Showing papers by "Antonio Pich published in 2010"
TL;DR: In this article, the authors discuss the phenomenological consequences of the presence of a charged scalar in the two-Higgs-doublet model at low energies and derive the corresponding constraints on the parameters of the aligned twoHiggs doublet model.
Abstract: The alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents. In addition to the usual fermion masses and mixings, the aligned Yukawa structure only contains three complex parameters ς
f
, which are potential new sources of CP violation [1]. For particular values of these three parameters all known specific implementations of the model based on discrete $ {\mathcal{Z}_2} $
symmetries are recovered. One of the most distinctive features of the two-Higgs-doublet model is the presence of a charged scalar H
±. In this work, we discuss its main phenomenological consequences in flavour-changing processes at low energies and derive the corresponding constraints on the parameters of the aligned two-Higgs-doublet model.
176 citations
Carleton University1, Imperial College London2, Fermilab3, RWTH Aachen University4, Queen Mary University of London5, Max Planck Society6, CERN7, Budker Institute of Nuclear Physics8, Karlsruhe Institute of Technology9, Technische Universität München10, Sapienza University of Rome11, Los Alamos National Laboratory12, Stanford University13, University of Minnesota14, University of Glasgow15, Charles University in Prague16, University of Pisa17, Austrian Academy of Sciences18, University of Bergen19, University of Southampton20, Nara Women's University21, University of Florida22, University of Turin23, University of Edinburgh24, University of Warwick25, University of Massachusetts Amherst26, University of Bern27, University of Mainz28, Wayne State University29, Brookhaven National Laboratory30, Folkwang University of the Arts31, University of Victoria32, Washington University in St. Louis33, Indian Institute of Technology Madras34, University of Melbourne35, Princeton University36, Roma Tre University37, York University38, University of California, Irvine39, University of Valencia40, University of Padua41, University of Barcelona42, Tata Institute of Fundamental Research43, University of Vienna44, University of Paris-Sud45, University of Kentucky46, University of Oxford47, Iowa State University48, University of Bristol49, Rutherford Appleton Laboratory50, University of Texas at Austin51, École Polytechnique Fédérale de Lausanne52, University of California, Santa Cruz53, University of Cincinnati54, Purdue University55, ETH Zurich56, Queen's University57, Indiana University58, University of Cambridge59, University of Ljubljana60
TL;DR: In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously as mentioned in this paper and a much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions.
165 citations
09 Aug 2010
TL;DR: The SuperB Collaboration as discussed by the authors extended and updated the studies presented in both the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.
Abstract: 84 paginas, 38 figuras, 25 tablas.-- This report extends and updates the studies presented in both the SuperB Conceptual Design Report in 2007
and the Proceedings of SuperB Workshop VI in Valencia in 2008.-- This report is the result of the joint e ort between the named authors and from the following contributing
institutions who are working on the SuperB project: SuperB Collaboration: et al.
89 citations
TL;DR: In this paper, Gomez Dumm, A. Pich, J. Portoles, and A. Gasser have studied the τ → π π ν τ decay process.
73 citations
TL;DR: In this article, it was shown that the use of pinched weights allows to determine with high accuracy the dimension six and eight contributions in the operator-product expansion, O{sub 6}=(-4.3{sub -0.7}{sup + 0.9})x10{sup -3} GeV{sup 6} and O {sub 8}=( −7.2{sub 5.3}{sup+4.2})x 10{sup + 4.2
Abstract: We analyze the so-called pinched weights, that are generally thought to reduce the violation of quark-hadron duality in finite-energy sum rules. After showing how this is not true in general, we explain how to address this question for the left-right correlator and any particular pinched weight, taking advantage of our previous work [1], where the possible high-energy behavior of the left-right spectral function was studied. In particular, we show that the use of pinched weights allows to determine with high accuracy the dimension six and eight contributions in the operator-product expansion, O{sub 6}=(-4.3{sub -0.7}{sup +0.9})x10{sup -3} GeV{sup 6} and O{sub 8}=(-7.2{sub -5.3}{sup +4.2})x10{sup -3} GeV{sup 8}.
51 citations
TL;DR: In this article, the authors analyzed the spectral moments of the two-point correlation function and determined the lowest spectral moments, trying to assess the uncertainties associated with the so-called violations of quark-hadron duality.
Abstract: We analyze the spectral moments of the $V\ensuremath{-}A$ two-point correlation function. Using all known short-distance constraints and the most recent experimental data from tau decays, we determine the lowest spectral moments, trying to assess the uncertainties associated with the so-called violations of quark-hadron duality. We have generated a large number of acceptable spectral functions, satisfying all conditions, and have used them to extract the wanted hadronic parameters through a careful statistical analysis. We obtain accurate values for the $\ensuremath{\chi}\mathrm{PT}$ couplings ${L}_{10}$ and ${C}_{87}$, and a realistic determination of the dimension six and eight contributions in the operator product expansion, ${\mathcal{O}}_{6}=(\ensuremath{-}{5.4}_{\ensuremath{-}1.6}^{+3.6})\ifmmode\cdot\else\textperiodcentered\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{GeV}}^{6}$ and ${\mathcal{O}}_{8}=(\ensuremath{-}{8.9}_{\ensuremath{-}7.4}^{+12.6})\ifmmode\cdot\else\textperiodcentered\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{GeV}}^{8}$, showing that the duality-violation effects have been underestimated in previous literature.
41 citations
TL;DR: In this paper, Eidelman, Hayashii, Malaescu, O. Shekhovtsova, and Z. P. Roig have been partially supported by a FPU contract (MEC), the DFG cluster of excellence (DFG), and a Marie Curie ESR Contract (FLAVIAnet).
Abstract: We wish to thank S. Eidelman, H. Hayashii, B. Malaescu, O. Shekhovtsova and Z. Was for
their interest in this work and many useful discussions on the topic of this article. P. Roig has
been partially supported by a FPU contract (MEC), the DFG cluster of excellence ’Origin and
Structure of the Universe’ and a Marie Curie ESR Contract (FLAVIAnet). This work has been
supported in part by the EU MRTN-CT-2006-035482 (FLAVIAnet), by MEC (Spain) under
grant FPA2007-60323, by the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-
00042) and by Generalitat Valenciana under grant PROMETEO/2008/069. This work has also
been supported by CONICET and ANPCyT (Argentina), under grants PIP6009, PIP02495,
PICT04-03-25374 and PICT07-03-00818.
39 citations
TL;DR: In this paper, the alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents.
Abstract: The alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents. In addition to the usual fermion masses and mixings, the aligned Yukawa structure only contains three complex parameters, which are potential new sources of CP violation. For particular values of these three parameters all known specific implementations of the model based on discrete Z_2 symmetries are recovered. One of the most distinctive features of the two-Higgs-doublet model is the presence of a charged scalar. In this work, we discuss its main phenomenological consequences in flavour-changing processes at low energies and derive the corresponding constraints on the parameters of the aligned two-Higgs-doublet model.
37 citations
TL;DR: In this article, the vector form factor of the pion at the next-to-leading order (NLO) in the 1/N(C) expansion was calculated using the Resonance Chiral Theory Lagrangian.
Abstract: Using the Resonance Chiral Theory Lagrangian, we perform a calculation of the vector form factor of the pion at the next-to-leading order (NLO) in the 1/N(C) expansion. Imposing the correct QCD short-distance constraints, one fixes the amplitude in terms of the pion decay constant F and resonance masses. Its low momentum expansion determines then the corresponding O(p4) and O(p6) low-energy chiral couplings at NLO, keeping control of their renormalization scale dependence. At mu0=0.77 GeV, we obtain L9(mu0) = (7.9 \pm 0.4) 10^{-3} and C88(mu0)-C90(mu0)=(-4.6 \pm 0.4) 10^{-5}.
32 citations
01 Dec 2010
TL;DR: In this paper, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation.
Abstract: In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation. With N Higgs doublets (and no right-handed neutrinos) the Yukawa Lagrangian is characterized by the fermion masses, the CKM quark mixing matrix and 3 ( N − 1 ) complex couplings. Quantum corrections break the alignment, generating a minimal-flavour-violation structure with flavour-blind phases. The aligned multi-Higgs-doublet models lead to a rich and viable phenomenology with an interesting hierarchy of flavour-changing neutral current effects, suppressing them in light-quark systems while allowing potentially relevant signals in heavy-quark transitions.
13 Jan 2010
TL;DR: Topical Workshop on Low Energy Constraints on Extensions of the Standard Model (SME) as discussed by the authors, presented by Kazimierz et al., has been held in Warsaw, Poland.
Abstract: Topical Workshop on Low Energy Constraints on Extensions of the Standard Model
Kazimierz, POLAND, JUL 23-27, 2009
Posted Content•
TL;DR: In this article, the alignment of the Yukawa flavour matrices of the two scalar doublets guarantees the absence of tree-level flavour-changing neutral couplings, and the resulting fermion-scalar interactions are parameterized in terms of three complex parameters.
Abstract: In the two-Higgs-Doublet model the alignment of the Yukawa flavour matrices of the two scalar doublets guarantees the absence of tree-level flavour-changing neutral couplings. The resulting fermion-scalar interactions are parameterized in terms of three complex parameters, leading to a generic Yukawa structure which contains as particular cases all known specific implementations of the model based on Z2 symmetries. These three complex parameters are potential new sources of CP violation.
Posted Content•
TL;DR: In this paper, the total tau hadronic width can be accurately calculated using analyticity and the operator product expansion, and the result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant.
Abstract: The total tau hadronic width can be accurately calculated using analyticity and the operator product expansion. The result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant. The theoretical description of this observable is updated, including the recently computed O(alpha_s^4) contributions. The experimental determination of alpha_s(m_tau^2) and its actual uncertainties are discussed.
TL;DR: In this paper, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation.
Abstract: In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation. With N Higgs doublets (and no right-handed neutrinos) the Yukawa Lagrangian is characterized by the fermion masses, the CKM quark mixing matrix and 3(N-1) complex couplings. Quantum corrections break the alignment, generating a minimal-flavour-violation structure with flavour-blind phases. The aligned multi-Higgs-doublet models lead to a rich and viable phenomenology with an interesting hierarchy of flavour-changing neutral current effects, suppressing them in light-quark systems while allowing potentially relevant signals in heavy-quark transitions.
01 Jan 2010
TL;DR: In this article, the total tau hadronic width can be accurately calculated using analyticity and the operator product expansion, and the result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant.
Abstract: The total tau hadronic width can be accurately calculated using analyticity and the operator product expansion. The result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant. The theoretical description of this observable is updated, including the recently computed O(alpha_s^4) contributions. The experimental determination of alpha_s(m_tau^2) and its actual uncertainties are discussed.
TL;DR: In this paper, the so-called violations of quark-hadron duality in Finite Energy Sum Rules with the LR correlator were analyzed through the study of the possible high-energy behavior of the LR spectral function, taking into account all known short-distance constraints and the experimental tau-decay data.
Abstract: We analyse the so-called violations of quark-hadron duality in Finite Energy Sum Rules with the LR correlator, through the study of the possible high-energy behavior of the LR spectral function, taking into account all known short-distance constraints and the experimental tau-decay data. In particular we show that the use of pinched weights allows to determine with high accuracy the dimension six and eight contributions in the Operator-Product Expansion, O_6 = (-4.3^{+0.9}_{-0.7}) 10^{-3} GeV^6 and O_8 = (-7.2^{+4.2}_{-5.3}) 10^{-3} GeV^8.
25 Feb 2010
TL;DR: The 6o International Workshop on Chiral Dynamics (IWCD 2009) as mentioned in this paper was held in Bern (Suiza), Spain, 6-10 de Julio 2009, 6.9 paginas, 2 figuras, 2 tablas.
Abstract: 9 paginas, 2 figuras, 2 tablas.-- Comunicacion presentada en el 6o International Workshop on Chiral Dynamics, celebrado del 6 al 10 de Julio de 2009 en Bern (Suiza).
01 Oct 2010
TL;DR: Gonzalez-Alonso et al. as mentioned in this paper analyzed the so-called violations of quark-hadron duality in finite energy sum rules with the LR correlator, through the study of the possible high-energy behavior of the LR spectral function, taking into account all known short-distance constraints and the experimental tau-decay data.
Abstract: We analyse the so-called violations of quark-hadron duality in Finite Energy Sum Rules (FESRs) with the LR correlator, through the study of the possible high-energy behavior of the LR spectral function, taking into account all known short-distance constraints and the experimental tau-decay data. In particular we show that the use of pinched weights (PWs) allows to determine with high accuracy the dimension six and eight contributions in the Operator-Product Expansion, O 6 = ( − 4.3 − 0.7 + 0.9 ) ⋅ 10 − 3 GeV 6 and O 8 = ( − 7.2 − 5.3 + 4.2 ) ⋅ 10 − 3 GeV 8 [M. Gonzalez-Alonso, A. Pich, and J. Prades, Phys. Rev. D81 (2010) 074007, arXiv:1001.2269 [hep-ph] ; M. Gonzalez-Alonso, A. Pich, and J. Prades, Phys. Rev. D82 (2010) 014019, arXiv:1004.4987 [hep-ph] ].