We search for lepton-flavor and lepton-number-violating I decays into a lepton (a= electron or muon) and two charged mesons (h , h a2 = pi +/- or K +/-) using 854 fb - 1 of data collected with the ...Belle detector at the KEKB asymmetric-energy e + e - collider. We obtain 90% confidence level upper limits on the I a a h h a2 branching fractions in the range (2.0 a 8.4) X 10 - 8 . These results improve upon our previously published upper limits by factors of about 1.8 on average.
Following Rosner hep-ph/0312269, we consider B-decay production channels for the exotic I=0 and I=3/2 pentaquarks that have been recently reported. We also discuss new search channels for isovector ...pentaquarks, such as the Θ∗++(s̄duuu), that are generically present in chiral soliton models but were not observed in recent experiments. Furthermore, we argue that weak decays of charmed baryons, such as the Λc+ and Ξc0, provide another clean way of detecting exotic baryons made of light quarks only. We also discuss discovery channels for charmed pentaquarks, such as the isosinglet Θc0(c̄udud), in weak decays of bottom mesons and baryons. Finally, we discuss prospects for inclusive production of pentaquarks in e+e− collisions, with associated production of particles carrying the opposite baryon number.
We report the results of a study of B super(+/-) arrow right K super(+/) eta c and B super(+/-) arrow right K super(+/-) eta c(2S) decays followed by eta and eta (2S) decays to super(0)(KSK pi ). The ...results are obtained from a data sample containing 535 million inline image-meson pairs collected by the Belle experiment at the KEKB e super(+)e super(-) collider. We measure the products of the branching fractions inline image and inline image. Interference with the non-resonant component leads to significant model uncertainty in the measurement of these product branching fractions. Our analysis accounts for this interference and allows the model uncertainty to be reduced. We also obtain the following charmonia masses and widths: inline image, inline image, inline image, inline image.
▪ Abstract We review recent experimental results on lifetimes and on hadronic decays of hadrons that contain c and b quarks. The theoretical implications of these results are also considered. An ...understanding of hadronic decays of heavy quarks is required to interpret the charge-parity–violating asymmetries in B decays that will be observed in experiments planned for the near future.
We have searched for the lepton-flavor-violating decays l-K sub(s) super(0) and l-K sub(s) super(0)K sub(s) super(0) (l=e or k), using a data sample of 671 fb super(-1) collected with the Belle ...detector at the KEKB asymmetric-energy e super(+)e super(-) collider. No evidence for a signal was found in any of the decay modes, and we set the following upper limits for the branching fractions: Display omitted at the 90% confidence level.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).We report a search for B decays to selected final states with the eta sub( c) meson: B super( plus or minus ) arrow right K ...super( plus or minus ) eta sub(c) pi super(+) pi super(-), B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) omega , B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) eta and B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) pi super(0). The analysis is based on 772 10 super(6) ... pairs collected at the Upsilon (4S) resonance with the Belle detector at the KEKB asymmetric-energy e super(+) e super(-) collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0.6-5.3) 10 super(-4). We also search for molecular-state candidates in the ... and ... combinations, neutral partners of the Z(3900) super( plus or minus ) and Z(4020) super( plus or minus ), and a poorly understood state X(3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0.6-6.9) 10 super(-5). Figure not available: see fulltext.
B mesons Browder, Thomas E.; Honscheid, Klaus
Progress in particle and nuclear physics,
1995, 1995-1-00, Letnik:
35
Journal Article
Recenzirano
B mesons are bound states of a b quark and a light anti-quark. While the binding is provided by the strong interaction B mesons can only decay by the weak interaction. Since the top quark mass is ...large, B mesons are the only mesons containg quarks of the third geneation and thus their decays provide a unique opportunity to measure the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements
V
cb
,
V
ub
,
V
ts
, and
V
td
which describe the couplings of the third generation of quarks to the lighter quarks.
We review experimental results on masses, lifetimes and decays of B mesons. These include measurements of the inclusive production of charmed and non-charmed mesons and baryons, observations of semileptonic B decays,
B-
B
mixing, B meson lifetimes, measurements of exclusive hadronic final states with charmed mesons, the search for exclusive hadronic final states without charmed mesons, the first observation of the decay
B → K
∗γ
which is described by an electromagnetic penguin diagram and measurement of the inclusive
b →
sγ rate. The theoretical implications of these results will be considered.
We present a search for lepton-flavor-violating tau decays into three leptons (electrons or muons) using 782 fb super(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e ...super(+)e super(-) collider. No evidence for these decays is observed and we set 90% confidence level upper limits on the branching fractions between 1.5x10 super(-8) and 2.7x10 super(-8).
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