Nuclear Theory·nucl-th

Tuesday·December 22, 2020

10 papers—5 primary·5 cross-listed

06
International Workshop on Next Generation Gamma-Ray Source
C. R. Howell🇺🇸 · M. W. Ahmed🇺🇸 · A. Afanasev🇺🇸 · D. Alesini🇮🇹 · J. R. M. Annand🇬🇧 · A. Aprahamian🇺🇸 · D. L. Balabanski🇷🇴 · S. V. Benson🇺🇸 · A. Bernstein🇺🇸 · C. R. Brune🇺🇸 · J. Byrd🇺🇸 · B. E. Carlsten🇺🇸 and 41 other authors
A workshop on The Next Generation Gamma-Ray Sources sponsored by the Office of Nuclear Physics at the Department of Energy, was held November 17--19, 2016 in Bethesda, Maryland. The goals of the workshop were to identify basic and applied research opportunities at the frontiers of nuclear physics that would be made possible by the beam capabilities of an advanced laser Compton beam facility. To anchor the scientific vision to realistically achievable beam specifications using proven technologies, the workshop brought together experts in the fields of electron accelerators, lasers, and optics to examine the technical options for achieving the beam specifications required by the most compelling parts of the proposed research programs. An international assembly of participants included current and prospective $γ$ -ray beam users, accelerator and light-source physicists, and federal agency program managers. Sessions were organized to foster interactions between the beam users and facility developers, allowing for information sharing and mutual feedback between the two groups. The workshop findings and recommendations are summarized in this whitepaper.
↳ nucl-exnucl-thphysics.acc-phJ.Phys.G(2022)·35 citations
07
\boldmath{ $Υ$ } and \boldmath{ $η_{b}$ } mass shifts in nuclear matter
G. N. Zeminiani🇧🇷 · J. J. Cobos-Martinez🇲🇽 · K. Tsushima🇧🇷
We estimate the $Υ$ , $η_{b}$ and $B^{*}$ meson mass shifts in symmetric nuclear matter. The interest is, whether the strengths of the bottomonium-(nuclear matter) and charmonium-(nuclear matter) interactions are similar or different. This is because, each ( $J /Ψ, Υ$ ) and ( $η_{c}, η_{b}$ ) meson group is usually assumed to have very similar properties based on the heavy charm and bottom quark masses. The estimate for the $Υ$ is made using an SU(5) effective Lagrangian and the anomalous coupling one, by studying the $B B$ , $B B^{*}$ , and $B^{*} B^{*}$ meson loop contributions for the self-energy. As for the $η_{b}$ , we include the $B B^{*}$ and $B^{*} B^{*}$ meson loop contributions in the self-energy. The in-medium masses of the $B$ and $B^{*}$ mesons appearing in the self-energy are calculated by the quark-meson coupling model. An analysis on the $B B$ , $B B^{*}$ , and $B^{*} B^{*}$ meson loops in the $Υ$ mass shift is made by comparing with the corresponding $D D, D D^{*}$ , and $D^{*} D^{*}$ meson loops for the $J /Ψ$ mass shift. Our prediction for the $η_{b}$ mass shift is made including only the lowest order $B B^{*}$ meson loop. The $Υ$ mass shift, with including only the $B B$ loop, is predicted to be -16 to -22 MeV at the nuclear matter saturation density using the $Υ B B$ coupling constant determined by the vector meson dominance model with the experimental data, while the $η_{b}$ mass shift is predicted to be -75 to -82 MeV with the SU(5) universal coupling constant determined by the $Υ B B$ coupling constant. Our results show an appreciable difference between the bottomonium-(nuclear matter) and charmonium-(nuclear matter) interaction strengths. We also study the $Υ$ and $η_{b}$ mass shifts in a heavy quark (heavy meson) symmetry limit.
↳ hep-phhep-exhep-latnucl-ex+1EPJA(2021)·24 citations
08
Reweighted nuclear PDFs using Heavy-Flavor Production Data at the LHC: nCTEQ15_rwHF & EPPS16_rwHF
Aleksander Kusina🇵🇱 · Jean-Philippe Lansberg🇫🇷 · Ingo Schienbein🇫🇷 · Hua-Sheng Shao🇫🇷
We present the reweighting of two sets of nuclear PDFs, nCTEQ15 and EPPS16, using a selection of experimental data on heavy-flavor meson [D0, J/psi, J/psi from B and Upsilon(1S)] production in proton-lead collisions at the LHC which were not used in the original determination of these nuclear PDFs. The reweighted PDFs exhibit significantly smaller uncertainties thanks to these new heavy-flavor constraints. We present a comparison with another selection of data from the LHC and RHIC which were not included in our reweighting procedure. The comparison is overall very good and serves as a validation of these reweighted nuclear PDF sets, which we dub nCTEQ15_rwHF & EPPS16_rwHF. This indicates that the LHC and forward RHIC heavy-flavor data can be described within the standard collinear factorization framework with the same (universal) small-x gluon distribution. We discuss how we believe such reweighted PDFs should be used as well as the limitations of our procedure.
↳ hep-phhep-exnucl-exnucl-thPRD(2021)·38 citations
09
Measurement of the Ar(e,e $^{'}$ p) and Ti(e,e $^{'}$ p) cross sections in Jefferson Lab Hall A
L. Gu🇺🇸 · D. Abrams🇺🇸 · A. M. Ankowski🇺🇸 · L. Jiang🇺🇸 · B. Aljawrneh🇺🇸 · S. Alsalmi🇸🇦 · J. Bane🇺🇸 · A. Batz🇺🇸 · S. Barcus🇺🇸 · M. Barroso🇺🇸 · O. Benhar🇮🇹 · V. Bellini🇮🇹 and 49 other authors
The E12-14-012 experiment, performed in Jefferson Lab Hall A, has collected exclusive electron-scattering data (e,e $^{'}$ p) in parallel kinematics using natural argon and natural titanium targets. Here, we report the first results of the analysis of the data set corresponding to beam energy of 2,222 MeV, electron scattering angle 21.5 deg, and proton emission angle -50 deg. The differential cross sections, measured with $\sim$ 4% uncertainty, have been studied as a function of missing energy and missing momentum, and compared to the results of Monte Carlo simulations, obtained from a model based on the Distorted Wave Impulse Approximation.
↳ nucl-exnucl-thPRC(2021)·22 citations
10
nCTEQ15HIX -- Extending nPDF Analyses into the High- $x$ , Low $Q^{2}$ Region
E.P. Segarra🇺🇸 · T. Ježo🇩🇪 · A. Accardi🇺🇸 · P. Duwentäster🇩🇪 · O. Hen🇺🇸 · T.J. Hobbs🇺🇸 · C. Keppel🇺🇸 · M. Klasen🇩🇪 · K. Kovařík🇩🇪 · A. Kusina🇵🇱 · J.G. Morfín🇺🇸 · K.F. Muzakka🇩🇪 and 3 other authors
We use the nCTEQ analysis framework to investigate nuclear Parton Distribution Functions (nPDFs) in the region of large x and intermediate-to-low $Q$ , with special attention to recent JLab Deep Inelastic Scattering data on nuclear targets. This data lies in a region which is often excluded by $W$ and $Q$ cuts in global nPDF analyses. As we relax these cuts, we enter a new kinematic region, which requires new phenomenology. In particular, we study the impact of i) target mass corrections, ii) higher twist corrections, iii) deuteron corrections, and iv) the shape of the nuclear PDF parametrization at large- $x$ close to one. Using the above tools, we produce a new nPDF set (named nCTEQ15HIX) which yields a good description of the new JLab data in this challenging kinematic region, and displays reduced uncertainties at large $x$ , in particular for up and down quark flavors.
↳ hep-phnucl-thPRD(2021)·49 citations

Affiliations

first authorsco-authorsvia INSPIRE

International Workshop on Next Generation Gamma-Ray Source

\boldmath{Υ} and \boldmath{ηb​} mass shifts in nuclear matter

Reweighted nuclear PDFs using Heavy-Flavor Production Data at the LHC: nCTEQ15_rwHF & EPPS16_rwHF

Measurement of the Ar(e,e′ p) and Ti(e,e′ p) cross sections in Jefferson Lab Hall A

nCTEQ15HIX -- Extending nPDF Analyses into the High-x, Low Q2 Region

Affiliations

\boldmath{ $Υ$ } and \boldmath{ $η_{b}$ } mass shifts in nuclear matter

Measurement of the Ar(e,e $^{'}$ p) and Ti(e,e $^{'}$ p) cross sections in Jefferson Lab Hall A

nCTEQ15HIX -- Extending nPDF Analyses into the High- $x$ , Low $Q^{2}$ Region