Conveners
Low-Energy Processes: 1
- Achim Denig (Johannes Gutenberg University Mainz)
Low-Energy Processes: 2
- Jan Friedrich (TUM)
Description
Non-resonance physics
Prof.
Fabio Ambrosino
(Dipartimento di Scienze Fisiche Università degli Studi di Napoli "Federico II" e Sezione INFN Napoli)
6/14/11, 2:30 PM
Low-Energy Processes
talk
A compact review of experimental tests of chiral dynamics involving the low lying pseudoscalars is presented with particular emphasis on results from KLOE and from the detectors operating at MAMI, at the ELSA facility, and at COSY. The status of the experimental knowledge on the dynamics of eta and eta’ decays is discussed and an outlook on future perspectives is given. Finally,...
Mr
Jose Manuel Alarcón
(Universidad de Murcia)
6/14/11, 2:55 PM
Low-Energy Processes
talk
We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of Infrared Regularization up to {\cal O}(q^3) in the chiral expansion, where q is a generic small momentum. We describe the low-energy phase shifts with a similar quality as previously achieved with Heavy Baryon Chiral Perturbation Theory, \sqrt{s}\lesssim 1.14 GeV. New values are provided for the...
Dr
Manuel Pavon Valderrama
(IFIC-UV)
6/14/11, 3:15 PM
Low-Energy Processes
talk
In this talk I consider the perturbative renormalizability of chiral two-pion exchange within the effective field theory formulation of nuclear forces, provided that the one pion exchange potential has been fully iterated. This particular prescription implements the modified Weinberg counting proposal made by Nogga, Timmermans and van Kolck[1] up to next-to-next-to-leading order.
It is...
Mr
Martin Hoferichter
(Bonn University)
6/14/11, 3:35 PM
Low-Energy Processes
talk
Starting from hyperbolic dispersion relations, we present a system of Roy-Steiner equations for pion Compton scattering that respects analyticity and unitarity requirements, gauge invariance, as well as crossing symmetry, and thus all symmetries of the underlying quantum field theory. To suppress the dependence on the high-energy region, we also consider a once- and twice-subtracted version of...
Michael Döring
(Forschungszentrum Jülich)
6/17/11, 9:00 AM
Low-Energy Processes
talk
Recently, eta photoproduction on the neutron has received intense experimental interest at GRAAL, ELSA and MAMI due to the appearance of a sharp structure at around W=1670 MeV. We show that this peak can be explained conventionally within coupled channels chiral dynamics. Also, predictions for the I^s and I^c and other polarization observables in the related gamma p --> pi0 eta p reaction,...
Dr
Alvaro Calle Cordon
(Jefferson Lab)
6/17/11, 9:25 AM
Low-Energy Processes
talk
In analogy with atomic physics and using the quiral quark model we derive a Nucleon-Nucleon (NN) potential in the Born-Oppenheimer approximation at second order in perturbation theory where the
$\Delta$ resonance is included implicitly [1,2]. This NN potential
turns out to be singular at short distances with a van der Waals like
behavior and hence needs to be renormalized. In fact, the...
Dr
Hua-Xing Chen
(IFIC, Valencia University)
6/17/11, 9:45 AM
Low-Energy Processes
talk
We report on a theoretical study of the pp \to p Lambda K+ and pp \to p Sigma0 K+ reactions near threshold using a chiral dynamical approach. The production process is described by single-pion and single-kaon exchange. The final state interactions of nucleon-hyperon, K-hyperon and K-nucleon systems are also taken into account. We show that our model leads to a fairly good description of the...
Stefanie Grabmüller
(TU München)
6/17/11, 10:05 AM
Low-Energy Processes
talk
COMPASS is a multi-purpose fixed-target experiment at CERN SPS, that investigates the structure and spectroscopy of hadrons. Dissociation of pions on nuclear or hydrogen targets provides clean access to the light meson spectrum. During a short run with 190 GeV/c pi- beam on lead in the year 2004, about 4 million exclusive pi-pi-pi+ events have been collected. For the 3 million events with low...
Dr
Dmitry Ryabchikov
(Institute for High Energy Physics)
6/17/11, 10:25 AM
Low-Energy Processes
talk
The reaction pi-Pb->pi-pi-pi+Pb with E_beam = 190 GeV
is studied in great detail by Partial-Wave analysis methods.
The low momentum transfer region t' < 0.01 GeV/c^2 shows the dominance of
coherent diffraction production mechanism and also clear contribution of Coulomb production.
For several M=1 amplitudes the intensities as functions of t'
demonstrate very sharp peaks near...
Mauro Piccini
(University of Perugia)
6/17/11, 10:40 AM
Low-Energy Processes
talk
The NA48/2 collaboration has accumulated ~45000 semi-leptonic K charged
decays to pi0 pi0 e+- neutrino (Ke400), increasing the world available
statistics by more than two orders of magnitude. Low background contamination
and very good pi0 reconstruction bring the first precise measurement of the
Branching Fraction and decay Form Factor at the percent level.
Concurrently, more than one...
