A study on the hadroproduction of heavy resonances in ATLAS experiment at the LHC

This work is devoted to the study of the hadroproduction of heavy resonances and related topics. The study begins with a chapter that analyzes some experimental issues on heavy quarkonia production, pointing out the important role that the ATLAS detector at LHC can play in this regard. The main goal of chapter 2 is revising some theoretical aspects on bottomonia production, some relevant heavy quarkonia production models are visited, pointing out the most relevant features involved in this work. Later, chapter 3 describes the most relevant techniques used in order to generate the Upsilon(nS) family, as well as a description on the changes and new implementations in the original software of PYTHIA: In summary, all the tools that we needed when carrying out the bottomonia hadroproduction analysis. In chapter 4 we focused on the study of the information available on Upsilon production, basing our analysis of bottomonia inclusive production on the results from Run IB of the CDF collaboration : We analyze the differential Upsilon(nS) cross sections, extracting some relevant NRQCD matrix elements, paying attention to the problem concerning the factorization of the cross section, etc. In chapter 5 we make some predictions on bottomonium hadroproduction at the forthcoming LHC energies and kinematic conditions: We show the expected differential and integrated cross section for all Upsilon(nS) resonances, etc. In chapter 6 we present a proposal to probe gluon densities in the proton using Upsilon hadroproduction, within the framework of the colour-octet mechanism. Aside the proposal, we included predicted production rates, and details that arose during the development of the idea. Finally, in order to help the reading of this work, a lot of technical details have been separated from the main body of the text, gathering them in the appendices A-B-C

Prospects for probing the gluon density in protons using heavy quarkonium hadroproduction

We examine carefully bottomonia hadroproduction in proton colliders, especially focusing on the LHC, as a way of probing the gluon density in protons. To this end we develop some previous work, getting quantitative predictions and concluding that our proposal can be useful to perform consistency checks of the parameterization sets of different parton distribution functions.Comment: LaTeX, 14 pages, 6 EPS figure

A first estimate of triply heavy baryon masses from the pNRQCD perturbative static potential

Within pNRQCD we compute the masses of spin-averaged triply heavy baryons using the now-available NNLO pNRQCD potentials and three-body variational approach. We focus in particular on the role of the purely three-body interaction in perturbation theory. This we find to be reasonably small and of the order 25 MeV Our prediction for the Omega_ccc baryon mass is 4900(250) in keeping with other approaches. We propose to search for this hitherto unobserved state at B factories by examining the end point of the recoil spectrum against triple charm.Comment: 18 figures, 21 page

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Thrust measurements and mesothermal plasma plume of the Alternative Low Power Hybrid Ion Engine (alphie)

The high specific impulse Alternative Low Power Ion Engine (alphie) is a gridded plasma thruster different from conventional (Kaufman) ion engines. In this disruptive concept, the ionization of the propellant neutral gas and the neutralization of ion outflow is achieved with only one cathode located in front and outside of the thruster. Electrons and ions move under the self-consistent field created by the DC voltage applied to its two planar grids together with the currents of charges flowing through them, unlike to conventional ion engines, where only ions move through its ion optics system. The stationary mesothermal flow of ions and electrons in the plasma plume is characterized with a retarded field energy analyzer in conjunction with Langmuir and emissive probes. The ion velocity distribution functions and the electron energy spectra for different operating conditions of the alphie thruster are discussed. The observed high ion temperatures are explained by the collisional interaction between the fast ionizing electrons and the neutral atoms that increases their average kinetic energy. Finally, the alphie delivers 0.8-3.5 mN throttleable thrusts giving specific impulses in the range of 14000-20000 s with estimated thruster efficiencies between 8% and 40%

Thrust measurements and mesothermal plasma plume of the Alternative Low Power Hybrid Ion Engine (alphie)

The high specific impulse Alternative Low Power Ion Engine (alphie) is a gridded plasma thruster different from conventional (Kaufman) ion engines. In this disruptive concept, the ionization of the propellant neutral gas and the neutralization of ion outflow is achieved with only one cathode located in front and outside of the thruster. Electrons and ions move under the self-consistent field created by the DC voltage applied to its two planar grids together with the currents of charges flowing through them, unlike to conventional ion engines, where only ions move through its ion optics system. The stationary mesothermal flow of ions and electrons in the plasma plume is characterized with a retarded field energy analyzer in conjunction with Langmuir and emissive probes. The ion velocity distribution functions and the electron energy spectra for different operating conditions of the alphie thruster are discussed. The observed high ion temperatures are explained by the collisional interaction between the fast ionizing electrons and the neutral atoms that increases their average kinetic energy. Finally, the alphie delivers 0.8-3.5 mN throttleable thrusts giving specific impulses in the range of 14000-20000 s with estimated thruster efficiencies between 8% and 40%