119515666
Study of jet properties at the Tevatron
The Run II at the Tevatron will define a new level of precision for QCD studies in hadron collisions. Both collider experiments, CDF and D0, expect to collect up to 8 fb{sup -1} of data in this new run period. The increase in instantaneous luminosity, center-of-mass energy (from 1.8 TeV to 2 TeV) and the improved acceptance of the detectors will allow stringent tests of the Standard Model (SM) predictions in extended regions of jet transverse momentum, P{sub T}{sup jet}, and jet rapidity, Y{sup jet}. The hadronic final states in hadron-hadron collisions are characterized by the presence of soft contributions (the so-called underlying event) from initial-state gluon radiation and multiple parton interactions between remnants, in addition to the jets of hadrons originated by the hard interaction. A proper comparison with pQCD predictions at the parton level requires an adequate modeling of these soft contributions which become important at low P{sub T}{sup jet}. In this letter, a review of some of the most important QCD results from Run II is presented.
17360856
Jet Production at CDF
The Run 2 at Tevatron will define a new level of precision for QCD studies in hadron collisions. Both collider experiments, CDF and D0, expect to collect up to 15 fb{sup -1} of data in this new run period. The increase in instantaneous luminosity, center-of-mass energy (from 1.8 TeV to 2 TeV) and the improved acceptance of the detectors will allow stringent tests of the Standard Model (SM) predictions in extended regions of jet transverse energy, E{sub T}{sup jet}, and jet pseudorapidity, {eta}{sup jet}. In the following, a review of some of the most important QCD results from Run 1 is presented, together with first preliminary Run 2 measurements (based on the very first data collected by the experiment) and future prospects as the integrated luminosity increases.
115308001
Jet physics at 2-TeV
In this contribution, a review of some of the most important QCD jet preliminary results from both CDF and D0 experiments in Run II is presented, together with future prospects as the integrated luminosity increases.
125341960
High $p_{T}$ Jet Physics
123410491
Z plus jets production at the tevatron
We present preliminary results on inclusive Z(→ee) boson plus jets production in pp collisions at s√ = 1.96 TeV, based on 1.7 fb-1 of data collected by the CDF experiment. Inclusive jet measurements are performed as function of pTjet and jet multiplicity for jets in the region of pTjet > 30 GeV/c and |yjet | < 2.1. Results are compared to NLO pQCD predictions and are found to be in good agreement.
123275219
Measurement of the Inclusive Z+Jet(s) Production Cross Section at CDF
We present preliminary results on inclusive Z(→ ee) boson plus jets production in p p ¯ collisions at s = 1.96 TeV , based on 1 fb −1 of data collected by the CDF experiment between February 2002 and March 2006. Inclusive jet measurements are performed as a function of p T jet and jet multiplicity for jets in the region p T jet > 30 GeV/c and | y jet | 2.1 . Results are compared to NLO pQCD predictions.
118691614
Coherence effects between the initial and final state radiation in a dense QCD medium
Abstract In these proceedings contribution we review our recent results of medium modifications to the coherence pattern between the initial and final state radiation. We study single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. Multiple scatterings lead to a partial suppression of the interferences between different emitters that opens the phase space for large angle emissions. We briefly discuss the generalization of this setup to describe gluon production in the case of pA collisions by including finite length and energy corrections. The configuration studied here may have phenomenological consequences in high-energy nuclear collisions.
38739765
The ALICE Silicon Drift Detector system
The project of the two Silicon Drift Detector (SDD) layers of the ALICE Inner Tracking System is reviewed, with details on the barrel construction and on the front-end electronics. The results on the SDD spatial resolution are reported as obtained in the 2000 beam test from a whole drift region of the detector.
119256392
Constraining the onset of viscous hydrodynamics
Abstract We derive two general criteria that can be used to constrain the initial time of the onset of 2nd-order conformal viscous hydrodynamics in relativistic heavy-ion collisions. We show this explicitly for 0+1 dimensional viscous hydrodynamics and discuss how to extend the constraint to higher dimensions.
39887402
New exact solution of the relativistic Boltzmann equation and its hydrodynamic limit.
We present an exact solution of the relativistic Boltzmann equation for a system undergoing boost-invariant longitudinal and azimuthally symmetric transverse flow ("Gubser flow"). The resulting exact nonequilibrium dynamics is compared to first and second order relativistic hydrodynamic approximations for various shear viscosity to entropy density ratios. This novel solution can be used to test the validity and accuracy of different hydrodynamic approximations in conditions similar to those generated in relativistic heavy-ion collisions.
120530727
Decoherence between the initial and final state radiation in a dense QCD medium
Abstract We study medium modifications to the interference pattern between initial and final state radiation. We compute single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. Multiple soft scatterings with the medium are resumed within the harmonic oscillator approximation. We find the decoherence of correlated partons traversing the medium depends on two scales: the medium length L and the decorrelation time of the gluon due to the medium τ f . This interplay gives origin to two different asymptotic limits of the gluon spectrum: the coherent ( τ f ≫ L ) and incoherent regime ( τ f ≪ L ). We discuss the main characteristics of each regime. We show that in both cases there is a gradual onset of decoherence between the initial and final state radiation due to multiple scatterings, that opens the phase space for large angle emissions. We comment on the phenomenological consequences (such as radiative energy loss) of this setup in pA collisions.