Parton distribution functions of proton in a light-front quark-diquark model

We present the parton distribution functions (PDFs) for un- polarised, longitudinally polarized and transversely polarized quarks in a proton using the light-front quark diquark model. We also present the scale evolution of PDFs and calculate axial charge and tecsor charge for $u$ and $d$ quarks at a scale of experimental findings.Comment: XXII DAE-BRNS High Energy Physics Symposium, December 12-16, 2016, University of Delhi, India; 4 pages, 1 figur

Teenage Pregnancy in St. Kitts-Nevis: Psychosocial and Familial Factors

Problem. This study was conducted to examine some of the factors that are related to teenage pregnancy in St. Kitts-Nevis. It focused on the relationship between teenage pregnancy and father absence/presence, intergenerational teenage pregnancy, childhood sexual abuse, and domestic violence. A young girl\u27s view of her relationship with both parents, the self-esteem of respondents, and their level of attendance and participation in church-related activities were also studied. Method. Two instruments were incorporated into the questionnaire administered to females in St. Kitts and Nevis between the ages of 12 and 21, some of whom had experienced a pregnancy, and others who had not. These groups were called pregnant and nonpregnant groups. The Coopersmith Self-Esteem Inventory (SEI) was used to measure self-esteem. The Factors Related to Teenage Pregnancy Questionnaire gathered data pertinent to the research questions and other demographic information. Of the 319 respondents, approximately 71% came from St. Kitts and 29% from Nevis. Results. Significant differences were found between both groups on four of the eight variables in the Attitude to Father cluster, and on three of the eight on the Attitude to Mother cluster, with the nonpregnant group giving more positive evaluations of their relationships with parents than the other group. No significant relationship was established between father presence/absence and teenage pregnancy and none was found between teenage pregnancyand intergenerational teenage pregnancy. Significant differences between groups were found on two of the six variables in the Domestic Violence cluster, and a significant relationship was found between childhood sexual abuse and early pregnancy. All five variables in the Attitude to Church factor produced significant differences, but no significant difference was found between the self-esteem scores of both groups. Conclusions. Nonpregnant respondents evaluated their relationships with father and mother more positively than their counterparts. Both groups\u27 experience of father absence/presence was comparable. The data suggest that intragenerational influences on teenage pregnancy are stronger than intergenerational patterns. Domestic violence occurs more frequently in the experience of the pregnant group, as did childhood sexual abuse in which case grandfathers and fathers were the least likely perpetrators and uncles and brothers were the main perpetrators. The nonpregnant group placed higher value on their religious experience, but levels of self-esteem were comparable for both groups

Extraction of Polarized Gluon Distributions from Large-pt Light Hadron Pair Production

We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is produced via photon-gluon fusion(PGF) and QCD Compton at the lowest order of QCD. The PGF gives us a direct information on $\Delta g$ in the nucleon, while QCD Compton becomes background to the signal process for extracting $\Delta g$. We show that the contribution from this background, i.e. the QCD Compton process, can be removed by using symmetry relation among fragmentation functions and taking an appropriate combination of various light hadron pair production processes, and thus the double spin asymmetry can be described in terms of $\Delta g/g$ alone.Comment: 14 pages 3 EPS figures Late

Polarized Gluon Distribution Function from η′\eta' Production

Using the recently proposed $gg\eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in polarized pp collisions. We show that by measuring $A_{LL}$ in $\eta'$ production, one can extract the polarized gluon distribution $\Delta G(x,Q^2)$ at Q^2 \sim 1 \GeV^2 and in a wide range of x.Comment: 11 pages, 3 figure

An absolute polarimeter for high energy protons

A study of the spin asymmetries for polarized elastic proton proton collisions in the electromagnetic hadronic interference (CNI) region of momentum transfer provides a method of self calibration of proton polarization. The method can be extended to non-identical spin half scattering so that, in principle, the polarization of a proton may be obtained through an analysis of its elastic collision with a different polarized particle, helium 3 for instance. Sufficiently large CNI spin asymmetries provide enough information to facilitate the evaluation of nearly all the helicity amplitudes at small t as well as the polarization of both initial spin half fermions. Thus it can serve equally well as a polarimeter for helium 3

Community Attitudes Toward Wildlife and Protected Areas in Ethiopia

Across Africa, national policies that established protected areas (PAs) typically limited local use of wildlife and other resources. Over time, these policies have raised tensions with rural communities and today threaten to undermine conservation goals. This article examines community–PA relationships at four important sites in Ethiopia—a country of rich tradition with an unusual colonial past. Using focus groups and household surveys, we found that despite local tensions, most respondents held positive views toward wildlife and nearby PAs. Factors influencing positive views included receiving PA benefits, good relations with PA staff, higher education levels, being older, having a large family, diversified income sources, owning fewer livestock, and fewer incidents of wildlife conflicts. In contrast, the devolved control of PAs from federal to regional levels has not influenced community–PA relations as intended. Our results suggest that relations could be improved through involving communities in co-management arrangements, honoring resource tenure and use rights, providing benefits, and implementing conservation education programs

Resonant Production of Scalar Diquarks at the Next Generation Electron-Positron Colliders

We investigate the potential of TESLA and JLC/NLC electron-positron linear collider designs to observe diquarks produced resonantly in processes involving hard photons.Comment: 14 pages, 8 figures, coded in RevTEX, uses epsfi

Delta s density in a proton and unpolarized lepton - polarized proton scatterings

It is shown that the parity--violating deep--inelastic scatterings of unpolarized charged leptons on polarized protons, $\ell^{\mp} + \vec P\to \stackrel{\scriptscriptstyle(-)}{\nu_{\ell}} + X$, could provide a sensitive test for the behavior and magnitude of the polarized strange--quark density in a proton. Below charm threshold these processes are also helpful to uniquely determine the magnitude of individual polarized parton distributions.Comment: LaTeX file, 12 pages+4 fiigures not included (available upon request

Stability of string defects in models of non-Abelian symmetry breaking

In this paper we describe a new type of topological defect, called a homilia string, which is stabilized via interactions with the string network. Using analytical and numerical techniques, we investigate the stability and dynamics of homilia strings, and show that they can form stable electroweak strings. In SU(2)xU(1) models of symmetry breaking the intersection of two homilia strings is identified with a sphaleron. Due to repulsive forces, the homilia strings seperate, resulting in sphaleron annihilation. It is shown that electroweak homilia string loops cannot stabilize as vortons, which circumvents the adverse cosmological problems associated with stable loops. The consequences for GUT scale homilia strings are also discussed.Comment: 15 pages, revtex, with 8 figures. Submitted to PR

Determination of polarized parton distribution functions and their uncertainties

We investigate the polarized parton distribution functions (PDFs) and their uncertainties by using the world data on the spin asymmetry A_1. The uncertainties of the polarized PDFs are estimated by the Hessian method. The up and down valence-quark distributions are determined well. However, the antiquark distributions have large uncertainties at this stage, and it is particularly difficult to fix the gluon distribution. The \chi^2 analysis produces a positively polarized gluon distribution, but even \Delta g(x)=0 could be allowed according to our uncertainty estimation. In comparison with the previous AAC (Asymmetry Analysis Collaboration) parameterization in 2000, accurate SLAC-E155 proton data are added to the analysis. We find that the E155 data improve the determination of the polarized PDFs, especially the polarized antiquark distributions. In addition, the gluon-distribution uncertainties are reduced due to the correlation with the antiquark distributions. We also show the global analysis results with the condition \Delta g(x)=0 at the initial scale, Q^2=1 GeV^2, for clarifying the error correlation effects with the gluon distribution.Comment: 9 pages, 15 eps figures, REVTeX, FORTRAN package is available at the web site http://www-hs.phys.saga-u.ac.jp/aac.html. Replaced 3 eps figures in Fig.