Search for new physics at a super-B factory

Abstract

The importance of a Super-B Factory in the search for New Physics, in particular, due to CP-od phase(s) from physics beyond the Standard Model is surveyed. The first point to emphasize is that we know now how to directly measure all three angles of the unitarity triangle very cleanly, i.e. without theoretical assumptions with irreducible theory error < ∼ 1%; however this requires much more luminosity than is currently available at B-factories. Direct searches via penguin-dominated hadronic modes as well as radiative, pair-leptonic and semileptonic decays are also discussed. Null tests of the SM are stressed as these will play a crucial role especially if the effects of BSM phase(s) on B-physics are small.

Measuring V ub and probing SUSY with double ratios of purely leptonic decays of B and D mesons

“…The unprecedented data samples provided by the B factories have enabled the first JHEP10(2010)038 measurements of B u → τ ν [10][11][12][13][14] despite its relatively small BR and challenging signature. The current world average of BR(B u → τ ν) has an error of 20%, although proposed highluminosity flavour factories could reach a precision of 5% [15][16][17][18][19][20][21][22][23][24]. A measurement of |V ub |f B can be obtained from this decay, where f B is the decay constant for the B u meson, which has been calculated by Lattice Quantum Chromodynamics (LQCD).…”

α≃π/2from supersymmetric spontaneous flavor breaking

“…In this regard, a precise measurement of γ and α, which is the next challenge for B factories, is of paramount importance. It is expected [23,24] that if the luminosity in the upgraded B factories is high enough, γ could be determined with approximately 5% percent uncertainty; a measurement with an uncertainty at the level of 1% will require a superB factory. A determination of α at less than the 5% level may also have to wait for the superB factories [24].…”

Solving the supersymmetricCPproblem with flavor breakingFterms

“…B factories have verified, especially through measurements of the CP asymmetry in the B d → ψK S decay [61,62], that the CP symmetry is significantly violated in the B sector, in agreement with Standard Model predictions, providing a confirmation of the so called CKM paradigm [63,64]. This fact does not rule out the possibility that the effects of CP phases of a different origin, as for instance the phases in the soft supersymmetry breaking sector [65,66,67], could manifest in the near future [68] through other CP violating observables, especially penguin dominated amplitudes such as B → φK 0 , η ′ K s . In this section we will study the constraints that the currents measurements of CP asymmetries in several Bdecays imposse on the model under consideration.…”