Mon·Feb 11, 2019Monday·February 11, 2019

1. 01*

   Impact of restricted spin-ranges in the Oslo Method: The example of (d,p)${}^{240}\mathrm{Pu}$

   F. Zeiser🇳🇴 · G. Potel🇺🇸 · G.M. Tveten🇳🇴 · A.C. Larsen🇳🇴 · M. Guttormsen🇳🇴 · T.A. Laplace🇺🇸 · S. Siem🇳🇴 · D.L. Bleuel🇺🇸 · B.L. Goldblum🇺🇸 · L.A. Bernstein🇺🇸 · F.L. Bello Garrote🇳🇴 · L. Crespo Campo🇳🇴 and 9 other authors

   In this paper we present the first systematic analysis of the impact of the populated vs. intrinsic spin distribution on the nuclear level density and $\gamma$-ray strength function retrieved through the Oslo Method. We illustrate the effect of the spin distribution on the recently performed ${}^{239}\mathrm{Pu}$(d,p$\gamma$)${}^{240}\mathrm{Pu}$ experiment using a 12 MeV deuteron beam performed at the Oslo Cyclotron Lab. In the analysis we couple state-of-the-art calculations for the populated spin-distributions with the Monte-Carlo nuclear decay code RAINIER to compare Oslo Method results to the known input. We find that good knowledge of the populated spin distribution is crucial and show that the populated distribution has a significant impact on the extracted nuclear level density and $\gamma$-ray strength function for the ${}^{239}\mathrm{Pu}$(d,p$\gamma$)${}^{240}\mathrm{Pu}$ case.

   nucl-exSpringer Proc.Phys.(2020)·4 citations
2. 02*

   Decay pion spectroscopy: a new approach

   A. Margaryan🇦🇲 · R. Ajvazyan🇦🇲 · N. Grigoryan🇦🇲 · V. Kakoyan🇦🇲 · V. Khacatryan · H. Vardanyan🇦🇲 · S. Zhamkochyan🇦🇲 · P. Achenbach🇩🇪 · J. Pochodzalla🇩🇪 · S.N.Nakamura · S.Nagao · Y.Toyama and 3 other authors

   We propose a new experiment for decay pion spectroscopy of light hypernuclei at electron- and proton-beam facilities, using the recoil distance technique for separation of produced hypernuclei and a magnetic spectrometer for precise measurement of the decay pion momentum. Low-pressure MWPCs are advocated for low-energy recoil detection as they provide position and time information and are highly insensitive to gamma-ray and electron background. The position and timing characteristics of such a recoil detector were studied using ~5 MeV {\alpha}-particles. By using the present proposed approach the rate of the detected hypernuclei can be increased by one-to-two orders of magnitude compared to a recent experiment carried out at the MAMI electron accelerator in Mainz. The possibility of realizing a high luminosity decay pion spectroscopy experiment with proton beams is also discussed.

   nucl-exNucl.Instrum.Meth.A(2019)·1 citation
3. 03*

   Evaluation of the inclusive electron scattering observables in the resonance region from the experimental data

   A. A. Golubenko🇷🇺 · V. V. Chesnokov🇷🇺 · B. S. Ishkhanov🇷🇺 · V. I. Mokeev🇺🇸

   The method for evaluation of inclusive electron scattering observables in the resonance region from the experimental data is presented. The computer codes in the web page allow user to evaluate inclusive electron scattering, virtual photon-proton cross sections and the $F_1$ and $F_2$ structure functions at the invariant masses of the final hadrons 1.0 GeV $<$ W $<$ 4.0 GeV and at photon virtualities 0.5 GeV${}^2$ $<$ Q${}^2$ $<$ 7.0 GeV${}^2$. The developed approach is of interest for analyses of the experimental data on exploration of the hadron structure in the experiments with electromagnetic probes.

   ↳ hep-exnucl-exPhys.Part.Nucl.(2019)·6 citations
4. 04*

   Jet quenching as a probe of the initial stages in heavy-ion collisions

   Carlota Andres🇺🇸 · Néstor Armesto🇪🇸 · Harri Niemi🇫🇮 · Risto Paatelainen🇨🇭 · Carlos A. Salgado🇪🇸

   Jet quenching provides a very flexible variety of observables which are sensitive to different energy- and time-scales of the strongly interacting matter created in heavy-ion collisions. Exploiting this versatility would make jet quenching an excellent chronometer of the yoctosecond structure of the evolution process. Here we show, for the first time, that a combination of jet quenching observables is sensitive to the initial stages of heavy-ion collisions, when the approach to local thermal equilibrium is expected to happen. Specifically, we find that in order to reproduce at the same time the inclusive particle production suppression, $R_{AA}$, and the high-$p_T$ azimuthal asymmetries, $v_2$, energy loss must be strongly suppressed for the first $\sim 0.6$ fm. This exploratory analysis shows the potential of jet observables, possibly more sophisticated than the ones studied here, to constrain the dynamics of the initial stages of the evolution.

   ↳ hep-phnucl-exnucl-thPLB(2020)·94 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.