Transverse Spin: HERMES Results and Future Plans

Results from the HERMES experiment are presented on single-spin asymmetries in semi-inclusive hadron production from longitudinally polarized targets. The data are compared with a number of theoretical calculations which relate the azimuthal dependence of the asymmetries to the transversity structure function h_1(x).Comment: 9 pages, 4 figures requiring 9 EPS files, contribution to the European Workshop On The QCD Structure Of The Nucleon (QCD-N'02), to be published in Nucl. Phys.

Radiative corrections for (e,e′p) reactions at GeV energies

A general framework for applying radiative corrections to (e,e′p) coincidence reactions at GeV energies is presented, with special emphasis to higher-order bremsstrahlung effects, radiation from the scattered hadron, and the validity of peaking approximations. The sensitivity to the assumptions made in practically applying radiative corrections to (e,e′p) data is extensively discussed. The general framework is tested against experimental data of the 1H(e,e′p) reaction at momentum transfer values larger than 1.0 (GeV/c)^2, where radiative processes become a dominant source of uncertainty. The formulas presented here can easily be modified for any other electron-induced coincidence reaction

Momentum Transfer Dependence of Nuclear Transparency from the Quasielastic ^(12)C(e, e'p) Reaction

The cross section for quasielastic ^(12)C(e,e’p) scattering has been measured at momentum transfer Q^2=1, 3, 5, and 6.8 (GeV/c)^2. The results are consistent with scattering from a single nucleon as the dominant process. The nuclear transparency is obtained and compared with theoretical calculations that incorporate color transparency effects. No significant rise of the transparency with Q^2 is observed

Factors influencing the likelihood of acceptance of postpartum intrauterine devices across four countries: India, Nepal, Sri Lanka, and Tanzania.

OBJECTIVE: To examine the factors that positively influenced the likelihood of accepting provision of postpartum intrauterine devices (PPIUDs) across four countries: Sri Lanka, Nepal, Tanzania, and India. METHODS: Healthcare providers were trained across 24 facilities in counselling and insertion of PPIUDs as part of a large multicountry study. Women delivered were asked to take part in a 15-minute face-to-face structured interview conducted by in-country data collection officers prior to discharge. Univariate analysis was performed to investigate factors associated with acceptance. RESULTS: From January 2016 to November 2017, 6477 health providers were trained, 239 033 deliveries occurred, and 219 242 interviews were conducted. Of those interviewed, 68% were counselled on family planning and 56% on PPIUD, with 20% consenting to PPIUD. Multiple counselling sessions was the only factor resulting in higher consent rates (OR 1.30-1.39) across all countries. Odds ratios for women's age, parity, and cadre of provider counselling varied between countries. CONCLUSION: Consent for contraception, specifically PPIUD, is such a culturally specific topic and generalization across countries is not possible. When planning contraceptive policy changes, it is important to have an understanding of the sociocultural factors at play

FIGO postpartum intrauterine device initiative: Complication rates across six countries.

OBJECTIVE: To record and analyze complication rates following postpartum intrauterine device (PPIUD) insertion in 48 hospitals in six countries: Sri Lanka, India, Nepal, Bangladesh, Tanzania, and Kenya. METHODS: Healthcare providers were trained in counselling and insertion of PPIUD via a training-the-trainer model. Data were collected on methodology, timing, cadre of staff providing care, and number of insertions. Data on complications were collected at 6-week follow-up. Statistical analysis was performed to elucidate factors associated with increased expulsion and absence of threads. RESULTS: From May 2014 to September 2017, 36 766 PPIUDs were inserted: 53% vaginal and 47% at cesarean delivery; 74% were inserted by doctors. Follow-up was attended by 52%. Expulsion and removal rates were 2.5% and 3.6%, respectively. Threads were not visible in 29%. Expulsion was less likely after cesarean insertion (aOR 0.33; 95% CI, 0.26-0.41), following vaginal insertion at between 10 minutes and 48 hours (aOR 0.59; 95% CI, 0.42-0.83), and when insertion was performed by a nurse (aOR 0.33; 95% CI, 0.22-0.50). CONCLUSION: PPIUD has low complication rates and can be safely inserted by a variety of trained health staff. Given the immediate benefit of the one-stop approach, governments should urgently consider adopting this model

Nuclear transparencies for nucleons, knocked-out under various semi-inclusive conditions

Using hadron dynamics we calculate nuclear transparencies for protons, knocked-out in high-$Q^2$, semi-inclusive reactions. Predicted transparencies are, roughly half a standard deviation above the NE18 data. The latter contain the effects of binned proton missing momenta and mass, and of finite detector acceptances. In order to test sensitivity we compare computed transparencies without restrictions and the same with maximal cuts for missing momenta and the electron energy loss. We find hardly any variation, enabling a meaningful comparison with data and predictions based on hadron dynamics. Should discrepancies persist in high-statistics data, the above may with greater confidence be attributed to exotic components in the description of the outgoing proton.Comment: 13 pages + 3 figsin appended PS file, report # WIS-94/43/Oct-P

Correlation Effects in Nuclear Transparency

The Glauber approximation is used to calculate the contribution of nucleon correlations in high-energy $A(e,e'N)$ reactions. When the excitation energy of the residual nucleus is small, the increase of the nuclear transparency due to correlations between the struck nucleon and the other nucleons is mostly compensated by a decrease of the transparency due to the correlations between non detected nucleons. We derive Glauber model predictions for nuclear transparency for the differential cross section when nuclear shell level excitations are measured. The role of correlations in color transparency is briefly discussed.Comment: 24 pages revtex, 4 uuencoded PostScript Figures as separate fil

Exclusive Hadronic Processes and Color Transparency

We review the current status of high energy exclusive processes and color transparency.Comment: 17 pages, 8 figures, based on talk given at International Symposium on Nuclear Physics, Mumbai, Dec 18-22, 200

Investigation of the high momentum component of nuclear wave function using hard quasielastic A(p,2p)X reactions

We present theoretical analysis of the first data on the high energy and momentum transfer (hard) quasielastic $C(p,2p)X$ reactions. The cross section of hard $A(p,2p)X$ reaction is calculated within the light-cone impulse approximation based on two-nucleon correlation model for the high-momentum component of the nuclear wave function. The nuclear effects due to modification of the bound nucleon structure, soft nucleon-nucleon reinteraction in the initial and final states of the reaction with and without color coherence have been considered. The calculations including these nuclear effects show that the distribution of the bound proton light-cone momentum fraction $(\alpha)$ shifts towards small values ($\alpha < 1$), effect which was previously derived only within plane wave impulse approximation. This shift is very sensitive to the strength of the short range correlations in nuclei. Also calculated is an excess of the total longitudinal momentum of outgoing protons. The calculations are compared with data on the $C(p,2p)X$ reaction obtained from the EVA/AGS experiment at Brookhaven National Laboratory. These data show $\alpha$-shift in agreement with the calculations. The comparison allows also to single out the contribution from short-range nucleon correlations. The obtained strength of the correlations is in agreement with the values previously obtained from electroproduction reactions on nuclei.Comment: 30 pages LaTex file and 19 eps figure

Inclusive Electron Scattering from Nuclei at x≃1x \simeq 1

The inclusive A(e,e') cross section for $x \simeq 1$ was measured on $^2$H, C, Fe, and Au for momentum transfers $Q^2$ from 1-7 (GeV/c)$^2$. The scaling behavior of the data was examined in the region of transition from y-scaling to x-scaling. Throughout this transitional region, the data exhibit $\xi$-scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.Comment: 4 pages, RevTeX; 4 figures (postscript in .tar.Z file