Initial state nuclear effects for jet production measured in sNN=200GeV\sqrt{s_\mathrm{NN}} = 200 \mathrm{GeV} d+Au collisions by STAR

Full jet reconstruction in heavy-ion collisions is a promising tool for quantitative study of properties of the dense medium produced at RHIC. Measurements of d+Au collisions are important to disentangle initial state nuclear effects from medium-induced $k_\mathrm{T}$ broadening and jet quenching. We report measurements of mid-rapidity ($|\eta_{jet}| < 0.4|$) di-jet correlations in d+Au using high-statistics run 8 RHIC data at $\sqrt{s_\mathrm{NN}} = 200 \mathrm{GeV}$.Comment: 2 pages, 2 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Exploring Jet Properties in p-p Collisions at 200 GeV with STAR

The mechanisms underlying hadronization are not well understood, both in vacuum and in hot QCD matter. Precise characterization of jet fragmentation to hadrons in p-p collisions will help elucidate the fundamental process of hadronization, and will serve as essential reference to measure the modification of hadronization in heavy ion collisions. We present measurements of fragmentation functions for unidentified particles in jets produced in p-p collisions at 200 GeV using the STAR detector at RHIC. The results from different jet reconstruction algorithms are compared, including variations of the resolution parameter. It is found that the results are largely insensitive to details of the jet-finding algorithm at RHIC energies. Particle production inside and outside of these reconstructed jets will be compared to improve our understanding of the hadronization mechanisms for soft and hard particles in p-p events at RHIC energies.Comment: 4 pages, 7 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee Final version after referee's comment

Measurement of jet spectra in Pb-Pb collisions at sNN\sqrt{s_{NN}}=2.76 TeV with the ALICE detector at the LHC

We report a measurement of transverse momentum spectra of jets detected with the ALICE detector in Pb-Pb collisions at sqrt(sNN)=2.76 TeV. Jets are reconstructed from charged particles using the anti-kt jet algorithm. The background from soft particle production is determined for each event and subtracted. The remaining influence of underlying event fluctuations is quantified by embedding different probes into heavy-ion data. The reconstructed transverse momentum spectrum is corrected for background fluctuations by unfolding. We compare the inclusive jet spectra reconstructed with R=0.2 and R=0.3 for different centrality classes and compare the jet yield in Pb-Pb and pp events.Comment: * Temporary entry *; 4 pages, 7 figures, proceedings from 5th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2012) at Cagliari (Italia

Heavy Quarks: Lessons Learned from HERA and Tevatron

We review some of the recent developments which have enabled the heavy quark mass to be incorporated into both the calculation of the hard-scattering cross section and the PDFs. We compare and contrast some of the schemes that have been used in recent global PDF analyses, and look at issues that arise when these calculations are extended to NNLO.Comment: 11 pages, 9 figures, to appear in the proceedings of the Ringberg Workshop "New Trends in HERA Physics 2008

Collinear Subtractions in Hadroproduction of Heavy Quarks

We present a detailed discussion of the collinear subtraction terms needed to establish a massive variable-flavour-number scheme for the one-particle inclusive production of heavy quarks in hadronic collisions. The subtraction terms are computed by convoluting appropriate partonic cross sections with perturbative parton distribution and fragmentation functions relying on the method of mass factorization. We find (with one minor exception) complete agreement with the subtraction terms obtained in a previous publication by comparing the zero-mass limit of a fixed-order calculation with the genuine massles results in the MSbar scheme. This presentation will be useful for extending the massive variable-flavour-number scheme to other processes.Comment: 29 pages, 17 figures include

Measurement of charged jet cross sections and jet shapes in proton-proton collisions at sqrt(s) = 2.76 TeV with the ALICE detector at LHC

We present measurements of charged jet cross sections and jet shape observables in leading jet in proton-proton (pp) collisions at sqrt(s) = 2.76 TeV with the ALICE detector at LHC. Jets are reconstructed at the midrapidity from charged particle using sequential recombination anti-kT jet finding algorithm for various R values. The results are compared to measurements from HERWIG, PHOJET and different tunes of PYTHIA6 and earlier measurements at 7 TeV.Comment: Proceedings of XXII DAE-BRNS High Energy Physics Symposium 2016 conference, 12-16 December, 201

Perturbative and Non-Perturbative Issues in Heavy Quark Fragmentation

We review the state-of-the-art of our understanding of heavy quark fragmentation. Recent e^+e^- data for B mesons are compared to the most up-to-date theoretical predictions, and the need for inclusion of a non-perturbative component is discussed. Experimental analyses in moments space are suggested, and it is pointed out how perturbative and non-perturbative contributions are to be properly matched. Failure to do so can result in large phenomenological discrepancies. An example is given for B^+ hadroproduction at the Tevatron.Comment: 6 pages, LaTeX2e, Talk given at the 37th Rencontres de Moriond on QCD and Hadronic Interactions, Les Arcs, France, 16-23 March 2002. To be published in the Proceeding

QCD Predictions for Charm and Bottom Production at RHIC

We present up-to-date QCD predictions for open charm and bottom production at RHIC in nucleon-nucleon collisions at \sqrt{S} = 200 GeV. The electron spectrum resulting from heavy flavor decays is also evaluated for direct comparison to the PHENIX and STAR data. These predictions seek to establish a rigorous benchmark, including the theoretical uncertainties, against which nuclear collision data can be compared to obtain evidence for nuclear effects.Comment: 4 pages, to appear in the proceedings of the International Europhysics Conference on High Energy Physics, 21-27 July 2005, Lisbon, Portuga