Jet-Quenching in pp collisions at LHC
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Transcript of Jet-Quenching in pp collisions at LHC
Jet-Quenching in pp collisions at LHC
Quark Matter Studies by PrET (Proton-Expansion-Tomography) at LHC pp in collisions
Budapest – Purdue Common Project
L. Gutay, K. Krajczar, F. Sikler, G. Veres and G. Vesztergombi
Bodrum, Turkey
September 2010
OUTLINES
First QGP in pp in 1982
RHIC Heavy Ion QGP signature: jet quenching ( Low-pt diagnostic with high-pt jets)
LHC QGP in pp : spacetime structure - jet tomography
Experimental FACTS ( CERN SppS and E735 and LHC)
Naive „dressed” quark-model for multiple interactions in pp
Proposed QGP and DM related signatures in pp at LHC
Flattening effect in E735
KNO-scaling as function of C.M. energy
New components are emerging at higher energies in E735
Subtracting lower energy KNO-curve, new KNO appears
3 components at highest energies
Bose-Einstein interference versus multiplicity
Higher multiplicity means higher source radii both at E735 and CMS
Remark: Quark Matter is observed in larger expanding volumes in correlation with the violance of the collision.
CMS 2.36 TeV
Naive „dressed” quark-model
Heavy quarks are created by exciting the mini glue-ball
Resonance states without flavour change are produced by exciting soft gluons
(u or d )
SOFT COLLISIONS
12 3
Primary KNO-scaling Secondary KNO-scaling Not measured yet
HARD + SOFT COLLISIONS
The aim of this study is to identify these processes
1 hard 2
hard 3hard
David Enterria 2005 Orsay-Paris
HARD + SOFT COLLISIONS
Transversal view
Single soft + hard Double soft + hard
ETnear ET
near
ETaway (single soft) ET
away (double soft)<<
Away jet must traverse more excited Quark Matter in case of double soft interaction
„Jet physics” at heavy ions: Single inclusive high pT spectra
IN pp INTERACTIONS both TRACK and JET metods are possible!!!
Near and away jet ratios as function of multiplicity
Prediction: Zaway = ETaway/ET
near
Zaway Zaway
ETnear
ETnear
Low multiplicity events High multiplicity events
One expects similar results if highest pT tracks are used instead of jets
From the energy loss difference one can determine the nature of traversed medium
Compare near-away correlations at different multiplicities in LHC pp
One expects that higher multiplicity will have similar effect as larger nucleus size
Search for DARK MATTER from QGP
DARK MATTER (DM) versus QGP
IF at Big-Bang the Dark Matter was produced during the hadronization
THEN
at LHC Dark Matter will be produced at QGP cooling=hadronization
ONE SHOULD look for METs as function of multiplicity:
Higher multiplicity could mean larger QGP volume!!!!
The relatively small volume of QGP created in pp is important for MET observability!!!
In large volume one expects many DM particles per event averaging out MET.
In small volume there is higher probability that 1-2 DM (black-hole or pair of SUSY) particle generated with high MET.
Hadrons
DM(s)
MET
SUMMARY
One expects jet quenching measured in near-away jet-jet
and track-track correlations due to change of QGP volume
implied by multiplicity dependence
Missing ET can indicate dark matter