Searcharxiv⌕ Search

arXiv · nucl-ex/9908024

Initial singlet and triplet spin state contributions to pp -> pp pi0

Abstract

The PINTEX facility at the IUCF Cooler ring, dedicated to the study of spin dependence in nucleon-nucleon interactions, has been used to measure polarization observables of the reaction pp -> pp pi0 at beam energies between 325 and 400 MeV. The stored polarized proton beam had spin projections both in the longitudinal and the transverse directions with respect to the beam momentum. We report here on the measurements of the relative transverse and longitudinal spin-dependent cross sections, deltasigma_T/sigma_tot and deltasigma_L/sigma_tot, and how from these observables the initial spin singlet and triplet cross sections are obtained. Considering angular momentum states less or equal to one, the contribution of the Ps partial waves to the cross section can be extracted.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P. Thorngren Engblom, H. O. Meyer, J. T. Balewski, W. W. Daehnick, J. Doskow, W. Haeberli, B. Lorentz, P. V. Pancella, R. E. Pollock, B. von Przewoski F. Rathmann, T. Rinckel, Swapan K. Saha, B. Schwartz, A. Wellinghausen, T. Wise.. 1999-08-31. Initial singlet and triplet spin state contributions to pp -> pp pi0. https://doi.org/10.1016/s0375-9474(99)00604-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Neutron Optical Constraints on Exotic Parity-odd Interactions between Neutrons and Nucleons

Many theories beyond the standard model of particle physics predict the existence of weakly-coupled exotic spin-dependent interactions between standard model particles. We use experimental upper bounds on neutron-nucleus parity violation at meV and keV neutron energies in the forward scattering limit described by neutron optics to constrain exotic parity-odd interactions of the neutron with nucleons from exotic vector boson exchange for force ranges between $10^{-2}$ to $10^{-14}$ meters.

nucl-ex↗

Sizeable mixing between the coexisting normal and intruder structures of $^{96}$Zr revealed through lifetime measurements

Lifetimes of excited states of the nucleus $^{96}$Zr were studied with the Doppler-shift attenuation method following the $^{94}$Zr($^{18}$O,$^{16}$O)$^{96}$Zr two-neutron transfer reaction. The obtained $B(E2;2^+_2\to0^+_2)$ and $B(E2;4^+_1\to2^+_2)$ transition strengths, amounting to $26(2)$ and $39(7)$\,W.u., respectively, firmly attribute the $2^+_2$ and $4^+_1$ states to the collective intruder band built on top of the $0^+_2$ state. The nature of this structure is discussed against predictions of the collective model using the Bohr Hamiltonian, the interacting boson model with configuration mixing, and the quasiparticle vacua shell model. The collective, interband $B(E2;4^+_1\to2^+_1)=11.2(8)$\,W.u. transition strength, refuting the previously assumed purity of both structures, is reproduced in the calculations. The quasiparticle vacua shell model predicts, in agreement with a simple two-state model based on experimental $E2$ transition strengths, considerable mixing between the normal and intruder $2^+$ states.

nucl-ex↗

Search for $^4\overline{\mathrm{Li}}$ from $\overline{\mathrm{p}}+{}^3\overline{\mathrm{He}}$ femtoscopy in Pb-Pb collisions at $\sqrt{s_\mathrm{NN}} =5.36$ TeV with ALICE

In these proceedings, the search for $^4\overline{\mathrm{Li}}$ in Pb-Pb collisions with ALICE is presented. The particle is reconstructed via its two-body decay channel $^4\overline{\mathrm{Li}} \rightarrow \overline{\mathrm{p}} + {}^3\overline{\mathrm{He}}$, using femtoscopic correlations. A dedicated analysis procedure has been developed to subtract the correlated and uncorrelated $\overline{\mathrm{p}} + ^3\overline{\mathrm{He}}$ combinatorial background. The production yield of $^4\overline{\mathrm{Li}}$ is compared with that of $^4\overline{\mathrm{He}}$. Owing to the presence of several $^4\mathrm{Li}$ resonances and their spin degeneracy, the production of $^4\overline{\mathrm{Li}}$ is expected to be enhanced with respect to the compact $^4\overline{\mathrm{He}}$, making this new measurement a sensitive probe for testing nucleosynthesis models in high-energy hadronic collisions.

nucl-ex↗