariant light-front framework has been adopted. As non perturbative input, the pion wave function obtained within the so-called soft-wall AdS/QCD model has been used. Results show how novel dynamical information on the structure of the pion, not accessible through one-body quantities, are encoded in double parton distribution functions.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Aparisi Pozo, J. A., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., et al. (2018). Prompt and non-prompt J/psi elliptic flow in Pb plus Pb collisions at root S-NN=5.02 TeV with the ATLAS detector. Eur. Phys. J. C, 78(9), 784–23pp.
Abstract: The elliptic flow of prompt and non-prompt J/psi was measured in the dimuon decay channel in Pb+Pb collisions at root S-NN = 5.02 TeV with an integrated luminosity of 0.42 nb(-1) with the ATLAS detector at the LHC. The prompt and non-prompt signals are separated using a two-dimensional simultaneous fit of the invariant mass and pseudo-proper decay time of the dimuon system from the J/psi decay. The measurement is performed in the kinematic range of dimuon transverse momentum and rapidity 9 < p(T) < 30 GeV, vertical bar y vertical bar < 2, and 0-60% collision centrality. The elliptic flow coefficient, v(2), is evaluated relative to the event plane and the results are presented as a function of transverse momentum, rapidity and centrality. It is found that prompt and non-prompt J/psi mesons have non-zero elliptic flow. Prompt J/psi v(2 )decreases as a function of p(T), while for non-prompt J/psi it is, with limited statistical significance, consistent with a flat behaviour over the studied kinematic region. There is no observed dependence on rapidity or centrality.
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Afonso, V. I., Olmo, G. J., Orazi, E., & Rubiera-Garcia, D. (2018). Mapping nonlinear gravity into General Relativity with nonlinear electrodynamics. Eur. Phys. J. C, 78(10), 866–11pp.
Abstract: We show that families of nonlinear gravity theories formulated in a metric-affine approach and coupled to a nonlinear theory of electrodynamics can be mapped into general relativity (GR) coupled to another nonlinear theory of electrodynamics. This allows to generate solutions of the former from those of the latter using purely algebraic transformations. This correspondence is explicitly illustrated with the Eddington-inspired Born-Infeld theory of gravity, for which we consider a family of nonlinear electrodynamics and show that, under the map, preserve their algebraic structure. For the particular case of Maxwell electrodynamics coupled to Born-Infeld gravity we find, via this correspondence, a Born-Infeld-type nonlinear electrodynamics on the GR side. Solving the spherically symmetric electrovacuum case for the latter, we show how the map provides directly the right solutions for the former. This procedure opens a new door to explore astrophysical and cosmological scenarios in nonlinear gravity theories by exploiting the full power of the analytical and numerical methods developed within the framework of GR.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., Castillo, F. L., et al. (2018). Search for Higgs boson pair production in the..WW * channel using pp collision data recorded at v s=13 TeV with the ATLAS detector. Eur. Phys. J. C, 78(12), 1007–26pp.
Abstract: Searches for non- resonant and resonant Higgs boson pair production are performed in the..WW * channel with the final state of.. .j j using 36.1 fb – 1 of protonpv roton collision data recorded at a centre- of- mass energy of s = 13 TeV by the ATLAS detector at the Large Hadron Collider. No significant deviation from the Standard Model prediction is observed. A 95% confidence- level observed upper limit of 7.7 pb is set on the cross section for nonresonant production, while the expected limit is 5.4 pb. A search for a narrow- width resonance X decaying to a pair of Standard Model Higgs bosons HH is performed with the same set of data, and the observed upper limits on s( pp. X) x B( X. HH) range between 40.0 and 6.1 pb for masses of the resonance between 260 and 500GeV, while the expected limits range between 17.6 and 4.4 pb. When deriving the limits above, the StandardModel branching ratios of the H... and H. WW * are assumed.
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ANTARES Collaboration(Albert, A. et al), Barrios-Marti, J., Coleiro, A., Colomer, M., Hernandez-Rey, J. J., Illuminati, G., et al. (2018). The cosmic ray shadow of the Moon observed with the ANTARES neutrino telescope. Eur. Phys. J. C, 78(12), 1006–9pp.
Abstract: One of the main objectives of the ANTARES telescope is the search for point- like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliableway to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i. e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, theMoon shadow is observed with 3.5s statistical significance. The detector angular resolution for downwardgoing muons is 0.73. +/- 0.14.. The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.
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