Asymmetries between the production of D+ and D− mesons from 500 GeV/c π−-nucleus interactions as a function of xF and pt2

Recombination models

“…This is impressively confirmed by recent experimental results, e.g. from the FNAL E791 collaboration [13]. With a π − beam impinging on a fixed nuclear target, they measure a D − /D + asymmetry that goes to 1 in the very forward direction.…”

Λc+/Λc−andLai1, Leibovich2 2015Phys. Rev. D

“…The asymmetry in D ± production has been observed in the forward region at LHCb [14], and can be explained using the heavy quark recombination mechanism [15]. The heavy quark recombination mechanism also successfully explained production asymmetries of D ± and Λ ± c in fixed-target experiments [11][12][13]16]. Therefore, the prediction on production asymmetries of Λ + c /Λ − c and Λ 0 b /Λ 0 b using the heavy quark recombination mechanism should give a sensible estimate for the contribution to the asymmetries from the standard model.…”

Quark coalescence and charm(onium) in QGP

“…At high momenta c-quarks rescatter perturbatively inducing a softening of the primordially power-like p t -spectra, with subsequent hadronization in the vacuum (fragmentation). The predicted suppression [22,23] compared to coalescence + fragmentation calculations [6]. Upper data points and curves are for D1=D − and D2=D + , whereas lower data points and curves are for D1=D 0 and D2=D 0 .…”