760 citations · 1.8k across the 24 of their papers we have counts for
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Cottingham formula and nucleon polarizabilities
J. Gasser, M. Hoferichter, H. Leutwyler +1
The difference between the electromagnetic self-energies of proton and neutron can be calculated with the Cottingham formula, which expresses the self-energies as an integral over…
On the pion decay constant
J. Gasser, G. R. S. Zarnauskas
The pion decay constant f_pi plays a crucial role in many areas of low energy particle physics. Its value may e.g. be deduced from experimental data on leptonic pion decays. Here,…
Relations between SU(2)- and SU(3)-LECs in chiral perturbation theory
Juerg Gasser, Christoph Haefeli, Mikhail A. Ivanov +1
Chiral perturbation theory in the two--flavour sector allows one to analyse Green functions in QCD in the limit where the strange quark mass is considered to be large in comparison…
Radiative corrections in K --> 3 pi decays
M. Bissegger, A. Fuhrer, J. Gasser +2
We investigate radiative corrections to K --> 3 pi decays. In particular, we extend the non-relativistic framework developed recently to include real and virtual photons and show t…
Hadronic atoms in QCD + QED
J. Gasser, V. E. Lyubovitskij, A. Rusetsky
We review the theory of hadronic atoms in QCD + QED, based on a non-relativistic effective Lagrangian framework. We first provide an introduction to the theory, and then describe s…
Cusps in K_L --> 3 pi decays
M. Bissegger, A. Fuhrer, J. Gasser +2
The pion mass difference generates a pronounced cusp in K --> 3 pi decays, the strength of which is related to the pi pi S-wave scattering lengths. We apply an effective field theo…
Integrating out strange quarks in ChPT
Jurg Gasser, Christoph Haefeli, Mikhail A. Ivanov +1
We study three flavour chiral perturbation theory in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the e…
Aspects of radiative K^+_e3 decays
Bastian Kubis, Eike H. Müller, Jürg Gasser +1
We re-investigate the radiative charged kaon decay K+- --> pi0 e+- nu_e gamma in chiral perturbation theory, merging the chiral expansion with Low's theorem. We thoroughly analyze…
Kaonic atoms in QCD
J. Gasser
In this talk, I comment on the theoretical and experimental status of kaonic atoms, in particular, \bar Kπand \bar Kp bound states.
Radiative Ke3 decays revisited
J. Gasser, B. Kubis, N. Paver +1
Motivated by recent experimental results and ongoing measurements, we review the chiral perturbation theory prediction for radiative Ke3 decays (neutral kaons). Special emphasis is…
Scalar form factors of light mesons
B. Ananthanarayan, I. Caprini, G. Colangelo +2
The scalar radius of the pion plays an important role in CHPT, because it is related to one of the basic effective coupling constants, viz. the one which controls the quark mass de…
Ground-state energy of pionic hydrogen to one loop
J. Gasser, M. A. Ivanov, E. Lipartia +2
We investigate the ground-state energy of the pi- p atom (pionic hydrogen) in the framework of QCD+QED. In particular, we evaluate the strong energy-level shift. We perform the cal…
ππscattering
G. Colangelo, J. Gasser, H. Leutwyler
We demonstrate that, together with the available experimental information, chiral symmetry determines the low energy behaviour of the scattering amplitude to within very small…
Effective Lagrangians in bound state calculations
V. Antonelli, A. Gall, J. Gasser +1
In order to investigate specific aspects of bound state calculations in a non-relativistic framework, we consider the energy-levels of a massive scalar particle, which moves in an…
Sigma-term physics
J. Gasser, M. E. Sainio
We consider sigma-terms in , and scattering. While the state of the art in is in principle crystal clear, the kaon-nucleon case is largely unexplored. The pion-…
Hadronic Atoms in QCD
J. Gasser, V. E. Lyubovitskij, A. Rusetsky
We propose a non relativistic effective Lagrangian approach to study hadronic atom observables in the framework of QCD (including photons). We apply our formalism to derive a gener…
Numerical analysis of the pi+pi- atom lifetime in ChPT
J. Gasser, V. E. Lyubovitskij, A. Rusetsky
We apply Chiral Perturbation Theory at one loop to analyze the general formula for the pi+pi- atom lifetime derived recently in the framework of QCD. The corresponding analytic exp…
Chiral Dynamics
J. Gasser
After a short summary of my talk, I discuss decays and elastic scattering in the framework of chiral perturbation theory.
On the Lifetime of the pi+pi- Atom
A. Gall, J. Gasser, V. E. Lyubovitskij +1
The pi+pi- atom decays -in the ground state - predominantly into two neutral pions. We present a general expression for the corresponding decay width in the framework of QCD (inclu…
ππscattering at low energy: status report
J. Gasser
I discuss the status of ongoing work to determine numerically the elastic scattering amplitude at order in the framework of chiral perturbation theory.
Two--loop integrals in chiral perturbation theory
J. Gasser, M. E. Sainio
We consider chiral perturbation theory in the meson sector at order . In the terminology of the external field technique, the two--loop graphs so generated are of the sunset t…
The scattering amplitude in chiral perturbation theory
J. Gasser
We discuss scattering in the framework of chiral perturbation theory. In particular, we recall the predictions made some time ago for the threshold parameters and for the phas…
- Decays Beyond One Loop
J. Bijnens, G. Colangelo, J. Gasser
The matrix elements for decays are described by four form factors and . We complete previous calculations by evaluating at next-to-leading order…
Low-Energy Photon-Photon Collisions to Two-Loop Order
S. Bellucci, J. Gasser, M. E. Sainio
We evaluate the amplitude for to two loops in chiral perturbation theory. The three new counterterms which enter at this order in the low-energy expansion a…