JOHAN BIJNENS Research Interests
My main interest is in theoretical hadronic and high-energy physics. This
is the study of Quantum Chromo Dynamics at low energies and effects
of the strong interaction in the study of rare decays, CP violation,
mixings, determination of quark masses, etc.
Hadronic physics thus straddles the boundary between nuclear and
high-energy physics. In addition I am interested in other applications of
My publication list
can be obtained from
- I am involved in various European collaborations:
Entering the high-precision era of flavour physics through the alliance of
lattice simulations, effective field theories and experiment;
I3HP: Study of Strongly Interacting
Matter and HEP-EST:an EU funded
graduate school in Lund.
- Chiral Perturbation Theory: A lot of my work
is in doing higher order calculations in the low-energy effective field theory
of quantum chromodynamics. This theory is known as Chiral Perturbation Theory.
In precision experiments at low
energies many processes involve hadrons directly or indirectly. In
order to get the best constraints on the underlying standard model
physics (or beyond), it is necessary that all strong interaction effects
are calculated to a sufficient precision. My work involves several examples
of this in various settings, often using Chiral Perturbation Theory.
- Various precision observables need to have hadronic effects calculated.
These often go under the name of nonleptonic matrix-elements. This
is important in weak decays, but also for the muon anomalous magnetic moment.
Some examples of my work, links
lead to the SPIRES data base, from where one can go on to find the papers.
- The introduction of the electro-magnetic Penguin
- Work on Kaon decays and CP violation.
In weak non-leptonic decays the interplay of weak and strong interactions
can lead to enormous enhancement factors. If we do not understand these
we should be very aware that our predictions for the rest are very
uncertain. Our approach which combines Chiral perturbation theory, Models
and QCD in a consistent fashion has had reasonable success in explaining
Kaon decays to two-pions and neutral Kaon mixing. Some of the relevant papers
- Some work using QCD sum rules
- One of the simplest strong interaction processes is
pi-pi scattering. It has now been calculated at next-to-next-to-leading order
in both two and three-flavour Chiral Perturbation Theory.
- We are working on improving the calculation of kaon semileptonic
decays. This has two goals, improving the accuracy with which we now
the down-strange mixing angle, which is a fundamental parameter in the
standard model, and improving the precision on the
parameters needed for pi-pi scattering. Examples of published results are
- A lot of work was done in extending Chiral Perturbation Theory to two-loop
order and applying it to varoious processes of physical interest.
This is described in the review.
- Experimental verification of anomalies at high precision. There will
be future experiments both on pi,eta decays and photon-pi-pi-pi vertices.
The quantitative corrections to the prediction from the anomaly need to
be studied in more detail. I have been very involved in formulating Chiral
Perturbation Theory needed for this, see the review and
- The hadronic light-by-light contribution to the muon anomalous magnetic
moment. The first full analysisand more recent updates in
2001 and 2007.
- Work in Chiral Perturbation Theory relevant for connection with numerical
lattice QCD in partially quenched QCD as well as
volume. See my talk at LATTICE 2007 for more relevant
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This document was last modified Friday, 17-Feb-2017 11:57:24 CET