Dihadron tomography of high-energy nuclear collisions in next-to-leading order perturbative QCD

作者：Zhang Hanzhong^*; Owens Joseph F; Wang Enke; Wang Xin Nian

来源：Physical Review Letters, 2007, 98(21): 212301.

DOI：10.1103/PhysRevLett.98.212301

Dihadron spectra in high-energy heavy-ion collisions are studied within the next-to-leading order perturbative QCD parton model with modified jet fragmentation functions due to jet quenching. High-p(T) back-to-back dihadrons are found to originate mainly from jet pairs produced close and tangential to the surface of the dense matter. However, a substantial fraction also comes from jets produced at the center with finite energy loss. Consequently, high-p(T) dihadron spectra are found to be more sensitive to the initial gluon density than the single hadron spectra that are more dominated by surface emission. A simultaneous chi(2) fit to both the single and dihadron spectra can be achieved within a range of the energy loss parameter epsilon(0)=1.6-2.1 GeV/fm. Because of the flattening of the initial jet production spectra at root s=5.5 TeV, high p(T) dihadrons are found to be more robust as probes of the dense medium.

• 出版日期2007-5-25
• 单位华中师范大学