Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0705.1712

Heaviness of Heavy Quarkonia in Heavy Ion Collisions

J. L. Nagle
View original source ↗Read source document ↗Export metadata ↓

Abstract

High energy heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) produce a novel medium characterized by an initial energy density over an order of magnitude above the expected phase transformation value and that then evolves as a nearly inviscid liquid. Probing the medium with auto-generated particles is a key methodology to quantitatively determine the medium properties. Pairs of heavy quarks are an excellent probe since their spatial separation to form various quarkonia states spans the relevant range of color screening lengths in the medium. In this proceedings, we describe results from the PHENIX experiment on $J/ψ$ production and discuss initial physics implications of the measurements.

Explore related subjects

nucl-ex

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J. L. Nagle. 2007-05-11. Heaviness of Heavy Quarkonia in Heavy Ion Collisions. https://arxiv.org/abs/0705.1712

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

KEEP EXPLORING

Related papers

arXiv2026

Macroscopic Nuclear Resonance Energy Transfer Mediated by Coherent Magnons

Phonon-mediated nuclear Resonance Energy Transfer (RET) in metal deuterides is severely constrained by inertial rest-mass dilution, lattice fracture limits, and thermal nuclear spin cancellation. Extending the generalized nuclear Dicke model to Ferromagnetic Resonance (FMR) magnons eliminates mass dilution via hyperfine-amplified M1 coupling while unlocking relativistic Dirac M2 coupling via Overhauser spin polarization. We derive a Suhl-clamped FMR scaling law predicting 14.2 MeV (Pd-106) and 11.4 MeV (Ni-58) breakup neutrons, 19.9 MeV alpha particles, and reconciled sub-keV fusion anomalies.

nucl-ex↗
arXiv2026

Lifetime of the singly charged $^{229}$Th nuclear isomer

The nucleus of thorium-229 ($^{229}$Th) has an exceptionally low-energy isomeric state ($^{229\mathrm{m}}$Th). Because its excitation energy is close to the energy levels of valence electrons, the lifetime of $^{229\mathrm{m}}$Th varies substantially depending on its electronic state. Although internal conversion and radiative decay were recently observed, the electronic bridge decay of $^{229\mathrm{m}}$Th, a higher-order decay process through an electronic transition, has not yet been confirmed. A promising candidate to search for this decay channel is singly charged $^{229\mathrm{m}}$Th$^+$ in the electronic ground state. Here we produce $^{229\mathrm{m}}$Th$^+$ by a charge exchange reaction in an ion trap and detect the isomers through measuring the electrons emitted from internal conversion processes. We determined the half-life of $^{229\mathrm{m}}$Th$^+$ to be 0.46(8) s. Our result differs by several orders of magnitude from the half-lives of internal conversion and radiative decay, indirectly suggesting the existence of the electronic bridge decay of $^{229\mathrm{m}}$Th. This will enable the direct observation and further investigation of the electronic bridge process, which will contribute to understanding nuclear-electron interactions and accelerating nuclear deexcitation in the operation of a thorium-based nuclear clock.

nucl-ex↗
arXiv2026

Experimental determination of the double $K$-shell vacancy creation probability in the electron-capture decay of $^{55}$Fe with a microcalorimeter

The probability of double \(K\)-shell vacancy production following electron-capture decay is determined for $^{55}$Fe using a high-resolution microcalorimeter. The \(K\)-hypersatellite lines arising from double \(K\)-shell-vacancy filling are directly resolved within the measured spectra of X-ray emissions which are dominated by Mn \(K\)-X-ray diagram lines. The energies of the Mn \textit{K}-hypersatellite lines, \(Kα_2^h\), \(Kα_1^h\), and \(Kβ_{1,3}^h\), are measured as $(6143.5\pm0.5)$ eV, $(6162.1\pm1.5)$ eV and $(6811.9\pm2.6)$ eV, respectively. The relative intensities of \textit{K}-hypersatellite to diagram X-rays are measured to be $(1.30 \pm 0.07) \times 10^{-4}$. From the relative intensities together with established fluorescence yield values, the probability of double-vacancy creation per \(K\)-shell capture ($P_{KK}$) is determined as $(1.22 \pm 0.09) \times 10^{-4}$. Comparisons with previous experimental results and theoretical calculations are discussed.

nucl-ex↗