The Angular Momentum and g_1^p Sum Rules for the Proton

The gauge invariant operator formulation of the angular momentum sum rule ${1\over2} = J_q + J_g$ for the proton is presented and contrasted with the sum rule for the first moment of the polarised structure function $g_1^p$. The decoupling of the axial charge $a^0$ from the angular momentum sum rule is highlighted and the possible QCD field-theoretic basis for an angular momentum sum rule of the form {1\over2} = {1\over2}\D q + \D g + L_q + L_g is critically discussed.Comment: 5 pages, LaTeX, uses espcrc2.sty; invited talk at QCD00, Montpellier, July 200

KIDS COUNT Indicator Brief: Reducing the Child Poverty Rate

Outlines trends in child poverty rates and offers strategies to help families gain economic security: building political will, making work pay, strengthening the safety net, and helping families keep more of what they earn and build savings and assets

KIDS COUNT Indicator Brief: Increasing the Percentage of Children Living in Two-Parent Families

Examines trends, by race/ethnicity, in the percentage of children with the economic and other benefits of two-parent families. Offers strategies to raise the percentage, such as basing policies on research linking economic security and family stability

KIDS COUNT Indicator Brief: Preventing Low Birthweight

Outlines trends in low birthweight and preterm births and offers prevention strategies such as expanding access to comprehensive health care, ensuring good nutrition for pregnant women, and addressing demographic, social, and environmental risk factors

KIDS COUNT Indicator Brief: Reducing the High School Dropout Rate

Outlines the economic costs of dropping out of high school and proposes dropout prevention strategies, such as taking a long-term approach starting with school readiness, enhancing schools' holding power, and addressing outside factors and at-risk groups

KIDS COUNT Indicator Brief: Reducing the Teen Death Rate

Reviews data on causes of teen deaths and outlines strategies for improving motor vehicle safety; preventing violence, risky behavior, and suicide; supporting role models; and enhancing families' and communities' capacity to support healthy development

KIDS COUNT Indicator Brief: Increasing the Percentage of Children Whose Parents Have Stable Employment

Outlines how living without a parent working full-time year-round can affect children's development. Details workforce development strategies such as comprehensive employment and educational services for low-skill workers and expanded childcare options

KIDS COUNT Indicator Brief: Reducing Infant Mortality

Examines U.S. infant mortality trends by race/ethnicity and among industrialized nations. Outlines strategies to improve women's health, ensure timely prenatal care, address racial/ethnic disparities, and continue prevention efforts past the first month

KIDS COUNT Indicator Brief: Reducing the Teen Birth Rate

Examines U.S. trends in births among 15- to 19-year-olds compared with other industrialized nations. Explores contributing factors, implications, and strategies to reduce teen pregnancies, including broadening education and prevention efforts

Pseudoscalar Meson Decay Constants and Couplings, the Witten-Veneziano Formula beyond large N_c, and the Topological Susceptibility

The QCD formulae for the radiative decays \eta,\eta'\to\c\c, and the corresponding Dashen--Gell-Mann--Oakes--Renner relations, differ from conventional PCAC results due to the gluonic $U(1)_A$ axial anomaly. This introduces a critical dependence on the gluon topological susceptibility. In this paper, we revisit our earlier theoretical analysis of radiative pseudoscalar decays and the DGMOR relations and extract explicit experimental values for the decay constants. This is our main result. The flavour singlet DGMOR relation is the generalisation of the Witten-Veneziano formula beyond large $N_c$, so we are able to give a quantitative assessment of the realisation of the $1/N_c$ expansion in the $U(1)_A$ sector of QCD. Applications to other aspects of $\eta'$ physics, including the relation with the first moment sum rule for the polarised photon structure function g_1^\c, are highlighted. The $U(1)_A$ Goldberger-Treiman relation is extended to accommodate SU(3) flavour breaking and the implications of a more precise measurement of the $\eta$ and $\eta'$-nucleon couplings are discussed. A comparison with the existing literature on pseudoscalar meson decay constants using large-$N_c$ chiral Lagrangians is also made.Comment: 27 pages, 4 figure