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We present lattice calculations for the ground state energies of tritium, helium-3, helium-4, lithium-6, and carbon-12 nuclei. Our results were previously summarized in a letter publication. This paper provides full details of the calculations. We include isospin-breaking, Coulomb effects, and interactions up to next-to-next-to-leading order in chiral effective field theory., Comment: 38 pages, 11 figures, final publication version

We discuss lattice simulations of light nuclei at leading order in chiral effective field theory. Using lattice pion fields and auxiliary fields, we include the physics of instantaneous one-pion exchange and the leading-order S-wave contact interactions. We also consider higher-derivative contact interactions which adjust the S-wave scattering amplitude at higher momenta. By construction our lattice path integral is positive definite in the limit of exact Wigner SU(4) symmetry for any even number of nucleons. This SU(4) positivity and the approximate SU(4) symmetry of the low-energy interactions play an important role in suppressing sign and phase oscillations in Monte Carlo simulations. We assess the computational scaling of the lattice algorithm for light nuclei with up to eight nucleons and analyze in detail calculations of the deuteron, triton, and helium-4., 44 pages, 15 figures

We present a new parameterization of the trinucleon wavefunction. As a novel feature a separable parameterization for the complete wavefunction is given. In this way any calculation that considers two body forces only is largely simplified. To demonstrate this we calculate the $\pi^3$He scattering length., Comment: 19 pages, 4 figures

We calculate electromagnetic neutral pion production off tri-nucleon bound states (3H, 3He) at threshold in chiral nuclear effective field theory to fourth order in the standard heavy baryon counting. We show that the fourth order two-nucleon corrections to the S-wave multipoles at threshold are very small. This implies that a precise measurement of the S-wave cross section for neutral pion production off 3He allows for a stringent test of the chiral perturbation theory prediction for the S-wave electric multipole E_{0+}^{pi0 n}., Comment: 17 pages, 5 figures, title changed, final version to appear in EPJA. arXiv admin note: substantial text overlap with arXiv:1103.3400

Single (SSA) and double spin asymmetries (DSA) in semi-inclusive DIS reactions using polarized nucleon targets provide a powerful method to probe transverse momentum dependent parton distribution functions (TMDs). The Jefferson Lab 12 GeV upgrade will provide a unique opportunity to perform precision measurements and to map out these multi-dimensional PDFs. Future plans for performing these measurements in Hall-A using the Solenoidal Large Intensity Device (SoLID) and polarized proton and $^3$He (neutron) targets are discussed. The high luminosities from these targets and the large acceptance of the SoLID spectrometer will allow for a 4-dimensional (x, $Q^2$, $z$, $P_T$) mapping of SSA and DSA. These experiments will provide the most precise data to extract transversity ($h_{1}$), Sivers ($f^{\perp}_{1T}$) and Worm-gear ($g_{1T}$ and $h^{\perp}_{1L}$) distributions of u and d-quarks and provide comprehensive information on the correlation between quark angular momentum and the nucleon's spin., Proc. of DIS 2012, 1043 - 1046; DESY-PROC-2012-02; ISSN 1435-8077

Jefferson Lab experiment E06-010 measured the target-single spin (SSA) and double spin asymmetries (DSA) in semi-inclusive deep inelastic $^{3}\rm He^{\uparrow}(e,e'\pi^{\pm})X$ reactions on a polarized $^3\rm He$ target. The measured asymmetry ($A_{\mathrm{UT}}$) is sensitive to the nucleon ttransversity and Sivers distribution functions, whereas the measured $A_{LT}$ asymmetry is related to the transverse momentum dependent PDF $g_{1T}$. The kinematics were chosen to be in the valence quark region with $x \sim$ 0.16-0.35 and $Q^2 \sim$ \unit{1.4-2.7}{\squaren{(\GeVoverc)}}. The Collins moment, which is sensitive to transversity, the Sivers and $A_{\mathrm{LT}}$ moments, which are sensitive to the orbital motion of the quarks, were extracted using the azimuthal angular dependence of the measured asymmetries. The final semi-inclusive results for the electroproduction of pions are presented and discussed., Proc. of DIS 2012, 963 - 966; DESY-PROC-2012-02; ISSN 1435-8077

Antiproton scattering off $^3\He$ and $^4\He$ targets is considered at beam energies below 300 MeV within the Glauber-Sitenko approach, utilizing the $\bar N N$ amplitudes of the J\"ulich model as input. A good agreement with available data on differential $\bar p ^4\He$ cross sections and on $\bar p ^3\He$ and $\pbar ^4\He$ reaction cross sections is obtained. Predictions for polarized total $\bar p ^3$He cross sections are presented, calculated within the single-scattering approximation and including Coulomb-nuclear interference effects. The kinetics of the polarization buildup is discussed., Comment: 11 pages, 6 figures

We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the Helium-3 nucleus. We calculate $\gamma ^3$He elastic scattering observables using chiral perturbation theory to next-to-leading order (${\mathcal O}(e^2 Q)$). We find that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities. [Note added in 2018] An erratum for this paper has been posted as arXiv:1804.01206. Overall conclusions are unchanged, but quantitative results are affected appreciably., Comment: 4 pages, 4 figures; version published in Phys. Rev. Lett

The differential and total cross sections for the d+p->3He+eta reaction have been measured in a high precision high statistics COSY-ANKE experiment near threshold using a continuous beam energy ramp up to an excess energy Q of 11.3 MeV with essentially 100% acceptance. The kinematics allowed the mean value of Q to be determined to about 9 keV. Evidence is found for the effects of higher partial waves for Q>4 MeV. The very rapid rise of the total cross section to its maximum value within 0.5 MeV of threshold implies a very large eta-3He scattering length and hence the presence of a quasi-bound state extremely close to threshold., Comment: 4 pages, 4 figures, 1 table, submitted to Phys. Rev. Lett

We investigate the K^- ^3He and K^+ K^- interactions in the reaction pd -> ^3He K^+ K^- near threshold and compare our model calculations with data from the MOMO experiment at COSY-Juelich. A large attractive effective K^- p amplitude would give a significant K^- ^3He final-state interaction effect which is not supported by the experimental data. We also estimate upper limits for the a_0(980) and f_0(980) contributions to the produced K^+ K^- pairs., Comment: 5 pages, 2 figures, accepted for publication in PRC

The possible existence of $\eta$-mesic nuclei poses an interesting and still open issue of research. Since the occurence of such $\eta$-nucleus bound states is reflected in the corresponding $\eta$-nucleus scattering length, we critically review the present knowledge for the $\eta$$^3$He system. Specifically, we scrutinize the available experimental information for the reaction $p{+}d \to \eta {+} ^3{\rm He}$ which is commonly used to extract the $\eta$$^3$He scattering length. We point out several striking discrepancies between the various measurements. Subject to those inconsistencies we deduce a value of $a{=}|4.3{\pm}0.3|{+}i(0.5{\pm}0.5)$ fm., Comment: 8 pages, 9 figures, accepted for publication in Eur. Phys. J. A

We study pion absorption on 3He employing trinucleon wave functions calculated from modern realistic NN interactions (Paris, CD Bonn). Even though the use of the new wave functions leads to a significant improvement over older calculations with regard to both cross section and polarization data, there are hints that polarization data with quasifree kinematics cannot be described by just two-nucleon absorption mechanisms., 14 pages, 6 figures

Beam momentum dependence of the experimental cross sections for pd-->(3)Hpi(+)/(3)Hepi(0) reactions have been studied at large proton-pion relative angle. The measurements were performed for five beam momenta in the region of the eta meson production threshold. Observed behavior of the measured cross sections ratio reveals manifestations of the isospin symmetry breaking effects. A simple model allows one to interpret the isospin symmetry breaking in terms of pi(0)-eta meson mixing. Based on that model analysis of the experimental results leads to the mixing angle value of 0.006+/-0.005 rad.

The mechanism of $p^3$He backward elastic scattering is studied. It is found that the triangle diagrams with the subprocesses $pd\to ^3$He$ \pi^0$, $pd^*\to ^3$He$ \pi^0$ and $p(pp)\to^3$He$ \pi^+$, where $d^*$ and $pp$ denote the singlet deuteron and diproton pair in the $^1S_0$ state, respectively, dominate in the cross section at 0.3-0.8 GeV, and their contribution is comparable with that for a sequential transfer of a $np$ pair at 1-1.5 GeV. The contribution of the $d^*+pp$, estimated on the basis of the spectator mechanism of the $p(NN)\to ^3$He$ \pi$ reaction, increases the $p^3$He$\to ^3$He$ p$ cross section by one order of magnitude as compared to the contribution of the deuteron alone. Effects of the initial and final states interaction are taken into account., Comment: 17 pages, Latex, 4 postscript figures, expanded version, accepted by Physical Review C

137 pp. (1999)., The outline of this work is as follows. Chapter 2 gives an introduction to polarised deep inelastic scattering and provides the formalism used to extract the quark spin distributions from inclusive and semi-inclusive spin-dependcnt cross section asymmetries. In chapter 3 the HERMES experimental apparatus is introduced. The analysis of inclusive and semi-inclusive charged hadron asymmetries is presented in chapter 4 and the extraction of the polarised quark distributions from the measured cross section asymmetries is described in chapter 5. The HERMES results on the polarised quark distributions are discussed and compared to existing experimental results and to predictions from quark models and lattice QCD.

Total and differential cross sections for the dp -> He-3 eta reaction have been measured near threshold for He-3 center-of-mass momenta in the range from 17.1 MeV/c to 87.5 MeV/c. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target detecting the He-3 ejectiles with the COSY-11 facility. The forward-backward asymmetries of the differential cross sections deviate clearly from zero for center-of-mass momenta above 50 MeV/c indicating the presence of higher partial waves in the final state. Below 50 MeV/c center-of-mass momenta a fit of the final state enhancement factor to the data of the total cross sections results in the He-3-eta scattering length of vertical bar a vertical bar = 4.3 +/- 0.5fm. (C) 2007 Elsevier B.V. All rights reserved.