Related papers: Probing proton halos through pion photoproduction
In this contribution we report on the investigation of the photoproduction of W and Z bosons in the planned electron-proton/nucleus collider, the LHeC. The production cross sections and the number of events are provided and theoretical…
Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We estimate the soft contributions to this process, with an eye toward delineating the region where…
We report on the first measurement of $J/\psi$ photoproduction from nuclei in the photon energy range of $7$ to $10.8$ GeV, extending above and below the photoproduction threshold in the free proton of $\sim8.2$ GeV. The experiment used a…
We report on our studies of the physical structure of the planetary nebula (PN) NGC7662. Using (3D) Integral Field Spectroscopy we have been able to measure the electron temperature more accurately and at a larger number of radial locations…
The utility of prompt photon plus associated jet production for constraining the size and shape of the polarized gluon density of the proton $\Delta G$ is examined at $\sqrt{S}=40$ GeV, appropriate for the proposed HERA-$\vec{N}$ polarized…
The $^{12}$C$(\gamma,ppn)$ reaction has been measured for E$_{\gamma}$=150-800 MeV in the first study of this reaction in a target heavier than $^3$He. The experimental data are compared to a microscopic many body calculation. The model,…
In this paper we show how effective parameters such as effective binding energies can be defined for a proton in the combined nuclear-Coulomb potential, including also the target potential, in the case in which the proton is bound in a…
We propose a new experimental method to probe the photon parton distribution function inside the proton (photon PDF) at LHC energies. The method is based on the measurement of dilepton production from the $\gamma p\rightarrow\ell^+\ell^-+X$…
A simple model for the photoproduction of kaons off protons with a lambda hyperon in the final state is presented. In a quark model, the interaction is modelled by the pair-creation of the (anti-) strange quarks in the final state which…
The cross section for the $A(e,e'\gamma)A$ reaction is calculated, investigating the contribution from the nuclear target with respect to the radiative corrections from the electron. The reaction mechanism is studied for photon emission in…
The three-body description of two-neutron halo nuclei relies on the two-body interactions between the constituents. In order to provide constraints on calculations devoted to $^{14}$Be and $^{17}$B, neutron unbound states of $^{13}$Be and…
We present a new and improved model independent amplitude analysis of reactions $\pi^+ n_\uparrow \to \pi^+ \pi^- p$ at 5.98 and 11.85 GeV/c and $\pi^- p_\uparrow \to \pi^- \pi^+ n$ at 17.2 GeV/c measured with transversely polarized targets…
Reactions A(\gamma, pi^+p) are considered to proceed through the formation of pion-proton pairs on delta constituents in nuclei. We develop the nonrelativistic operator for \Delta^{++}(\gamma, pi^+)p process in an arbitrary frame. The…
The differential cross section, $d\sigma/dt$, for $\rho^0$ meson photoproduction on the proton above the resonance region ($2.6<W<2.9$ GeV) was measured up to a momentum transfer $-t = 5$ GeV$^2$ using the CLAS detector at the Thomas…
Differential cross sections for the gamma p -> pi^0 p reaction have been measured with the A2 tagged-photon facilities at the Mainz Microtron, MAMI C, up to the center-of-mass energy W=1.9 GeV. The new results, obtained with a fine energy…
Inspired by the recent debate as to whether the proton drip-line nucleus 22Al demonstrates a halo structure in its ground state and in order to assess such a possibility, we have analyzed theoretical results obtained within the relativistic…
The halo effect in the final states of astrophysically relevant direct neutron--capture reactions by neutron--rich nuclei is discussed. As an example, we calculate the cross sections for $^{18}$O(n,$\gamma$)$^{19}$O at thermonuclear and…
Data for the scattering of 6He, 8He, 9Li, and 11Li from hydrogen are analyzed within a fully microscopic folding model of proton-nucleus scattering. Current data suggest that of these only 11Li has a noticeable halo. For 6He, we have also…
We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…
The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb^-1 collected by the H1…