ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Aparisi Pozo, J. A., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., et al. (2019). Search for a right-handed gauge boson decaying into a high-momentum heavy neutrino and a charged lepton in pp collisions with the ATLAS detector at root s=13 TeV. Phys. Lett. B, 798, 134942–23pp.
Abstract: A search for a right-handed gauge boson W-R, decaying into a boosted right-handed heavy neutrino N-R, in the framework of Left-Right Symmetric Models is presented. It is based on data from proton-proton collisions with a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider during the years 2015, 2016 and 2017, corresponding to an integrated luminosity of 80 fb(-1). The search is performed separately for electrons and muons in the final state. A distinguishing feature of the search is the use of large-radius jets containing electrons. Selections based on the signal topology result in smaller background compared to the expected signal. No significant deviation from the Standard Model prediction is observed and lower limits are set in the W-R and N-R mass plane. Mass values of the W-R smaller than 3.8-5 TeV are excluded for N-R in the mass range 0.1-1.8 TeV.
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ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Aparisi Pozo, J. A., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., et al. (2019). Evidence for the production of three massive vector bosons with the ATLAS detector. Phys. Lett. B, 798, 134913–22pp.
Abstract: A search for the production of three massive vector bosons in proton-proton collisions is performed using data at root s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in the years 2015-2017, corresponding to an integrated luminosity of 79.8 fb(-1). Events with two same-sign leptons l (electrons or muons) and at least two reconstructed jets are selected to search for WWW -> l nu l nu qq. Events with three leptons without any same-flavour opposite-sign lepton pairs are used to search for WWW > l nu l nu l nu, while events with three leptons and at least one same-flavour opposite-sign lepton pair and one or more reconstructed jets are used to search for WWZ -> l nu qqll. Finally, events with four leptons are analysed to search for WWZ > l nu l nu ll and WZZ > qqllll. Evidence for the joint production of three massive vector bosons is observed with a significance of 4.1 standard deviations, where the expectation is 3.1 standard deviations.
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Kang, S. K., Popov, O., Srivastava, R., Valle, J. W. F., & Vaquera-Araujo, C. A. (2019). Scotogenic dark matter stability from gauged matter parity. Phys. Lett. B, 798, 135013–10pp.
Abstract: We explore the idea that dark matter stability results from the presence of a matter-parity symmetry, arising naturally as a consequence of the spontaneous breaking of an extended SU(3) circle times SU(3)(L) circle times U(1)(X) circle times U(1)(N) electroweak gauge symmetry with fully gauged B-L. Using this framework we construct a theory for scotogenic dark matter and analyze its main features.
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De Romeri, V., Kelly, K. J., & Machado, P. A. N. (2019). DUNE-PRISM sensitivity to light dark matter. Phys. Rev. D, 100(9), 095010–13pp.
Abstract: We explore the sensitivity of the Deep Underground Neutrino Experiment (DUNE) near detector and the proposed DUNE-PRISM movable near detector to sub-GeV dark matter, specifically scalar dark matter coupled to the standard model via a sub-GeV dark photon. We consider dark matter produced in the DUNE target that travels to the detector and scatters off electrons. By combining searches for dark matter at many off-axis positions with DUNE-PRISM, sensitivity to this scenario can be much stronger than when performing a measurement at one on-axis position.
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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. (2019). Measurement of W-+/-boson and Z-boson production cross-sections in pp collisions at root s=2.76 TeV with the ATLAS detector. Eur. Phys. J. C, 79(11), 901–29pp.
Abstract: The production cross-sections for W +/- and Z bosons are measured using ATLAS data corresponding to an integrated luminosity of 4.0 pb-1 collected at a centre-ofmass energy v s = 2.76 TeV. The decay channels W and Z. are used, where can be an electron or a muon. The cross-sections are presented for a fiducial region defined by the detector acceptance and are also extrapolated to the full phase space for the total inclusive production cross-section. The combined (average) total inclusive cross-sections for the electron and muon channels are: s tot W+ = 2312 +/- 26 (stat.) +/- 27 (syst.) +/- 72 (lumi.) +/- 30 (extr.) pb, s tot W- = 1399 +/- 21 (stat.) +/- 17 (syst.) +/- 43 (lumi.) +/- 21 (extr.) pb, s tot Z. = 323.4 +/- 9.8 (stat.) +/- 5.0 (syst.) +/- 10.0 (lumi.) +/- 5.5(extr.) pb. Measured ratios and asymmetries constructed using these cross-sections are also presented. These observables benefit from full or partial cancellation of many systematic uncertainties that are correlated between the different measurements.
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