nucl-ex digest · Dec 31, 2021

New Baryon States in Exclusive Meson Photo-/Electroproduction with CLAS

Impressive progress achieved in the past decade in experimental studies of exclusive meson photoproduction off protons and global multi-channel amplitude analyses has resulted in the discovery of several long-awaited new nucleon resonances, with a decisive impact from the results of

K Λ

and

K Σ

photoproduction measured with the CLAS detector at Jefferson Lab. Further extension of these efforts towards combined studies of exclusive meson photo- and electroproduction data off protons will be presented. A new excited state of the nucleon, the

N^{'} (1720) 3/ 2^{+}

, discovered from combined analyses of

π^{+} π^{-} p

photo- and electroproduction data, in addition to new resonances discovered in photo- and hadroproduction data, demonstrate the promising prospects of this new research avenue for discovery of additional new resonances.

nucl-exRev.Mex.Fis.Suppl.(2022)·4 citations

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Perturbative and non-perturbative interactions between heavy quarks and quark-gluon plasma within a unified approach

Wen-Jing Xing🇨🇳 · Guang-You Qin🇨🇳 · Shanshan Cao🇨🇳

While perturbative QCD is sufficient for understanding the color, mass and energy dependences of parton energy loss and jet quenching at large transverse momentum in heavy-ion collisions, a simultaneous description of heavy flavor nuclear modification factor $R_{AA}$ and elliptic flow coefficient $v_{2}$ at low and intermediate $p_{T}$ still remains a challenge due to the effects from non-perturbative interactions. In this work, we extend the linear Boltzmann transport model by implementing a generalized Cornell-type potential that incorporates both short-range Yukawa interaction and long-range color confining interaction between heavy quarks and the QGP medium. Combining our new approach for heavy-quark-QGP interaction with a (3+1)-dimensional hydrodynamic model CLVisc for the QGP evolution and a hybrid fragmentation-coalescence model for heavy quark hadronization, we obtain a satisfactory description of heavy meson $R_{AA}$ and $v_{2}$ from low to intermediate to high $p_{T}$ observed at both RHIC and the LHC. By model-data-comparison, we extract for the first time the in-medium heavy quark potential from open heavy flavor measurements; the result is in agreement with the lattice QCD calculation. Our study indicates that while jet quenching at high $p_{T}$ is dominated by perturbative QCD interactions, non-perturbative interactions are indispensible for understanding heavy flavor quenching and flow at low and intermediate $p_{T}$ .

↳ hep-phnucl-exnucl-thPLB(2023)·35 citations