We report the first observation of the line shape of the Lambda(1405) from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of K+ Lambda(1405) off the proton was studied by using data from CLAS at Jefferson Lab in the range 1.0 < Q(2) < 3.0 (GeV/c)(2). The analysis utilized the decay channels Sigma(+)pi(-) of the Lambda(1405) and p pi(0) of the Sigma(+). Neither the standard Particle Data Group resonance parameters, nor free parameters fitting to a single Breit-Wigner resonance represent the line shape. In our fits, the line shape corresponds approximately to predictions of a two-pole meson-baryon picture of the Lambda(1405), with a lower mass pole near 1368 MeV/c(2) and a higher mass pole near 1423 MeV/c(2). Furthermore, with increasing photon virtuality the mass distribution shifts toward the higher mass pole.

Lu H, Y., Schumacher R, A., Adhikari K, P., Adikaram, D., Aghasyan, M., Amaryan M, J., et al. (2013). First observation of the Lambda(1405) line shape in electroproduction. PHYSICAL REVIEW. C, NUCLEAR PHYSICS, 88(4), 045202-045202--1--045202--7 [10.1103/PhysRevC.88.045202].

First observation of the Lambda(1405) line shape in electroproduction

D'ANGELO, ANNALISA;PISANO, SILVIA;
2013-10-17

Abstract

We report the first observation of the line shape of the Lambda(1405) from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of K+ Lambda(1405) off the proton was studied by using data from CLAS at Jefferson Lab in the range 1.0 < Q(2) < 3.0 (GeV/c)(2). The analysis utilized the decay channels Sigma(+)pi(-) of the Lambda(1405) and p pi(0) of the Sigma(+). Neither the standard Particle Data Group resonance parameters, nor free parameters fitting to a single Breit-Wigner resonance represent the line shape. In our fits, the line shape corresponds approximately to predictions of a two-pole meson-baryon picture of the Lambda(1405), with a lower mass pole near 1368 MeV/c(2) and a higher mass pole near 1423 MeV/c(2). Furthermore, with increasing photon virtuality the mass distribution shifts toward the higher mass pole.
17-ott-2013
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/04 - FISICA NUCLEARE E SUBNUCLEARE
English
Con Impact Factor ISI
QUARK-MODEL; HYPERFINE INTERACTIONS; NUCLEON INTERACTIONS; CHIRAL DYNAMICS; BARYONS; SCATTERING; CONSTRAINTS; STATES
CLAS Collaboration
http://journals.aps.org/prc/abstract/10.1103/PhysRevC.88.045202
Lu H, Y., Schumacher R, A., Adhikari K, P., Adikaram, D., Aghasyan, M., Amaryan M, J., et al. (2013). First observation of the Lambda(1405) line shape in electroproduction. PHYSICAL REVIEW. C, NUCLEAR PHYSICS, 88(4), 045202-045202--1--045202--7 [10.1103/PhysRevC.88.045202].
Lu H, Y; Schumacher R, A; Adhikari K, P; Adikaram, D; Aghasyan, M; Amaryan M, J; Pereira S, A; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; B...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/105128
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