Nuclear Theory·nucl-th

Monday·August 2, 2021

11 papers—6 primary·5 cross-listed

07
[Submitted on 29 Jul 2021] (cross-list from nucl-ex)
Constraining new physics with a novel measurement of the $^{23}$ Ne $β$ -decay branching ratio
Yonatan Mishnayot · Ayala Glick-Magid · Hitesh Rahangdale · Guy Ron · Doron Gazit · Jason T. Harke · Micha Hass · Ben Ohayon · Aaron Gallant · Nicholas D. Scielzo · Sergey Vaintruab · Richard O. Hughes and 11 other authors
Measurements of the beta-neutrino correlation coefficient (a $_{β ν}$ ) in nuclear beta decay, together with the Fierz interference term (b $_{F}$ ), provide a robust test for the existence of exotic interactions beyond the Standard Model of Particle Physics. The extraction of these quantities from the recoil ion spectra in $β$ -decay requires accurate knowledge, decay branching ratios, and high-precision calculations of higher order nuclear effects. Here, we report on a new measurement of the $^{23}$ Ne $β$ -decay branching ratio, which allows a reanalysis of existing high-precision measurements. Together with new theoretical calculations of nuclear structure effects, augmented with robust theoretical uncertainty, this measurement improves on the current knowledge of a $_{β ν}$ in $^{23}$ Ne by an order of magnitude, and strongly constrains the Fierz term in beta decays, making this one of the first extractions to constrain both terms simultaneously. Together, these results place bounds on the existence of exotic tensor interactions and pave the way for new, even higher precision, experiments.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.14355 [pdf]
5 citations
08
[Submitted on 30 Jul 2021] (cross-list from hep-ph)
Constraining the nuclear gluon PDF with inclusive hadron production data
P. Duwentäster🇩🇪 · L. A. Husová🇩🇪 · T. Ježo🇩🇪 · M. Klasen🇩🇪 · K. Kovařík🇩🇪 · A. Kusina🇵🇱 · K. F. Muzakka🇩🇪 · F. I. Olness🇺🇸 · I. Schienbein🇫🇷 · J.Y. Yu🇺🇸
The nuclear parton distribution functions (nPDFs) of gluons are known to be difficult to determine with fits of deep inelastic scattering (DIS) and Drell-Yan (DY) data alone. Therefore, the nCTEQ15 analysis of nuclear PDFs added inclusive neutral pion production data from RHIC to help in constraining the gluon. In this analysis, we present a new global analysis of nuclear PDFs based on a much larger set of single inclusive light hadron data from RHIC and the LHC. Using our new nCTEQ code (nCTEQ++) with an optimized version of INCNLO we study systematically the limitations of the theory and the impact of the fragmentation function uncertainty.
Comments:
6 pages, 2 figures, Submission to SciPost Physics Proceedings
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.14514 [pdf]
SciPost Phys.Proc.(2022)·1 citation
09
[Submitted on 30 Jul 2021] (cross-list from nucl-ex)
DIS2021 Workshop Proceedings: Backward-Angle (u-Channel) Meson Production from JLab 12 GeV Hall C to EIC
W. B. Li🇺🇸
The recent exclusive backward-angle electroproduction of omega from Jefferson Lab Hall C electron-proton fixed-target scattering experiments above the resonance region hints at a new domain of applicability of QCD factorization in a unique u-channel kinematics regime. Thanks to this effort, the interest in studying nucleon structure through u-channel meson production observables has grown significantly. In the fixed target configuration, the u-channel meson electroproduction observables feature a unique interaction picture: the target proton absorbs nearly all momentum induced by virtual photons and recoils forward, while the produced mesons (such as omega or pions) are left behind almost at rest near the target station. In this presentation, We provide a summary of the key observations of the existing u-channel meson production results, update-to-date theory insights, and a path to further exploration from JLab 12 GeV Hall C program to the future Electron-Ion Colliders.
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.14657 [pdf]
SciPost Phys.Proc.(2022)·1 citation
10
[Submitted on 30 Jul 2021] (cross-list from hep-ph)
Update on $∣ V_{u s} ∣$ and $∣ V_{u s} / V_{u d} ∣$ from semileptonic kaon and pion decays
Chien-Yeah Seng🇩🇪 · Daniel Galviz🇩🇪 · William J. Marciano🇺🇸 · Ulf-G. Meißner🇩🇪
We discuss the recent progress in the study of semileptonic kaon and pion decays, including new experimental results, improved electroweak radiative corrections, form factor calculations and isospin-breaking effects. As a result, we obtain $∣ V_{u s} ∣ = 0.22309 (40) (39) (3)$ from kaon semileptonic decays and $∣ V_{u s} / V_{u d} ∣ = 0.22908 (66) (41) (40) (2) (1)$ from the ratio between the kaon and pion semileptonic decay rates. We report an apparent violation of the top-row Cabibbo-Kobayashi-Maskawa matrix unitarity at a $3.2 \sim 5.6 σ$ level, and a discrepancy at a $2.2 σ$ level between the value of $∣ V_{u s} / V_{u d} ∣$ determined from the vector and axial charged weak interactions. Prospects for future improvements in those comparative precision tests involving $∣ V_{u d} ∣$ , $∣ V_{u s} ∣$ and their implications for physics beyond the Standard Model are described.
Comments:
Version accepted by PRD. A figure is added, and a previous mistake in the discussion of the PIONEER precision goal is corrected
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.14708 [pdf]
PRD(2022)·67 citations
11
[Submitted on 30 Jul 2021] (cross-list from hep-ph)
$η / s - q^/ T^{3}$ Relation at Next-to-Leading Order in QCD
Berndt Müller🇺🇸
The relation between the specific shear viscosity $η / s$ and the dimensionless jet quenching parameter $q^/ T^{3}$ in perturbative QCD is explored at next-to-leading order in the coupling constant. It is shown that the relation changes little, although both transport coefficients independently are subject to large modifications at the NLO level. This finding confirms that the relationship is robust.
Comments:
Slightly amended version submitted for journal publication
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.14775 [pdf]
PRD(2021)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

Constraining new physics with a novel measurement of the 23Ne β-decay branching ratio

Constraining the nuclear gluon PDF with inclusive hadron production data

DIS2021 Workshop Proceedings: Backward-Angle (u-Channel) Meson Production from JLab 12 GeV Hall C to EIC

Update on ∣Vus​∣ and ∣Vus​/Vud​∣ from semileptonic kaon and pion decays

η/s−q^​/T3 Relation at Next-to-Leading Order in QCD

Affiliations

Constraining new physics with a novel measurement of the $^{23}$ Ne $β$ -decay branching ratio

Update on $∣ V_{u s} ∣$ and $∣ V_{u s} / V_{u d} ∣$ from semileptonic kaon and pion decays

$η / s - q^/ T^{3}$ Relation at Next-to-Leading Order in QCD