Publications (29)
Analysis and interpretation of new low-energy Pi-Pi scattering data
S. Descotes, N. H. Fuchs, L. Girlanda +1
The recently published E865 data on charged K_e4 decays and Pi-Pi phases are reanalyzed to extract values of the two S-wave scattering lengths, of the subthreshold parameters alpha…
The Amplitude in Generalized Chiral Perturbation Theory
M. Knecht, B. Moussallam, J. Stern
The interaction is studied at one loop order in the framework of Generalized Chiral Perturbation theory
Deconstructing the narrow-line region of the nearest obscured quasar
M. Villar Martin, E. Bellocchi, J. Stern +3
We study the physical and kinematic properties of the narrow line region (NLR) of the nearest obscured quasar MRK 477 (z=0.037), using optical and near-infrared spectroscopy. We ex…
Comment on the Prediction of Two-loop Standard Chiral Perturbation Theory for Low-Energy ÏÏScattering
L. Girlanda, M. Knecht, B. Moussallam +1
Four of the six parameters defining the two-loop ÏÏscattering amplitude have been determined using Roy dispersion relations. Combining this information with the Standard ÏPT exp…
CGM properties in VELA and NIHAO simulations; the OVI ionization mechanism: dependence on redshift, halo mass and radius
S. Roca-FÃ brega, A. Dekel, Y. Faerman +8
We study the components of cool and warm/hot gas in the circumgalactic medium (CGM) of simulated galaxies and address the relative production of OVI by photoionization versus colli…
Vacuum fluctuations of \bar{q}q and values of low-energy constants
S. Descotes, J. Stern
We discuss the influence of the vacuum fluctuations of \bar{q}q pairs on low-energy constants and condensates. The analysis of the Goldstone boson masses and decay constants shows…
Conceptual design of 20 T hybrid accelerator dipole magnets
P. Ferracin, G. Ambrosio, M. Anerella +17
Hybrid magnets are currently under consideration as an economically viable option towards 20 T dipole magnets for next generation of particle accelerators. In these magnets, High T…
A possible experimental determination of from decays
M. Knecht, H. Sazdjian, J. Stern +1
scattering and decays are studied at leading order of improved chiral perturbation theory. It is shown that high precision experiments at, e.g., DANE…
The first ultraviolet quasar stacked spectrum at z=2.4 from WFC3
E. Lusso, G. Worseck, J. F. Hennawi +4
The ionising continuum from active galactic nuclei (AGN) is fundamental for interpreting their broad emission lines and understanding their impact on the surrounding gas. Furthermo…
Resumming QCD vacuum fluctuations in three-flavour Chiral Perturbation Theory
S. Descotes-Genon, N. H. Fuchs, L. Girlanda +1
Due to its light mass of order Lambda_QCD, the strange quark can play a special role in Chiral Symmetry Breaking (ChSB): differences in the pattern of ChSB in the limits N_f=2 (m_u…
Light Quark Masses from Exclusive Tau Decays: An Experimental Proposal
J. Stern, N. H. Fuchs, M. Knecht
A method of indirect measurement of the light quark running mass is elaborated in detail. It is based on measuring 1\%-level azimuthal angular asymmetries…
The Origins of the Circumgalactic Medium in the FIRE Simulations
Z. Hafen, C. -A. Faucher-Giguere, D. Angles-Alcazar +10
We use a particle tracking analysis to study the origins of the circumgalactic medium (CGM), separating it into (1) accretion from the intergalactic medium (IGM), (2) wind from the…
Generalized Chiral Perturbation Theory
M. Knecht, J. Stern
The Generalized Chiral Perturbation Theory enlarges the framework of the standard PT, relaxing certain assumptions which do not necessarily follow from QCD or from experiment,…
Towards 20 T Hybrid Accelerator Dipole Magnets
P. Ferracin, G. Ambrosio, D. Arbelaez +13
The most effective way to achieve very high collision energies in a circular particle accelerator is to maximize the field strength of the main bending dipoles. In dipole magnets u…
Properties of the Line-of-Sight Velocity Field in the Hot and X-ray Emitting Circumgalactic Medium of Nearby Simulated Disk Galaxies
J. A. ZuHone, G. Schellenberger, A. Ogorzalek +16
The hot, X-ray-emitting phase of the circumgalactic medium of massive galaxies is believed to be the reservoir of baryons from which gas flows onto the central galaxy and into whic…
The Low Energy Amplitude to One and Two Loops
M. Knecht, B. Moussallam, J. Stern +1
The low-energy amplitude is computed explicitly to two-loop accuracy in the chiral expansion. It depends only on six independent (combinations of) low-energy constants which…
Tests of non-standard electroweak couplings of right-handed quarks
V. Bernard, M. Oertel, E. Passemar +1
The standard model can be interpreted as the leading order of a Low-Energy Effective Theory (LEET) invariant under a higher non linearly realized symmetry $S_{nat}\supset SU(2)_W \…
Dispersive analysis of K_{L mu3} and K_{L e3} scalar and vector form factors using KTeV data
KTeV collaboration, E. Abouzaid et al., V. Bernard +3
Using the published KTeV samples of K_L --> pi^{\pm} e^{\mp} nu and K_L --> pi^{\pm} mu^{\mp} nu decays [1], we perform a reanalysis of the scalar and vector form factors based on…
Determination of Two-Loop Scattering Amplitude Parameters
M. Knecht, B. Moussallam, J. Stern +1
The chiral expansion of the amplitude to the order of two loops was expressed in terms of six independent parameters in a previous paper: four of these are shown here to sat…
On the Pais--Treiman method to measure phase shifts in decays
G. Colangelo, M. Knecht, J. Stern
We evaluate theoretical uncertainties to the method of Pais and Treiman to measure the phase shifts in decays. We find that they are very small, below .
Science Priorities for the Extraction of the Solid MSR Samples from their Sample Tubes
N. Dauphas, S. S. Russell, D. Beaty +20
Preservation of the chemical and structural integrity of samples that will be brought back from Mars is paramount to achieving the scientific objectives of MSR. Given our knowledge…
Eta' Mass and Chiral Symmetry Breaking at Large Nc and Nf
L. Girlanda, J. Stern, P. Talavera
We propose a method for implementing the large-Nc, large-Nf limit of QCD at the effective Lagrangian level. Depending on the value of the ratio Nf/Nc, different patterns of chiral…
The Fates of the Circumgalactic Medium in the FIRE Simulations
Z. Hafen, C. -A. Faucher-Giguere, D. Angles-Alcazar +7
We analyze the different fates of the circumgalactic medium (CGM) in FIRE-2 cosmological simulations, focusing on the redshifts z=0.25 and z=2 representative of recent surveys. Our…
Chiral order and fluctuations in multi-flavour QCD
S. Descotes-Genon, L. Girlanda, J. Stern
Multi-flavour (N_f>=3) Chiral Perturbation Theory (ChPT) may exhibit instabilities due to vacuum fluctuations of sea q-bar q pairs. Keeping the fluctuations small would require a v…
Contributions of order to form factors and unitarity of the CKM matrix
N. H. Fuchs, M. Knecht, J. Stern
The form factors for the semileptonic decay are computed to order in generalized chiral perturbation theory. The main difference with the standard ex…
Chiral Symmetry Aspects of the Scalars
B. Moussallam, J. Stern
Electromagnetic decays of the scalar mesons are shown to be constrained by chiral symmetry as a consequence of the fact that, in the chiral limit, the two and three-point functions…
Finite Energy Chiral Sum Rules and Tau Spectral Functions
M. Davier, L. Girlanda, A. Hoecker +1
A combination of finite energy sum rule techniques and Chiral Perturbation Theory (ChPT) is used in order to exploit recent ALEPH data on the non-strange tau vector (V) and axial-v…
What Scattering Tells Us About Chiral Perturbation Theory
J. Stern, H. Sazdjian, N. H. Fuchs
We describe a rearrangement of the standard expansion of the symmetry breaking part of the QCD effective Lagrangian that includes into each order additional terms which in the stan…
The Reaction in Generalized Chiral Perturbation Theory
M. Knecht, B. Moussallam, J. Stern
The cross section for and the pion polarizabilities are computed, within generalized chiral perturbation theory, in the full one loop approximation, {\it i.e.} up…