Conveners
Low-Energy Processes: 1
- Achim Denig (Johannes Gutenberg University Mainz)
Low-Energy Processes: 2
- Jan Friedrich (TUM)
Description
Non-resonance physics
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Prof. Fabio Ambrosino (Dipartimento di Scienze Fisiche Università degli Studi di Napoli "Federico II" e Sezione INFN Napoli)14/06/2011, 14:30Low-Energy ProcessestalkA 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,...Go to contribution page
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Mr Jose Manuel Alarcón (Universidad de Murcia)14/06/2011, 14:55Low-Energy ProcessestalkWe 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...Go to contribution page
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Dr Manuel Pavon Valderrama (IFIC-UV)14/06/2011, 15:15Low-Energy ProcessestalkIn 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...Go to contribution page
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Mr Martin Hoferichter (Bonn University)14/06/2011, 15:35Low-Energy ProcessestalkStarting 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...Go to contribution page
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Michael Döring (Forschungszentrum Jülich)17/06/2011, 09:00Low-Energy ProcessestalkRecently, 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,...Go to contribution page
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Dr Alvaro Calle Cordon (Jefferson Lab)17/06/2011, 09:25Low-Energy ProcessestalkIn 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...Go to contribution page
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Dr Hua-Xing Chen (IFIC, Valencia University)17/06/2011, 09:45Low-Energy ProcessestalkWe 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...Go to contribution page
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Stefanie Grabmüller (TU München)17/06/2011, 10:05Low-Energy ProcessestalkCOMPASS 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...Go to contribution page
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Dr Dmitry Ryabchikov (Institute for High Energy Physics)17/06/2011, 10:25Low-Energy ProcessestalkThe 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...Go to contribution page
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Mauro Piccini (University of Perugia)17/06/2011, 10:40Low-Energy ProcessestalkThe 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...Go to contribution page