Search arXivSearch

arXiv · 1505.06074

Antimagnetic rotation and sudden change of electric quadrupole transition strength in 143Eu

Abstract

Lifetimes of the states in the quadrupole structure in 143Eu have been measured using the Doppler shift attenuation method as well as parity of the states in the sequence has been firmly identified from polarization measurement using the Indian National Gamma Array. The decreasing trends of the deduced quadrupole transition strength B(E2) with spin, along with increasing J (2) /B(E2) values before band crossing, conclusively establish the origin of these states as arising out of antimagnetic rotation. The abrupt increase in the B(E2) values after the band crossing in the quadrupole band, a novel feature observed in the present experiment, may indicates the crossing of different shears configurations resulting in re-opening of shears structure. The results are well reproduced by numerical calculation within the framework of semi-classical geometric model.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. Rajbanshi, S. Roy, Somnath Nag, Abhijit Bisoi, S. Saha, J. Sethi, T. Trivedi, T. Bhattacharjee, S. Bhattacharyya, S. Chattopadhyay, G. Gangopadhyay, G. Mukherjee, R. Palit, R. Raut, M. Saha Sarkar, A. K. Singh, A. Goswami. 2015-05-22. Antimagnetic rotation and sudden change of electric quadrupole transition strength in 143Eu. https://doi.org/10.1016/j.physletb.2015.07.033

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

First Measurement of Near-Threshold J/ψ Photoproduction on the Neutron

We report the first measurement of the total and t-differential cross sections for near-threshold J/$ψ$ photoproduction on the neutron, obtained with the CLAS12 detector at the Thomas Jefferson National Accelerator Facility. The measurements, performed using a liquid-deuterium target, also provide the incoherent total and t-differential cross sections on the bound proton, enabling the first direct comparison of near-threshold J/$ψ$ photoproduction on bound protons and neutrons. Interpreted within Vector Meson Dominance, holographic QCD, and GPD-based frameworks, the data allow for the investigation of the gluonic structure of bound nucleons. A comparison with free proton results reveals hints of modifications to the gluon structure of nucleons in the nuclear medium, within the assumptions of the extraction and on the underlying production mechanism. The comparison of bound neutron and bound proton cross sections provides new constraints on the near-threshold J/$ψ$ production mechanism, which is crucial in order to establish J/$ψ$ photoproduction as a probe of the nucleon's gluonic structure.

nucl-ex

Photon-induced $J/ψ$ as a linearly polarized probe of collision geometry in relativistic heavy-ion collisions

In relativistic heavy-ion collisions, the linear polarization of quasi-real photons can correlate the spin orientation of photon-induced vector mesons with the collision geometry. To explore this sensitivity, we present the first measurement of the decay angular distribution of photon-induced $J/ψ$ with respect to the event plane in heavy-ion collisions with hadronic overlap. The analysis uses Ru+Ru and Zr+Zr collisions at a nucleon--nucleon center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}=200$ GeV recorded by STAR. After correcting for the finite event-plane resolution and subtracting the residual hadronic contribution, we extract a negative second-order modulation, $A_2^{\rm phot} = -0.39 \pm 0.11~(\mathrm{stat.}) \pm 0.04~(\mathrm{sys.})$, for $|y^{ee}|<0.8$, $p_{\mathrm T}^{ee}<0.2~\mathrm{GeV}/c$, and 30--80% centrality. This modulation provides evidence that the $J/ψ$ polarization is correlated with the event plane, as expected for linearly polarized photons. The observed modulation establishes polarized $J/ψ$ photoproduction as a direct probe of the transverse orientation of the initial collision geometry.

nucl-ex

Low-energy collective structure of $^{92,94}$Zr and $^{94}$Mo from ($e,e^{\prime}$) and ($p,p^{\prime}$) scattering I. Experimental results

This is the first of two papers discussing a new signature of quadrupole mixed-symmetry states in the vibrational nuclei $^{92,94}$Zr and $^{94}$Mo based on proton and neutron transition densities derived from the comparison of inelastic electron and proton scattering experiments. Results of the $(e,e^\prime)$ and $(p,p^\prime)$ experiments on these nuclei as well as $(p,p^\prime)$ data for other potential cases $^{96}$Mo and $^{70}$Zn are presented. Spin and parity quantum numbers of excited states are assigned based on angular distributions from the proton scattering data in comparison to calculations employing form factors from the collective model in distorted-wave Born approximation. Possible candidates of one-phonon fully symmetric and mixed-symmetry states as well as members of two-phonon multiplets are identified.

nucl-ex