Photoproduction of events with rapidity gaps between jets at HERA
The photoproduction of dijet events, where the two jets with the highest transverse energy are separated by a large gap in pseudorapidity, have been studied with the ZEUS detector using an integrated luminosity of 39 pb-1. Rapidity-gap events are defined in terms of the energy flow between the jets, such that the total summed transverse energy in this region is less than some value ETCUT. The data show a clear excess over the predictions of standard photoproduction models. This is interpreted as evidence for a strongly interacting exchange of a color-singlet object. Monte Carlo models which include such a color-singlet exchange are able to describe the data.

title: Measurement of prompt photons with associated jets in photoproduction at HERA
abstract: 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.

title: Measurement of charm fragmentation ratios and fractions in photoproduction at HERA
abstract: The production of D, D, D, D s and Λ + c charm hadrons and their antiparticles in ep scattering at HERA was measured with the ZEUS detector using an integrated luminosity of 79 pb. The measurement has been performed in the photoproduction regime with the exchanged-photon virtuality Q < 1 GeV and for photon-proton centre-of-mass energies in the range 130 < W < 300 GeV. The charm hadrons were reconstructed in the range of transverse momentum pT (D, Λc) > 3.8 GeV and pseudorapidity |η(D, Λc)| < 1.6. The production cross sections were used to determine the ratio of neutral and charged D-meson production rates, Ru/d, the strangeness-suppression factor, γs, and the fraction of charged D mesons produced in a vector state, P d v . The measured Ru/d and γs values agree with those obtained in deep inelastic scattering and in ee annihilations. The measured P d v value is smaller than, but consistent with, the previous measurements. The fractions of c quarks hadronising as a particular charm hadron, f(c → D, Λc), were derived in the given kinematic range. The measured open-charm fragmentation fractions are consistent with previous results, although the measured f(c → D) is smaller and f(c → Λc ) is larger than those obtained in ee annihilations. These results generally support the hypothesis that fragmentation proceeds independently of the hard sub-process. The ZEUS Collaboration S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida Argonne National Laboratory, Argonne, Illinois 60439-4815, USA n M.C.K. Mattingly Andrews University, Berrien Springs, Michigan 49104-0380, USA N. Pavel, A.G. Yagües Molina Institut für Physik der Humboldt-Universität zu Berlin, Berlin, Germany P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, A. Polini, L. Rinaldi, G. Sartorelli, A. Zichichi University and INFN Bologna, Bologna, Italy e G. Aghuzumtsyan, D. Bartsch, I. Brock, S. Goers, H. Hartmann, E. Hilger, P. Irrgang, H.-P. Jakob, O.M. Kind, U. Meyer, E. Paul, J. Rautenberg, R. Renner, M. Wang, M. Wlasenko Physikalisches Institut der Universität Bonn, Bonn, Germany b D.S. Bailey, N.H. Brook, J.E. Cole, G.P. Heath, T. Namsoo, S. Robins H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom m M. Capua, S. Fazio, A. Mastroberardino, M. Schioppa, G. Susinno, E. Tassi Calabria University, Physics Department and INFN, Cosenza, Italy e J.Y. Kim, K.J. Ma Chonnam National University, Kwangju, South Korea g M. Helbich, Y. Ning, Z. Ren, W.B. Schmidke, F. Sciulli Nevis Laboratories, Columbia University, Irvington on Hudson, New York 10027 o J. Chwastowski, A. Eskreys, J. Figiel, A. Galas, M. Gil, K. Olkiewicz, P. Stopa, D. Szuba, L. Zawiejski The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland i L. Adamczyk, T. Bo ld, I. Grabowska-Bo ld, D. Kisielewska, J. Lukasik, M. Przybycień, L. Suszycki, J. Szuba Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Cracow, Poland p A. Kotański, W. S lomiński Department of Physics, Jagellonian University, Cracow, Poland

title: Measurement of isolated photons accompanied by jets in deep inelastic ep scattering
abstract: The production of isolated high-energy photons accompanied by jets has been measured in deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 326pb -1 . Measurements were made for exchanged photon virtualities, Q 2 , in the range 10 to 350GeV 2 . The photons were measured in the transverse-energy and pseudorapidity ranges 4 γ jet <1.8. Differential cross sections are presented as functions of these quantities. Perturbative QCD predictions give a reasonable description of the shape of the measured cross sections over most of the kinematic range, but the absolute normalisation is typically in disagreement by 20-30%.

title: Measurement of azimuthal asymmetries in neutral current deep inelastic scattering at HERA
abstract: The distribution of the azimuthal angle of charged and neutral hadrons relative to the lepton plane has been studied for neutral current deep inelastic ep scattering using an integrated luminosity of 45 pb-1 taken with the ZEUS detector. The kinematic range is 100<Q2<8000 GeV2, 0.2<y<0.8 and 0.01<x<0.1 where Q2 is the virtuality of the exchanged boson, y is the inelasticity and x is the Bjorken variable. The measurements were made in the hadronic centre-of-mass system. The analysis exploits the energy-flow method, which allows the measurement to be made over a larger range of pseudorapidity compared to previous results. The dependence of the moments of the azimuthal distributions on the pseudorapidity and minimum transverse energy of the final-state hadrons are presented. Although the predictions from next-to-leading-order QCD describe the data better than do the Monte Carlo models incorporating leading-logarithm parton showers, they still fail to describe the magnitude of the asymmetries. This suggests that higher-order calculations may be necessary to describe these data.

title: The spectrometer system for measuring ZEUS luminosity at HERA
abstract: The upgrade of the HERA accelerator has provided much increased collider luminosity. In turn, the improvements have necessitated a new design for the ZEUS luminosity measurements. The intense synchrotron radiation field, as well as the high probability of a bremsstrahlung photon in each bunch crossing, posed new experimental constraints. In this report, we describe how these challenges were met with the ZEUS luminosity spectrometer system. The design, testing and commissioning of the device are described, and the results from the initial operational experience are reported.

title: Global calculation of α-decay half-lives with a deformed density-dependent cluster model

title: Coupled-channel representation to describe fine structure in the alpha decay of odd-mass Bk isotopes
abstract: An extension of the multichannel cluster model (MCCM) is presented to investigate the a decay of odd-mass Bk isotopes from their ground states to more than one rotational band in the daughter Am nuclei. In these cases, the alpha intensity for the other rotational bands is comparable or dominant with respect to the favored one. Three rotational bands are taken into account for the alpha decays of Bk-243,Bk-245,Bk-247 from their 3/2(-) ground states. The available experimental data concerning fine structure and a-decay half-lives are well reproduced within the same framework. Moreover, the ground-state and favored rotational bands are considered for the alpha decay of Bk-249 from its 7/2(+) ground state. The calculated results also show good agreement with the latest experimental data [I. Ahmad et al.,  (2013)]. This is the first calculation of the alpha transitions to several rotational bands including favored and unfavored ones within the coupled-channel framework.

title: Systematic calculation of fine structure in the α decay of deformed nuclei
abstract: We perform an extensive investigation on the a decay of well-deformed even-even nuclei by using the coupled-channel Schrodinger equation with outgoing wave boundary conditions. The internal effect of daughter states is taken into account in dealing with the interaction matrix and the α-cluster formation. In contrast to the traditional α-decay theories, the five-channel microscopic calculations of this work well reproduce the available experimental data concerning α-decay half-lives and fine structures. Some predictions on the fine structure are made for superheavy nuclei. Moreover, the sensitivity of the results to the model quantities is discussed in detail.

title: α-decay energy formula for superheavy nuclei based on the liquid-drop model
abstract: A formula of $\ensuremath{\alpha}$-decay energy for superheavy nuclei based on the method of macroscopic model plus shell corrections is proposed. The macroscopic part of this formula is derived from the Bethe-Weizs\"acker binding energy formula, and the shell corrections at $N=152$ and $N=162$ are expressed by the Mexican hat wavelet functions. The parameters of this formula are obtained through fitting to 170 $\ensuremath{\alpha}$-decay energies for nuclei ranging from $Z=90$ to $Z=118$ with $N\ensuremath{\geqslant}140$. Numerical results show that 170 existing $\ensuremath{\alpha}$-decay energies can be reproduced very well; the average and standard deviations between theoretical results and experimental data are 0.177 and 0.226 MeV, respectively. The $\ensuremath{\alpha}$-decay energies of newly synthesized nuclei ${}^{293,294}117$ and their $\ensuremath{\alpha}$-decay products are also reproduced very well. In addition, the $\ensuremath{\alpha}$-decay energies for nuclei with $Z=110$\char21{}120 are predicted and compared with the results calculated by the macroscopic-microscopic model. Great differences are found for nuclei with $Z\ensuremath{\geqslant}116$ and $N\ensuremath{\geqslant}176$ due to the shell effects near the hypothetical doubly magic nucleus ${}^{298}$${114}_{184}$ in the macroscopic-microscopic model. Therefore, by comparing experimental $\ensuremath{\alpha}$-decay energies measured in the future with the ones predicted by these two methods, one can obtain useful information about the next proton and neutron magic numbers.

title: Systematic study of the symmetry energy under the local density approximation
abstract: The nuclear matter symmetry energy ${C}_{\mathrm{sym}}(\ensuremath{\rho})$ and its slope parameter $L$ are studied using local density approximation. With this method, the symmetry energy of nuclear matter can be deduced from matter density distributions of finite nuclei. By systematically analyzing the extracted $L$ for different isotopes, the variation trends of values of extracted $L$ along isotopic chains can be obtained. The study can explain why the neutron rich nuclei in isotopic chains such as ${}^{208}$Pb can be used to extract $L$ under local density approximation. By studying the regularity of extracted $L$ for different isotopic chains, we finally obtain the value of $L$ and its error bar: $L=66\ifmmode\pm\else\textpm\fi{}7$ MeV. Besides, the density dependence parameter $\ensuremath{\gamma}$ is constrained to be $0.69\ifmmode\pm\else\textpm\fi{}0.07$ for the ansatz of symmetry energy ${C}_{\mathrm{sym}}(\ensuremath{\rho})={C}_{\mathrm{sym}}({\ensuremath{\rho}}_{0}){(\frac{\ensuremath{\rho}}{{\ensuremath{\rho}}_{0}})}^{\ensuremath{\gamma}}$.