The KVI Lamb-shift polarimeter

et al. 2013

Physics Letters B

Spin observables in the three-body break-up process near the quasi-free limit in deuterondeuteron scattering Ramazani-Moghaddam-Arani, A.; Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacher, A. D.; Bailey, C. D.; Biegun, A.; Eslami-Kalantari, M.; Gasparic, I.; Joulaeizadeh, L.; KalantarNayestanaki, N. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. We have studied spin observables in the three-body break-up reaction in deuteron-deuteron scattering in the phase-space regime that corresponds to the quasi-free deuteron-proton scattering process with the neutron as spectator. The data are compared to measurements of the elastic deuteron-proton scattering process and state-of-the-art Faddeev calculations. The results for iT 11 and T 22 for the quasi-free scattering data agree very well with previously published elastic-scattering data. A significant discrepancy is found for T 20 , which could point to a break-down of the quasi-free assumption.

Section: Methodsmentioning

confidence: 54%

Spin observables in the three-body break-up process near the quasi-free limit in deuteron–deuteron scattering

Ramazani-Moghaddam-Arani

Mahjour‐Shafiei

et al. 2013

Physics Letters B

“…A polarized beam of deuterons originating from the polarized ion source (POLIS) [49] was accelerated by AGOR (Accélérateur Groningen ORsay) to a kinetic energy of 65 MeV/nucleon and bombarded on a liquid-deuterium target [50]. The polarization of the deuteron beam was measured in the low-energy beam line with a Lamb-Shift Polarimeter (LSP) [51] as well as in the high-energy beam line with BINA [48]. For the polarization measurements using the LSP, the low-energy beam was decelerated and focused on to the LSP detection system.…”

Section: Experiments and Experimental Setupmentioning

confidence: 99%

Three-body break-up in deuteron-deuteron scattering at 65 MeV/nucleon

Ramazani-Moghaddam-Arani

Bacher

et al. 2011

Phys. Rev. C

Abstract. We successfully identified several multibody final states in deuteron-deuteron scattering at 65 MeV/nucleon at KVI using a unique and advanced detection system called BINA. This facility enabled us to perform cross sections and polarization measurements with an improved statistical and systematic precision. The analysis procedure and a part of the results of the three-body break-up channel in the deuteron-deuteron scattering at 65 MeV/nucleon are presented.The physics phenomena of nuclei are for a large part understood by considering the interaction between their building blocks, the nucleons. In 1935 Yukawa described the nucleon-nucleon (NN) force by the exchange of massive mesons [1] in analogy to the electromagnetic interaction which can be represented by the exchange of of a massless photon. Several phenomenological nucleonnucleon potentials have been derived based on Yukawa's theory and are able to reproduce the whole bulk of data points in neutron-proton and proton-proton scattering with extremely high precision. These so-called high-quality NN potentials are used in Faddeev equations [2,3] to give an exact solution of the scattering problem of the threenucleon system. Already, for the simplest three-nucleon system, the triton, an exact solution of the three-nucleon Faddeev equations employing two-nucleon forces (2NFs) underestimates the experimental binding energy [4], showing that 2NFs are not sufficient to describe the threenucleon system accurately. The existence of an additional force, the three-nucleon (3N) interaction, was predicted by Primakov [5] and confirmed by a comparison between precision data and state-of-the-art calculations. In general, adding 3NF effects to the NN potentials gives a better agreement between the cross section data of the protondeuteron scattering and corresponding calculations [6][7][8][9][10][11][12][13][14][15][16][17], whereas a similar comparison for the spin observables yields various discrepancies [7][8][9][18][19][20][21][22]. This demona e-mail: ramazani@kvi.nl strated that spin-dependent parts of the 3NFs are poorly understood and that more studies in this field are needed.The 3NF effects are in general small in the threenucleon system. A complementary approach is to examine heavier systems for which the 3NF effects are significantly enhanced in magnitude. For this, it was proposed to study the four-nucleon system since the experimental database in the four-nucleon system is presently poor in comparison with that of the three-nucleon system. Most of the available data have been measured at very low energies, in particular below the three-body break-up threshold of 2.2 MeV. Also, theoretical developments are evolving rapidly at low energies [23][24][25][26], but lag behind at higher energies. The experimental database at intermediate energies is very limited [27][28][29]. This situation calls for extensive four-nucleon studies at intermediate energies. The goal of our work was to perform a comprehensive measurement of the cross sections and spin observab...

“…The polarization of the deuteron beam was monitored with a Lamb-Shift Polarimeter [35] at the low-energy beam line and determined with BINA after the beam acceleration using a measurement of the elastic deuteron-proton scattering. The vector and tensor polarizations of the deuteron beams were found to be p Z = −0.601±0.029 and p Z Z = −1.517±0.032, respectively, whereby the errors include uncertainties in the analyzing powers in elastic d p scattering.…”

Section: Methodsmentioning

confidence: 99%

Quasi-free limit in the deuteron-deuteron three-body break-up process

Ramazani-Sharifabadi

Bayat

et al. 2020

SciPost Phys. Proc.

Detailed measurements of vector and tensor analyzing powers of the 2 H( d, d p)n breakup process are presented. The data were obtained using a polarized deuteron-beam with an energy of 65 MeV/nucleon impinging on a liquid-deuterium target. The experiment was conducted at the AGOR facility at KVI using the BINA 4π-detection system. The focus of this contribution is to analyze data of the d d scattering process in the regime at which the neutron acts as a spectator, which we refer to as the quasi-free (QF) limit. To achieve this, events for which the final-state deuteron and proton are coplanar have been analyzed and the data have been sorted for various reconstructed momenta of the missing neutron. In the limit of vanishing neutron momentum and at small deuteron-proton momentum transfer, the data match very well with measured and predicted spin observables of the elastic deuteron-proton scattering process. The agreement deteriorates rapidly with increasing neutron momentum and deuteron-proton momentum transfer. The results of coplanar configurations in four-body phase space are compared with the results of recent available theoretical calculations based on the Single-Scattering Approximation.