Bandyopadhyay D

Bio: Bandyopadhyay D is an academic researcher from University of Alberta. The author has contributed to research in topics: Neutron & Energy (signal processing). The author has an hindex of 3, co-authored 5 publications receiving 91 citations.

Test of charge symmetry in neutron-proton elastic scattering at 477 MeV

Abstract: An experiment resulting in the first measurement of the isospin-mixing, charge-symmetry violating component of the n-italic-p-italic interaction has been performed. The experiment determined the difference in the angles of the zero crossing of the neutron and proton analyzing powers A-italic/sub n-italic/ and A-italic/sub p-italic/ at 477 MeV. In terms of the laboratory scattering angle of the neutron, the measured difference t-italich-italice-italict-italica-italic/sub 0//sub n-italic/(A/sub n/)= -t-italich-italice-italict-italica-italic/sub 0//sub n-italic/(A/sub p/) = +0.13X(de +- 0.06 X(de( +- 0.03X(de) where the second error is a worst case estimate of systematic error. The resulting difference in the analyzing powers at the zero-crossing angle A-italic/sub n-italic/-A/sub p/ = +0.0037 +- 0.0017( +- 0 .0008).

Spin correlation parameter and analyzing power in n-p elastic scattering at intermediate energies.

Abstract: In order to improve existing {ital I}=0 phase shift solutions, the spin correlation parameter {ital A}{sub {ital NN}} and the analyzing powers {ital A}{sub 0{ital N}} and {ital A}{sub {ital N}0} have been measured in {ital n}-{ital p} elastic scattering over an angular range of 50{degree}--150{degree} (c.m.) at three neutron energies (220, 325, and 425 MeV) to an absolute accuracy of {plus minus}0.03. The data have a profound effect on various phase parameters, particularly the {sup 1}P{sub 1}, {sup 3}D{sub 2}, and {epsilon}{sub 1} phase parameters which in some cases change by almost a degree. With the exception of the highest energy, the data support the predictions of the latest version of the Bonn potential. Also, the analyzing power data ({ital A}{sub 0{ital N}} and {ital A}{sub {ital N}0}) measured at 477 MeV in a different experiment over a limited angular range (60{degree}--80{degree} (c.m.)) are reported here.

np elastic scattering analyzing power characteristics at intermediate energies.

Abstract: Recent measurements of charge symmetry breaking in the {ital np} system at 477 MeV, and of {ital A}{sub 00{ital nn}} for {ital np} elastic scattering at 220, 325, and 425 MeV also yield accurate analyzing power data. These data allow the energy dependence of the analyzing power zero-crossing angle and the slope of the analyzing power at the zero-crossing angle to be determined. The incident neutron energies span a region where the zero-crossing angle is strongly energy dependent ({ital E}{sub {ital n}}{lt}250 MeV) to where it is almost independent of energy ({ital E}{sub {ital n}}{gt}350 MeV). The results are compared to current phase-shift analysis predictions, recently published data, and the predictions of the Bonn and Paris potentials.

The Meson Theory of Nuclear Forces and Nuclear Structure

Abstract: Nowadays it has become customary in nuclear physics to denote by “tradition” the approach that considers nucleons and mesons as the relevant degrees of freedom. It is the purpose of this chapter to review this “traditional” approach in the area of nuclear forces and their applications to nuclear structure.

Covariant spectator theory of np scattering: Phase shifts obtained from precision fits to data below 350-MeV

Abstract: Using the covariant spectator theory (CST), we present two one-boson-exchange kernels that have been successfully adjusted to fit the 2007 world $\mathit{np}$ data (containing 3788 data) below 350 MeV. One model (which we designate WJC-1) has 27 parameters and fits with a ${\ensuremath{\chi}}^{2}/{N}_{\mathrm{data}}=1.06$. The other model (designated WJC-2) has only 15 parameters and fits with a ${\ensuremath{\chi}}^{2}/{N}_{\mathrm{data}}=1.12$. Both of these models also reproduce the experimental triton binding energy without introducing additional irreducible three-nucleon forces. One result of this work is a new phase-shift analysis, updated for all data until 2006, which is useful even if one does not work within the CST. In carrying out these fits we have reviewed the entire database, adding new data not previously used in other high precision fits and restoring some data omitted in previous fits. A full discussion and evaluation of the 2007 database is presented.

Charge Symmetry Breaking and QCD

Abstract: ▪ Abstract Charge symmetry breaking (CSB) in the strong interaction occurs because of the difference between the masses of the up and down quarks. The use of effective field theories allows us to follow this influence of confined quarks in hadronic and nuclear systems. We review the progress in observing and understanding CSB, with particular attention to the recent successful observations of CSB in measurements involving the production of a single neutral pion, and to the related theoretical progress.