|
Records |
Links ![sorted by URL field, ascending order (up)](img/sort_asc.gif) |
|
Author |
Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
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 |
ISI:000278250000044 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ elepoucu @ |
Serial |
434 |
|
Permanent link to this record |
|
|
|
|
Author |
Kleiss, R.H.P.; Malamos, I.; Papadopoulos, C.G.; Verheyen, R. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Counting to one: reducibility of one- and two-loop amplitudes at the integrand level |
Type |
Journal Article |
|
Year |
2012 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
|
Volume |
12 |
Issue |
12 |
Pages |
038 - 24pp |
|
|
Keywords |
QCD Phenomenology; NLO Computations |
|
|
Abstract |
Calculation of amplitudes in perturbative quantum field theory involve large loop integrals. The complexity of those integrals, in combination with the large number of Feynman diagrams, make the calculations very difficult. Reduction methods proved to be very helpful, lowering the number of integrals that need to be actually calculated. Especially reduction at the integrand level improves the speed and set-up of these calculations. In this article we demonstrate, by counting the numbers of tensor structures and independent coefficients, how to write such relations at the integrand level for one-and two-loop amplitudes. We clarify their connection to the so-called spurious terms at one loop and discuss their structure in the two-loop case. This method is also applicable to higher loops, and the results obtained apply to both planar and non-planar diagrams. |
|
|
Address |
[Kleiss, Ronald H. P.; Verheyen, Rob] Radboud Univ Nijmegen, NL-6525 ED Nijmegen, Netherlands, Email: R.Kleiss@science.ru.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 |
WOS:000313123800038 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
1346 |
|
Permanent link to this record |
|
|
|
|
Author |
Deak, M. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Estimation of saturation and coherence effects in the KGBJS equation – a non-linear CCFM equation |
Type |
Journal Article |
|
Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
|
Volume |
07 |
Issue |
7 |
Pages |
087 - 18pp |
|
|
Keywords |
QCD Phenomenology |
|
|
Abstract |
We solve the modified non-linear extension of the CCFM equation – KGBJS equation – numerically for certain initial conditions and compare the resulting dipole amplitudes with those obtained front solving the original CCFM equation and the BFKL and BK equations for the same initial conditions. We improve the low transversal momentum behaviour of the KGBJS equation by a small modification. |
|
|
Address |
[Deak, M.] Univ Santiago de Compostela, Fac Fis, Dept Fis Particulas, Santiago De Compostela 15706, Spain, Email: michal.deak@ific.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 |
1029-8479 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:000323202600087 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
no |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
1636 |
|
Permanent link to this record |
|
|
|
|
Author |
Buchta, S.; Chachamis, G.; Draggiotis, P.; Malamos, I.; Rodrigo, G. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
On the singular behaviour of scattering amplitudes in quantum field theory |
Type |
Journal Article |
|
Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
|
Volume |
11 |
Issue |
11 |
Pages |
014 - 13pp |
|
|
Keywords |
QCD Phenomenology; NLO Computations |
|
|
Abstract |
We analyse the singular behaviour of one-loop integrals and scattering amplitudes in the framework of the loop-tree duality approach. We show that there is a partial cancellation of singularities at the loop integrand level among the different components of the corresponding dual representation that can be interpreted in terms of causality. The remaining threshold and infrared singularities are restricted to a finite region of the loop momentum space, which is of the size of the external momenta and can be mapped to the phase-space of real corrections to cancel the soft and collinear divergences. |
|
|
Address |
[Buchta, Sebastian; Chachamis, Grigorios; Malamos, Ioannis; Rodrigo, German] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46980 Valencia, Spain, Email: sbuchta@ific.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 |
1029-8479 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:000344788000003 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
2065 |
|
Permanent link to this record |
|
|
|
|
Author |
Deak, M.; Kutak, K. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Kinematical constraint effects in the evolution equations based on angular ordering |
Type |
Journal Article |
|
Year |
2015 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
|
|
Volume |
05 |
Issue |
5 |
Pages |
068 - 13pp |
|
|
Keywords |
QCD Phenomenology; Deep Inelastic Scattering (Phenomenology) |
|
|
Abstract |
We study effects of imposing various forms of the kinematical constraint on the full form of the CCFM equation and its non-linear extension. We find, that imposing the constraint in its complete form modifies significantly the shape of gluon density as compared to forms of the constraint used in numerical calculations and phenomenological applications. In particular the resulting gluon density is suppressed for large values of the hard scale related parameter and k(T) of gluon. This result might be important in description of jet correlations at Large Hadron Collider within the CCFM approach. |
|
|
Address |
[Deak, Michal] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: michal.deak@ific.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 |
1029-8479 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:000356951500006 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
2290 |
|
Permanent link to this record |