Related papers: Gluon Radiation and Top Quark Physics
The recently found excess of high E$_T$ jets over current QCD predictions is attributed to gluon radiation at double scattering process inside a nucleon. The order of magnitude estimate of the cross section fits experimental findings rather…
I discuss some recent progress in our understanding of high energy nuclear collisions. I will focus on two topics which I was lucky to co-pioneer in the recent past. One is recombination of quarks and its interpretation as a signal for…
In this talk, I discuss some recent results obtained in Heavy Ion Collisions and what they tell us -- or what questions they raise -- about the physics of the system of quarks and gluons formed in these collisions.
We extend the Gunion Bertsch calculation of gluon radiation in single scattering to the case of finite mass quarks. This case applies to the radiative energy-loss of heavy quarks of intermediate energies propagating in a quark gluon plasma.…
We estimate the radiative energy-loss of heavy quarks, produced from the initial fusion of partons, while propagating in a quark-gluon plasma which may be formed in the wake of relativistic heavy ion collisions. We find that the radiative…
At hadron colliders, the production of heavy new particles is associated with additional quarks and gluons with significant transeverse momentum. The additional jets complicates the reconstruction of new particle masses. Taking gluino pair…
The status of top quark searches will be briefly reviewed. Theoretical predictions for the top quark decay rate are presented including QCD and electroweak radiative corrections. The possibilities for quarkonium searches at an hadron…
Several sources of direct photons are known to contribute to the total photon yield in high energy nuclear collisions. All of these photons carry characteristic and important information on the initial nuclei or the hot and dense fireball…
A large fraction of top quark events in $\pp$ collisions at $1.8\ \TeV$ will contain additional soft hadronic jets from gluon bremsstrahlung off the quarks and gluons in the hard processes $\qq, gg \to \tt \to \bb \ww$. These extra jets can…
We present a complete calculation of the matrix elements for the processes $q \bar q, gg \to b W^+ \bar b W^- g$ and $qg \to b W^+ \bar b W^- q$ which are relevant for the study of events with an additional jet in $t \bar t$ production at…
The gluon radiation induced by multiple scattering of a hard parton in expanding quark-gluon plasma is investigated. The radiative energy loss of hard parton jet is shown to decrease considerably when angular size of extracted jet goes up,…
We introduce photon-like refraction for gluon jet in quark gluon plasma created in high energy nucleus-nucleus collisions. A quark jet goes straightly while a gluon jet is assumed to bend in the non-homogeneous medium. Combining refraction…
We present a model for radiative energy loss of heavy quarks in quark gluon plasma which incorporates coherence effects. We then study its consequences on the radiation spectra as well as on the nuclear modification factor of open heavy…
We investigate whether and how different fragmentation properties of quarks and gluons affect identified particle spectra. We present a systematic study of $\pi$, $K$ and $p$ production in minimum bias (inelastic, non-diffractive), two- and…
High energy quarks and gluons play essential roles in the tomographic study of relativistic heavy-ion collisions and of the quark-gluon plasma. They interact with the traversed dense matter through elastic and inelastic collisions, and lose…
We consider three jet production at high $p_T$ in the $\gamma\gamma \to q \bar q g$ process and calculate quark and gluon jet spectra. The possibility of quark-gluon jet separation is discussed and compared with the $e^+ e^- \to q \bar q g$…
The semi-inclusive decay processes of a top quark into a charged pseudo-scalar meson and a jet are studied within the framework of QCD factorization. The leading power of the decay matrix elements can be factorized into heavy-to-light quark…
The lowest-order induced soft gluon radiation processes of heavy quarks have been analyzed to quantify the dead cone effect. This effect is most likely expected to suppress significantly the energy loss of charm quarks passing an amorphous…
An overview is given on the experimental study of quark-gluon matter produced in relativistic nucleus-nucleus collisions, with emphasis on recent measurements at the Large Hadron Collider.
Jet quenching studies play a prominent role in our current understanding of ultra-relativistic heavy ion collisions. In this review I first present the available formalism to compute medium-induced gluon radiation. Then I discuss its effect…