77 research outputs found
CP Asymmetries in (Semi-)Inclusive B0 Decays
It was recently pointed out that inclusive B^0(t) decays could show CP
violation. The totally inclusive asymmetry is expected to be tiny [O(10^{-3})]
because of large cancellations among the asymmetries in the charmless, single
charm and double charm final states. Enriching particular final state
configurations could significantly increase the CP-asymmetry and observability.
Such studies can extract fundamental CKM (Cabibbo-Kobayashi-Maskawa)
parameters, and (perhaps) even Delta m(B_s). A superb vertex detector could see
CP violation with 10^5 (10^6) flavor-tagged B_s (B_d) mesons within the CKM
model. Because the effects could be significantly larger due to new physics,
they should be searched for in existing or soon available data samples.Comment: RevTex, 20 pages, no figure
Resolving a Discrete Ambiguity in the CKM Angle through and Decays
It is well known that , where is one of the angles of
the unitarity triangle of the CKM matrix, can be determined in a theoretically
clean way by measuring mixing-induced CP violation in the decay . Another clean extraction of this CKM angle is provided by the
time-dependent angular distribution for the decay products of , where we have more observables at
our disposal than in the case of , so that in addition to
also can be probed in a direct way. Unfortunately
a sign ambiguity remains in . If it could be resolved, a discrete
ambiguity in the extraction of the CKM angle could be resolved as well,
which would allow a more incisive test of the CKM model of CP violation. This
note shows that detailed time-dependent studies of and decay processes can determine the sign of
, thereby removing the corresponding ambiguity in the extraction
of the CKM angle .Comment: 5 pages, LaTeX, no figure
Clean CKM Information from Bd(t) -> D(*)+/- pi-/+
It has been known for many years that the Bd(t) -> D(*)+/- {pi-/+, rho-/+,
a1-/+} modes may involve observable CP violating effects. This note describes
how to determine cleanly the Cabibbo-Kobayashi-Maskawa (CKM) phase phi = -2
beta - gamma = -pi + alpha - beta, even in the presence of possible final state
interactions. A discrete ambiguity remains.Comment: 8 pages, revte
Beautiful CP Violation
CP violation is observed to date only in K^0 decays and is parameterizable by
a single quantity epsilon. Because it is one of the least understood phenomena
in the Standard Model and holds a clue to baryogenesis, it must be investigated
further. Highly specialized searches in K^0 decays are possible. Effects in B
decays are much larger. In addition to the traditional B_d -> J/\psi K_S,
pi^+pi^- asymmetries, CP violation could be searched for in already existing
inclusive B data samples. The rapid B_s - B_s.bar oscillations cancel in
untagged B_s data samples, which therefore allow feasibility studies for the
observation of CP violation and the extraction of CKM elements with present
vertex detectors. The favored method for the extraction of the CKM angle gamma
is shown to be unfeasible and a solution is presented involving striking direct
CP violation in charged B decays. Novel methods for determining the B_s mixing
parameter Delta m are described without the traditional requirement of
flavor-specific final states.Comment: 11 pages, latex, 2 postscript figures included, talk presented at the
b20 conference, June 29 - July 2, 1997, IIT, Chicag
Enhanced CP Violation with Modes and Extraction of the CKM Angle gamma
The Gronau-London-Wyler (GLW) method extracts the CKM angle by
measuring decay rates involving mesons. Since that
method necessitates the interference between two amplitudes that are
significantly different in magnitude, the resulting asymmetries tend to be
small. CP violation can be greatly enhanced for decays to final states that are
common to both D^0 and and that are not CP eigenstates. In
particular, large asymmetries are possible for final states f such that is doubly Cabibbo suppressed while is Cabibbo allowed.
The measurement of interference effects in two such modes allows the extraction
of without prior knowledge of , which
may be difficult to determine due to backgrounds.Comment: 12 pages, LaTeX, no figure
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