A Dual-Frequency Series-Fed Patch Array Antenna

Abstract-A novel dual-frequency concept for series-fed microstrip patch array antennas is proposed. An identical near field distribution following an identical far field characteristic was achieved at two different frequencies. The conventional series fed array comes with a uniform aperture distribution for patches of same width. By exploiting the dispersion of this periodic structure the same cosine aperture distribution at two different frequencies is obtained. Due to the cosine aperture distribution a low side lobe level of 23 dB is intrinsically achieved for the two operating frequencies, 23 GHz and 25 GHz. This concept is particularly suited for small frequency ratios (f+/f− < 1.3)

An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

Performance of missing transverse momentum reconstruction in proton-proton collisions at root s=13 TeV using the CMS detector

The performance of missing transverse momentum ((p) over right arrow (miss)(T)) reconstruction algorithms for the CMS experiment is presented, using proton-proton collisions at a center-of-mass energy of 13 TeV, collected at the CERN LHC in 2016. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The results include measurements of the scale and resolution of (p) over right arrow (miss)(T), and detailed studies of events identified with anomalous (p) over right arrow (miss)(T). The performance is presented of a (p) over right arrow (miss)(T) reconstruction algorithm that mitigates the effects of multiple proton-proton interactions, using the "pileup per particle identification" method. The performance is shown of an algorithm used to estimate the compatibility of the reconstructed (p) over right arrow (miss)(T) with the hypothesis that it originates from resolution effects.Peer reviewe

Surface photoemission in the 4d band from polycrystalline silver surfaces

SIGLEDEGerman

Climate and the Evolution of the Ocean: The Paleoceanographic Data

International audienc

Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state

A search for the rare decays B-s(0) -> pi(+) pi-mu(+) mu-and B-0 -> pi(+) pi-mu(+) mu-is performed in a data set corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3GeV/c(2) and with muon pairs that do not originate from a resonance are considered. The first observation of the decay B-s(0) -> pi(+) pi-mu(+) mu- and the first evidence of the decay B-0 -> pi(+) pi-mu(+) mu-are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(B-s(0) -> pi(+) pi-mu(+) mu(-)) =(8.6 +/- 1.5(stat) +/- 0.7(syst) +/- 0.7 (norm)) x 10(-8) and B(B-0 -> pi(+) pi-mu(+) mu(-)) =(2.11 +/- 0.51(stat) +/- 0.15(syst) +/- 0.16(norm)) x10(-8), where the third uncertainty is due to the branching fraction of the decay B-0. -> J/Psi(mu(+) mu(-)) K*(892)(0)(-> K+ pi(-)), used as a normalisation. (C) 2015 The Authors. Published by Elsevier B.V