Insensitivity to symmetry breaking in the very excited spectrum

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Leader Name: Felipe J. Llanes Estrada

Leader Institution: Univ. Complutense

We are exploring the high spectrum of a complex, relativistic quantum system with three particles in three dimensions, the excited baryon spectrum. We try to numerically establish a new implementation of symmetry in quantum mechanics, where, although the symmetry is broken (just as in the Standard Model of particle physics, or in a ferromagnet), the high spectrum is insensitive to the breaking. As lattice methods can at present not access very excited states, we employ a Hamiltonian model of Coulomb gauge Chromodynamics, but still use Montecarlo methods to evaluate the very complex matrix elements in a large function basis. The computation of the matrix requires the outstanding supercomputer capabilities of Barcelona┬┤s MareNostrum. Our results, especially for fast spinning states, will motivate experimental work at Jefferson Laboratory.

In this period we have developed and partly executed the computer programme that computes the basis of orthogonal, properly antisymmetrized wavefunctions. The computation has not reached a state of maturity where one can answer with a "yes" or "no" the question of whether chiral symmetry is indeed restored in the high spectrum, but progress has been made and we hope to finish this investigation within 2012.

In a separate development, we have performed a preliminary computation of the mass of baryons made of three heavy quarks. We hope to stimulate the search for these unknown particles at the LHC and at a future accelerator planned for Italy, Super-B. With the help of supercomputer resources (for the many nine-dimensional integrals needed to obtain the Energy as function of the system parameters), we have estimated both the ground state energy and the effect of the three body force, that we find to be small.



  • Felipe J. Llanes-Estrada et al., "A first estimate of triply heavy baryon masses from the pNRQCD perturbative static potential", e-Print: arXiv:1111.7087 [hep-ph] under peer review.
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