Apostolos Pilaftsis

Flavour Geometry and Effective Yukawa Couplings in the MSSM (2009)

Ellis, John, Hodgkinson, Robert N, Lee, Jae Sik, Pilaftsis, Apostolos

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...

Flavour Geometry and Effective Yukawa Couplings in the MSSM (2009)

Ellis, John, Hodgkinson, Robert N., Lee, Jae Sik, Pilaftsis, Apostolos

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...

Supersymmetric Lepton Flavor Violation (2009)

Ilakovac, Amon, Pilaftsis, Apostolos

We study a new supersymmetric mechanism for lepton flavor violation in a minimal extension of the MSSM with low-mass heavy singlet neutrinos, which is fully independent of the flavor structure of the...

Supersymmetric Lepton Flavour Violation in Low-Scale Seesaw Models (2009)

Ilakovac, Amon, Pilaftsis, Apostolos

We study a new supersymmetric mechanism for lepton flavour violation in muon and tau decays and muon -> e conversion in nuclei, within a minimal extension of the MSSM with low-mass heavy singlet...

The Little Review on Leptogenesis (2009)

Pilaftsis, Apostolos

This is a brief review on the scenario of baryogenesis through leptogenesis. Leptogenesis is an appealing scenario that may relate the observed baryon asymmetry in the Universe to the low-energy...

Thermal Right-Handed Sneutrino Dark Matter (2008)

Deppisch, Frank, Pilaftsis, Apostolos

We discuss the relic abundance of the right-handed sneutrinos in the supersymmetric F_D-term model of hybrid inflation. As well as providing a natural solution to the mu- and gravitino overabundance...

The One-Loop Effective Potential in Non-Linear Gauges (2008)

Alexander, Lisa P., Pilaftsis, Apostolos

We calculate the 1-loop effective potential of an Abelian Higgs model within the R_{\xi/\sigma} class of non-linear gauges that preserves the Higgs-boson low-energy theorem. The R_{\xi/\sigma} gauge...

Electric Dipole Moments in the MSSM Reloaded (2008)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

We present a detailed study of the Thallium, neutron, Mercury and deuteron electric dipole moments (EDMs) in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take...

Electric Dipole Moments in the MSSM Reloaded (2008)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

We present a detailed study of the Thallium, neutron, Mercury and deuteron electric dipole moments (EDMs) in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take...

Thermal Right-Handed Sneutrino Dark Matter in the F_D-Term Model of Hybrid Inflation (2008)

Deppisch, Frank, Pilaftsis, Apostolos

We compute the relic abundance of the right-handed sneutrinos in the supersymmetric F_D-term model of hybrid inflation. As well as providing a natural solution to the mu- and gravitino overabundance...

Supersymmetric Higgs Singlet Effects on B-Meson FCNC Observables at Large tan(beta) (2008)

Hodgkinson, Robert N., Pilaftsis, Apostolos

Higgs singlet superfields are usually present in most extensions of the Minimal Supersymmetric Standard Model (MSSM) that address the mu-problem, such as the Next-to-Minimal Supersymmetric Standard...

Textures and Semi-Local Strings in SUSY Hybrid Inflation (2008)

Battye, Richard A., Garbrecht, Bjorn, Pilaftsis, Apostolos

Global topological defects may account for the large cold spot observed in the Cosmic Microwave Background. We explore possibilities of constructing models of supersymmetric F-term hybrid inflation,...

Electroweak Resonant Leptogenesis in the Singlet Majoron Model (2008)

Pilaftsis, Apostolos

We study resonant leptogenesis at the electroweak phase transition in the singlet Majoron model with right-handed neutrinos. We consider a scenario, where the SM gauge group and the lepton number...

CPsuperH2.0: an Improved Computational Tool for Higgs Phenomenology in the MSSM with Explicit CP Violation (2007)

Lee, J S, Carena, M S, Ellis, Jonathan Richard, Pilaftsis, Apostolos, Wagner, C E M

We describe the Fortran code CPsuperH2.}, which contains several improvements and extensions of its predecessor CPsuperH. It implements improved calculations of the Higgs-boson pole masses, notably a...

Comments on Spontaneous Spin-Statistics Violation by Fermion Condensates (2007)

Pilaftsis, Apostolos

Scalar condensation, the well-established Higgs phenomenon, is the standard paradigm for building up renormalizable gauge-invariant theories of massive gauge bosons. In this short note, we...

B-Meson Observables in the Maximally CP-Violating MSSM with Minimal Flavour Violation (2007)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

Additional sources of CP violation in the MSSM may affect B-meson mixings and decays, even in scenarios with minimal flavour violation (MFV). We formulate the maximally CP-violating and minimally...

B-Meson Observables in the Maximally CP-Violating MSSM with Minimal Flavour Violation (2007)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

Additional sources of CP violation in the MSSM may affect B-meson mixings and decays, even in scenarios with minimal flavour violation (MFV). We formulate the maximally CP-violating and minimally...

Resonant CP Violation due to Heavy Neutrinos at the LHC (2007)

Bray, Simon, Lee, Jae Sik, Pilaftsis, Apostolos

The observed light neutrinos may be related to the existence of new heavy neutrinos in the spectrum of the SM. If a pair of heavy neutrinos has nearly degenerate masses, then CP violation from the...

Radiative Yukawa Couplings for Supersymmetric Higgs Singlets at Large tan(beta) (2006)

Hodgkinson, Robert N., Pilaftsis, Apostolos

Singlet Higgs bosons present in extensions of the MSSM can have sizable Yukawa couplings to the b quark and the tau lepton for large values of tan(beta) at the 1-loop level. We present an effective...

Higgs Phenomenology with CPsuperH (2006)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

The MSSM contains CP-violating phases that may have important observable effects in Higgs physics. We review recent highlights in Higgs phenomenology obtained with the code CPsuperH, a useful tool...

Anatomy of $F_D$-Term Hybrid Inflation (2006)

Garbrecht, B, Pallis, C, Pilaftsis, Apostolos

We analyze the cosmological implications of F-term hybrid inflation with a subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a D-parity in the inflaton-waterfall sector. This...

Higgs Phenomenology with CPsuperH (2006)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

The MSSM contains CP-violating phases that may have important observable effects in Higgs physics. We review recent highlights in Higgs phenomenology obtained with the code CPsuperH, a useful tool...

Anatomy of F_D-Term Hybrid Inflation (2006)

Garbrecht, Bjorn, Pallis, Constantinos, Pilaftsis, Apostolos

We analyze the cosmological implications of F-term hybrid inflation with a subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a D-parity in the inflaton-waterfall sector. This...

Les Houches "Physics at TeV Colliders 2005'' Beyond the Standard Model working group: summary report (2006)

Accomando, E, Azuelos, Georges, Baer, H, Balázs, C, Bélanger, G, Benakli, Karim, ...

The work contained herein constitutes a report of the "Beyond the Standard Model'' working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. We present reviews...

$F_D$-Term Hybrid Inflation with Electroweak-Scale Lepton Number Violation (2006)

Garbrecht, B, Pilaftsis, Apostolos

We study F-term hybrid inflation in a novel supersymmetric extension of the SM with a subdominant Fayet-Iliopoulos D-term. We call this particular form of inflation, in short, F_D-term hybrid...

F_D-Term Hybrid Inflation with Electroweak-Scale Lepton Number Violation (2006)

Garbrecht, Bjorn, Pilaftsis, Apostolos

We study F-term hybrid inflation in a novel supersymmetric extension of the SM with a subdominant Fayet-Iliopoulos D-term. We call this particular form of inflation, in short, F_D-term hybrid...

Displacement Operator Formalism (2005)

Papavassiliou, J, Binosi, D, Pilaftsis, Apostolos

We review the D-formalism, a new method for determining the renormalization of Green functions to all orders in perturbation theory. This formalism exploits the fact that the renormalized Green...

Displacement Operator Formalism (2005)

Papavassiliou, Joannis, Binosi, Daniele, Pilaftsis, Apostolos

We review the D-formalism, a new method for determining the renormalization of Green functions to all orders in perturbation theory. This formalism exploits the fact that the renormalized Green...

Theory of Neutrinos: A White Paper (2005)

Mohapatra, Rabindra N, Antusch, S, Babu, K S, Barenboim, G, Chen, M C, Davidson, Sacha, ...

During 2004, four divisions of the American Physical Society commissioned a study of neutrino physics to take stock of where the field is at the moment and where it is going in the near and far...

1st Workshop on CP Studies and Non-standard Higgs Physics (2005)

Kraml, Sabine, Azuelos, Georges, Dominici, Daniele, Ellis, Jonathan Richard, Grenier, Gérald, Haber, Howard E, ...

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between...

Heavy Majorana Neutrino Production at e- gamma Colliders (2005)

Bray, Simon, Lee, Jae Sik, Pilaftsis, Apostolos

We study signatures of heavy Majorana neutrinos at e- gamma colliders. Since these particles violate lepton number, they can give rise to the reactions e- gamma -> W- W- e+ and e- gamma -> W+ mu- mu-...

Resonant CP Violation in Higgsstrahlung at an $e^{+}e^{-}$ Linear Collider (2005)

Ellis, J, Lee Jae Sik, Pilaftsis, Apostolos

We study resonant CP violation in the Higgsstrahlung process e^+e^- -> H_{1,2,3} (Z -> e^+e^-, \mu^+\mu^-) and subsequent decays H_{1,2,3} -> b \bar{b}, \tau^-\tau^+, in the MSSM with Higgs-sector CP...

Resonant CP Violation in Higgsstrahlung at an $e^{+}e^{-}$ Linear Collider (2005)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

We study resonant CP violation in the Higgsstrahlung process e^+e^- -> H_{1,2,3} (Z -> e^+e^-, \mu^+\mu^-) and subsequent decays H_{1,2,3} -> b \bar{b}, \tau^-\tau^+, in the MSSM with Higgs-sector CP...

Resonant CP Violation in Higgs Radiation at e^+e^- Linear Collider (2005)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

We study resonant CP violation in the Higgsstrahlung process e^+e^- -> H_{1,2,3} (Z -> e^+e^-, \mu^+\mu^-) and subsequent decays H_{1,2,3} -> b \bar{b}, \tau^-\tau^+, in the MSSM with Higgs-sector CP...

Electroweak-Scale Resonant Leptogenesis (2005)

Pilaftsis, Apostolos, Underwood, Thomas E. J.

We study minimal scenarios of resonant leptogenesis near the electroweak phase transition. These models offer a number of testable phenomenological signatures for low-energy experiments and future...

Diffraction as a CP and Lineshape Analyzer for MSSM Higgs Bosons at the LHC (2005)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

We study the production and decay of a coupled system of mixed neutral MSSM Higgs bosons in exclusive double-diffractive processes at the LHC, including non-vanishing CP phases in the soft...

Diffraction as a CP and Lineshape Analyzer for MSSM Higgs Bosons at the LHC (2005)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

We study the production and decay of a coupled system of mixed neutral MSSM Higgs bosons in exclusive double-diffractive processes at the LHC, including non-vanishing CP phases in the soft...

Diffraction as a CP and Lineshape Analyzer for MSSM Higgs Bosons at the LHC (2005)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

We study the production and decay of a coupled system of mixed neutral MSSM Higgs bosons in exclusive double-diffractive processes at the LHC, including non-vanishing CP phases in the soft...

Displacement Operator Formalism for Renormalization and Gauge Dependence to All Orders (2005)

Binosi, Daniele, Papavassiliou, Joannis, Pilaftsis, Apostolos

We present a new method for determining the renormalization of Green functions to all orders in perturbation theory, which we call the displacement operator formalism, or the D-formalism, in short....

Resonant CP Violation in MSSM Higgs Production and Decay at $\gamma \gamma$ Colliders (2004)

Ellis, Jonathan Richard, Lee Jae Sik, Pilaftsis, Apostolos

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at \gamma \gamma colliders, assuming a Minimal Supersymmetric Standard...

Resonant CP Violation in MSSM Higgs Production and Decay at $\gamma \gamma$ Colliders (2004)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at \gamma \gamma colliders, assuming a Minimal Supersymmetric Standard...

Quantization and High Energy Unitarity of 5D Orbifold Theories with Brane Kinetic Terms (2004)

Mück, Alexander, Nilse, Lars, Pilaftsis, Apostolos, Rückl, Reinhold

Five-dimensional field theories compactified on an S^1/Z_2 orbifold naturally include local brane kinetic terms at the orbifold fixed points at the tree as well as the quantum level. We study the...

Probing Minimal 5D Extensions of the Standard Model (2004)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We analyze non-universal 5D standard model extension, where some or all of the gauge and Higgs fields propagate in a flat extra dimension, while all other degrees of freedom are localized on a...

Resonant \tau-Leptogenesis with Observable Lepton Number Violation (2004)

Pilaftsis, Apostolos

We consider a minimal extension of the Standard Model with one singlet neutrino per generation that can realize resonant leptogenesis at the electroweak scale. In particular, the baryon asymmetry in...

Higgs bosons in the minimal supersymmetric standard model with explicit CP violation (2004)

Pilaftsis, Apostolos, Wagner, C E M

We study the Higgs-boson mass spectrum of the minimal supersymmetric standard model, in which the tree-level CP invariance of the Higgs potential is broken explicitly by loop effects of...

LHC Signatures of Resonant CP Violation in a Minimal Supersymmetric Higgs Sector (2004)

Ellis, Jonathan Richard, Pilaftsis, Apostolos, Sik Lee Jae

We present the general formalism for studying CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at high-energy colliders. Considering...

LHC Signatures of Resonant CP Violation in a Minimal Supersymmetric Higgs Sector (2004)

Ellis, John, Lee, Jae Sik, Pilaftsis, Apostolos

We present the general formalism for studying CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at high-energy colliders. Considering...

Probing Minimal 5D Extensions of the Standard Model: From LEP to an $e^{+} e^{-}$ Linear Collider (2003)

Mück, A, Pilaftsis, Apostolos, Rückl, R

We derive new improved constraints on the compactification scale of minimal 5-dimensional (5D) extensions of the Standard Model (SM) from electroweak and LEP2 data and estimate the reach of an e^+e^-...

Probing Minimal 5D Extensions of the Standard Model: From LEP to an e^+e^- Linear Collider (2003)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We derive new improved constraints on the compactification scale of minimal 5-dimensional (5D) extensions of the Standard Model (SM) from electroweak and LEP2 data and estimate the reach of an e^+e^-...

Resonant Leptogenesis (2003)

Pilaftsis, Apostolos, Underwood, Thomas E. J.

We study the scenario of thermal leptogenesis in which the leptonic asymmetries are resonantly enhanced through the mixing of nearly degenerate heavy Majorana neutrinos that have mass differences...

CPsuperH: a Computational Tool for Higgs Phenomenology in the Minimal Supersymmetric Standard Model with Explicit CP Violation (2003)

Lee Jae Sik, Pilaftsis, Apostolos, Carena, M S, Choi, S Y, Drees, Manuel, Ellis, Jonathan Richard, ...

We provide a detailed description of the Fortran code CPsuperH, a newly--developed computational package that calculates the mass spectrum and decay widths of the neutral and charged Higgs bosons in...

Collider Probes of the MSSM Higgs Sector with Explicit CP Violation (2002)

Carena, M S, Ellis, Jonathan Richard, Mrenna, S, Pilaftsis, Apostolos, Wagner, C E M

We investigate the hadron collider phenomenology of the Minimal Supersymmetric Standard Model (MSSM) with explicit CP violation for Higgs bosons that can be observed in Standard Model search...

LEP Constraints on 5-Dimensional Extensions of the Standard Model (2002)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We study minimal 5-dimensional extensions of the Standard Model, in which all or only some of the SU(2)$_L$ and U(1)$_Y$ gauge fields and Higgs bosons propagate in the fifth compact dimension. In all...

An Introduction to 5-Dimensional Extensions of the Standard Model (2002)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We give a pedagogical introduction to the physics of large extra dimensions. We focus our discussion on minimal extensions of the Standard Model in which gauge fields may propagate in a single,...

Resummed Effective Lagrangian for Higgs-Mediated FCNC Interactions in the CP-Violating MSSM (2002)

Dedes, Athanasios, Pilaftsis, Apostolos

We derive the general resummed effective Lagrangian for Higgs-mediated flavour-changing neutral-current (FCNC) interactions in the Minimal Supersymmetric Standard Model (MSSM), without resorting to...

Higgs-Mediated Electric Dipole Moments in the MSSM: An Application to Baryogenesis and Higgs Searches (2002)

Pilaftsis, Apostolos

We perform a comprehensive study of the dominant two- and higher-loop contributions to the Tl(205), neutron and muon electric dipole moments induced by Higgs bosons, third-generation quarks and...

Higgs-Mediated Electric Dipole Moments in the MSSM: An Application to Baryogenesis and Higgs Searches (2002)

Pilaftsis, Apostolos

We perform a comprehensive study of the dominant two- and higher-loop contributions to the $^{205}$Tl, neutron and muon electric dipole moments induced by Higgs bosons, third-generation quarks and...

Gauge and Scheme Dependence of Mixing Matrix Renormalization (2002)

Pilaftsis, Apostolos

We revisit the issue of mixing matrix renormalization in theories that include Dirac or Majorana fermions. We show how a gauge-variant on-shell renormalized mixing matrix can be related to a...

Electroweak Constraints on Minimal Higher-Dimensional Extensions of the Standard Model (2002)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We derive electroweak constraints on the compactification scale of minimal 5-dimensional extensions of the Standard Model, in which all or only some of the SU(2)$_L$ and U(1)$_Y$ gauge fields and...

Physics opportunities at $\mu^{+}\mu^{-}$ Higgs factories (2002)

Blöchinger, C, Carena, M S, Ellis, Jonathan Richard, Fraas, H, Franke, F, García, D, ...

We update theoretical studies of the physics opportunities presented by mu+mu- Higgs factories. Interesting measurements of the Standard Model Higgs decays into {\bar b}b, tau+tau- and WW* may be...

Higgs-Boson Pole Masses in the MSSM with Explicit CP Violation (2001)

Carena, M S, Ellis, Jonathan Richard, Pilaftsis, Apostolos, Wagner, C E M

Extending previous results obtained in the effective-potential approach, we derive analytic expressions for the pole masses of the charged and neutral Higgs bosons in the minimal supersymmetric...

Minimal Higher-Dimensional Extensions of the Standard Model and Electroweak Observables (2001)

Mück, Alexander, Pilaftsis, Apostolos, Rückl, Reinhold

We consider minimal 5-dimensional extensions of the Standard Model compactified on an $S^1/Z_2$ orbifold, in which the SU(2)$_L$ and U(1)$_Y$ gauge fields and Higgs bosons may or may not all...

Laboratory Limits on Theories with Sterile Neutrinos in the Bulk (2000)

Ioannisian, Ara, Pilaftsis, Apostolos

We discuss the phenomenological consequences of theories which describe sterile neutrinos in large extra dimensions, in the so-called bulk. We briefly outline how the cumulative non-decoupling effect...

CP-Violating MSSM Higgs Bosons in the Light of LEP 2 (2000)

Carena, M S, Ellis, Jonathan Richard, Pilaftsis, Apostolos, Wagner, C E M

In the MSSM, the CP parities of the neutral Higgs bosons may be mixed by radiative effects induced by explicit CP violation in the third generation of squarks. To allow for this possibility, we argue...

Search for solar Kaluza-Klein axions in theories of low-scale quantum gravity (2000)

Di Lella, L, Pilaftsis, Apostolos, Raffelt, G G, Zioutas, Konstantin

We explore the physics potential of a terrestrial detector for observing axionic Kaluza-Klein excitations coming from the Sun within the context of higher-dimensional theories of low-scale quantum...

Radiative Higgs-Sector CP Violation in the MSSM (2000)

Pilaftsis, Apostolos

We briefly review the phenomenological implications of the minimal supersymmetric standard model (MSSM) with explicit radiative breaking of CP invariance in the Higgs sector for the LEP2 and Tevatron...

Radiative Higgs-Sector CP Violation in the MSSM (2000)

Pilaftsis, Apostolos

We briefly review the phenomenological implications of the minimal supersymmetric standard model (MSSM) with explicit radiative breaking of CP invariance in the Higgs sector for the LEP2 and Tevatron...

Renormalization-Group-Improved Effective Potential for the MSSM Higgs Sector with Explicit CP Violation (2000)

Carena, M S, Ellis, Jonathan Richard, Pilaftsis, Apostolos, Wagner, C E M

We perform a systematic study of the one-loop renormalization-group-improved effective potential of the minimal supersymmetric extension of the Standard Model (MSSM), including CP violation induced...

Loop-Induced CP Violation in the Gaugino and Higgsino Sectors of Supersymmetric Theories (1999)

Pilaftsis, Apostolos

We show that the gaugino and higgsino sectors of supersymmetric theories can naturally acquire observable CP violation through radiative effects which originate from large CP-violating trilinear...

Loop-Induced CP Violation in the Gaugino and Higgsino Sectors of Supersymmetric Theories (1999)

Pilaftsis, Apostolos

We show that the gaugino and higgsino sectors of supersymmetric theories can naturally acquire observable CP violation through radiative effects which originate from large CP-violating trilinear...

Higgs-Boson Two-Loop Contributions to Electric Dipole Moments in the MSSM (1999)

Pilaftsis, Apostolos

The complete set of Higgs-boson two-loop contributions to electric dipole moments of the electron and neutron is calculated in the minimal supersymmetric standard model. The electric dipole moments...

Higgs-Boson Two-Loop Contributions to Electric Dipole Moments in the MSSM (1999)

Pilaftsis, Apostolos

The complete set of Higgs-boson two-loop contributions to electric dipole moments of the electron and neutron is calculated in the minimal supersymmetric standard model. The electric dipole moments...

CP Violation in the Higgs Sector of the MSSM (1999)

Pilaftsis, Apostolos

Recently, it has been found that the tree-level CP invariance of the Higgs potential in the MSSM can be sizeably broken by loop effects due to soft-CP-violating trilinear interactions involving third...

CP Violation in the Higgs Sector of the MSSM (1999)

Pilaftsis, Apostolos

Recently, it has been found that the tree-level CP invariance of the Higgs potential in the MSSM can be sizeably broken by loop effects due to soft-CP-violating trilinear interactions involving third...

Cumulative Non-decoupling Effects of Kaluza-Klein Neutrinos in Electroweak Processes (1999)

Ioannisian, A N, Pilaftsis, Apostolos

In Kaluza-Klein theories of low-scale quantum gravity, gravitons and iso-singlet neutrinos may propagate in a higher-dimensional space with large compact dimensions, whereas all particles of the...

Cumulative Non-Decoupling Effects of Kaluza-Klein Neutrinos in Electroweak Processes (1999)

Ioannisian, Ara, Pilaftsis, Apostolos

In Kaluza-Klein theories of low-scale quantum gravity, gravitons and isosinglet neutrinos may propagate in a higher-dimensional space with large compact dimensions, whereas all particles of the...

Leptogenesis in Theories with Large Extra Dimensions (1999)

Pilaftsis, Apostolos

We study the scenario of baryogenesis through leptogenesis in higher-dimensional theories, in which the scale of quantum gravity may be as low as few TeV. The minimal realization of these theories...

Leptogenesis in Theories with Large Extra Dimensions (1999)

Pilaftsis, Apostolos

We study the scenario of baryogenesis through leptogenesis in higher-dimensional theories, in which the scale of quantum gravity is many orders of magnitude smaller than the usual Planck mass. The...

Higgs Bosons in the Minimal Supersymmetric Standard Model with Explicit CP Violation (1999)

Pilaftsis, Apostolos, Wagner, Carlos E. M.

We study the Higgs-boson mass spectrum of the minimal supersymmetric standard model, in which the tree-level CP invariance of the Higgs potential is broken explicitly by loop effects of...

Radiatively Induced Neutrino Masses and Large Higgs-Neutrino Couplings in the Standard Model with Majorana Fields (1999)

Pilaftsis, Apostolos

The Higgs sector of the Standard Model with one right-handed neutrino per family is systematically analyzed. In a model with intergenerational independent mixings between families, we can account for...

Radiatively Induced Neutrino Masses and Large Higgs-Neutrino Couplings in the Standard Model with Majorana Fields (1999)

Pilaftsis, Apostolos

The Higgs sector of the Standard Model with one right-handed neutrino per family is systematically analyzed. In a model with intergenerational independent mixings between families, we can account for...

Heavy Majorana neutrinos and baryogenesis (1998)

Pilaftsis, Apostolos

The scenario of baryogenesis through leptogenesis is reviewed in models involving heavy Majorana neutrinos. The various mechanisms of CP violation occurring in the out-of-equilibrium...

Heavy Majorana Neutrinos and Baryogenesis (1998)

Pilaftsis, Apostolos

The scenario of baryogenesis through leptogenesis is reviewed in models involving heavy Majorana neutrinos. The various mechanisms of CP violation occurring in the out-of-equilibrium...

New two-loop contribution to electric dipole moment in supersymmetric theories (1998)

Chang, D, Keung, W Y, Pilaftsis, Apostolos

We calculate a new type of two-loop contributions to the electric dipole moments of the electron and neutron in supersymmetric theories. The new contributions are originated from the potential CP...

New two-loop contribution to electric dipole moment in supersymmetric theories (1998)

Chang, Darwin, Keung, Wai-Yee, Pilaftsis, Apostolos

We calculate a new type of two-loop contributions to the electric dipole moments of the electron and neutron in supersymmetric theories. The new contributions are originated from the potential CP...

Baryogenesis through mixing of heavy Majorana neutrinos (1998)

Pilaftsis, Apostolos

We review the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy neutrinos. We pay special attention to the resonant phenomenon of CP violation through...

Baryogenesis through mixing of heavy Majorana neutrinos (1998)

Pilaftsis, Apostolos

We review the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy neutrinos. We pay special attention to the resonant phenomenon of CP violation through...

Neutrino oscillations in space within a solvable model (1998)

Ioannisian, Ara, Pilaftsis, Apostolos

We study neutrino oscillations in space within a realistic model in which both the source and the target are considered to be stationary having Gaussian-form localizations. The model admits an exact...

Higgs Scalar-Pseudoscalar Mixing in the Minimal Supersymmetric Standard Model (1998)

Pilaftsis, Apostolos

In the minimal supersymmetric Standard Model, the heaviest CP-even Higgs boson H and the CP-odd Higgs scalar A are predicted to be almost degenerate in mass at the tree level, for the wide kinematic...

CP-Odd Tadpole Renormalization of Higgs Scalar-Pseudoscalar Mixing (1998)

Pilaftsis, Apostolos

We consider an Abelian model with a CP-conserving Higgs potential spanned by two complex Higgs fields. The CP invariance of the Higgs potential is then broken explicitly beyond the Born approximation...

Higgs-Boson Low-Energy Theorem and Compatible Gauge-Fixing Conditions (1997)

Pilaftsis, Apostolos

Conventional gauge-fixing schemes such as R$_\xi$ gauges may lead to a violation of the Higgs-boson low-energy theorem beyond the tree level. To elucidate this fact, we study a simple model whose...

Gauge- and Renormalization-Group-Invariant Formulation of the Higgs-Boson Resonance (1997)

Papavassiliou, J, Pilaftsis, Apostolos

A gauge- and renormalization-group- invariant approach implemented by the pinch technique is formulated for resonant transitions involving the Higgs boson. The lineshape of the Higgs boson is shown...

Gauge- and Renormalization-Group- Invariant Formulation of the Higgs-Boson Resonance (1997)

Papavassiliou, Joannis, Pilaftsis, Apostolos

A gauge- and renormalization-group- invariant approach implemented by the pinch technique is formulated for resonant transitions involving the Higgs boson. The lineshape of the Higgs boson is shown...

Effective Charge of the Higgs Boson (1997)

Papavassiliou, J, Pilaftsis, Apostolos

The Higgs-boson lineshape is studied within the pinch technique resummation formalism. It is shown that any resonant Higgs-boson amplitude contains a universal part which is gauge independent,...

Effective Charge of the Higgs Boson (1997)

Papavassiliou, Joannis, Pilaftsis, Apostolos

The Higgs-boson lineshape is studied within the pinch technique resummation formalism. It is shown that any resonant Higgs-boson amplitude contains a universal part which is gauge independent,...

Gauge-Independent Analysis of K_L --> e \mu in Left-Right Models (1997)

Gagyi-Palffy, Zoltan, Pilaftsis, Apostolos, Schilcher, Karl

The lepton-flavour-violating decay K_L --> e \mu is studied in detail within the context of SU(2)_R x SU(2)_L x U(1)_(B-L) models, which include heavy Majorana neutrinos. Particular attention is paid...

CP Violation and Baryogenesis due to Heavy Majorana Neutrinos (1997)

Pilaftsis, Apostolos

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently...

Resonant CP Violation in Higgs Production, Mixing and Decay (1997)

Pilaftsis, Apostolos

CP violation induced by resonant transitions of a scalar to a pseudoscalar intermediate state is analyzed within a gauge-invariant resummation approach based on the pinch technique. Necessary...

Resonant CP violation induced by particle mixing in transition amplitudes (1997)

Pilaftsis, Apostolos

We analyze CP violation in resonant transitions involving scalar as well as fermionic intermediate states, using a gauge-invariant resummation approach implemented by the pinch technique. We derive...

Generalized Pinch Technique and the Background Field Method in General Gauges (1996)

Pilaftsis, Apostolos

It is shown that Cornwall's pinch technique can be extended in a consistent diagrammatic way, so as to describe general background field gauges in Yang-Mills theories. The resulting one-loop Green's...

Mixing and CP Violation: Status and Prospects (1996)

Pilaftsis, Apostolos

Brief overview of the present status on mixing and CP violation in kaons and B mesons is given by means of the unitarity triangle. Theoretical predictions on epsilon'/epsilon are confronted with...

Gauge-Invariant Resummation Formalism for Two-Point Correlation Functions (1996)

Papavassiliou, Joannis, Pilaftsis, Apostolos

The consistent description of unstable particles, renormalons, or other Schwinger--Dyson-type of solutions within the framework of perturbative gauge field theories necessitates the definition and...

Resonant CP-Violating Scalar--Pseudoscalar Transitions at mu+ mu- Colliders (1996)

Pilaftsis, Apostolos

A mu+ mu- collider is an appealing machine to probe resonant CP-violating transitions of a CP-even Higgs particle into the Z boson or into another CP-odd Higgs scalar. These phenomena are studied...

Mixing Renormalization in Majorana Neutrino Theories (1996)

Kniehl, Bernd A., Pilaftsis, Apostolos

The renormalization of general theories with inter-family mixing of Dirac and/or Majorana fermions is studied at the one-loop electroweak order. The phenomenological significance of the mixing-matrix...

W- and Z-Boson Interactions in Supersymmetric Models with Explicit R-Parity Violation (1995)

Nowakowski, Marek, Pilaftsis, Apostolos

The minimal supersymmetric Standard Model with explicit R-parity nonconservation contains bilinear terms involving the left-handed lepton superfields and the Higgs chiral multiplet with hypercharge...

A Gauge-Independent Approach to Resonant Transition Amplitudes (1995)

Papavassiliou, Joannis, Pilaftsis, Apostolos

We present a new gauge-independent approach to resonant transition amplitudes with nonconserved external currents, based on the pinch technique method. In the context of $2\to 2$ and $2\to 3$...

Gauge Invariance and Unstable Particles (1995)

Papavassiliou, Joannis, Pilaftsis, Apostolos

A gauge-independent approach to resonant transition amplitudes with nonconserved external currents is presented, which is implemented by the pinch technique. The analytic expressions derived with...

SEMILEPTONIC LEPTON-NUMBER/FLAVOUR-VIOLATING tau DECAYS IN MAJORANA NEUTRINO MODELS (1995)

Ilakovac, Amon, Kniehl, Bernd A., Pilaftsis, Apostolos

Motivated by the recent investigation of neutrinoless $\tau$-lepton decays by the CLEO collaboration, we perform a systematic analysis of such decays in a possible new-physics scenario with heavy...

SLC/LEP CONSTRAINTS ON UNIFIED MODELS (1995)

Pilaftsis, Apostolos

We examine the potential of constraining possible nondecoupling effects of heavy neutrinos and Higgs bosons at LEP and SLC that may show up in the nonoblique part of the $Zl_il_j$ couplings. We...

CONFRONTING LEFT-RIGHT SYMMETRIC MODELS WITH ELECTROWEAK PRECISION DATA AT THE Z PEAK (1995)

Pilaftsis, Apostolos

In view of the recent and future electroweak precision data accumulated at LEP and SLC, we systematically analyze possible new physics effects that may occur in the leptonic sector within the context...

Signatures of Higgs-Triplet Representations at Tev--e+e- Colliders (1994)

Cheung, Kingman, Phillips, Roger J. N., Pilaftsis, Apostolos

We investigate the potential of future TeV linear e^+e^- colliders to observe singly-charged Higgs bosons ($H^\pm$) via the coupling $H^\pm W^\mp Z$, which would signal the existence of exotic Higgs...

Heavy-Neutrino Effects on tau-Lepton Decays (1994)

Pilaftsis, Apostolos

Minimal extensions of the Standard Model that are motivated by grand unified theories or superstring models with an E_6 symmetry can naturally predict heavy neutrinos of Dirac or Majorana nature....

Astrophysical and Terrestrial Constraints on Singlet Majoron Models (1993)

Pilaftsis, Apostolos

The general Lagrangian containing the couplings of the Higgs scalars to Majorana neutrinos is presented in the context of singlet Majoron models with intergenerational mixings. The analytical...

CP-violating scattering processes at high energy colliders. (1990)

Pilaftsis, Apostolos.

Dortmund, Univ., Diss., 1991 (Nicht für den Austausch).