Stopping in central Pb + Pb collisions at SPS energies and beyond

We investigate stopping and baryon transport in central relativistic Pb + Pb and Au + Au collisions. At energies reached at the CERN Super Proton Synchrotron [sqrt(s_NN) = 6.3-17.3 GeV] and at RHIC (62.4 GeV), we determine the fragmentation-peak positions from the data. The resulting linear growth of the peak positions with beam rapidity is in agreement with our results from a QCD-based approach that accounts for gluon saturation. No discontinuities in the net-proton fragmentation peak positions occur in the expected transition region from partons to hadrons at 6-10 GeV.Comment: 5 pages, 3 figures, 1 table. Figures updated, table shortened, 1 reference adde

Projections of Future Demand and Costs of Aged Care Services in China

The growing demand for aged care services has become a pressing challenge worldwide. However, the future changes in demand for aged care services and the corresponding socioeconomic consequences in rapidly aging societies are not yet adequately understood. To achieve a better understanding of the future demand for aged care services, this study provides a set of comprehensive projections of the scale of demand for aged care services and the associated economic burdens between 2010 and 2050 in the context of China. Using a research framework based on the life cycle approach and a modified Personal Social Services Research Unit model, the study projects that the size of Chinese elderly population (i.e., aged ≥ 60) demanding aged care services will grow considerably, reaching 127.4 million in 2050 and costing 2.6 trillion yuan (or 1.01% of Chinese gross domestic product). Home-/community-based care services will be the form of aged care most in demand by the 70.21 million Chinese elderly people in 2050, and the most needed types of aged care services will be feeding assistance. The results of the sensitivity analysis indicate that demand for and costs of aged care services are sensitive to the assumptions about patterns of elderly disability and the prices of aged care services. The projected growth in the future demand and costs of aged care services warrants more heightened attention from Chinese policymakers and providers of aged care services. The implications for other rapidly aging societies are also discussed

Jet quenching and broadening: the transport coefficient q^\hat{q} in an anisotropic plasma

The jet quenching parameter $\hat{q}$ is analyzed for a quark jet propagating in an anisotropic plasma. The momentum anisotropy is calculated at high temperature of the underlying quark-gluon plasma. $\hat{q}$ is explicitly estimated in leading-logarithmic approximation by the broadening of the massless quark interacting via gluon exchange. A plasma instability is present. Strong indications are found that $\hat{q}$ is increasing with increasing anisotropy. Possible implications for the saturation scale $Q_s$ in $A-A$ collisions are pointed out.Comment: 1

Improved Nonrelativistic QCD for Heavy Quark Physics

We construct an improved version of nonrelativistic QCD for use in lattice simulations of heavy quark physics, with the goal of reducing systematic errors from all sources to below 10\%. We develop power counting rules to assess the importance of the various operators in the action and compute all leading order corrections required by relativity and finite lattice spacing. We discuss radiative corrections to tree level coupling constants, presenting a procedure that effectively resums the largest such corrections to all orders in perturbation theory. Finally, we comment on the size of nonperturbative contributions to the coupling constants.Comment: 40 pages, 2 figures (not included), in LaTe