Flavor Violation in Theories with TeV Scale Quantum Gravity
| dc.creator | Berezhiani, Zurab | |
| dc.creator | Dvali, Gia | |
| dc.date | 1998-11-17 | |
| dc.date.accessioned | 2026-07-07T10:33:46Z | |
| dc.date.available | 2026-07-07T10:33:46Z | |
| dc.description | We study the effects of possible flavor-violating operators in theories with the TeV scale quantum gravity, in which the ordinary matter is localized on a 3-brane embedded in the space with $N$ extra dimensions, whereas gravity propagates in the bulk. These operators are scaled by the fundamental Planck mass $M_{Pf}\sim$ TeV and must be suppressed by the gauge family symmetries. We study suppression of the most dangerous and model-independent operators. Several points emerge. First, we show that the Abelian symmetries can not do the job and one has to invoke non-Abelian $U(2)_F$ (or $U(3)_F$) symmetries. However, even in this case there emerge severe restrictions on the fermion mixing pattern and the whole structure of the theory. In order not to be immediately excluded by the well-known bounds, the horizontal gauge fields {\it must} be the bulk modes, like gravitons. For the generic hierarchical breaking pattern the four-fermion operators induced by the tree-level exchange of the bulk gauge fields are unsuppressed for $N = 2$. For $N > 3$ the suppression factor goes as a square of the largest $U(2)_F$-non-invariant Yukawa coupling, which implies the lower bound $M_{Pf} > 10$ TeV or so from the $K^0 - \bar K^0$ system. Situation is different in the scenarios when flavor Higgs fields live on a ($3 + N'$)-brane of lower dimensionality than the gauge fields. The further suppression of gauge-mediated operators can be achieved by an explicit construction: for instance, if $U(2)_F$ is broken by a vacuum expectation value of the doublet, the troublesome operators are suppressed in the leading order, due to custodial SO(4) symmetry of the Higgs-gauge quartic coupling. | |
| dc.description | 18 pages, Latex | |
| dc.identifier | https://arxiv.org/abs/hep-ph/9811378 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/9811378 | |
| dc.identifier | Phys.Lett.B450:24-33,1999 | |
| dc.identifier | doi:10.1016/S0370-2693(99)00135-5 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/179234 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Flavor Violation in Theories with TeV Scale Quantum Gravity | |
| dc.type | text |