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Author Coppola, M.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Magnetic field driven enhancement of the weak decay width of charged pions Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 058 - 19pp
Keywords (up) QCD Phenomenology
Abstract We study the effect of a uniform magnetic field B on the decays pi- > l- nu_l bar, where l(-)=e(-), μ(-), carrying out a general analysis that includes four pi (-) decay constants. Taking the values of these constants from a chiral effective Nambu-Jona-Lasinio (NJL) model, it is seen that the total decay rate gets strongly increased with respect to the B = 0 case, with an enhancement factor ranging from similar to 10 for eB = 0.1 GeV2 up to similar to 10(3) for eB = 1 GeV2. The ratio between electronic and muonic decays gets also enhanced, reaching a value of about 1 : 2 for eB = 1 GeV2. In addition, we find that for large B the angular distribution of outgoing antineutrinos shows a significant suppression in the direction of the magnetic field.
Address [Coppola, Maximo; Scoccola, Norberto N.] Consejo Nacl Invest Cient & Tecn, Rivadavia 1917, RA-1033 Buenos Aires, DF, Argentina, Email: coppola@tandar.cnea.gov.ar;
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:000570908100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4534
Permanent link to this record
 
 
Author Deak, M.; Kutak, K.
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 (up) 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
 
 
Author Campanario, F.; Kubocz, M.
Title Higgs boson CP-properties of the gluonic contributions in Higgs plus three jet production via gluon fusion at the LHC Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 173 - 16pp
Keywords (up) QCD Phenomenology; Monte Carlo Simulations
Abstract in high energy hadronic collisions, a general CP-violating Higgs boson Phi with accompanying jets can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. In this article, we study the dominant sub-channel gg -> ggg Phi of the gluon fusion production process with triple real emission corrections at order alpha(5)(s). We go beyond the heavy top-quark approximation and include the full mass dependence of the top- and bottom-quark contributions. Furthermore, in a specific model we demonstrate the features of our program and show the impact of bottom-quark loop contributions in combination with large values of tan beta on differential distributions sensitive to CP-rneasurements of the Higgs boson.
Address [Campanario, Francisco] Univ Valencia CSIC, IFIC, Div Theory, E-46100 Valencia, Spain, Email: francisco.campanario@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:000344652800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2007
Permanent link to this record
 
 
Author Kleiss, R.H.P.; Malamos, I.; Papadopoulos, C.G.; Verheyen, R.
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 (up) 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 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 (up) 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;
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:000317521200025 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1418
Permanent link to this record
 
 
Author Buchta, S.; Chachamis, G.; Draggiotis, P.; Malamos, I.; Rodrigo, G.
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 (up) 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 Chachamis, G.; Deak, M.; Hentschinski, M.; Rodrigo, G.; Sabio Vera, A.
Title Single bottom quark production in kT-factorisation Type Journal Article
Year 2015 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 123 - 17pp
Keywords (up) QCD Phenomenology; NLO Computations
Abstract We present a study within the k(T)-factorisation scheme on single bottom quark production at the LHC. In particular, we calculate the rapidity and transverse momentum differential distributions for single bottom quark/anti-quark production. In our setup, the unintegrated gluon density is obtained from the NLx BFKL Green function whereas we included mass effects to the Lx heavy quark jet vertex. We compare our results to the corresponding distributions predicted by the usual collinear factorisation scheme. The latter were produced with Pythia 8.1.
Address [Chachamis, Grigorios; Sabio Vera, Agustin] Univ Autonoma Madrid, E-28049 Madrid, Spain, Email: grigorios.chachamis@csic.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:000361753300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2614
Permanent link to this record
 
 
Author Du, M.L.; Baru, V.; Guo, F.K.; Hanhart, C.; Meissner, U.G.; Oller, J.A.; Wang, Q.
Title Revisiting the nature of the P-c pentaquarks Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 157 - 50pp
Keywords (up) QCD Phenomenology; Non-perturbative renormalization
Abstract The nature of the three narrow hidden-charm pentaquark P-c states, i.e., P-c (4312), P-c (4440) and P-c (4457), is under intense discussion since their discovery from the updated analysis of the process Lambda(0)(b) -> I ) J/psi pK(-) by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. 124, 072001 (2020)], in which the Pc states are treated as Sigma(()(c)*()) (D) over bar (()*()) molecules, by including the Lambda(c)(D) over bar (()*()) and eta(c)p as explicit inelastic channels in addition to the J/psi p, as required by unitarity and heavy quark spin symmetry (HQSS), respectively. Since inelastic parameters are very badly constrained by the current data, three calculation schemes are considered: (a) scheme I with pure contact interactions between the elastic, i.e., Sigma(()(c)*()) (D) over bar (()*()), and inelastic channels and without the Lambda(c)(D) over bar (()*()) interactions, (b) scheme II, where the one-pion exchange (OPE) is added to scheme I, and (c) scheme III, where the Lambda(c)(D) over bar (()*()) interactions are included in addition. It is shown that to obtain cutoff independent results, OPE in the multichannel system is to be supplemented with S-wave-to-D-wave mixing contact terms. As a result, in line with our previous analysis, we demonstrate that the experimental data for the J/psi p invariant mass distribution are consistent with the interpretation of the P-c(4312) and P-c(4440)/P-c(4457) as Sigma(c)(D) over bar and Sigma(c)(D) over bar* hadronic molecules, respectively, and that the data show clear evidence for a new narrow state, P-c(4380), identified as a Sigma(c)*(D) over bar molecule, which should exist as a consequence of HQSS. While two statistically equally good solutions are found in scheme I, only one of these solutions with the quantum numbers of the P-c (4440) and P-c (4457) being J(P) = 3/2(-) and 1/2(-), respectively, survives the requirement of regulator independence once the OPE is included. Moreover, we predict the line shapes in the elastic and inelastic channels and demonstrate that those related to the P-c (4440) and the P-c (4457) in the Sigma(()(c)*())<(D)over ( )anf eta(c)p mass distributions from Lambda(0)(b) ->( )Sigma(()(c)*()) (D) over barK(-) and Lambda(0)(b) -> eta(c)pK(-) will shed light on the quantum numbers of those states, once the data are available. We also investigate possible pentaquark signals in the Lambda(c)(D) over bar (()*()) final states.
Address [Du, Meng-Lin; Meissner, Ulf-G.] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, Email: du@hiskp.uni-bonn.de
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:000693090600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4958
Permanent link to this record
 
 
Author Greynat, D.; de Rafael, E.; Vulvert, G.
Title Asymptotic behaviour of pion-pion total cross-sections Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 107 - 21pp
Keywords (up) QCD Phenomenology; Phenomenological Models
Abstract We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the pi pi total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log(2)s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for pi(+)pi(-), pi(+/-)pi(0) and pi(0)pi(0) scattering within the framework of the constituent chiral quark model (C chi QM) in the limit of a large number of colours N-c and discuss their asymptotic behaviours. The same pi pi cross sections are also discussed within the general framework of Large-N-c QCD and we show that it is possible to make an Ansatz for the isospin I = 1 and I = 0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N-c counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the sigma(total)(pi +/-pi 0)(s) cross section predicted by the CxQM with the high energy behaviour predicted by the Large-N-c Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp scattering total cross sections.
Address [Greynat, David] Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy, Email: david.greynat@gmail.com;
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:000333803000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1747
Permanent link to this record
 
 
Author Alioli, S.; Fuster, J.; Garzelli, M.V.; Gavardi, A.; Irles, A.; Melini, D.; Moch, S.O.; Uwer, P.; Voss, K.
Title Phenomenology of t(t)over-barj plus X production at the LHC Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 146 - 63pp
Keywords (up) Specific QCD Phenomenology; Top Quark
Abstract We present phenomenological results for t (t) over barj + X production at the Large Hadron Collider, of interest for designing forthcoming experimental analyses of this process. We focus on those cases where the t (t) over barj + X process is considered as a signal. We discuss present theoretical uncertainties and the dependence on relevant input parameters entering the computation. For the R. distribution, which depends on the invariant mass of the t (t) over barj-system, we present reference predictions in the on-shell, (MS) over bar and MSR top-quark mass renormalization schemes, applying the latter scheme to this process for the first time. Our conclusions are particularly interesting for those analyses aiming at extracting the topquark mass from cross-section measurements.
Address [Alioli, Simone; Gavardi, Alessandro] Univ Milano Bicocca, Dipartimento Fis G Occhialini, Piazza Sci 3, I-20126 Bicocca, Italy, Email: simone.alioli@unimib.it;
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:000801110800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5236
Permanent link to this record