Nuclear Theory·nucl-th

Tuesday·July 28, 2020

11 papers—6 primary·5 cross-listed

07
Hadronic vacuum polarization and vector-meson resonance parameters from $e^{+} e^{-} \to π^{0} γ$
Bai-Long Hoid🇩🇪 · Martin Hoferichter🇨🇭 · Bastian Kubis🇩🇪
We study the reaction $e^{+} e^{-} \to π^{0} γ$ based on a dispersive representation of the underlying $π^{0} \to γ γ^{*}$ transition form factor. As a first application, we evaluate the contribution of the $π^{0} γ$ channel to the hadronic-vacuum-polarization correction to the anomalous magnetic moment of the muon. We find $a_{μ}^{π^{0} γ}_{\leq 1.35 GeV} = 43.8 (6) \times 1 0^{- 11}$ , in line with evaluations from the direct integration of the data. Second, our fit determines the resonance parameters of $ω$ and $ϕ$ . We observe good agreement with the $e^{+} e^{-} \to 3 π$ channel, explaining a previous tension in the $ω$ mass between $π^{0} γ$ and $3 π$ by an unphysical phase in the fit function. Combining both channels we find $M ˉ_{ω} = 782.736 (24) MeV$ and $M ˉ_{ϕ} = 1019.457 (20) MeV$ for the masses including vacuum-polarization corrections. The $ϕ$ mass agrees perfectly with the PDG average, which is dominated by determinations from the $K ˉ K$ channel, demonstrating consistency with $3 π$ and $π^{0} γ$ . For the $ω$ mass, our result is consistent but more precise, exacerbating tensions with the $ω$ mass extracted via isospin-breaking effects from the $2 π$ channel.
↳ hep-phhep-exhep-latnucl-thEPJC(2020)·107 citations
08
Determination of the masses and decay widths of the scalar-isoscalar and vector-isovector mesons below $2$ GeV
Evangelos Matsinos
This study revisits the issue of the extraction of estimates for the masses and for the partial decay widths to two pions of the scalar-isoscalar $I^{G} (J^{P C}) = 0^{+} (0^{++})$ and vector-isovector $I^{G} (J^{P C}) = 1^{+} (1^{--})$ mesons below $2$ GeV, from the data contained in the recent compilation by the Particle Data Group.
↳ hep-phnucl-th4 citations
09
Simulating hadron test beams in liquid argon
Alexander Friedland (SLAC)🇺🇸 · Shirley Weishi Li (SLAC)🇺🇸
Thorough modeling of the physics involved in liquid argon calorimetry is essential for accurately predicting the performance of DUNE and optimizing its design and analysis pipeline. At the fundamental level, it is essential to quantify the detector response to individual hadrons---protons, charged pions, and neutrons---at different injection energies. We report such a simulation, analyzed under different assumptions about event reconstruction, such as particle identification and neutron detection. The role of event containment is also quantified. The results of this simulation can help inform the ProtoDUNE test-beam data analysis, while also providing a framework for assessing the impact of various cross section uncertainties.
↳ hep-phhep-exnucl-exnucl-thPRD(2020)·12 citations
10
Coherent and incoherent $J /Ψ$ photoproduction in $P b P b$ collisions at the LHC, HE -- LHC and FCC
Victor P. Goncalves🇧🇷 · Daniel E. Martins🇧🇷 · Celso R. Sena🇧🇷
The coherent and incoherent $J /Ψ$ photoproduction in $P b P b$ collisions are investigated considering the possible states of nucleon configurations in the nuclear wave function and taking into account of the non - linear corrections to the QCD dynamics. The cross sections and the rapidity and transverse momentum distributions are estimated for the energies of the next run of the LHC, High -- Energy LHC and Future Circular Collider. Our results indicate that a future experimental analysis of these processes will be useful to discriminate between different approaches for the QCD dynamics as well to improve our description of the gluon saturation effects.
↳ hep-phhep-exnucl-thEPJA(2021)·13 citations
11
Turbulence Fingerprint on Collective Oscillations of Supernova Neutrinos
Sajad Abbar🇩🇪
We bring to light a novel mechanism through which turbulent matter density fluctuations can induce collective neutrino flavor conversions in core-collapse supernovae, i.e., the leakage of flavor instabilities between different Fourier modes. The leakage mechanism leaves its notable fingerprint on the flavor stability of a dense neutrino gas by coupling flavor conversion modes on different scales which in turn, makes the flavor instabilities almost ubiquitous in the Fourier space. The most remarkable consequence of this effect is in that it allows for the presence of significant flavor conversions in the deepest supernova regions even in the absence of the so-called fast modes. This is yet another crucial impact of turbulence on the physics of core-collapse supernovae which can profoundly change our understanding of neutrino flavor conversions in the supernova environment.
↳ astro-ph.HEnucl-thPRD(2021)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE

Hadronic vacuum polarization and vector-meson resonance parameters from e+e−→π0γ

Determination of the masses and decay widths of the scalar-isoscalar and vector-isovector mesons below 2 GeV

Simulating hadron test beams in liquid argon

Coherent and incoherent J/Ψ photoproduction in PbPb collisions at the LHC, HE -- LHC and FCC

Turbulence Fingerprint on Collective Oscillations of Supernova Neutrinos

Affiliations

Hadronic vacuum polarization and vector-meson resonance parameters from $e^{+} e^{-} \to π^{0} γ$

Determination of the masses and decay widths of the scalar-isoscalar and vector-isovector mesons below $2$ GeV

Coherent and incoherent $J /Ψ$ photoproduction in $P b P b$ collisions at the LHC, HE -- LHC and FCC