Fu-Sin Ling
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Fu-Sin Ling has a total of 13 co-authors. Here are the top co-authors by number of shared publications:
- Emmanuel Nezri
Laboratoire d’Astrophysique de Marseille - LAM; Université d’Aix-Marseille & CNRS; UMR7326, 38 rue F. Joliot-Curie; 13388; Marseille Cedex 13; France
3 shared publications - Romain Teyssier
Department of Astrophysical Sciences, Peyton Hall, Princeton University
3 shared publications - Jean-Marie Frère
Service de Physique Théorique Université Libre de Bruxelles Boulevard du Triomphe CP225 1050 Brussels Belgium
2 shared publications - Jonathan Rocher
Service de Physique Théorique Université Libre de Bruxelles Bld du Triomphe CP225 1050 Brussels Belgium
2 shared publications - Julien Lavalle
Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier & CNRS, Place Eugène Bataillon, 34095 Montpellier Cedex 05
2 shared publications - Laura Lopez-Honorez
Service de Physique Théorique, C.P. 225, Université Libre de Bruxelles
2 shared publications
Latest Publications
- 21 September 2010
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2010 (9) , 1-23
See-saw neutrino masses and large mixing angles in the vortex background on a sphere
- 21 September 2010
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2010 (9) , 1-23
See-saw neutrino masses and large mixing angles in the vortex background on a sphere
- Open Access
Neutrino masses and the Cabibbo expansion
We adopt a bottom-up approach to reconstruct the possible neutrino mass matrix patterns, in the hypothesis that $\lambda = \sin \theta_C$, where $\theta_C$ is the Cabibbo angle, is a useful expansion parameter in the neutrino sector as it is in the quark sector. A numerical analysis of these Cabibbo structures shows that an inverted hierarchy spectrum is statistically favored by the neutrino oscillation data. We then discuss how apparently conflicting mass and mixing data for quarks, charged leptons and neutrinos can fit in a unified perspective. We show that large mixing angles can appear through the seesaw mechanism, even if the neutrino Dirac mass matrix has hierarchical eigenvalues and small mixing angles. Finally, it is shown that the form of the heavy Majorana mass matrix may point towards theories with extra-dimensions.Open AccessNeutrino masses and the Cabibbo expansion
We adopt a bottom-up approach to reconstruct the possible neutrino mass matrix patterns, in the hypothesis that $\lambda = \sin \theta_C$, where $\theta_C$ is the Cabibbo angle, is a useful expansion parameter in the neutrino sector as it is in the quark sector. A numerical analysis of these Cabibbo structures shows that an inverted hierarchy spectrum is statistically favored by the neutrino oscillation data. We then discuss how apparently conflicting mass and mixing data for quarks, charged leptons and neutrinos can fit in a unified perspective. We show that large mixing angles can appear through the seesaw mechanism, even if the neutrino Dirac mass matrix has hierarchical eigenvalues and small mixing angles. Finally, it is shown that the form of the heavy Majorana mass matrix may point towards theories with extra-dimensions. - Open Access
See-saw neutrino masses and large mixing angles in the vortex background on a sphere
In the vortex background on a sphere, a single 6-dimensional fermion family gives rise to 3 zero-modes in the 4-dimensional point of view, which may explain the replication of families in the Standard Model. Previously, it had been shown that realistic hierarchical mass and mixing patterns can be reproduced for the quarks and the charged leptons. Here, we show that the addition of a single heavy 6-dimensional field that is gauge singlet, unbound to the vortex, and embedded with a bulk Majorana mass enables to generate 4D Majorana masses for the light neutrinos through the see-saw mechanism. The scheme is very predictive. The hierarchical structure of the fermion zero-modes leads automatically to an inverted pseudo-Dirac mass pattern, and always predicts one maximal angle in the neutrino see-saw matrix. It is possible to obtain a second large mixing angle from either the charged lepton or the neutrino sector, and we demonstrate that this model can fit all observed data in neutrino oscillations experiments. Also, U_{e3} is found to be of the order ~0.1.
Open AccessSee-saw neutrino masses and large mixing angles in the vortex background on a sphere
In the vortex background on a sphere, a single 6-dimensional fermion family gives rise to 3 zero-modes in the 4-dimensional point of view, which may explain the replication of families in the Standard Model. Previously, it had been shown that realistic hierarchical mass and mixing patterns can be reproduced for the quarks and the charged leptons. Here, we show that the addition of a single heavy 6-dimensional field that is gauge singlet, unbound to the vortex, and embedded with a bulk Majorana mass enables to generate 4D Majorana masses for the light neutrinos through the see-saw mechanism. The scheme is very predictive. The hierarchical structure of the fermion zero-modes leads automatically to an inverted pseudo-Dirac mass pattern, and always predicts one maximal angle in the neutrino see-saw matrix. It is possible to obtain a second large mixing angle from either the charged lepton or the neutrino sector, and we demonstrate that this model can fit all observed data in neutrino oscillations experiments. Also, U_{e3} is found to be of the order ~0.1.
- 30 July 2010
- Published by American Physical Society (APS) in Physical Review D
- Vol. 82 (2)
Is the dark disc contribution to dark matter signals important?
Recent N-body simulations indicate that a thick disc of dark matter, corotating with the stellar disc, forms in a galactic halo after a merger at a redshift . The existence of such a dark disc component in the Milky Way could affect dramatically dark matter signals in direct and indirect detection. In this letter, we discuss the possible signal enhancement in connection with the characteristics of the local velocity distributions. We argue that the enhancement is rather mild, but some subtle effects may arise. In particular, the annual modulation observed by DAMA becomes less constrained by other direct detection experiments. DOI: http://dx.doi.org/10.1103/PhysRevD.82.023534 © 2010 The American Physical Society- 30 July 2010
- Published by American Physical Society (APS) in Physical Review D
- Vol. 82 (2)
Is the dark disc contribution to dark matter signals important?
Recent N-body simulations indicate that a thick disc of dark matter, corotating with the stellar disc, forms in a galactic halo after a merger at a redshift . The existence of such a dark disc component in the Milky Way could affect dramatically dark matter signals in direct and indirect detection. In this letter, we discuss the possible signal enhancement in connection with the characteristics of the local velocity distributions. We argue that the enhancement is rather mild, but some subtle effects may arise. In particular, the annual modulation observed by DAMA becomes less constrained by other direct detection experiments. DOI: http://dx.doi.org/10.1103/PhysRevD.82.023534 © 2010 The American Physical Society- Open Access
Is the Dark Disc contribution to Dark Matter Signals important ?
Recent N-body simulations indicate that a thick disc of dark matter, co-rotating with the stellar disc, forms in a galactic halo after a merger at a redshift $z<2$. The existence of such a dark disc component in the Milky Way could affect dramatically dark matter signals in direct and indirect detection. In this letter, we discuss the possible signal enhancement in connection with the characteristics of the local velocity distributions. We argue that the enhancement is rather mild, but some subtle effects may arise. In particular, the annual modulation observed by DAMA becomes less constrained by other direct detection experiments.Open AccessIs the Dark Disc contribution to Dark Matter Signals important ?
Recent N-body simulations indicate that a thick disc of dark matter, co-rotating with the stellar disc, forms in a galactic halo after a merger at a redshift $z<2$. The existence of such a dark disc component in the Milky Way could affect dramatically dark matter signals in direct and indirect detection. In this letter, we discuss the possible signal enhancement in connection with the characteristics of the local velocity distributions. We argue that the enhancement is rather mild, but some subtle effects may arise. In particular, the annual modulation observed by DAMA becomes less constrained by other direct detection experiments. - Open Access
- 19 May 2010
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2010 (5) , 1
Erratum: scalar multiplet dark matter
- 19 May 2010
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2010 (5) , 1
Open AccessErratum: scalar multiplet dark matter
- Open Access
Dark Matter Direct Detection Signals inferred from a Cosmological N-body Simulation with Baryons
We extract at redshift z=0 a Milky Way sized object including gas, stars and dark matter (DM) from a recent, high-resolution cosmological N-body simulation with baryons. Its resolution is sufficient to witness the formation of a rotating disk and bulge at the center of the halo potential. The phase-space structure of the central galactic halo reveals the presence of a dark disk component, that is co-rotating with the stellar disk. At the Earth's location, it contributes to around 25% of the total DM local density, whose value is rho_DM ~ 0.37 GeV/cm^3. The velocity distributions also show strong deviations from pure Gaussian and Maxwellian distributions, with a sharper drop of the high velocity tail. We give a detailed study of the impact of these features on the predictions for DM signals in direct detection experiments. In particular, the question of whether the modulation signal observed by DAMA is or is not excluded by limits set by other experiments (CDMS, XENON and CRESST...) is re-analyzed and compared to the case of a standard Maxwellian halo, in both the elastic and the inelastic scattering scenarios. We find that the compatibility between DAMA and the other experiments is improved. In the elastic scenario, the DAMA modulation signal is slightly enhanced in the so-called channeling region, as a result of several effects. For the inelastic scenario, the improvement of the fit is mainly attributable to the departure from a Maxwellian distribution at high velocity.
Open AccessDark Matter Direct Detection Signals inferred from a Cosmological N-body Simulation with Baryons
We extract at redshift z=0 a Milky Way sized object including gas, stars and dark matter (DM) from a recent, high-resolution cosmological N-body simulation with baryons. Its resolution is sufficient to witness the formation of a rotating disk and bulge at the center of the halo potential. The phase-space structure of the central galactic halo reveals the presence of a dark disk component, that is co-rotating with the stellar disk. At the Earth's location, it contributes to around 25% of the total DM local density, whose value is rho_DM ~ 0.37 GeV/cm^3. The velocity distributions also show strong deviations from pure Gaussian and Maxwellian distributions, with a sharper drop of the high velocity tail. We give a detailed study of the impact of these features on the predictions for DM signals in direct detection experiments. In particular, the question of whether the modulation signal observed by DAMA is or is not excluded by limits set by other experiments (CDMS, XENON and CRESST...) is re-analyzed and compared to the case of a standard Maxwellian halo, in both the elastic and the inelastic scattering scenarios. We find that the compatibility between DAMA and the other experiments is improved. In the elastic scenario, the DAMA modulation signal is slightly enhanced in the so-called channeling region, as a result of several effects. For the inelastic scenario, the improvement of the fit is mainly attributable to the departure from a Maxwellian distribution at high velocity.
- Open Access
The Inert Doublet Model and Inelastic Dark Matter
The annual modulation observed by DAMA/NaI and DAMA/Libra may be interpreted in terms of elastic or inelastic scattering of dark matter particles. In this paper we confront these two scenarios within the framework of a very simple extension of the Standard Model, the Inert Doublet Model (IDM). In this model the dark matter candidate is a scalar, the lightest component of an extra Higgs doublet. We first revisit the case for the elastic scattering of a light scalar WIMP, M_DM~10 GeV, a scenario which requires that a fraction of events in DAMA are channelled. Second we consider the possibility of inelastic Dark Matter (iDM). This option is technically natural in the IDM, in the sense that the mass splitting between the lightest and next-to-lightest neutral scalars may be protected by a Peccei-Quinn (PQ) symmetry. We show that candidates with a mass M_DM between ~535 GeV and ~50 TeV may reproduce the DAMA data and have a cosmic abundance in agreement with WMAP. This range may be extended to candidates as light as ~50 GeV if we exploit the possibility that the approximate PQ symmetry is effectively conserved and that a primordial asymmetry in the dark sector may survive until freeze-out.
Open AccessThe Inert Doublet Model and Inelastic Dark Matter
The annual modulation observed by DAMA/NaI and DAMA/Libra may be interpreted in terms of elastic or inelastic scattering of dark matter particles. In this paper we confront these two scenarios within the framework of a very simple extension of the Standard Model, the Inert Doublet Model (IDM). In this model the dark matter candidate is a scalar, the lightest component of an extra Higgs doublet. We first revisit the case for the elastic scattering of a light scalar WIMP, M_DM~10 GeV, a scenario which requires that a fraction of events in DAMA are channelled. Second we consider the possibility of inelastic Dark Matter (iDM). This option is technically natural in the IDM, in the sense that the mass splitting between the lightest and next-to-lightest neutral scalars may be protected by a Peccei-Quinn (PQ) symmetry. We show that candidates with a mass M_DM between ~535 GeV and ~50 TeV may reproduce the DAMA data and have a cosmic abundance in agreement with WMAP. This range may be extended to candidates as light as ~50 GeV if we exploit the possibility that the approximate PQ symmetry is effectively conserved and that a primordial asymmetry in the dark sector may survive until freeze-out.
- Open Access
Scalar Multiplet Dark Matter
We perform a systematic study of the phenomenology associated to models where the dark matter consists in the neutral component of a scalar SU(2)_L n-uplet, up to n=7. If one includes only the pure gauge induced annihilation cross-sections it is known that such particles provide good dark matter candidates, leading to the observed dark matter relic abundance for a particular value of their mass around the TeV scale. We show that these values actually become ranges of values -which we determine- if one takes into account the annihilations induced by the various scalar couplings appearing in these models. This leads to predictions for both direct and indirect detection signatures as a function of the dark matter mass within these ranges. Both can be largely enhanced by the quartic coupling contributions. We also explain how, if one adds right-handed neutrinos to the scalar doublet case, the results of this analysis allow to have altogether a viable dark matter candidate, successful generation of neutrino masses, and leptogenesis in a particularly minimal way with all new physics at the TeV scale.
Open AccessScalar Multiplet Dark Matter
We perform a systematic study of the phenomenology associated to models where the dark matter consists in the neutral component of a scalar SU(2)_L n-uplet, up to n=7. If one includes only the pure gauge induced annihilation cross-sections it is known that such particles provide good dark matter candidates, leading to the observed dark matter relic abundance for a particular value of their mass around the TeV scale. We show that these values actually become ranges of values -which we determine- if one takes into account the annihilations induced by the various scalar couplings appearing in these models. This leads to predictions for both direct and indirect detection signatures as a function of the dark matter mass within these ranges. Both can be largely enhanced by the quartic coupling contributions. We also explain how, if one adds right-handed neutrinos to the scalar doublet case, the results of this analysis allow to have altogether a viable dark matter candidate, successful generation of neutrino masses, and leptogenesis in a particularly minimal way with all new physics at the TeV scale.
- 25 November 2008
- Published by American Physical Society (APS) in Physical Review D
- Vol. 78 (10) , 103526
Antimatter cosmic rays from dark matter annihilation: First results from an N-body experiment
While the particle hypothesis for dark matter may be very soon investigated at the LHC, and as the PAMELA and GLAST satellites are currently taking new data on charged and gamma cosmic rays, the need of controlling the theoretical uncertainties affecting the possible indirect signatures of dark matter annihilation is of paramount importance. The uncertainties which originate from the dark matter distribution are difficult to estimate because current astrophysical observations provide rather weak dynamical constraints and because, according to cosmological N-body simulations, dark matter is neither smoothly nor spherically distributed in galactic halos. Some previous studies made use of N-body simulations to compute the -ray flux from dark matter annihilation, but such a work has never been performed for the antimatter (positron and antiproton) primary fluxes, for which transport processes complicate the calculations. We take advantage of the galaxylike 3D dark matter map extracted from the Horizon Project results to calculate the positron and antiproton fluxes from dark matter annihilation, in a model-independent approach as well as for dark matter particle benchmarks relevant at the LHC scale (from supersymmetric and extradimensional theories). We find that the flux uncertainties arise mainly from fluctuations of the local dark matter density, and are of order of magnitude. We compare our results to analytic descriptions of the dark matter halo, showing how the latter can well reproduce the former. The overall antimatter predictions associated with our benchmark models are shown to lie far below the existing measurements and, in particular, that of the positron fraction recently reported by PAMELA, and far below the background predictions as well. Finally, we stress the limits of the use of an N-body framework in this context.- 25 November 2008
- Published by American Physical Society (APS) in Physical Review D
- Vol. 78 (10) , 103526
Antimatter cosmic rays from dark matter annihilation: First results from an N-body experiment
While the particle hypothesis for dark matter may be very soon investigated at the LHC, and as the PAMELA and GLAST satellites are currently taking new data on charged and gamma cosmic rays, the need of controlling the theoretical uncertainties affecting the possible indirect signatures of dark matter annihilation is of paramount importance. The uncertainties which originate from the dark matter distribution are difficult to estimate because current astrophysical observations provide rather weak dynamical constraints and because, according to cosmological N-body simulations, dark matter is neither smoothly nor spherically distributed in galactic halos. Some previous studies made use of N-body simulations to compute the -ray flux from dark matter annihilation, but such a work has never been performed for the antimatter (positron and antiproton) primary fluxes, for which transport processes complicate the calculations. We take advantage of the galaxylike 3D dark matter map extracted from the Horizon Project results to calculate the positron and antiproton fluxes from dark matter annihilation, in a model-independent approach as well as for dark matter particle benchmarks relevant at the LHC scale (from supersymmetric and extradimensional theories). We find that the flux uncertainties arise mainly from fluctuations of the local dark matter density, and are of order of magnitude. We compare our results to analytic descriptions of the dark matter halo, showing how the latter can well reproduce the former. The overall antimatter predictions associated with our benchmark models are shown to lie far below the existing measurements and, in particular, that of the positron fraction recently reported by PAMELA, and far below the background predictions as well. Finally, we stress the limits of the use of an N-body framework in this context.