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Author Ellis, J.; Hodgkinson, R.N.; Lee, J.S.; Pilaftsis, A.
Title Flavour geometry and effective Yukawa couplings in the MSSM Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume (up) 02 Issue 2 Pages 016 - 35pp
Keywords Supersymmetric Standard Model; B-Physics
Abstract We present a new geometric approach to the flavour decomposition of an arbitrary soft supersymmetry-breaking sector in the MSSM. Our approach is based on the geometry that results from the quark and lepton Yukawa couplings, and enables us to derive the necessary and sufficient conditions for a linearly-independent basis of matrices related to the completeness of the internal [SU(3) circle times U(1)](5) flavour space. In a second step, we calculate the effective Yukawa couplings that are enhanced at large values of tan beta for general soft supersymmetry-breaking mass parameters. We highlight the contributions due to non-universal terms in the flavour decompositions of the sfermion mass matrices. We present numerical examples illustrating how such terms are induced by renormalization-group evolution starting from universal input boundary conditions, and demonstrate their importance for the flavour-violating effective Yukawa couplings of quarks.
Address [Ellis, John] CERN, Div Theory, CH-1211 Geneva 23, Switzerland, Email: John.Ellis@cern.ch
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:000275223100016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 482
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Author Battye, R.A.; Brawn, G.D.; Pilaftsis, A.
Title Vacuum topology of the two Higgs doublet model Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume (up) 08 Issue 8 Pages 020 - 75pp
Keywords Higgs Physics; Spontaneous Symmetry Breaking; CP violation
Abstract We perform a systematic study of generic accidental Higgs-family and CP symmetries that could occur in the two-Higgs-doublet-model potential, based on a Majorana scalar-field formalism which realizes a subgroup of GL(8, C). We derive the general conditions of convexity and stability of the scalar potential and present analytical solutions for two non-zero neutral vacuum expectation values of the Higgs doublets for a typical set of six symmetries, in terms of the gauge-invariant parameters of the theory. By means of a homotopy-group analysis, we identify the topological defects associated with the spontaneous symmetry breaking of each symmetry, as well as the massless Goldstone bosons emerging from the breaking of the continuous symmetries. We find the existence of domain walls from the breaking of Z(2), CP1 and CP2 discrete symmetries, vortices in models with broken U(1)(PQ) and CP3 symmetries and a global monopole in the SO(3)(HF)-broken model. The spatial profile of the topological defect solutions is studied in detail, as functions of the potential parameters of the two-Higgs doublet model. The application of our Majorana scalar-field formalism in studying more general scalar potentials that are not constrained by the U(1)(Y) hypercharge symmetry is discussed. In particular, the same formalism may be used to properly identify seven additional symmetries that may take place in a U(1)(Y)-invariant scalar potential.
Address [Battye, RA; Brawn, GD] Univ Manchester, Jodrell Bank, Ctr Astrophys, Sch Phys & Astron, Manchester M13 9PL, Lancs, England, Email: rbattye@jb.man.ac.uk
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:000294901400062 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 765
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Author Lee, J.S.; Pilaftsis, A.
Title Radiative corrections to scalar masses and mixing in a scale invariant two Higgs doublet model Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume (up) 86 Issue 3 Pages 035004 - 14pp
Keywords
Abstract We study the Higgs boson mass spectrum of a classical scale invariant realization of the two Higgs doublet model (SI-2HDM). The classical scale symmetry of the theory is explicitly broken by quantum loop effects due to gauge interactions, Higgs self-couplings and top quark Yukawa couplings. We determine the allowed parameter space compatible with perturbative unitarity and electroweak precision data. Taking into account the LEP and the recent LHC exclusion limits on a standard-model-like Higgs boson HSM, we obtain rather strict constraints on the mass spectrum of the heavy Higgs sector of the SI-2HDM. In particular, if MHSM 125 GeV, the SI-2HDM strongly favors scenarios in which at least one of the nonstandard neutral Higgs bosons has a mass close to 400 GeV and is generically degenerate with the charged Higgs boson, whilst the third neutral Higgs scalar is lighter than 500 GeV.
Address [Lee, Jae Sik] Natl Tsing Hua Univ, Dept Phys, Hsinchu 300, Taiwan
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000307122700007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1113
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Author Pilaftsis, A.
Title On the classification of accidental symmetries of the two Higgs doublet model potential Type Journal Article
Year 2012 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume (up) 706 Issue 4-5 Pages 465-469
Keywords Symmetries; Extended Higgs sector
Abstract Recently, it has been shown Battye et al. (2011) that the two Higgs doublet model potential may exhibit a maximum of 13 distinct accidental symmetries. Such a classification is based on a six-dimensional bilinear scalar field formalism realizing the SO(1.5) symmetry group. This Letter presents the transformation relations for each of the 13 symmetries in the original scalar field space and their one-to-one correspondence to the space of scalar bilinears, thereby providing firm support for the completeness of the classification.
Address [Pilaftsis, Apostolos] Univ Manchester, Sch Phys & Astron, LMS Consortium Fundamental Phys, Manchester M13 9PL, Lancs, England, Email: apostolos.pilaftsis@manchester.ac.uk
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000299756800035 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 889
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Author Kittel, O.; Pilaftsis, A.
Title CP violation in correlated production and decay of unstable particles Type Journal Article
Year 2012 Publication Nuclear Physics B Abbreviated Journal Nucl. Phys. B
Volume (up) 856 Issue 3 Pages 682-697
Keywords EPR correlation; Resonant CP violation; Collider phenomenology
Abstract We study resonant CP-violating Einstein-Podolsky-Rosen correlations that may take place in the production and decay of unstable scalar particles at high-energy colliders. We show that as a consequence of unitarity and CPT invariance of the S-matrix, in 2 -> 2 scatterings mediated by mixed scalar particles, at least three linearly independent decay matrices associated with the unstable scalar states are needed to obtain non-zero CP-odd observables that are also odd under C-conjugation. Instead, for the correlated production and decay of two unstable particle systems in 2 -> 4 processes, we find that only two independent decay matrices are sufficient to induce a net non-vanishing CP-violating phenomenon. As an application of this theorem, we present numerical estimates of CP asymmetries for the correlated production and decay of supersymmetric scalar top anti-top pairs at the LHC, and demonstrate that these could reach values of order one. As a byproduct of our analysis, we develop a novel spinorial trace technique, which enables us to efficiently evaluate lengthy expressions of squared amplitudes describing the resonant scalar transitions.
Address [Kittel, Olaf] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain, Email: kittel@th.physik.uni-bonn.de
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0550-3213 ISBN Medium
Area Expedition Conference
Notes WOS:000300028200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 892
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