17,814 research outputs found

    Gluon structure function for deeply inelastic scattering with nucleus in QCD

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    In this talk we present the first calculation of the gluon structure function for nucleus in QCD. We discuss the Glauber formula for the gluon structure function and the violation of this simple approach that we anticipate in QCD. (Talk given by E. Levin at QCD and nuclear target session at the Workshop on Deep Inelastic Scattering and QCD, Paris, April 1995).Comment: 10 pages(latex file),4 fig (eps.files

    Gluon density in nuclei

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    In this talk we present our detail study ( theory and numbers) [1] on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather contraversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula [2] and estimate the value of the shadowing corrections in this case. Than we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus - nucleus cascade.Comment: Talk at RHIC'96, 43 pages, 23 figure

    QCD Collisional Energy Loss in an Increasingly Interacting Quark Gluon Plasma

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    The discovery of the jet quenching in central Au + Au collisions at the Relativistic Heavy-ion Collider (RHIC) at Brookhaven National Laboratory has provided clear evidence for the formation of strongly interacting dense matter. It has been predicted to occur due to the energy loss of high energy partons that propagate through the quark gluon plasma. In this paper we investigate the dependence of the parton energy loss due to elastic scatterings in a parton plasma on the value of the strong coupling and its running with the evolution of the system. We analyze different prescriptions for the QCD coupling and calculate the energy and length dependence of the fractional energy loss. Moreover, the partonic quenching factor for light and heavy quarks is estimated. We found that the predicted enhancement of the heavy to light hadrons (D/Ď€D/\pi) ratio is strongly dependent on the running of the QCD coupling constant.Comment: 16 pages, 8 figures. Version to be published in the International Journal of Modern Physics

    On duality relations for session types

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    Session types are a type formalism used to describe communication protocols over private session channels. Each participant in a binary session owns one endpoint of a session channel. A key notion is that of duality: the endpoints of a session channel should have dual session types in order to guarantee communication safety. Duality relations have been independently defined in different ways and different works, without considering their effect on the type system. In this paper we systematically study the existing duality relations and some new ones, and compare them in order to understand their expressiveness. The outcome is that those relations are split into two groups, one related to the na¨ıve inductive duality, and the other related to a notion of mutual compliance, which we borrow from the literature on contracts for web-services

    Scaling violation and shadowing corrections at HERA

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    We study the value of shadowing corrections (SC) in HERA kinematic region in Glauber - Mueller approach. Since the Glauber - Mueller approach was proven in perturbative QCD in the double logarithmic approximation (DLA), we develop the DLA approach for deep inelastic structure function which takes into account the SC. Our estimates show small SC for F2F_2 in HERA kinematic region while they turn out to be sizable for the gluon structure function. We compare our estimates with those for gluon distribution in leading order (LO) and next to leading order (NLO) in the DGLAP evolution equations.Comment: 9pp,6 figures in eps file

    Extending an Effective Classroom-Based Math Board Game Intervention to Preschoolers’ Homes

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    The preschool years are a critical time for math development. Unfortunately, children from low-income backgrounds often enter kindergarten with lower math skills than middle-income peers, perhaps due to less math exposure at home. Few home-based math interventions are available for preschool age children; those that do exist are costly and difficult to implement. Interventions conducted in children’s schools using linear numeric board games developed by researchers have been particularly successful with low-income preschool children. Researchers have suggested they may be adapted for home-use by using commercially available board games, such as Chutes and Ladders, and teaching parents how to play. The two studies described in this paper explored the effectiveness of using Chutes and Ladders with a specialized counting procedure with Head Start families. Implementation proved to be challenging and children did not improve as much as in previous classroom-based interventions

    LEARNING AN ETHICS OF COMMITMENT: A SCHOLARLY PERSONAL NARRATIVE ABOUT CREATING A COMMUNITY AND FAMILY OF CHOICE

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    Using a Scholarly Personal Narrative (SPN) methodology, this study began as an exploration of marriage and its impact on lesbian identity, community, and relationship. What ultimately emerged was a study that considered how living a life excluded from the cultural context of legal marriage prompted learning an ethics of commitment and creating a community and family of choice. Personal story provided perspective and lesbian, feminist, and queer theories provided an initial framework for analysis. In addition, theories of community and relationship informed reflections moving from specific to general. This study is based on the views of one lesbian living and loving, beginning in the closets of the 1970s through the current day of marriage expansion. Marking a moment in civil rights history to legalize same-sex marriage, the study found that lesbians, gay men, bisexuals, and queer people, despite current differences about the rationality of pursuing legal marriage, have created love and family throughout their lives. Through personal experiences, many have consequently discovered universal principles about commitment, community, and family even without marriage. Though important and symbolic of broader “acceptance,” a focus on marriage with its social benefits is not enough to achieve full equality and civil rights for sexual minorities. Further lesbian, gay, and queer reflections and interpretations are needed to add to the lessons and ethics of commitment of this lesbian and continue expanding equality within the larger cultures and communities

    An Interview with Dr. Trish Hatch: An Advocate for School Counseling Policy

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    Dr. Trish Hatch has served as a leader in school counselor policy and advocacy for over 30 years. As a co-author of the ASCA National Model, Dr. Hatch has worked tirelessly to establish school-based policies to promote the profession of school counseling at the district, state, and federal levels. This interview serves to provide readers with insight on the importance of advocacy and understanding how to navigate political systems to affect policies that influence the profession of school counseling
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