Mon·Mar 25, 2019Monday·March 25, 2019

1. 01*

   Measurement of Moller Scattering at 2.5 MeV

   C. S. Epstein🇺🇸 · R. Johnston🇺🇸 · S. Lee🇺🇸 · J. C. Bernauer🇺🇸 · R. Corliss🇺🇸 · K. Dow🇺🇸 · P. Fisher🇺🇸 · I. Friscic🇺🇸 · D. Hasell🇺🇸 · R. G. Milner🇺🇸 · P. Moran🇺🇸 · S. G. Steadman🇺🇸 and 6 other authors

   Moller scattering is one of the most fundamental processes in QED. Understanding it to high precision is necessary for a variety of modern nuclear and particle physics experiments. In a recent calculation, existing soft-photon radiative corrections were combined with new hard-photon bremsstrahlung calculations to take into account the effect of photon emission at any photon energy, where the electron mass was included at all steps. To test the calculation, an experiment was carried out using the 3 MV Van de Graaff electrostatic accelerator at the MIT High Voltage Research Laboratory. Momentum spectra at three scattering angles at an incident electron energy of 2.5 MeV are reported here, and compared to the simulated radiative Moller spectra, based on our previous calculation. Good agreement between the measurements and our calculation is observed in the momentum spectrum at the three angles.

   nucl-exphysics.ins-detPRD(2020)·6 citations
2. 02*

   New Observables in Inclusive Production of Quarkonia

   Jean-Philippe Lansberg🇫🇷

   After an introduction motivating the study of quarkonium production, we review the recent developments in the phenomenology of quarkonium production in inclusive scatterings of hadrons and leptons. We naturally address data and predictions relevant for the LHC, the Tevatron, RHIC, HERA, LEP, B factories and EIC. An up-to-date discussion of the contributions from feed downs within the charmonium and bottomonium families as well as from b hadrons to charmonia is also provided. This contextualises an exhaustive overview of new observables such as the associated production along with a Standard Model boson (photon, W and Z), with another quarkonium, with another heavy quark as well as with light hadrons or jets. We address the relevance of these reactions in order to improve our understanding of the mechanisms underlying quarkonium production as well as the physics of multi-parton interactions, in particular the double parton scatterings. An outlook towards future studies and facilities concludes this review.

   ↳ hep-phhep-exnucl-exnucl-thPhys.Rept.(2020)·238 citations
3. 03*

   Neutron-induced background in the CONUS experiment

   J. Hakenmüller (1)🇩🇪 · C. Buck (1)🇩🇪 · K. Fülber (2)🇩🇪 · G. Heusser (1)🇩🇪 · T. Klages (3)🇩🇪 · M. Lindner (1)🇩🇪 · A. Lücke (3)🇩🇪 · W. Maneschg (1)🇩🇪 · M. Reginatto (3)🇩🇪 · T. Rink (1)🇩🇪 · T. Schierhuber (1)🇩🇪 · D. Solasse (2)🇩🇪 and 4 other authors

   CONUS is a novel experiment aiming at detecting elastic neutrino nucleus scattering in the fully coherent regime using high-purity Germanium (Ge) detectors and a reactor as antineutrino ($\bar{\nu }$) source. The detector setup is installed at the commercial nuclear power plant in Brokdorf, Germany, at a very small distance to the reactor core in order to guarantee a high flux of more than 10${}^{13}\bar{\nu }$/(s$\cdot$cm${}^2$). For the experiment, a good understanding of neutron-induced background events is required, as the neutron recoil signals can mimic the predicted neutrino interactions. Especially neutron-induced events correlated with the thermal power generation are troublesome for CONUS. On-site measurements revealed the presence of a thermal power correlated, highly thermalized neutron field with a fluence rate of (745$\pm$30)cm${}^{-2}$d${}^{-1}$. These neutrons that are produced by nuclear fission inside the reactor core, are reduced by a factor of $\sim$10${}^{20}$ on their way to the CONUS shield. With a high-purity Ge detector without shield the $\gamma$-ray background was examined including highly thermal power correlated ${}^{16}$N decay products as well as $\gamma$-lines from neutron capture. Using the measured neutron spectrum as input, it was shown, with the help of Monte Carlo simulations, that the thermal power correlated field is successfully mitigated by the installed CONUS shield. The reactor-induced background contribution in the region of interest is exceeded by the expected signal by at least one order of magnitude assuming a realistic ionization quenching factor of 0.2.

   ↳ physics.ins-detnucl-exEPJC(2019)·79 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.