| Records |
| Author |
Ferrario, P.; Rodrigo, G. |
| Title |
Heavy colored resonances in t(t)over-bar + jet at the LHC |
Type |
Journal Article |
| Year |
2010 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
051 - 13pp |
| Keywords |
QCD Phenomenology |
| Abstract |
The LHC is the perfect environment for the study of new physics in the top quark sector. We study the possibility of detecting signals of heavy color-octet vector resonances, through the charge asymmetry, in t (t) over bar + jet events. Besides contributions with the t (t) over bar pair in a color-singlet state, the asymmetry gets also contributions which are proportional to the color factor f(abc)(2). This process is particularly interesting for extra-dimensional models, where the inclusive charge asymmetry generated by Kaluza-Klein excitations of the gluon vanishes at the tree level. We find that the statistical significance for the measurement of such an asymmetry is sizable for different values of the coupling constants and already at low energies. |
| Address |
[Ferrario, Paola; Rodrigo, German] UVEG, Consejo Super Invest Cient, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: paola.ferrario@ific.uv.es |
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Thesis |
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Publisher  |
Springer |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1126-6708 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISI:000275223100051 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
483 |
| Permanent link to this record |
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| Author |
Kuhn, J.H.; Rodrigo, G. |
| Title |
Charge asymmetries of top quarks at hadron colliders revisited |
Type |
Journal Article |
| Year |
2012 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
01 |
Issue |
1 |
Pages |
063 - 25pp |
| Keywords |
Heavy Quark Physics; Hadronic Colliders; Standard Model; Beyond Standard Model |
| Abstract |
A sizeable difference in the differential production cross section of top-compared to antitop-quark production, denoted charge asymittetm has been observed at the Tevatron. The experimental results seem to exceed the theory predictions based on the Standard Model by a significant amount and have triggered a large number of suggestions for “new physics'. In the present paper the Standard Model predictions for Tevatron and LHe experiments are revisited. This includes a reanalysis of electromagnetic as well as weak corrections, leading to a shift of the asymmetry by roughly a factor 1.1 when compared to the results of the first papers on this subject. The impact of cuts on the transverse momentum of the top-antitop system is studied. Restricting the it system to a transverse momentum less than 20 GeV leads to an enhancement of the asymmetries by factors between 1.3 and 1.5, indicating the importance of an improved understanding of the tt-momentum distribution. Predictions for similar measurements at the LHC are presented, demonstrating the sensitivity of the large rapidity region bot ti to the Standard Model contribution and effects from ”new physics". |
| Address |
[Kuehn, Johann H.] Karlsruher Inst Technol, Inst Theoret Teilchenphys, D-76133 Karlsruhe, Germany, Email: johann.kuehn@kit.edu |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1126-6708 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000300181800063 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
971 |
| Permanent link to this record |
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| Author |
Catani, S.; de Florian, D.; Rodrigo, G. |
| Title |
Space-like (vs. time-like) collinear limits in QCD: is factorization violated? |
Type |
Journal Article |
| Year |
2012 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
07 |
Issue |
7 |
Pages |
026 - 88pp |
| Keywords |
NLO Computations; Hadronic Colliders |
| Abstract |
We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e. g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of squared amplitudes and, more generally, cross sections in hadron-hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order). |
| Address |
[Catani, Stefano] Univ Florence, Sez Firenze, Ist Nazl Fis Nucl, I-50019 Florence, Italy, Email: catani@fi.infn.it; |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1126-6708 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000307298400026 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1160 |
| Permanent link to this record |
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| Author |
Bierenbaum, I.; Buchta, S.; Draggiotis, P.; Malamos, I.; Rodrigo, G. |
| Title |
Tree-loop duality relation beyond single poles |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
03 |
Issue |
3 |
Pages |
025 - 24pp |
| Keywords |
QCD Phenomenology; NLO Computations |
| Abstract |
We develop the Tree-Loop Duality Relation for two- and three-loop integrals with multiple identical propagators (multiple poles). This is the extension of the Duality Relation for single poles and multi-loop integrals derived in previous publications. We prove a generalization of the formula for single poles to multiple poles and we develop a strategy for dealing with higher-order pole integrals by reducing them to single pole integrals using Integration By Parts. |
| Address |
Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany, Email: isabella.bierenbaum@desy.de; |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000317521200025 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1418 |
| Permanent link to this record |
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| Author |
Mateu, V.; Rodrigo, G. |
| Title |
Oriented event shapes at (NLL)-L-3 + O(alpha(2)(S)) |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
11 |
Issue |
11 |
Pages |
030 - 29pp |
| Keywords |
Jets; NLO Computations |
| Abstract |
We analyze oriented event-shapes in the context of Soft-Collinear Effective Theory (SCET) and in fixed-order perturbation theory. Oriented event-shapes are distributions of event-shape variables which are differential on the angle theta(T) that the thrust axis forms with the electron-positron beam. We show that at any order in perturbation theory and for any event shape, only two angular structures can appear: F-0 = 3/8 (1+cos(2) theta(T)) and F-1 = (1 – 3 cos(2) theta(T)). When integrating over theta(T) to recover the more familiar event-shape distributions, only F-0 survives. The validity of our proof goes beyond perturbation theory, and hence only these two structures are present at the hadron level. The proof also carries over massive particles. Using SCET techniques we show that singular terms can only arise in the F-0 term. Since only the hard function is sensitive to the orientation of the thrust axis, this statement applies also for recoil-sensitive variables such as Jet Broadening. We show how to carry out resummation of the singular terms at (NLL)-L-3 for Thrust, Heavy-Jet Mass, the sum of the Hemisphere Masses and C-parameter by using existing computations in SCET. We also compute the fixed-order distributions for these event-shapes at O(alpha(S)) analytically and at O(alpha(2)(S)) with the program Event2. |
| Address |
[Mateu, Vicent; Rodrigo, German] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular, E-46980 Paterna, Valencia, Spain, Email: mateu@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000326699400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
1675 |
| Permanent link to this record |
