dc.creator | Danko, Istvan Zsolt | |
dc.date.accessioned | 2020-08-23T15:57:12Z | |
dc.date.available | 2003-11-03 | |
dc.date.issued | 2002-11-03 | |
dc.identifier.uri | https://etd.library.vanderbilt.edu/etd-1130101-174336 | |
dc.identifier.uri | http://hdl.handle.net/1803/14882 | |
dc.description.abstract | A tremendous effort has been devoted to finding the
deep physical reason for the existence of the mass hierarchy and weak
mixing among the quarks and leptons. Despite the enormous amount
of data accumulated during the past three decades we still appear
to be far from the true understanding of the family structure of
fermions and the origin of particle generations (families).
A possible explanation based on a spontaneously broken continuous
global family symmetry was suggested some time ago. One of the
most important consequence of the spontaneous breakdown of this
family symmetry is the existence of neutral massless
Nambu-Goldstone bosons, called familons. Familons can have
flavor-conserving as well as flavor-changing couplings with the
fermions and the coupling strength is suppressed by the energy
scale at which the flavor symmetry is broken. In contrast to the
first two generations, experimental constraints on familons
coupled to the third generation of fermions are quite
modest, the only weak constraint is in the leptonic
sector from tau->e/mu X0 decay.
Flavor-changing couplings between the b quark and the familon
(f) would lead to the decay B->hf (h=pi,K) through
vector coupling and B->Vf (V=rho,K*) through axial
coupling. We have searched for the two-body decay of the B meson
to a light pseudoscalar meson h=pi,K,K0-short and a
massless neutral weakly-interacting particle X0 such as the
familon. We find no significant signal by analyzing a data sample
containing 9.7 million BB mesons collected with the CLEO
detector at the Cornell Electron Storage Ring, and set a 90% C.L.
upper limit of 4.9x10^{-5} and 5.3x10^{-5} on
the branching fraction for the decays B+->h+X^0$ and
B0->K0S X0, respectively. These upper limits
correspond to a lower bound of approximately 10^8 GeV on the
family symmetry breaking scale (with vector coupling) for the third
generation of quarks. | |
dc.format.mimetype | application/pdf | |
dc.subject | B meson decay | |
dc.subject | Family (flavor) symmetry | |
dc.subject | Familon | |
dc.subject | Spontaneous symmetry breaking | |
dc.subject | Goldstone boson | |
dc.title | Search for the Familon in Two-Body B Meson Decays | |
dc.type | dissertation | |
dc.contributor.committeeMember | Thomas W. Kephart | |
dc.contributor.committeeMember | Paul D. Sheldon | |
dc.contributor.committeeMember | Norman H. Tolk | |
dc.contributor.committeeMember | Thomas J. Weiler | |
dc.type.material | text | |
thesis.degree.name | PHD | |
thesis.degree.level | dissertation | |
thesis.degree.discipline | Physics | |
thesis.degree.grantor | Vanderbilt University | |
local.embargo.terms | 2003-11-03 | |
local.embargo.lift | 2003-11-03 | |
dc.contributor.committeeChair | Steven E. Csorna | |