Nuclear Theory·nucl-th

Friday·February 14, 2020

8 papers—5 primary·3 cross-listed

06
Precise determination of proton magnetic radius from electron scattering data
J. M. Alarcón🇪🇸 · D. W. Higinbotham🇺🇸 · C. Weiss🇺🇸
We extract the proton magnetic radius from the high-precision electron-proton elastic scattering cross section data. Our theoretical framework combines dispersion analysis and chiral effective field theory and implements the dynamics governing the shape of the low- $Q^{2}$ form factors. It allows us to use data up to $Q^{2} \sim$ 0.5 GeV $^{2}$ for constraining the radii and overcomes the difficulties of empirical fits and $Q^{2} \to 0$ extrapolation. We obtain a magnetic radius $r_{M}^{p}$ = 0.850 $\pm$ 0.001 (fit 68%) $\pm$ 0.010 (theory full range) fm, significantly different from earlier results obtained from the same data, and close to the extracted electric radius $r_{E}^{p}$ = 0.842 $\pm$ 0.002 (fit) $\pm$ 0.010 (theory) fm.
↳ hep-phhep-latnucl-exnucl-th+1PRC(2020)·42 citations
07
Probing Early-Time Dynamics and Quark-Gluon Plasma Transport Properties with Photons and Hadrons
Charles Gale🇨🇦 · Jean-François Paquet🇺🇸 · Björn Schenke🇺🇸 · Chun Shen🇺🇸
We use a hybrid model which relies on QCD effective kinetic theory -- K\oMP\oST -- to dynamically bridge the gap between IP-Glasma initial states and viscous hydrodynamics, for the theoretical interpretation of heavy-ion collision results. The hydrodynamic phase is then followed by dynamical freeze-out handled by UrQMD. It is observed that the new pre-equilibrium/pre-hydro phase does influence the extraction of transport coefficients. We also show how the early dynamics is reflected in photon observables.
↳ hep-phnucl-exnucl-thNPA(2021)·32 citations
08
A possible shortcut for neutron-antineutron oscillation through mirror world
Zurab Berezhiani🇮🇹
Existing bounds on the neutron-antineutron mass mixing, $ϵ_{n n ˉ} < few \times 1 0^{- 24}$ eV, impose a severe upper limit on $n - n ˉ$ transition probability, $P_{n n ˉ} (t) < (t /0.1 s)^{2} \times 1 0^{- 18}$ or so, where $t$ is the neutron flight time. Here we propose a new mechanism of $n - n ˉ$ transition which is not induced by direct mass mixing $ϵ_{n n ˉ}$ but is mediated instead by the neutron mixings with the hypothetical states of mirror neutron $n^{'}$ and mirror antineutron $n ˉ^{'}$ . The latter can be as large as $ϵ_{n n^{'}}, ϵ_{n n ˉ^{'}} \sim 1 0^{- 15}$ eV or so, without contradicting present experimental limits and nuclear stability bounds. The probabilities of $n - n^{'}$ and $n - n ˉ^{'}$ transitions, $P_{n n^{'}}$ and $P_{n n ˉ^{'}}$ , depend on environmental conditions in mirror sector, and they can be resonantly amplified by applying the magnetic field of the proper value. This opens up a possibility of $n - n ˉ$ transition with the probability $P_{n n ˉ} ≃ P_{n n^{'}} P_{n n ˉ^{'}}$ which can reach the values $\sim 1 0^{- 8}$ or even larger. For finding this effect in real experiments, the magnetic field should not be suppressed but properly varied. These mixings can be induced by new physics at the scale of few TeV which may also originate a new low scale co-baryogenesis mechanism between ordinary and mirror sectors.
↳ hep-phnucl-thEPJC(2021)·37 citations

Affiliations

first authorsco-authorsvia INSPIRE

Precise determination of proton magnetic radius from electron scattering data

Probing Early-Time Dynamics and Quark-Gluon Plasma Transport Properties with Photons and Hadrons

A possible shortcut for neutron-antineutron oscillation through mirror world

Affiliations