Related papers: Soft particle production and QCD coherence
We discuss average properties of the gluon cascade generated by an energetic parton propagating through a dense QCD medium. The cascade is mostly made with relatively soft gluons, whose production is not suppressed by the LPM effect. Unlike…
We analyze the inclusive spectra of hadrons produced in $pp$ collisions at high energies in the mid-rapidity region within the soft QCD and perturbative QCD assuming the possible creation of the soft gluons at low intrinsic transverse…
We consider the radiation of a soft gluon ($g$) and a soft quark-antiquark ($q{\bar q}$) pair in QCD hard scattering. In the soft limit the scattering amplitude has a singular behaviour that is factorized and controlled by a soft current,…
In this review we discuss the analytical perturbative approach, based on perturbative QCD and Local Parton Hadron Duality (LPHD), and its application to multiparticle production in jets in the semisoft region. Analytical formulae are…
We demonstrate that in the back-to-back kinematics the production of four jets in the collision of two partons is suppressed in the leading log approximation of pQCD, compared to the hard processes involving the collision of four partons.…
The momentum spectra of particles in different high energy processes, such as e^+e^- annihilation, pp and nuclear collisions in the limit p,p_T -> 0 exhibit similar properties because of the dominant role of coherent soft gluon…
We show that the onset and rise of QCD mini-jets provide the dynamical mechanism behind the appearance of a soft edge in pp collisions around ISR energies and thus such a soft edge is built in our mini-jet model with soft gluon resummation.…
Recent measurements of selected QCD processes at the Tevatron are reviewed and confronted with theoretical calculations. Results on inclusive jet production at large transverse momentum are compared to predictions from next-to-leading order…
Coherence phenomena, the increase with energy of coherence length and the non-universality of parton structure of the effective Pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of…
It is shown that the gluons produced with small transverse momenta $k_\perp$ inside a jet ($k_\perp <k_\perp^{cut}$, $k_\perp^{cut} \to 0$) are independently emitted from the primary parton, as QCD coherence suppresses their showering.…
Studies of hadron production in proton-proton collisions, including charged particle transverse momentum, pseudo-rapidity and event-by-event multiplicity distributions at \sqrt{s} = 0.9, 2.36 and 7 TeV are shown. Measured spectra of…
The quenching of jets (and high-pT particle spectra) observed in heavy-ion collisions is interpreted as due to the energy lost by hard partons crossing the Quark Gluon Plasma. Here we review recent efforts to include in its modeling…
Recent CMS soft QCD results in proton-proton collisions at three LHC center-of-mass energies are highlighted. The properties of minimum bias events such as charged particle transverse momentum spectra, event-by-event multiplicity…
The study of gluon radiation in QCD, in the limit of small ("soft") momentum, remains an active research area, with a variety of phenomenological and theoretical applications. Soft gluon emission leads to large logarithms in perturbation…
An effective theory for the soft field modes in hot QCD has been obtained recently by integrating out the field modes of momenta of order T and g T. The mean hard particle distribution obeys a transport equation with a collision term. The…
We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a sensitivity to emission at small angles and it…
The spectra of charged particles in the energy variable $\xi = \log 1/x$ (``the hump backed plateau'') are analyzed in terms of moments in order to investigate the sensitivity to the running of $\alpha_s$ in particular towards small scales,…
Charged particle energy spectra in e+e- annihilation are compared with the analytical predictions from the QCD evolution equation in the Modified Leading Log Approximation. With the nonperturbative initial condition shifted down to…
Using the analytical expression for transverse momentum dependent (TMD) gluon density in a proton, a self-consistent simultaneous description of low $Q^2$ data on proton structure function $F_2(x,Q^2)$, reduced cross section for the…
The hadroproduction of lepton pairs with mass Q and finite transverse momentum Q_T is described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton…