32 research outputs found
Precision measurement of vector and tensor analyzing powers in elastic deuteron-proton scattering
High precision vector and tensor analyzing powers of elastic deuteron-proton
d+p scattering have been measured at intermediate energies to investigate
effects of three-nucleon forces (3NF). Angular distribution in the range of
70-120 degree in the center-of mass frame for incident-deuteron energies of 130
and 180 MeV were obtained using the RIKEN facility. The beam polarization was
unambiguously determined by measuring the 12C(d,alpha)10B(2+) reaction at 0
degree. Results of the measurements are compared with state-of-the-art
three-nucleon calculations. The present modeling of nucleon-nucleon forces and
its extension to the three-nucleon system is not sufficient to describe the
high precision data consistently and requires, therefore, further
investigation
Optimizing the design of invasive placebo interventions in randomized controlled trials
The authors thank A. Skilton for preparing Fig. 1. This study was supported by the NIHR Biomedical Research Centre at University Hospitals Bristol National Health Service (NHS) Foundation Trust and the University of Bristol, MRC ConDuCTâII (Collaboration and innovation for Difficult and Complex randomised controlled Trials In Invasive procedures) Hub for Trials Methodology Research (MR/K025643/1) (http://www.bristol.ac.uk/populationâhealthâsciences/centres/conduct2), a NIHR senior investigator award (NFâSIâ0514â10114) and the Bristol Royal College of Surgeons Trials Centre. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. The funders played no role in any aspect of the study design, analysis or publication decisions.Peer reviewedPublisher PD
Measurement of the vector and tensor analyzing powers for dp- elastic scattering at 880 MeV
The vector Ay and tensor analyzing powers Ayy and Axx for dp- elastic
scattering were measured at Td = 880 MeV over the c.m. angular range from 60 to
140 degrees at the JINR Nuclotron. The data are compared with predictions of
different theoretical models based on the use of nucleon-nucleon forces only.
The observed discrepancies of the measured analyzing powers from the
calculations require the consideration of additional mechanisms.Comment: 5 pages,3 figure
Measurement of differential cross sections for deuteron-proton breakup reaction at 160 MeV
Differential cross sections for deuteron breakup reaction
were measured for a large set of 243 geometrical configurations at the beam
energy of 80 MeV/nucleon. The cross section data are normalized by the
luminosity factor obtained on the basis of simultaneous measurement of elastic
scattering channel and the existing cross section data for this process. The
results are compared to the theoretical calculations modeling nuclear
interaction with and without taking into account the three-nucleon force (3NF)
and Coulomb interaction. In the validated region of the phase space both the
Coulomb force and 3NF play an important role in a good description of the data.
There are also regions, where the improvements of description due to including
3NF are not sufficient
Spin-isospin selectivity in three-nucleon forces
Precision data are presented for the break-up reaction, (2)H((p) over right arrow, pp)n, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV impinging on a liquid-deuterium target and by exploiting the detector, BINA. Some of the vector-analyzing powers are presented and compared with state-of-the-art Faddeev calculations including three-nucleon forces effect. Significant discrepancies between the data and theoretical predictions were observed for kinematical configurations which correspond to the (2)H((p) over right arrow,(2)He)n channel. These results are compared to the (2)H((p) over right arrow, d)p reaction to test the isospin sensitivity of the present three-nucleon force models. The current modeling of two and three-nucleon forces is not sufficient to describe consistently polarization data for both isospin states. (C) 2010 Elsevier B.V. All rights reserved