T2K Collaboration(Abe, K. et al), Cervera-Villanueva, A., Izmaylov, A., Novella, P., Sorel, M., & Stamoulis, P. (2017). Search for Lorentz and CPT violation using sidereal time dependence of neutrino flavor transitions over a short baseline. Phys. Rev. D, 95(11), 111101–9pp.
Abstract: A class of extensions of the Standard Model allows Lorentz and CPT violations, which can be identified by the observation of sidereal modulations in the neutrino interaction rate. A search for such modulations was performed using the T2K on-axis near detector. Two complementary methods were used in this study, both of which resulted in no evidence of a signal. Limits on associated Lorentz and CPT-violating terms from the Standard Model extension have been derived by taking into account their correlations in this model for the first time. These results imply such symmetry violations are suppressed by a factor of more than 10(20) at the GeV scale.
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Ceccopieri, F. A., Rinaldi, M., & Scopetta, S. (2017). Parton correlations in same-sign W pair production via double parton scattering at the LHC. Phys. Rev. D, 95(11), 114030–6pp.
Abstract: Same-sign W boson pair production is a promising channel to look for signatures of double parton interactions at the LHC. The corresponding cross section has been calculated by using double parton distribution functions, encoding two parton correlations, evaluated in a light-front quark model. The obtained result is in line with previous estimates which make use of an external parameter, the so-called effective cross section, not necessary in our approach. The possibility to observe for the first time two-parton correlations, in the next LHC runs, has been established.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Measurements of integrated and differential cross sections for isolated photon pair production in pp collisions at root s=8 TeV with the ATLAS detector. Phys. Rev. D, 95(11), 112005–27pp.
Abstract: A measurement of the production cross section for two isolated photons in proton-proton collisions at a center-of-mass energy of root s = 8 TeV is presented. The results are based on an integrated luminosity of 20.2 fb(-1) recorded by the ATLAS detector at the Large Hadron Collider. The measurement considers photons with pseudorapidities satisfying vertical bar eta(gamma)vertical bar< 1.37 or 1.56 <vertical bar eta(gamma)vertical bar< 2.37 and transverse energies of respectively E-T,1(gamma) > 40 GeV and E-T,2(gamma) > 30 GeV for the two leading photons ordered in transverse energy produced in the interaction. The background due to hadronic jets and electrons is subtracted using data-driven techniques. The fiducial cross sections are corrected for detector effects and measured differentially as a function of six kinematic observables. The measured cross section integrated within the fiducial volume is 16.8 +/- 0.8 pb. The data are compared to fixed-order QCD calculations at next-to-leading-order and next-to-next-to-leading-order accuracy as well as next-to-leading-order computations including resummation of initial-state gluon radiation at next-to-next-to-leading logarithm or matched to a parton shower, with relative uncertainties varying from 5% to 20%.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2017). Observation of the Doubly Charmed Baryon Xi(++)(cc). Phys. Rev. Lett., 119(11), 112001–10pp.
Abstract: A highly significant structure is observed in the Lambda K-+(c)-pi(+)pi(+) mass spectrum, where the Lambda(+)(c) baryon is reconstructed in the decay mode pK(-)pi(+). The structure is consistent with originating from a weakly decaying particle, identified as the doubly charmed baryon Xi(++)(cc). The difference between the masses of the Xi(++)(cc) and Lambda(+)(c) states is measured to be 1334.94 +/- 0.72(stat.) +/- 0.27(syst.) MeV/c(2), and the Xi(++)(cc) mass is then determined to be 3621.40 +/- 0.72(stat.) +/- 0.27(syst.) +/- 0.14(Lambda(+)(c)) MeV/c(2), where the last uncertainty is due to the limited knowledge of the Lambda(+)(c) mass. The state is observed in a sample of proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7 fb(-1), and confirmed in an additional sample of data collected at 8 TeV.
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Sepehri, A., Pincak, R., & Olmo, G. J. (2017). M-theory, graphene-branes and superconducting wormholes. Int. J. Geom. Methods Mod. Phys., 14(11), 1750167–32pp.
Abstract: Exploiting an M-brane system whose structure and symmetries are inspired by those of graphene (what we call a graphene-brane), we propose here a similitude between two layers of graphene joined by a nanotube and wormholes scenarios in the brane world. By using the symmetries and mathematical properties of the M-brane system, we show here how to possibly increase its conductivity, to the point of making it as a superconductor. The questions of whether and under which condition this might point to the corresponding real graphene structures becoming superconducting are briefly outlined.
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