Isolating the Roper resonance in lattice QCD

We present results for the first positive parity excited state of the nucleon, namely, the Roper resonance (N12+=1440 MeV) from a variational analysis technique. The analysis is performed for pion masses as low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of smeared–smeare...

Full description

Saved in:
Bibliographic Details
Published in:Physics letters. B 2009-08, Vol.679 (4), p.418-422
Main Authors: Mahbub, M.S., Ó Cais, Alan, Kamleh, Waseem, Lasscock, Ben G., Leinweber, Derek B., Williams, Anthony G.
Format: Article
Language:English
Subjects:
Exact sciences and technology
Excited state
Nuclear physics
Physics
Positive parity
Roper resonance
Roper state
The physics of elementary particles and fields
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present results for the first positive parity excited state of the nucleon, namely, the Roper resonance (N12+=1440 MeV) from a variational analysis technique. The analysis is performed for pion masses as low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of smeared–smeared correlation functions are used to construct correlation matrices. This is done in order to find a suitable basis of operators for the variational analysis such that eigenstates of the QCD Hamiltonian may be isolated. A lower lying Roper state is observed that approaches the physical Roper state. To the best of our knowledge, the first time this state has been identified at light quark masses using a variational approach.
ISSN:0370-2693
1873-2445
DOI:10.1016/j.physletb.2009.07.063