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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Production of associated Y and open charm hadrons in pp collisions at root s=7 and 8 TeV via double parton scattering. J. High Energy Phys., 07(7), 052–36pp.
Abstract: Associated production of bottomonia and open charm hadrons in pp collisions at root s = 7 and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb(-1) accumulated with the LHCb detector. The observation of five combinations, Y(1S)D-0, Y(2S)D-0, Y(1S)D+, Y(2S)D+ and Y(1S)D (s) (+) , is reported. Production crosssections are measured for Y(1S)D-0 and Y(1S)D+ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism.
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Double Chooz collaboration(Abe, Y. et al), & Novella, P. (2016). Measurement of theta(13) in Double Chooz using neutron captures on hydrogen with novel background rejection techniques. J. High Energy Phys., 01(1), 163–29pp.
Abstract: The Double Chooz collaboration presents a measurement of the neutrino mixing angle theta(13) using reactor (nu) over bar (e) observed via the inverse beta decay reaction in which the neutron is captured on hydrogen. This measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respect to our previous publication by a multi-variate analysis. These improvements demonstrate the capability of precise measurement of reactor (nu) over bar (e) without gadolinium loading. Spectral distortions from the (nu) over bar (e) reactor flux predictions previously reported with the neutron capture on gadolinium events are confirmed in the independent data sample presented here. A value of sin(2) 2 theta(13) = 0.095(0.039)(+0.039)(stat+syst) is obtained from a fit to the observed event rate as a function of the reactor power, a method insensitive to the energy spectrum shape. A simultaneous fit of the hydrogen capture events and of the gadolinium capture events yields a measurement of sin(2) 2 theta(13) = 0.088 +/- 0.033(stat+syst).
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ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Fernandez Martinez, P., et al. (2016). A search for prompt lepton-jets in pp collisions at root s=8 TeV with the ATLAS detector. J. High Energy Phys., 02(2), 062–51pp.
Abstract: A search is presented for a new, light boson with a mass of about 1 GeV and decaying promptly to jets of collimated electrons and/or muons (lepton-jets). The analysis is performed with 20.3 fb(-1) of data collected by the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a centre-of-mass energy of 8 TeV. Events are required to contain at least two lepton-jets. This study finds no statistically significant deviation from predictions of the Standard Model and places 95% confidence-level upper limits on the contribution of new phenomena beyond the SM, incuding SUSY-portal and Higgs-portal models, on the number of events with lepton-jets.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Measurement of forward W and Z boson production in pp collisions at root s=8TeV. J. High Energy Phys., 01(1), 155–45pp.
Abstract: Measurements are presented of electroweak boson production using data from pp collisions at a centre-of-mass energy of root s = 8TeV. The analysis is based on an integrated luminosity of 2.0 fb(-1) recorded with the LHCb detector. The bosons are identified in the W -> μnu and Z -> mu(+)mu(-) decay channels. The cross-sections are measured for muons in the pseudorapidity range 2.0 < eta < 4.5, with transverse momenta p(T) > 20 GeV/c and, in the case of the Z boson, a dimuon mass within 60 < M mu+mu- < 120 GeV/c(2). The results are sigma(W+) -> mu(+)nu(-) = 1093.6 +/- 2.1 +/- 7.2 +/- 10.9 +/- 12.7 pb, sigma(W-) -> mu(-)nu(-) = 818.4 +/- 1.9 +/- 5.0 +/- 7.0 +/- 9.5 pb, sigma(Z) -> mu(+)mu(-) = 95.0 +/- 0.3 +/- 0.7 +/- 1.1 +/- 1.1 pb, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. The evolution of the W and Z boson cross-sections with centre-of-mass energy is studied using previously reported measurements with 1.0 fb(-1) of data at 7 TeV. Differential distributions are also presented. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.
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NEXT Collaboration(Martin-Albo, J. et al), Muñoz Vidal, J., Ferrario, P., Nebot-Guinot, M., Gomez-Cadenas, J. J., Alvarez, V., et al. (2016). Sensitivity of NEXT-100 to neutrinoless double beta decay. J. High Energy Phys., 05(5), 159–30pp.
Abstract: NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0v beta beta) decay of Xe-136. The detector possesses two features of great value for 0v beta beta searches: energy resolution better than 1% FWHM at the Q value of Xe-136 and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 x 10(-4) counts keV(-1) kg(-1) yr(-1). Accordingly, the detector will reach a sensitivity to the 0v beta beta-decay half-life of 2.8 x 10(25) years (90% CL) for an exposure of 100 kg.year, or 6.0 x 10(25) years after a run of 3 effective years.
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