D and Ds Hadronic Branching Fractions at B Factories Page: 1 of 8
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
D and Ds hadronic branching fractions at B factories
M. Pappagallo(on behalf of the B4B4? Collaboration)
University of Bari and I.N.FN., 70126 Bari, Italy
Recent measurements of hadronic branching fractions of D and D. mesons, performed by the BABAR and Belle
experiments at the asymmetric e+e- B factories colliders PEP II and KEKB, are reviewed.
Hadronic branching fractions of D and D, decays
are used as references mode in many measurements of
branching fractions of D and B-meson decays as well.
A precise measurement of such values improves our
knowledge of D and B-meson properties, and of fun-
damental parameters of the Standard Model, such as
the magnitude of the Cabibbo-Kobayashi-Maskawa 
2. Absolute branching fraction of
Do - K -+
BABAR collaboration measures the absolute branch-
ing fraction B(Do -> K-r+)l using Do -> K-r+
decays in a sample of D0 mesons preselected by their
production in D*+ decays, obtained with partial re-
construction of the decay B0 -> D*+Xf-t, with
D*+ - D0r+ . Such measurement is extremely
important because many of the past and current D
and B branching fraction measurements are indeed
systematically limited by the precision of B(D0 -
A sample of partially reconstructed B mesons in
the channel B0 -> D*+Xf-t is selected by retaining
events containing a charged lepton (f e, p) and a
low momentum pion (soft pion, or) which may arise
from the decay D*+ - D07rf . This sample of events
is referred to as the "inclusive sample".
Using conservation of momentum and energy, the
invariant mass squared of the undetected neutrino is
My (Ebeam ED* EF)2 (D* -+&)2,
where Ebeam is half the total center-of-mass energy,
Et (ED* ), it (iD*) are the energy and momentum
of the lepton (the D* meson) and the magnitude of
the B meson momentum, pB, is considered negligible
compared to pt and PD*. Figure 1 shows the M2 dis-
tribution and the results of a minimum X2 fit aiming
to determine the signal and background contribution.
'Charge conjugation is implied through the paper.
The number of signal events with Mv > -2 GeV2/c4
results Nincl = (2170.64 3.04(stat) 18.1(syst)) x 103.
-10 -8 -6 -4 2-2 0 2 42
Figure 1: The M distribution of the inclusive sample, for
right-charge (a) and wrong-charge (b) samples. The data
are represented by solid points with error. The MC fit
results are overlaid to the data, as explained in the figure.
The D0 -> K--r+ decays in the inclusive sam-
ple are selected requiring events in the mass range
1.82 < MK, < 1.91 GeV/c2 and 142.4 < AM < 149.9
MeV/c2 where AM M(K-r+x<)-M(K-r+) and
7j is the slow pion from D*+ decay. The exclusive se-
lection yields NexCl 33810 290 signal events, where
the error is statistical only.
The branching fraction is computed as
(D K + NincE
where e(K- +) is the D0 reconstruction efficiency as
computed in the simulation, and ( is the selection bias
introduced by the partial reconstruction.
The main systematic uncertainty on Ninca and Nexcl
are respectively due to the non-peaking combinatorial
BB background and the charged-track reconstruction
efficiency. The complete set of systematic uncertain-
ties is listed in Tab. I. The absolute branching fraction
of D0 -> K--r+ decay results
13(D0 - K--r+) (4.007 0.037 0.070)%,
Contributed to International Workshop on Charm Physics (Charm 2007), 8/5/2007-8/8/2007, Ithaca, NY, USA
Work supported in part by US Department of Energy contract DE-AC02-76SF00515
D 9 -> D*IV (a)
other Peakingob nttn u
Here’s what’s next.
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Pappagallo, Marco. D and Ds Hadronic Branching Fractions at B Factories, article, January 7, 2008; [Menlo Park, California]. (digital.library.unt.edu/ark:/67531/metadc898142/m1/1/: accessed December 11, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.