991 research outputs found

    Formal security analysis of NFC M-coupon protocols using Casper/FDR

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    Near field communication (NFC) is a standard-based, radio frequency (RF), wireless communication technology that allows data to be exchanged between devices that are less than 20 cm apart. NFC security protocols require formal security analysis before massive adoptions, in order to check whether these protocols meet its requirements and goals. In this paper we formally analyse NFC-based mobile coupon protocols using formal methods (Casper/FDR). We find an attack against the advanced protocol, and then we provide a solution that addresses the vulnerability formally

    Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fbāˆ’1 of pp collisions at s=13TeV with the ATLAS experiment

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    A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fbāˆ’1 of protonā€“proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqĪ³ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tĪ³ production via a left-handed (right-handed) tuĪ³ coupling of 36 fb (78 fb) and on the branching ratio for tā†’Ī³u of 2.8Ɨ10āˆ’5 (6.1Ɨ10āˆ’5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tĪ³ production via a left-handed (right-handed) tcĪ³ coupling of 40 fb (33 fb) and on the branching ratio for tā†’Ī³c of 22Ɨ10āˆ’5 (18Ɨ10āˆ’5)

    Measurement of J/Ļˆ production in association with a W Ā± boson with pp data at 8 TeV

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    A measurement of the production of a prompt J/Ļˆ meson in association with a WĀ± boson with WĀ± ā†’ Ī¼Ī½ and J/Ļˆ ā†’ Ī¼+Ī¼āˆ’ is presented for J/Ļˆ transverse momenta in the range 8.5ā€“150 GeV and rapidity |yJ/Ļˆ| < 2.1 using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of s = 8 TeV and correspond to an integrated luminosity of 20.3 fbāˆ’1. The ratio of the prompt J/Ļˆ plus WĀ± cross-section to the inclusive WĀ± cross-section is presented as a differential measurement as a function of J/Ļˆ transverse momenta and compared with theoretical predictions using different double-parton-scattering cross-sections. [Figure not available: see fulltext.]
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