26803736
Discovery of the thallium, lead, bismuth, and polonium isotopes
Currently, forty-two thallium, forty-two lead, forty-one bismuth, and forty-two polonium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the rst refereed publication, including the production and identication method, is presented.
38177292
Discovery of dysprosium, holmium, erbium, thulium, and ytterbium isotopes
Currently, 31 dysprosium, 32 holmium, 32 erbium, 33 thulium and 31 ytterbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the rst refereed publication, including the production and identication method, is presented.
12590893
Discovery of the astatine, radon, francium, and radium isotopes
Thirty-nine astatine, thirty-nine radon, thirty-five francium, and thirty-four radium isotopes have so far been observed; the discovery of these isotopes is described. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.
97142872
Discovery of actinium, thorium, protactinium, and uranium isotopes
Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the rst refereed publication, including the production and identication method, is presented.
123672736
Forward jet production in deep inelastic ep scattering and low-x parton dynamics at HERA
Abstract Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 38.7 pb −1 . The jets have been identified using the k T cluster algorithm in the longitudinally invariant inclusive mode in the laboratory frame; they have been selected with jet transverse energy, E T jet above 6 GeV and jet pseudorapidity, η jet , between −1 and 3. Measurements of cross sections as functions of E T jet , Bjorken x and the photon virtuality, Q 2 , are presented. Three phase-space regions have been selected in order to study parton dynamics from the most global to the most restrictive region of forward-going (close to the proton-beam direction) jets at low x , where the effects of BFKL evolution might be present. The measurements have been compared to the predictions of leading-logarithm parton-shower Monte Carlo models and fixed-order perturbative QCD calculations. In the forward region, O ( α s 1 ) QCD calculations underestimate the data up to an order of magnitude at low x . An improved description of the data in this region is obtained by including O ( α s 2 ) QCD corrections, which account for the lowest-order t ˆ -channel gluon-exchange diagrams, highlighting the importance of such terms in the parton dynamics at low x .
118189949
Inclusive jet cross sections and dijet correlations in D photoproduction at HERA
Inclusive jet cross sections in photoproduction for events containing a D ∗ D ∗ meson have been measured with the ZEUS detector at HERA using an integrated luminosity of 78.6 pb −1 78.6 pb −1 . The events were required to have a virtuality of the incoming photon, Q 2 Q 2 , of less than 1 GeV 2 , and a photon–proton centre-of-mass energy in the range 130 γp 130 W γ p 280 GeV . The measurements are compared with next-to-leading-order (NLO) QCD calculations. Good agreement is found with the NLO calculations over most of the measured kinematic region. Requiring a second jet in the event allowed a more detailed comparison with QCD calculations. The measured dijet cross sections are also compared to Monte Carlo (MC) models which incorporate leading-order matrix elements followed by parton showers and hadronisation. The NLO QCD predictions are in general agreement with the data although differences have been isolated to regions where contributions from higher orders are expected to be significant. The MC models give a better description than the NLO predictions of the shape of the measured cross sections.
15330351
Subjet distributions in deep inelastic scattering at HERA
Subjet distributions were measured in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb−1. Jets were identified using the kT cluster algorithm in the laboratory frame. Subjets were defined as jet-like substructures identified by a reapplication of the cluster algorithm at a smaller value of the resolution parameter $y_{\rm cut}$. Measurements of subjet distributions for jets with exactly two subjets for $y_{\rm cut}=0.05$ are presented as functions of observables sensitive to the pattern of parton radiation and to the colour coherence between the initial and final states. Perturbative QCD predictions give an adequate description of the data.
15474958
Measurement of prompt photons with associated jets in photoproduction at HERA
The photoproduction of prompt photons, together with an accompanying jet, has been studied in ep collisions at a centre-of-mass energy of 318 GeV with the ZEUS detector at HERA using an integrated luminosity of 77 pb-1. Cross sections were measured for the transverse energy of the photon and the jet larger than 5 and 6 GeV, respectively. The differential γ+jet cross sections were reconstructed as functions of the transverse energy, pseudorapidity and xγobs, the fraction of the incoming photon momentum taken by the photon-jet system. Predictions based on leading-logarithm parton-shower Monte Carlo models and next-to-leading-order (NLO) QCD generally underestimate the cross sections for the transverse energies of prompt photons below 7 GeV, while the kT-factorisation QCD calculation agrees with the data better. When the minimum transverse energy of prompt photons is increased to 7 GeV, both NLO QCD and the kT-factorisation calculations are in good agreement with the data.