Nuclear Theory·nucl-th

Thursday·June 14, 2018

11 papers—8 primary·3 cross-listed

09
Color randomization of fast gluon-gluon pairs in the quark-gluon plasma
B.G. Zakharov🇷🇺
We study the color randomization of two-gluon states produced after splitting of a primary fast gluon in the quark-gluon plasma. We find that for the LHC conditions the color randomization of the $g g$ pairs is rather slow. At jet energies $E = 100$ and $500$ GeV, for typical jet path length in the plasma in central Pb+Pb collisions, the $S U (3)$ -multiplet averaged color Casimir of the $g g$ pair differs considerably from its value $2 N_{c}$ for a fully randomized $g g$ state. Our calculations of the energy dependence for generation of the nearly collinear decuplet $g g$ states, that can lead to the baryon jet fragmentation, show that the contribution of the anomalous decuplet color states to the baryon production should become small at $p_{T} ≳ 10$ GeV.
↳ hep-phnucl-thJ.Exp.Theor.Phys.(2019)·13 citations
10
Two-photon exchange effects in $e^{+} e^{-} \to π^{+} π^{-}$ and time-like pion electromagnetic form factor
Hong-Yu Chen🇨🇳 · Hai-Qing Zhou🇨🇳
The two-photon-exchange (TPE) effects in the process $e^{+} e^{-} \to π^{+} π^{-}$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs) of pion are considered in the estimation. Different with the results under the one-photon-exchange (OPE) approximation, the TPE effects result in an asymmetry of the differential cross section on the scattering angle. The precise measurement of this asymmetry by the further experiment is an precise test of pQCD at large momentum transfer. The time-like electromagnetic form factor of pion at the leading order of pQCD is re-discussed and the comparison of our results with those in the references are presented.
↳ hep-phhep-exnucl-thPRD(2018)·7 citations
11
Transition magnetic moments of $J^{P} = \frac{3}{2}^{+}$ decuplet to $J^{P} = \frac{1}{2}^{+}$ octet baryons in the chiral constituent quark model
Harleen Dahiya🇮🇳
In light of the developments of the chiral constituent quark model ( $χ$ CQM) in studying low energy hadronic matrix elements of the ground-state baryons, we have extended this model to investigate their transition properties. The magnetic moments of transitions from the $J^{P} = \frac{3}{2}^{+}$ decuplet to $J^{P} = \frac{1}{2}^{+}$ octet baryons have been calculated with explicit valence quark spin, sea quark spin and sea quark orbital angular momentum contributions. Since the experimental data is available for only a few transitions, we have compared our results with the results of other available models. The implications of other complicated effects such as chiral symmetry breaking and SU(3) symmetry breaking arising due to confinement of quarks have also been discussed.
↳ hep-phnucl-thCPC(2018)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE

Color randomization of fast gluon-gluon pairs in the quark-gluon plasma

Two-photon exchange effects in e+e−→π+π− and time-like pion electromagnetic form factor

Transition magnetic moments of JP=23​+ decuplet to JP=21​+ octet baryons in the chiral constituent quark model

Affiliations

Two-photon exchange effects in $e^{+} e^{-} \to π^{+} π^{-}$ and time-like pion electromagnetic form factor

Transition magnetic moments of $J^{P} = \frac{3}{2}^{+}$ decuplet to $J^{P} = \frac{1}{2}^{+}$ octet baryons in the chiral constituent quark model