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Author Perez-Ramos, R.; Mathieu, V.; Sanchis-Lozano, M.A.
Title Heavy quark flavour dependence of multiparticle production in QCD jets Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 047 - 24pp
Keywords Jets; Hadronic Colliders; QCD
Abstract After inserting the heavy quark mass dependence into QCD partonic evolution equations, we determine the mean charged hadron multiplicity and second multiplicity correlators of jets produced in high energy collisions. We thereby extend the so-called dead cone effect to the phenomenology of multiparticle production in QCD jets and find that the average multiplicity of heavy-quark initiated jets decreases significantly as compared to the massless case, even taking into account the weak decay products of the leading primary quark. We emphasize the relevance of our study as a complementary check of b-tagging techniques at hadron colliders like the Tevatron and the LHC.
Address [Perez-Ramos, Redamy] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: redamy.perez@uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes (down) ISI:000282368500019 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 356
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Author Baron, R.; Boucaud, P.; Dimopoulos, P.; Frezzotti, R.; Palao, D.; Rossi, G.; Farchioni, F.; Munster, G.; Sudmann, T.; Gimenez, V.; Herdoiza, G.; Jansen, K.; Lubicz, V.; Simula, S.; Michael, C.; Scorzato, L.; Shindler, A.; Urbach, C.; Wenger, U.
Title Light meson physics from maximally twisted mass lattice QCD Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 097 - 41pp
Keywords Lattice QCD; Quark Masses and SM Parameters; QCD
Abstract We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N-f = 2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280 less than or similar to m(PS) less than or similar to 650MeV we control the major systematic effects of our calculation. This enables us to confront our N-f = 2 data with SU(2) chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass.
Address [Baron, Remi; Boucaud, Phillip] Univ Paris 11, Phys Theor Lab, Ctr Orsay, F-91405 Orsay, France, Email: remi.baron@centraliens.net
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes (down) ISI:000282367800036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 348
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Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title QCD effective charges from lattice data Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 002 - 24pp
Keywords Nonperturbative Effects; QCD
Abstract We use recent lattice data on the gluon and ghost propagators, as well as the Kugo-Ojima function, in order to extract the non-perturbative behavior of two particular definitions of the QCD effective charge, one based on the pinch technique construction, and one obtained from the standard ghost-gluon vertex. The construction relies crucially on the definition of two dimensionful quantities, which are invariant under the renormalization group, and are built out of very particular combinations of the aforementioned Green's functions. The main non-perturbative feature of both effective charges, encoded in the infrared finiteness of the gluon propagator and ghost dressing function used in their definition, is the freezing at a common finite (non-vanishing) value, in agreement with a plethora of theoretical and phenomenological expectations. We discuss the sizable discrepancy between the freezing values obtained from the present lattice analysis and the corresponding estimates derived from several phenomenological studies, and attribute its origin to the difference in the gauges employed. A particular toy calculation suggests that the modifications induced to the non-perturbative gluon propagator by the gauge choice may indeed account for the observed deviation of the freezing values.
Address [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil, Email: arlene.aguilar@ufabc.edu.br
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes (down) ISI:000281504500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 384
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Author Baron, R.; Boucaud, P.; Carbonell, J.; Deuzeman, A.; Drach, V.; Farchioni, F.; Gimenez, V.; Herdoiza, G.; Jansen, K.; McNeile, C.; Michael, C.; Montvay, I.; Palao, D.; Pallante, E.; Pene, O.; Urbach, C.; Wagner, M.; Wenger, U.
Title Light hadrons from lattice QCD with light (u, d), strange and charm dynamical quarks Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 111 - 31pp
Keywords Lattice QCD; Chiral Lagrangians
Abstract
Address [Deuzeman, A.; Pallante, E.; Urbach, C.] Univ Groningen, Ctr Theoret Phys, NL-9747 AG Groningen, Netherlands, Email: e.pallante@rug.nl
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes (down) ISI:000279630800058 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 415
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Author Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K.
Title Chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes-Renner relation Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 064 - 16pp
Keywords QCD Phenomenology
Abstract The next to leading order chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes- Renner (GMOR) relation are obtained using the pseudoscalar correlator to five-loop order in perturbative QCD, together with new finite energy sum rules (FESR) incorporating polynomial, Legendre type, integration kernels. The purpose of these kernels is to suppress hadronic contributions in the region where they are least known. This reduces considerably the systematic uncertainties arising from the lack of direct experimental information on the hadronic resonance spectral function. Three different methods are used to compute the FESR contour integral in the complex energy (squared) s-plane, i.e. Fixed Order Perturbation Theory, Contour Improved Perturbation Theory, and a fixed renormalization scale scheme. We obtain for the corrections to the GMOR relation, delta(pi), the value delta(pi) = (6.2 +/- 1.6)%. This result is substantially more accurate than previous determinations based on QCD sum rules; it is also more reliable as it is basically free of systematic uncertainties. It implies a light quark condensate < 0 vertical bar(u) over baru vertical bar 0 > similar or equal to < 0 vertical bar(d) over bard vertical bar 0 > < 0 vertical bar(q) over barq vertical bar 0 >vertical bar(2GeV) = (-267 +/- 5MeV)(3). As a byproduct, the chiral perturbation theory (unphysical) low energy constant H-2(r) is predicted to be H-2(r)(nu(X) = M-p) = -(5.1 +/- 1.8) x10(-3), or H-2(r) (nu(X) = M-eta) = -(5.7 +/- 2.0) x10(-3).
Address [Bordes, J.; Penarrocha, J.] Univ Valencia, Dept Fis Teor, CSICE, E-46100 Burjassot, Spain, Email: bordes@uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes (down) ISI:000278250000044 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 434
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