Research themes

My field of research is particle physics, and more precisely the theoretical analysis of experimental data from colliders. I exploit these results to study flavour physics, which deals with the six different kinds (or flavours) of quarks making matter, their interactions and their decays.


A central difficulty comes from the nuclear strong interaction that holds the constituents of atomic nuclei together. Indeed, in my domain, at low energies (a few GeV), nobody knows how to solve the theory describing this interaction -Quantum ChromoDynamics or QCD.


I use effective field theories to bypass this problem and study:

  • The "strange" quark and the breakdown of chiral symmetry (π K η mesons at low energy)
           DIRAC, NA48 and NA62 (CERN, Switzerland), FOCUS (Fermilab, USA)
  • The "charm" quark and the interplay of long and short distances in strong interactions (D mesons)
           CLEO-c (Cornell, USA), BES (Beijing, China)
  • The "bottom" quark and heavy-quark dynamics (B mesons, CP-violation)
           BaBar (SLAC, USA), Belle (KEK, Japan), CDF and D0 (Fermilab, USA), LHCb (CERN, Switzerland)
These axes of research lead me to consider not only the Standard Model, but also some of its extensions, in order to constrain them through flavour transitions. I am in particular a member of the CKMfitter group performing the global analysis of the flavour structure of the Standard Model (and some extensions) in a frequentist statistical approach.

You can obtain an updated list of my papers either below or on SPIRES (Stanford database), or on Web of Science (ISI).

Articles

Light quarks

  • V. Bernard, SDG and M. Knecht
    On some aspects of isospin breaking in the decay K± → π0π0e± νe
    Eur.Phys.J. C75 (2015) 4, 145 [arXiv:1501.07102]

  • SDG and B. Moussallam
    Analyticity of ηπ isospin-violating form factors and the τ→ηπν second-class decay
    Eur. Phys. J. C 74 (2014) 2946 [arXiv:1404.0251]

  • V. Bernard, SDG and M.Knecht
    Isospin breaking in the phases of the Ke4 form factors
    Eur.Phys.J. C 73 (2013) 2478 [arXiv:1305.3843]

  • V. Bernard, SDG and G. Toucas
    Determining the chiral condensate from the distribution of the winding number beyond topological susceptibility
    JHEP 12 (2012) 080 [arXiv:1209.4367]

  • V. Bernard, SDG and G. Toucas
    Topological susceptibility on the lattice and the three-flavour quark condensate
    JHEP 06 (2012) 051 [arXiv:1203.0508]

  • SDG and M.Knecht
    Two-loop representations of low-energy pion form factors and π-π scattering phases in the presence of isospin breaking
    Eur.Phys.J. C72 (2012) 1962 [arXiv:1202.5886]

  • V. Bernard, SDG and G. Toucas
    Chiral dynamics with strange quarks in the light of recent lattice simulations
    JHEP 1101 (2001) 107 [arXiv:1009.5066]

  • SDG and B. Malaescu
    A note on renormalon models for the determination of αs(Mτ)
    [arXiv:1002.2968]

  • SDG
    Low-energy ππ and πK scatterings revisited in three-flavour resummed chiral perturbation theory
    Eur. Phys. J. C 52 (2007) 141 [hep-ph/0703154]

  • SDG and B. Moussallam
    The K*0(800) scalar resonance from Roy-Steiner representations of πK scattering
    Eur. Phys. J. C 48 (2006) 553 [hep-ph/0607133]

  • SDG and B. Moussallam
    Radiative corrections in weak semi-leptonic processes at low energies: a two-step matching determination
    Eur. Phys. J. C 42 (2005) 403 [hep-ph/0505077]

  • SDG
    The role of strange sea quarks in chiral extrapolations on the lattice
    Eur. Phys. J. C 40 (2005) 81 [hep-ph/0410233]

  • SDG, L. Girlanda, N. H. Fuchs and J. Stern
    Resumming vacuum fluctuations in three-flavour Chiral Perturbation Theory
    Eur. Phys. J. C 34 (2004) 201 [hep-ph/0311120]

  • P. Büttiker, SDG and B. Moussallam
    A new analysis of π-K scattering from Roy and Steiner-type equations
    Eur. Phys. J. C 33 (2004) 409 [hep-ph/0310283]

  • SDG, L. Girlanda and J. Stern
    Chiral order and fluctuation in multi-flavour QCD
    Eur. Phys. J. C 27 (2003) 115 [hep-ph/0207337]

  • SDG, L. Girlanda, N. H. Fuchs and J. Stern
    Analysis and interpretation of new low-energy π-π scattering data
    Eur. Phys. J. C 24 (2002) 469 [hep-ph/0112088]

  • SDG
    Zweig-rule violation in the scalar sector and values of low-energy constants
    JHEP 0103 (2001) 002 [hep-ph/0012221]

  • SDG and J. Stern
    Vacuum fluctuations of q-q and values of low-energy constants
    Phys. Lett. B 488 (2000) 274 [hep-ph/0007082]

  • SDG and J. Stern
    Finite-volume analysis of Nf-induced chiral phase transitions
    Phys. Rev. D 62 (2000) 054011 [hep-ph/9912234]

  • SDG, L. Girlanda and J. Stern
    Paramagnetic effect of light quark loops
    JHEP 01 (2000) 041 [hep-ph/9910537]

Heavy quarks

  • SDG, J. Matias et J. Virto
    QCD uncertainties in the prediction of B → K* μ+ μ- observables
    [arXiv:1411.0922]

  • SDG, J. Matias and J. Virto
    An analysis of Bd,s mixing in the presence of New Physics and an update of Bs→ K0* K0*
    Phys.Rev. D85 (2012) 034010 [arXiv:1111.4882]

  • J. Charles, SDG, X.-W. Kang, H.-B. Li and G.-R. Lu
    Extracting CP violation and strong phase in D decays by using quantum correlations in ψ(3770) → D0D0 → (V1V2)(V3V4) and ψ(3770) → D0D0 → (V1V2)(K π)
    Phys.Rev. D81 (2010) 054032 upd[arXiv:0912.0899]

  • SDG, J. He, E. Kou and P. Robbe
    Non-leptonic charmless Bc decays and their search at LHCb
    Phys. Rev. D80 (2009) 114031 [arXiv:0907.2256]

  • SDG and N. Offen
    Three-particle contributions to the renormalisation of B-meson light-cone distribution amplitudes
    JHEP 0905 (2009) 091 [arXiv:0903.0790]

  • M. Davier, SDG, B. Malaescu, A. Hoecker and Z. Zhang
    The determination of αs from τ decays revisited
    Eur. Phys. J. C 56 (2008) 305 [arXiv:0803.0979]

  • SDG and A. Le Yaouanc
    Parametrisations of D → K l ν and the determination of g-hat
    J. Phys. G 35 (2008) 115005 [arXiv:0804.0203]

  • SDG, J. Matias and J. Virto
    Penguin-mediated Bd,s → VV decays and the Bs-Bs mixing angle
    Phys. Rev. D 76 (2007) 074005 [arXiv:0705.0477]

  • SDG, J. Matias and J. Virto
    Exploring Bd,s → KK decays through flavour symmetries and QCD-factorisation
    Phys. Rev. Lett. 97 (2006) 061801 [hep-ph/0603239]

  • SDG and C. T. Sachrajda
    Spectator interactions in B → V γ decays and QCD factorisation
    Nucl. Phys. B 693 (2004) 103 [hep-ph/0403277]

  • SDG and C. T. Sachrajda
    Universality of nonperturbative effects in radiative B-decays
    Phys. Lett. B 557 (2003) 213 [hep-ph/0212162]

  • SDG and C. T. Sachrajda
    Factorization, the light-cone distribution amplitude of the B-meson and the radiative decay B → γ l ν
    Nucl. Phys. B 650 (2003) 356 [hep-ph/0209216]

  • SDG and C. T. Sachrajda
    Sudakov effects in B→ π l ν form factors
    Nucl. Phys. B 625 (2002) 239 [hep-ph/0109260]

Flavour physics in and beyond the Standard Model

  • SDG et J. Virto
    Time dependence in B → V l l decays
    JHEP 1504 (2015) 045 [arXiv:1502.05509]

  • J. Charles et al.
    Current status of the Standard Model CKM fit and constraints on ΔF=2 New Physics
    Phys.Rev. D91 (2015) 7, 073007 [arXiv:1501.05013]

  • S. Davidson, SDG and P. Verdier
    Of Contact Interactions and Colliders
    [arXiv:1410.4798]

  • S. Davidson and SDG
    Constraining flavoured contact interactions at the LHC
    JHEP 1405 (2014) 066 [arXiv:1311.5981]

  • J. Charles, SDG, Z. Ligeti, S. Monteil, M. Papucci, K. Trabelsi
    Future sensitivity to new physics in Bd, Bs and K mixings
    Phys. Rev. D89 (2014) 033016 [arXiv:1309.2293]

  • SDG, J. Matias and J. Virto
    Understanding the B→K*μ+μ anomaly
    Phys.Rev. D88 (2013) 074002 [arXiv:1307.5683]

  • SDG, T. Hurth, J. Matias and J. Virto
    Optimizing the basis of B→K*l+l observables in the full kinematic range
    JHEP 1305 (2013) 137 [arXiv:1303.5794]

  • SDG and J. Kamenik
    On the origin of the D0 like-sign dimuon charge asymmetry
    Phys.Rev. D87 (2013) 074036 [arXiv:1207.4483]

  • A. Lenz and al.
    New Physics in B-B mixing in the light of recent LHCb data
    Phys.Rev. D86 (2012) 033008 [arXiv:1203.0238]

  • J. Charles and al.
    Predictions of selected flavour observables within the Standard Model.
    Phys.Rev. D84 (2011) 033005 [arXiv:1106.4041]

  • SDG, D. Ghosh, J. Matias and M. Ramon
    Exploring New Physics in the C7-C7' plane
    JHEP 1106 (2011) 099 [arXiv:1104.3342]

  • S. Davidson and SDG
    Minimal Flavour Violation for Leptoquarks
    JHEP 1011 (2010) 073 [arXiv:1009.1998]

  • A. Lenz and al.
    Anatomy of New Physics in B-B mixing
    Phys.Rev. D83 (2011) 036004 [arXiv:1008.1593]

  • O. Deschamps and al.
    The two-Higgs doublet model of type II facing flavour physics data
    Phys. Rev. D82 (2010) 073012 [arXiv:0907.5135]