69 research outputs found

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

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    Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the γp\gamma p centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    New way of healing : experienced counsellors’ perceptions of the influence of ch’i-related exercises on counselling practice in Taiwan

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    This study examines how Taiwanese senior counsellors with substantial experience of ch’i-related exercise (CRE) perceived the influence of their regular CRE on their counselling practice. I am interested in the perceived influence of CRE on both self-care and professional practice. In this studyn this studyn this study n this study n this study n this study, CRE, CRE, CRE, CRE, CRE refers to any refers to any refers to any refers to any ch'i enhancing exercise that coordinates movement with breathing and inner concentration wherein ch'i is a first order concept used by practitioners and regarded by them as an embodiment of ideas related to human life and human existence and able to be experienced and refined through any ch'i related exercise. CRE is a set of practices and an intrinsic part of local culture in Taiwan which in recent years, has become popular practice in Taiwanese society. There are growing numbers of counselling professionals involved in regular CRE in recent years. Studies examining the effects of CRE indicate the benefits of CRE on practitioners' global health and personal growth. However, no previous study has investigated the influence of the long-term regular use of CRE on counsellors‟ self-care and counselling practice. The narrative research design for this study was developed from a post-structural theoretical perspective located in the domain of social constructivism. The data were co-constructed between the researcher and 12 senior Taiwanese counsellors with substantial CRE experience using a semi-structured in-depth interview approach. Interview data were analysed using the structure-based approach developed by William Labov in the field of socio-linguistics. The study reveals an overall benefit of regular involvement in CRE for practitioners' global wellbeing and personal growth counsellor' self-care. The research findings also reveals the potential of ch’i to be used as a way of expressing health and illness and a way of understanding in therapy and CRE to be lived out in therapy as an embodiment. I argue that collectively the narratives, as a whole, give evidence of an increasing integratin of the ideas and practices of ch’i into counselling practice in contemporary Taiwan. This might even make up a new form of integrated and culturally appropriate practice, what I term "a new way of healing." These are therapeutic practices which value the potential of CRE for counsellor's self-care and personal growth; recognize the integral whole of the human person; promote conscious use of the knowledge and experience of ch’i and CRE in therapy as an important aspect of the therapeutic use of self. Implications for practice such as the potential of CRE to be introduced into counsellor training programmes for counsellors' preparation or ongoing education are provided. Recommendations for future research such as the development of a new healing modality based on the research findings are offered

    Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA

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    In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independent of Bjorken x and Q2 in the range 3 · 10-4 \u3c xBJ \u3c 6 · 10-3 and 10 \u3c Q2 \u3c 100 GeV2
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