Search arXiv⌕ Search

arXiv · 1306.1485

HBT interferometry relative to the triangular flow plane in heavy-ion collisions

Abstract

The PHENIX Collaboration has reported third-order harmonic oscillations of the source radius parameters when measuring the Hanbury Brown-Twiss correlation function for charged hadrons relative to the triangular flow angle. We explore possible origins of such third-order oscillations with a simple Gaussian source featuring both a triangular geometric deformation and triangular flow. Third-order oscillations of the HBT radii can arise from a purely geometric triangular deformation superimposed on an azimuthally symmetric radial flow, or from a radially symmetry spatial distribution which expands anisotropically with a triangular component in the flow velocity profile. In both cases the final particle momentum distribution features triangular flow. We show that the two alternatives can be distinguished experimentally through the phase of the azimuthal oscillations of the HBT radii relative to the triangular flow plane.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Christopher J Plumberg, Chun Shen, Ulrich W Heinz. 2013-06-06. HBT interferometry relative to the triangular flow plane in heavy-ion collisions. https://doi.org/10.1103/physrevc.88.044914

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

KEEP EXPLORING

Related papers

Toward testing antinucleon$\unicode{x2013}$nucleus optical potentials with antineutron scattering lengths

The antineutron$\unicode{x2013}$nucleus scattering length is currently known only indirectly, via antiproton$\unicode{x2013}$nucleus optical potentials fitted to level shifts and widths of antiprotonic atoms. The antineutron$\unicode{x2013}$nucleus and antiproton$\unicode{x2013}$nucleus potentials are related to each other through charge symmetry. We calculate the scattering length from optical potentials proposed for antiprotonic atoms using nucleon density distributions as input. We find that the scattering length for an $N>Z$ nuclide is largely affected by the poorly constrained neutron density distribution and by a possible isovector interaction, one of the mechanisms introduced to reproduce the isotope dependence of antiprotonic $^{40,48}\mathrm{Ca}$ data. For $^{48}\mathrm{Ca}$, the isovector term modifies the scattering length by $0.3\unicode{x2013}0.4\,\mathrm{fm}$ ($0.4\unicode{x2013}0.5\,\mathrm{fm}$) for the real (imaginary) part, an order of magnitude beyond the uncertainty propagated from the isoscalar potential. As no antineutron$\unicode{x2013}$nucleus scattering data are available below $76\,\mathrm{MeV}/c$, a direct measurement with recently proposed low-energy antineutron beams would provide the first access to the antinucleon$\unicode{x2013}$nucleus interaction in the $s$-wave regime.

nucl-th↗

Separable representations of two-body interactions for Faddeev calculations of light nuclei

Separable representations of the Ernst--Shakin--Thaler type are constructed for the charge-dependent Bonn (CD~Bonn) nucleon--nucleon potential ($j\le4$; $nn$, $np$, $pp$), for the Kanada--Kaneko--Nagata--Nomoto (KKNN) $αN$ interaction, and for the Buck--Friedrich--Wheatley (BFW) $αα$ interaction. They are the input for momentum-space Faddeev calculations of $A=3$, $6$, $9$, and $12$ systems. The representations are tested against six acceptance criteria: off-shell accuracy at the pair energies sampled by the three-body kernel, phase shifts, effective-range parameters, bound and resonant states, and numerical stability.

nucl-th↗

The Fock representation of the Coulomb interaction. I. Two-body problem

In the momentum-space few-body theory of light nuclei, where the Faddeev equations with separable two-body input close on one-variable amplitudes, the unscreened Coulomb interaction is exactly separable by the stereographic projection of Fock, with analytic form factors and strengths, and the truncation of the expansion converges at negative energies. It is derived here as an operator identity for the potential and added, without screening or fitting, as a block of separable terms to the separable nuclear input of a charged pair. The representation is compared with the screening--renormalization method and with Coulomb-distorted form factors on two-body benchmarks: the off-shell $t$~matrix, the Coulomb displacement of the $αp$ Pauli-forbidden state, and the Coulomb-modified phases of the $pp$, $αp$ and $αα$ pairs. The Feshbach--Schur projection of the Pauli-forbidden state is shown to require the Coulomb-dressed eigenstate, which the Fock block provides within the same separable problem. At positive energy a finite truncation is a screened Coulomb potential with an analytic, momentum-dependent radius.

nucl-th↗