Related papers: Probing proton halos through pion photoproduction
The halo nature of the low-lying $1/2$+ first excited state of the exotic weakly-bound proton drip-line nucleus $^{17}$F has long been hypothesized. The structure of such a halo nucleus would imply special nuclear properties including,…
We use halo effective field theory to analyze the universal features of proton halo nuclei bound due to a large S-wave scattering length. With a Lagrangian built from effective core and valence-proton fields, we derive a leading-order…
Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction $^6$He(p,$\gamma$) at 40 MeV. Capture into $^7$Li is observed…
The existence of non-strange partner of pentaquark, the J^p = 1/2^+ narrow resonance, has been investigated by utilizing kaon photoproduction off a proton. It is found that the corresponding mass is 1650 MeV and the appropriate observables…
Proton radii of $^{12-19}$C densities derived from first accurate charge changing cross section measurements at 900$A$ MeV with a carbon target are reported. A thick neutron surface evolves from $\sim$ 0.5 fm in $^{15}$C to $\sim$ 1 fm in…
In this paper we propose the analysis of the heavy quark photoproduction associated with a leading neutron in hadronic collisions at the LHC as an alternative to probe the pion gluon distribution in a kinematical range not covered by…
Selected topics on halo and molecular states in light, neutron-rich nuclei are discussed. In particular, work on $x\alpha$:X$n$ structures is briefly reviewed. The use of proton radiative capture as a probe of clustering is also presented…
The nuclide $^{17}$Ne is studied theoretically in a three-body $^{15}$O+$p$+$p$ model. We demonstrate that the experimental condition for existence of a proton halo in $^{17}$Ne can be reasonably quantified in terms of $s/d$ configuration…
We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The $^{12}$C$(\gamma,\pi^{0})^{12}$C$^{*}_{4.4MeV}$ reaction has been studied with the Glasgow photon tagger…
Photoproduction of charged pions pairs off protons is studied within the invariant masses of the final state hadrons from 1.6 to 2.4 GeV at the Thomas Jefferson National Accelerator Facility with the CLAS detector. The data are included in…
The ratio method has been developed to improve the study of one-neutron halo nuclei through reactions. By taking the ratio of angular distributions for two processes, viz. breakup and elastic scattering, this new observable is nearly…
Production of large-p_T hadron pairs by polarized photon on a longitudinally polarized proton towards probing the polarized gluon distribution is studied. Resolved photon contributions and the effect of changing the scales are taken into…
Neutron and proton densities in the nuclear periphery are investigated within (p,n) charge-exchange isobar transitions. For this purpose we have developed parameter-free optical potentials with a detailed treatment of the in-medium…
Two reactions, the photoproduction of a direct photon plus a jet and the photoproduction of a charged hadron plus a jet, are studied in view of their potential to constrain the gluon distribution in the proton. The results are based on a…
The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F->15O+p quasi-free one-proton knockout reaction has been performed at…
The polarization observables in phi photoproduction are suggested for probing the nucleon strangeness. Based on models for phi photoproduction, some double polarization observables are shown to be very sensitive to the strangeness content…
Photoproduction can be studied at hadron colliders by using the virtual photons associated with the hadron beams. The LHC will reach photonucleon energies 10 times higher than that available elsewhere. These reactions are already being…
Differential cross sections for the reaction $\gamma p \to n \pi^+$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.725 to 2.875 GeV. Where available, the results obtained…
We analyze the effects of finite-range corrections in halo effective field theory for S-wave proton halo nuclei. We calculate the charge radius to next-to-leading order and the astrophysical S-factor for low-energy proton capture to fifth…
Light, beyond-the-standard-model particles $X$ in the 1-100 MeV mass range can be produced in nuclear and hadronic reactions but would have to decay electromagnetically. We show that simple and well-understood low-energy hadronic processes…