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