[Eg2] Ridge

[Will Brooks]

  Dear all,

As we tangentially discussed today, here are the links:

http://arxiv.org/abs/1009.4122 CMS measurement.

from Stan Brodsky:

"I have conjectured that the ridge (in heavy ion collisions) is 
associated with the initial state DGLAP radiation.

See my talk:

Theory Seminar. Purdue University. West Lafayette, IN. "Heavy Quark 
Production at High xF and other Novel QCD Effects at RHIC" Part 1, Part 
2, Part 3. October 29, 2009

(Also presented at BNL October 27.) Posted at

http://www.slac.stanford.edu/grp/th/recentlectures.html
--------------
One also has contributions to hadron production at high $p_T (even at 
the LHC ! ) from hard QCD direct subprocesses in QCD such as

$u u \to p \bar q$ or $g q \to \pi q$

in which the trigger hadron is produced directly as a small 
color-singlet – not via fragmentation.

This accounts for the baryon anomaly as well as the anomalous power 
fall-off in $p_T$ observed at fixed $x_T.$

See:

Higher-Twist Dynamics in Large Transverse Momentum Hadron Production.
Francois Arleo, (Annecy, LAPTH) , Stanley J. Brodsky, (SLAC) , Dae Sung 
Hwang, (Sejong U.) , Anne M. Sickles, (Brookhaven) . LAPTH-1359-09, 
SLAC-PUB-13839, Nov 2009. (Published Aug 6, 2010). 4pp.
Published in Phys.Rev.Lett.105:062002,2010.
e-Print: arXiv:0911.4604 [hep-ph]"