Quasi-phase-matching high harmonic generation using trains of pulses produced using an array of birefringent plates.
Opt Express 20:6 (2012) 6236-6247
Abstract:
Quasi-phase-matched high harmonic generation using trains of up to 8 counter-propagating pulses is explored. For trains of up to 4 pulses the measured enhancement of the harmonic signal scales with the number of pulses N as (N + 1)², as expected. However, for trains with N > 4, no further enhancement of the harmonic signal is observed. This effect is ascribed to changes of the coherence length Lc within the generating medium. Techniques for overcoming the variation of Lc are discussed. The pressure dependence of quasi-phase-matching is investigated and the switch from true-phase-matching to quasi-phase-matching is observed.Measurement of the t dependence in exclusive photoproduction of Υ{hooked} (1S) mesons at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 708:1-2 (2012) 14-20
Abstract:
The exclusive photoproduction reaction γp→Υ{hooked} (1S)p has been studied with the ZEUS detector in ep collisions at HERA using an integrated luminosity of 468 pb -1. The measurement covers the kinematic range 60Search for single-top production in ep collisions at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 708:1-2 (2012) 27-36
Abstract:
A search for single-top production, ep→etX, has been performed with the ZEUS detector at HERA using data corresponding to an integrated luminosity of 0.37 fb -1. No evidence for top production was found, consistent with the expectation from the Standard Model. Limits were computed for single-top production via flavour changing neutral current transitions involving a neutral electroweak vector boson, γ or Z. The result was combined with a previous ZEUS result yielding a total luminosity of 0.50 fb -1. A 95% credibility level upper limit of 0.13 pb was obtained for the cross section at the centre-of-mass energy of √s=315 GeV. © 2012 Elsevier B.V.Measurement of the t dependence in exclusive photoproduction of ϒ(1S) mesons at HERA
Physics Letters B Elsevier 708:1-2 (2012) 14-20
Combined inclusive diffractive cross sections measured with forward proton spectrometers in deep inelastic ep scattering at HERA
European Physical Journal C 72:10 (2012) 1-17