Elastic, inelastic, and path length fluctuations in jet tomography

Abstract

Jet quenching theory using perturbative QCD is extended to include (1) elastic as well as (2) inelastic parton energy losses and (3) jet path length fluctuations. The extended theory is applied to non-photonic single electron production in central Au+Au collisions at √ s = 200 AGeV. The three effects combine to significantly reduce the discrepancy between theory and current data without violating the global entropy bounds from multiplicity and elliptic flow data. We also check for consistency with the pion suppression data out to 20 GeV. Fluctuations of the jet path lengths in realisitic geometry and the difference between the widths of fluctuations of elastic and inelastic energy loss are essential to take into account.

Collisional energy loss of heavy quarks

“…3 to the analytic formula (10). This comparison illustrates that sub-leading terms in E, which are not captured by (10), are reasonably small already for intermediate charm energies. It also shows that a potential dependence of the constant c(n f ) on the flow velocity β is suppressed at large energy, as anticipated in Section 2.…”

“…The resulting (numerical) mean energy loss is compared in Fig. 3 to the analytic formula (10). This comparison illustrates that sub-leading terms in E, which are not captured by (10), are reasonably small already for intermediate charm energies.…”

Energy loss of a heavy quark produced in a finite-size quark–gluon plasma

“…In order to single out contributions specific to collisional loss, we thus subtract from (5) the TM contribution. This is easily done by subtracting π sgn(ω) z s (k)δ(ω 2 − ω 2 s (k)) -which sets the gluons or plasmons on mass shell -from the spectral functions (2). Denoting −∆Ẽ andd ∞ the quantities of interest after this subtraction, we findd ∞ ≃ d∞ 2 for γ ≫ 1, i.e.…”

High-energy heavy-ions physics: from RHIC to LHC

“…3, right) [ 39,40] is in apparent conflict with the robust ∆E Q < ∆E q < ∆E g prediction of radiative energy loss models. In order to reproduce the high p T open charm/bottom suppression, jet quenching models require either initial gluon densities (dN g /dy ≈ 3000) inconsistent with those needed to describe the quenched light hadron spectra [ 41,42], or a smaller relative contribution of B relative to D mesons than theoretically expected in the measured decay electron p T range [ 38]. This discrepancy may point to an additional contribution from elastic (i.e.…”