Wed·May 4, 2022Wednesday·May 4, 2022

1. 01*

   Detailed Study of Quark-Hadron Duality in Spin Structure Functions of the Proton and Neutron

   Victoria Lagerquist🇺🇸 · Sebastian E. Kuhn🇺🇸 · Nobuo Sato🇺🇸

   In this paper, we present for the first time comprehensive and detailed results on the correspondence between the extrapolated deep inelastic structure function $g_1$ of both the proton and the neutron with the same quantity measured in the nucleon resonance region. We use a QCD parameterization of the world data on DIS spin structure functions, extrapolated into the nucleon resonance region and averaged over various intervals in the scaling variable $x$. We compare the results with the large data set collected in the quark-hadron transition region by the CLAS collaboration, averaged over the same intervals. We present this comparison as a function of the momentum transfer $Q^2$. We find that, depending on the averaging interval and the minimum momentum transfer chosen, a clear transition to quark-hadron duality can be observed in both nucleon species. Furthermore, we show, for the first time, the scaling behavior of $g_1$ measured in the resonance region at sufficiently high momentum transfer. Our results can be used to quantify the deviations from the applicability of pQCD for data taken at moderate energies, and help with extraction of quark distribution functions from such data.

   nucl-exhep-phnucl-thPRC(2023)·4 citations
2. 02*

   The Transverse Structure of the Deuteron with Drell-Yan

   D. Keller (for the SpinQuest Collaboration)🇺🇸

   We propose to measure neutron and deuteron transversity TMDs. The quark transversity distributions of the nucleon are decoupled from the deuteron gluon transversity in the $Q^2$ evolution due to the chiral-odd property in the transversely-polarized target. The gluon transversity TMD only exists for targets of spin greater or equal to 1 and does not mix with quark distributions at leading twist, thereby providing a particularly clean probe of gluonic degrees of freedom. This experiment would be the first of its kind and would probe the gluonic structure of the deuteron, investigating exotic glue contributions in the nucleus not associated with individual nucleons. This experiment can be performed with the SpinQuest polarized target recently assembled for experiment E1039 and the spectrometer already in place in NM4. This new experimental setup would require very minimal modification to the target system and no modification to the detector package. An additional RF-circuit and target coil are necessary to RF-modulate across the domain of the Larmor frequency to manipulate the solid-state target spin population densities. Dedicated beam-time with this novel target system is required to achieve our physics goals.

   nucl-ex18 citations
3. 03*

   Experimental determination of the QCD effective charge ${\alpha }_{g_1}(Q)$

   A. Deur🇺🇸 · V. Burkert🇺🇸 · J.P. Chen🇺🇸 · W. Korsch🇺🇸

   The QCD effective charge ${\alpha }_{g_1}(Q)$ is an observable that characterizes the magnitude of the strong interaction. At high momentum $Q$, it coincides with the QCD running coupling ${\alpha }_{\mathrm{s}}(Q)$. At low $Q$, it offers a nonperturbative definition of the running coupling. We have extracted ${\alpha }_{g_1}(Q)$ from measurements carried out at Jefferson Lab that span the very low to moderately high $Q$ domain, $0.14\le Q\le 2.18$ GeV. The precision of the new results is much improved over the previous extractions and the reach in $Q$ at the lower end is significantly expanded. The data show that ${\alpha }_{g_1}(Q)$ becomes $Q$-independent at very low $Q$. They compare well with two recent predictions of the QCD effective charge based on Dyson-Schwinger equations and on the AdS/CFT duality.

   ↳ hep-phhep-exnucl-exParticles(2022)·45 citations
4. 04*

   A method for determining the transition energies of ${}^{83m}$Kr at the KATRIN experiment

   C. Rodenbeck🇩🇪

   The neutrino mass experiment KATRIN uses conversion electrons from the 32.2 keV transition of the nuclear isomer ${}^{83m}$Kr for calibration. Comparing the measured energies to the appropriate literature values allows for an independent evaluation of the energy scale, but the uncertainties in some of the literature values obtained by gamma spectroscopy are a limiting factor. Building upon the already excellent linearity of KATRIN's energy scale, this paper proposes a novel method for determining the ${}^{83m}$Kr transition energies via high-precision electron spectroscopy. Notably, the method makes use of conversion electrons from the 41.6-keV direct transition of ${}^{83m}$Kr to its ground state in addition to conversion electrons from the much more frequent cascade of a 32.2-keV and a 9.4-keV transition. By implementing this method, KATRIN may be able to deliver order-of-magnitude improvements in precision over current ${}^{83m}$Kr transition energy literature values.

   ↳ physics.ins-detnucl-exEPJC(2022)·6 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.