Thu·Sep 5, 2019Thursday·September 5, 2019

1. 01*

   High-resolution conversion electron spectroscopy of the 125I electron-capture decay

   B.P.E. Tee🇦🇺 · A.E. Stuchbery🇦🇺 · M. Vos · J.T.H. Dowie🇦🇺 · B.Q. Lee · M. Alotiby · I. Greguric · T. Kibedi🇦🇺

   The conversion electrons from the decay of the 35.5-keV excited state of 125Te following the electron capture decay of 125I have been investigated at high resolution using an electrostatic spectrometer. The penetration parameter lambda = -1.2(6) and mixing ratio |delta| = 0.015(2) were deduced by fitting to literature values and present data. The shake probability of the conversion electrons is estimated to be 0.5, more than two times larger than the predicted value of 0.2.

   nucl-exphysics.atom-phPRC(2019)·6 citations
2. 02*

   Machine Learning based jet momentum reconstruction in Pb-Pb collisions measured with the ALICE detector

   Rüdiger Haake (for the ALICE Collaboration)🇺🇸

   The precise reconstruction of jet transverse momenta in heavy-ion collisions is a challenging task. A major obstacle is the large number of uncorrelated (mainly) low-$p_{\mathrm{T}}$ particles overlaying the jets. Strong region-to-region fluctuations of this background complicate the jet measurement and lead to significant uncertainties. We developed a novel approach to correct jet momenta (or energies) for the underlying background in heavy-ion collisions. The approach allows the measurement of jets down to extremely low transverse momenta and for large resolution $R$ by making use of common Machine Learning techniques to estimate the jet transverse momentum based on several parameters. In this conference proceeding, we will present transverse momentum spectra and nuclear modification factors of track-based jets that have been corrected by this Machine Learning approach and comparisons to published results where possible. The analysis was performed on Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV recorded with the ALICE detector and measures jets with large resolution parameters for low momenta, unprecedented thus far in data on heavy-ion collisions.

   nucl-exhep-exPoS(2020)·19 citations
3. 03*

   Measurement of azimuthal anisotropy of muons from charm and bottom hadrons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

   ATLAS Collaboration

   The elliptic flow of muons from the decay of charm and bottom hadrons is measured in $pp$ collisions at $\sqrt{s}=13$ TeV using a data sample with an integrated luminosity of 150 pb${}^{-1}$ recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range $|\eta |<2.4$. A significant non-zero elliptic anisotropy coefficient $v_2$ is observed for muons from charm decays, while the $v_2$ value for muons from bottom decays is consistent with zero within uncertainties.

   nucl-exhep-exPRL(2020)·62 citations
4. 04*

   Weak interaction studies at SARAF

   Ben Ohayon🇮🇱 · Joel Chocron · Tsviki Hirsh🇮🇱 · Ayala Glick-Magid🇮🇱 · Yonatan Mishnayot🇮🇱 · Ish Mukul🇨🇦 · Hitesh Rahangdale🇮🇱 · Sergei Vaintraub🇮🇱 · Oded Heber · Doron Gazit🇮🇱 · Guy Ron🇮🇱

   We review the current status of the radioisotopes program at the Soreq Applied Research Accelerator Facility (SARAF), where we utilize an electrostatic-ion-beam trap and a magneto-optical trap for studying the nuclear $\beta$-decay from trapped radioactive atoms and ions. The differential energy spectra of $\beta$'s and recoil ions emerging from the decay is sensitive to beyond standard model interactions and is complementary to high energy searches. The completed facility SARAF-II will be one of the world's most powerful deuteron, proton and fast neutron sources, producing light radioactive isotopes in unprecedented amounts, needed for obtaining enough statistics for a high precision measurement.

   nucl-exHyperfine Interact.(2018)·10 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.