Reig, M., Valle, J. W. F., Vaquera-Araujo, C. A., & Wilczek, F. (2017). A model of comprehensive unification. Phys. Lett. B, 774, 667–670.
Abstract: Comprehensive – that is, gauge and family – unification using spinors has many attractive features, but it has been challenged to explain chirality. Here, by combining an orbifold construction with more traditional ideas, we address that difficulty. Our candidate model features three chiral families and leads to an acceptable result for quantitative unification of couplings. A potential target for accelerator and astronomical searches emerges.
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Richard, J. M., Valcarce, A., & Vijande, J. (2017). Stable heavy pentaquarks in constituent models. Phys. Lett. B, 774, 710–714.
Abstract: It is shown that standard constituent quark models produce ((c)over-barcqqq) hidden-charm pentaquarks, where c denotes the charmed quark and q a light quark, which lie below the lowest threshold for spontaneous dissociation and thus are stable in the limit where the internal (c)over-barc annihilation is neglected. The binding is a cooperative effect of the chromoelectric and chromomagnetic components of the interaction, and it disappears in the static limit with a pure chromoelectric potential. Their wave function contains color sextet and color octet configurations for the subsystems and can hardly be reduced to a molecular state made of two interacting hadrons. These pentaquark states could be searched for in the experiments having discovered or confirmed the hidden-charm meson and baryon resonances.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2017). Measurement of the D* (2010)(+) -D+ Mass Difference. Phys. Rev. Lett., 119(20), 202003–7pp.
Abstract: We measure the mass difference, Delta m(+), between the D* (2010)(+) and the D+ using the decay chain D* (2010)(+) -> D+ pi(0) with D+ -> K- pi(+)pi(+). The data were recorded with the BABAR detector at center-of-mass energies at and near the (sic)(4S) resonance, and correspond to an integrated luminosity of approximately 468 fb(-1). We measure Delta m(+) = (140601.0 +/- 6.8[stat] +/- 12.9[syst]) keV. We combine this result with a previous BABAR measurement of Delta m(0) = m(D* (2010)(+)) – m(D-0) to obtain Delta m(D) = m(D+) – m(D-0) = (4824.9 +/- 6.8[stat] +/- 12.9[syst]) keV. These results are compatible with and approximately five times more precise than the Particle Data Group averages.
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NEXT Collaboration(Azevedo, C. D. R. et al), Gomez-Cadenas, J. J., Alvarez, V., Benlloch-Rodriguez, J. M., Botas, A., Carcel, S., et al. (2018). Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives. Nucl. Instrum. Methods Phys. Res. A, 877, 157–172.
Abstract: We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.
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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). Measurement of b-hadron pair production with the ATLAS detector in proton-proton collisions at root s=8 TeV. J. High Energy Phys., 11(11), 062–51pp.
Abstract: A measurement of b-hadron pair production is presented, based on a data set corresponding to an integrated luminosity of 11.4 fb(-1) of proton-proton collisions recorded at root s = 8TeV with the ATLAS detector at the LHC. Events are selected in which a b-hadron is reconstructed in a decay channel containing J = psi -> μmu, and a second b-hadron is reconstructed in a decay channel containing a muon. Results are presented in a fiducial volume de fined by kinematic requirements on three muons based on those used in the analysis. The fiducial cross section is measured to be 17.7 +/- 0.1(stat.) +/- 2.0(syst.) nb. A number of normalised differential cross sections are also measured, and compared to predictions from the PYTHIA8, HERWIG++, MADGRAPH5_AMC@NLO+PYTHIA8 and SHERPA event generators, providing new constraints on heavy flavour production.
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