English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Direct photon produced from first proton-neutron ($p$-$n$) collision duringthe early stage of heavy ion reaction is a sensitive probe to reflect energyand momentum distribution of nucleons. In this work, we embedded the hardphoton production channel in an extended quantum molecular dynamics (EQMD)model, and took the direct photon as a possible probe to improve namely theFermi motion in the EQMD model. A possible scheme is offered to handle thedynamical wave packet width within incoherent bremsstrahlung process. Directphotons calculated by our modified EQMD were compared with data of $^{14}$N +$^{12}$C at beam energies $E/A$ = 20, 30 and 40 MeV, and it is found that theyield, inverse slope and angular distribution of direct photons could bereasonably reproduced. In addition, asymmetric reaction systems of $^{4}$He + Cand $^{4}$He + Zn at $E/A$ = 53 MeV are also simulated in this work. It isfound that the symmetric angular distribution in the nucleon-nucleon ($N$-$N$)center-of-mass (c.m.) frame and the velocity of $ the \gamma$-emission sourcecan be reasonably obtained from our method although there is some quantitativedifferences.

Direct photon emission and influence of dynamical wave packets in an extended quantum molecular dynamics model