Hard Diffraction in Pythia 8

We present an overview of the options for diffraction implemented in the general--purpose event generator Pythia 8. We review the existing model for low-- and high--mass soft diffraction and present a new model for hard diffraction in pp and ppbar collisions. Both models uses the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a Pomeron PDF. The model for hard diffraction is implemented as a part of the multiparton interactions framework, thereby introducing a dynamical rapidity gap survival probability that explicitly breaks factorisation.Comment: 5 pages, 2 figures. Presented at the 16th conference on Elastic and Diffractive scattering (EDS Blois 2015

Models of Total, Elastic and Diffractive Cross Sections

The LHC has brought much new information on total, elastic and diffractive cross sections, which is not always in agreement with extrapolations from lower energies. The default framework in the Pythia event generator is one case in point. In this article we study and implement two recent models, as more realistic alternatives. Both describe total and elastic cross sections, whereas one also includes single diffraction. Noting some issues at high energies, a variant of the latter is proposed, and extended also to double and central diffraction. Further, the experimental definition of diffraction is based on the presence of rapidity gaps, which however also could be caused by colour reconnection in nondiffractive events, a phenomenon that is studied in the context of a specific model. Throughout comparisons with LHC and other data are presented.Comment: 37 pages, 18 figures, 2 table

Relationship between use of ankle-foot orthoses and quality of life and psychological well being : a research plan

An ankle-foot orthosis (AFO) is an externally applied device that encompasses the joints of the ankle and foot, used to modify the structural and functional characteristics of the neuromuscular and skeletal systems(ISO,1989,a&b). AFOs are prescribed for people who have a loss of function affecting their mobility, experienced in wide range of conditions such as stroke, poliomyelitis, cerebral palsy, spina bifida and osteoarthritis

Recent Pythia 8 developments: Hard diffraction, Colour reconnection and γγ\gamma\gamma collisions

An overview of recent developments in \pythia~8 is given. First the new hard diffraction model, which is implemented as a part of the multiparton interactions (MPI) framework, is discussed. Then the new colour reconnection model, which includes beyond leading colour effects that can become important when MPI are present, is briefly reviewed. As a last topic an introduction is given to our implementation of photon-photon collisions. In particular photon PDFs, required modifications for the initial state radiation algorithm and beam remnant handling with photon beams is discussed.Comment: Contribution to proceedings of 7th International Workshop on Multiple Partonic Interactions at the LHC, 23 - 27 November 2015, Miramare, Trieste, Ital

Dipole evolution: perspectives for collectivity and gamma*A collisions

The transverse, spatial structure of protons is an area revealing fundamental properties of matter, and provides key input for deeper understanding of emerging collective phenomena in high energy collisions of protons, as well as collisions of heavy ions. In this paper eccentricities and eccentricity fluctuations are predicted using the dipole formulation of BFKL evolution. Furthermore, first steps are taken towards generation of fully exclusive final states of $\gamma^*$A collisions, by assessing the importance of colour fluctuations in the initial state. Such steps are crucial for the preparation of event generators for a future electron-ion collider. Due to the connection between an impact parameter picture of the proton structure, and cross sections of ep and pp collisions, the model parameters can be fully determined by fits to such quantities, leaving results as real predictions of the model.Comment: 54 pages, 20 figures, replacement corresponding to published versio

Use of the ICF to investigate impairment, activity limitation and participation restriction in people using ankle-foot orthoses to manage mobility disabilities

This study investigated differences in impairment, activity limitation, participation restrictions and psychological distress between participants using ankle-foot orthoses (AFOs) as recommended, participants who did not use AFOs as recommended and participants who did not know recommendations for use.  Adults (n = 157) fitted with an AFO by an NHS Orthotic Service in Scotland completed a postal questionnaire that measured impairment, activity limitations participation restrictions and psychological distress using scales from the RAND 36-Item Health Survey 1.0 and the Hospital Anxiety and Depression Scale (HADS).  41% of participants used their AFOs as recommended, 32% did not use their AFOs as recommended and 27% did not know the recommendations for use. Participants using AFOs as recommended reported lower levels of impairment and activity limitations, indicated by higher energy levels (p = 0.005), higher physical functioning (p = 0.005), lower role-limitations due to emotional problems (p = 0.001) and lower levels of anxiety (p = 0.003) compared to people not using AFOs as recommended.  Health professionals need to ensure whether patients understand the recommendations for use of their AFO. Additionally, the results of the study support the value of evaluating patients' psychological well-being to gain a better understanding of AFO use. Implications for Rehabilitation Participants who reported using AFOs as recommended had significantly lower levels of impairment, activity limitations and anxiety compared to those who did not use their AFO as recommended. In this study, 27% of participants did not know recommendations for use of AFOs. Health professionals should give consideration as to how information, regarding wearing instructions and use of AFOs, is provided to people who are prescribed AFOs. Psychological outcomes in orthotics are rarely assessed. However, this study demonstrates there is a value in measuring psychological outcomes in orthotic management

Means test for Kansas farm families

Call number: LD2668 .T4 1965 R225Master of Scienc