Choose timezone
Your profile timezone:
Description
1. Jet quenching: Latest news from RHIC
by David d'Enterria / Nevis Labs, Columbia Univ.
Jet quenching, -- i.e. the absorption of a hard scattered parton produced in high-energy nucleus-nucleus collisions as it traverses the dense strongly interacting medium produced in the reaction --, has long been proposed as a clear signal of Quark-Gluon-Plasma formation. Non-Abelian radiative energy loss due to multiple gluon emission off the final partons results in calculable azimuthal and pseudo-rapidity modifications of the energy flow and particle multiplicity patterns within the final jets produced in relativistic heavy-ion reactions. I will review the latest experimental results on jet-quenching phenomena observed in Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) including: (i) excitation function of high pT leading hadron suppression, (ii) heavy-quark production at large pT, (iii) "dip" structure in away-side high-pT di-hadron azimuthal correlations, (iv) enhanced di-jet acoplanarity, and (v) di-jet pseudo-rapidity broadening; and confront them to theoretical expectations of non-Abelian parton energy loss in dense QCD matter.
2. Suppression of light and heavy flavored hadrons from RHIC to LHC
by Andrea Dainese / Padova Univ./INFN
Parton energy loss effects in heavy-ion collisions will be discussed within a model constructed using the BDMPS quenching weights and a realistic collision geometry. After tuning the only free parameter to the nuclear modification factor suppression measured in central Au-Au collisions at top RHIC energy, the model is consistently applied to other quenching observables: the centrality evolution of the nuclear modification factor, the suppression of the away-side jet-like correlations, and the azimuthal anisotropies for these observables. Extending the model to charm and beauty quarks, the ratios of nuclear modification factors of high-pT heavy-flavored mesons to light-flavored hadrons ("heavy-to-light ratios") will be shown to be sensitive to the mass and color-charge dependences of parton energy loss. The potential for identifying these two effects in D and B meson production at RHIC and at LHC will be assessed, and the predictions will be compared to the most recent charm nuclear modification factor data from RHIC.
3. Open heavy flavours: perspectives of ALICE for the detection of quark energy loss
by Rosario Turrisi / Padova Univ./INFN
Heavy flavoured hadrons can provide valuable information on the formation and evolution of hot and dense matter, that will be formed in heavy-ion collisions at LHC. In this study we present the ALICE performances for the detection of D and B mesons in the hadronic and the semielectronic channel respectively.
4. Basic concepts and recent applications of the light-cone path integral approach to the medium-induced energy loss
by Slava Zakharov/Landau Inst., Moscow/LAPTH, Annecy
The basic ideas of the light-cone path integral approach to the induced radiation in QED and QCD and its recent applications to the energy loss effects in QGP and cold nuclear matter are discussed. The applications include: quark energy loss in QGP and cold nuclear matter; evaluation of the nuclear modification factor for high-p_T hadron production in AA-collisions; medium-induced photon radiation in QGP in AA-collisions. We show that due to the finite-size effects the photon spectrum proportionaly to 1/(1-x) contrary to the 1/x Bethe-Heitler one. Our calculations, contrary to previous studies, demonstrate that medium effects do not suppress the high-p_T photon production, and even can enhance it. The numerical results are obtained using a new form of the medium-induced spectrum which allows one, for the first time, to perform calculations beyond the oscillator approximation which neglects the Coulomb effects in parton rescatterings. The role of the finite kinematic bounds is discussed. Our results show that the effect of the kinematic limits is relatively small, contrary to the prediction of Gyulassy, Vitev and Levai.
Organiser(s): Yiota Foka and Urs Achim Wiedemann
More information: http://home.cern.ch/a/alicedoc/www/chic/
by David d'Enterria / Nevis Labs, Columbia Univ.
Jet quenching, -- i.e. the absorption of a hard scattered parton produced in high-energy nucleus-nucleus collisions as it traverses the dense strongly interacting medium produced in the reaction --, has long been proposed as a clear signal of Quark-Gluon-Plasma formation. Non-Abelian radiative energy loss due to multiple gluon emission off the final partons results in calculable azimuthal and pseudo-rapidity modifications of the energy flow and particle multiplicity patterns within the final jets produced in relativistic heavy-ion reactions. I will review the latest experimental results on jet-quenching phenomena observed in Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) including: (i) excitation function of high pT leading hadron suppression, (ii) heavy-quark production at large pT, (iii) "dip" structure in away-side high-pT di-hadron azimuthal correlations, (iv) enhanced di-jet acoplanarity, and (v) di-jet pseudo-rapidity broadening; and confront them to theoretical expectations of non-Abelian parton energy loss in dense QCD matter.
2. Suppression of light and heavy flavored hadrons from RHIC to LHC
by Andrea Dainese / Padova Univ./INFN
Parton energy loss effects in heavy-ion collisions will be discussed within a model constructed using the BDMPS quenching weights and a realistic collision geometry. After tuning the only free parameter to the nuclear modification factor suppression measured in central Au-Au collisions at top RHIC energy, the model is consistently applied to other quenching observables: the centrality evolution of the nuclear modification factor, the suppression of the away-side jet-like correlations, and the azimuthal anisotropies for these observables. Extending the model to charm and beauty quarks, the ratios of nuclear modification factors of high-pT heavy-flavored mesons to light-flavored hadrons ("heavy-to-light ratios") will be shown to be sensitive to the mass and color-charge dependences of parton energy loss. The potential for identifying these two effects in D and B meson production at RHIC and at LHC will be assessed, and the predictions will be compared to the most recent charm nuclear modification factor data from RHIC.
3. Open heavy flavours: perspectives of ALICE for the detection of quark energy loss
by Rosario Turrisi / Padova Univ./INFN
Heavy flavoured hadrons can provide valuable information on the formation and evolution of hot and dense matter, that will be formed in heavy-ion collisions at LHC. In this study we present the ALICE performances for the detection of D and B mesons in the hadronic and the semielectronic channel respectively.
4. Basic concepts and recent applications of the light-cone path integral approach to the medium-induced energy loss
by Slava Zakharov/Landau Inst., Moscow/LAPTH, Annecy
The basic ideas of the light-cone path integral approach to the induced radiation in QED and QCD and its recent applications to the energy loss effects in QGP and cold nuclear matter are discussed. The applications include: quark energy loss in QGP and cold nuclear matter; evaluation of the nuclear modification factor for high-p_T hadron production in AA-collisions; medium-induced photon radiation in QGP in AA-collisions. We show that due to the finite-size effects the photon spectrum proportionaly to 1/(1-x) contrary to the 1/x Bethe-Heitler one. Our calculations, contrary to previous studies, demonstrate that medium effects do not suppress the high-p_T photon production, and even can enhance it. The numerical results are obtained using a new form of the medium-induced spectrum which allows one, for the first time, to perform calculations beyond the oscillator approximation which neglects the Coulomb effects in parton rescatterings. The role of the finite kinematic bounds is discussed. Our results show that the effect of the kinematic limits is relatively small, contrary to the prediction of Gyulassy, Vitev and Levai.
Organiser(s): Yiota Foka and Urs Achim Wiedemann
More information: http://home.cern.ch/a/alicedoc/www/chic/