Speaker
Dennis Vadimovich Perepelitsa
(Brookhaven National Laboratory (US))
Description
Recent measurements of high-$p_\mathrm{T}$ jet and dijet production in
centrality-selected proton--lead collisions at the LHC are observed to
grossly violate geometric models of the relationship between jet
production at mid-rapidity and soft particle production in the nuclear
fragmentation region. These modifications have been, variously,
attributed to the suppression of soft gluons in proton configurations
with a high Bjorken-$x$, taken as a direct observation of proton color
fluctuations, or interpreted as the result of a rapidity-separated
energy conservation between soft and hard processes. This poster
reports the measurement of high-$p_\mathrm{T}$ jet production in
$200$ GeV deuteron--gold and proton--proton collisions by the PHENIX
experiment at RHIC. Fully corrected invariant yields and spectra are
presented for jets at mid-rapidity covering the wide kinematic range
$12$ GeV/$c$ $< p_\mathrm{T} < 50$ GeV/$c$. The nuclear modification
factor $R_{d\mathrm{Au}}$ for minimum bias collisions is consistent
with unity. However, the centrality-selected $R_{d\mathrm{Au}}$ shows
substantial deviations from unity, with a qualitative pattern similar
that observed at the LHC albeit at a smaller $p_\mathrm{T}$. These
measurements provide crucial new information for understanding the
anomalous relationship between hard and soft processes in $p$/$d$+A
systems.
| On behalf of collaboration: | PHENIX |
|---|
Author
Dennis Vadimovich Perepelitsa
(Brookhaven National Laboratory (US))
