Tue·May 12, 2015Tuesday·May 12, 2015

1. 01*

   Studying re-scattering effect in heavy-ion collision through $K^{\ast }$ Production

   Subhash Singha🇺🇸 · Bedangadas Mohanty🇮🇳 · Zi-Wei Lin🇺🇸

   We have studied the $K^{\ast }$ production within A Multi-Phase Transport model (AMPT) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV to understand the hadronic re-scattering effect on the measured yields of the resonance. The hadronic re-scattering of the $K^{\ast }$ decay daughter particles ($\pi$ and K) will alter their momentum distribution thereby making it difficult to reconstruct the $K^{\ast }$ signal through the invariant mass method. An increased hadronic re-scattering effect thus leads to a decrease in the reconstructed yield of $K^{\ast }$ in heavy-ion collisions. Through this simulation study we argue that a decrease in $K^{\ast }$/K ratio with increase in collision centrality necessarily reflects the hadronic re-scattering effect. Since the re-scattering occurs in the hadronic phase and $K^{\ast }$ has a lifetime of 4 fm/c, we present a toy model based discussion on using measured $K^{\ast }$/K to put a lower limit on the hadronic phase lifetime in high energy nuclear collisions.

   nucl-exhep-phnucl-thIJMPE(2015)·23 citations
2. 02*

   Evaluation of the proton charge radius from e-p scattering

   John Arrington🇺🇸 · Ingo Sick🇨🇭

   In light of the proton radius puzzle, the discrepancy between measurements of the proton charge radius from muonic hydrogen and those from electronic hydrogen and electron-proton scattering measurements, we reexamine the charge radius extractions from electron scattering measurements. We provide a recommended value for the proton RMS charge radius, $r_E=0.879\pm 0.011$ fm, based on a global examination of elastic e-p scattering data. The uncertainties include contributions to account for tension between different data sets and inconsistencies between radii using different extraction procedures.

   nucl-exhep-phnucl-thphysics.atom-phJ.Phys.Chem.Ref.Data(2015)·67 citations
3. 03*

   Few-body calculations of $\eta$-nuclear quasibound states

   N. Barnea🇮🇱 · E. Friedman🇮🇱 · A. Gal🇮🇱

   We report on precise hyperspherical-basis calculations of $\eta NN$ and $\eta NNN$ quasibound states, using energy dependent $\eta N$ interaction potentials derived from coupled-channel models of the $S_{11}$ $N^{\ast }(1535)$ nucleon resonance. The $\eta N$ attraction generated in these models is too weak to generate a two-body bound state. No $\eta NN$ bound-state solution was found in our calculations in models where Re $a_{\eta N}\lesssim 1$ fm, with $a_{\eta N}$ the $\eta N$ scattering length, covering thereby the majority of $N^{\ast }(1535)$ resonance models. A near-threshold $\eta NNN$ bound-state solution, with $\eta$ separation energy of less than 1 MeV and width of about 15 MeV, was obtained in the 2005 Green-Wycech model where Re $a_{\eta N}\approx 1$ fm. The role of handling self consistently the subthreshold $\eta N$ interaction is carefully studied.

   ↳ nucl-thhep-phnucl-exPLB(2015)·33 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.