Charm Hadronic Decays from Focus: Lessons Learnt

Physical Review D, 1994

Alam, MS; Kim, IJ; Nemati, B.; O'neill, JJ; Severini, H.; Sun, CR; Zoeller, MM; Crawford, G.; Daubenmier, CM; Fulton, R.; Fujino, D.; Gan, KK; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Skovpen, Y.; Sung, ...

1995

Recent analyses of charm quark production mechanisms from Fermilab xed-target experiments are summarized. Measurements of single inclusive dierential cross sections for hadroproduced and photoproduced D mesons are compared to next-to-leading order QCD calculations. New data from hadroproduction and previous photoproduction measurements of charm meson pair correlations are compared to NLO calculations and also to parton shower Monte Carlo models. Nonperturbative eects, such a s i n trinsic k t and fragmentation, are seen to play an important role in most of these comparisons. Results on charm production asymmetries in both hadroproduction and photoproduction are summarized.

Nuclear Physics B - Proceedings Supplements, 1989

2018

A search is performed for the decay Λb → pKη′ using pp collision data collected with the LHCb detector at centre-of-mass energies of √ s = 7 TeV and √ s = 8 TeV, corresponding to an integrated luminosity of 3 fb−1. The search is performed in two decay channels; the η′ is reconstructed through the decays η′→ π+π−γ and η′→ π+π−η . In the η′→ π+π−γ decay channel 117 ± 15(stat.) ± 10(sys.) signal events are observed and 45 ± 8(stat.) ± 2(sys.) signal events are observed in the η′→ π+π−η decay channel. The combined statistical significance of these signals is 12.0σ, therefore this is the first observation of the decay Λb→ pKη′ . The branching fraction of the decay Λb→ pKη′ is measured relative to the decay B+→ K+η′ . The ratio of branching fractions is measured to be B(Λb→ pKη′) B(B+→ K+η′) = 0.120± 0.013(stat.)± 0.013(sys.). Using the world average value for the branching fraction of the decay B+→ K+η′ [1], the branching fraction of Λb→ pKη′ is measured to be B(Λb→ pKη′) = 8.48± 0.88(st...

Brazilian Journal of Physics, 2004

The connection between light quark spectroscopy and hadronic decays of D mesons is discussed, with emphasis on the physics of the light scalar mesons. Recent results from charm decays are presented.

arXiv: High Energy Physics - Experiment, 2016

In this review we report the recent results of open charm decays and spectroscopy using the data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.

The European Physical Journal C - Particles and Fields, 2004

The branching ratio of beauty hadrons to final states containing two charm hadrons, Br(b → DDX), has been measured using an inclusive method in hadronic Z 0 decays with the OPAL detector at LEP. The impact parameter significance of tracks opposite tagged b-jets is used to differentiate b → DDX decays from other decays. The result is

Arxiv preprint hep-ex/0312038, 2003

A biased review of recent results in charm physics is presented. New results on D 0 − D 0 mixing, rare decays of D 0 and D ± , scalar resonances in D + and D s decays, and new decay modes and mass measurements in Λ + c , Ξ +,0 c , Ω 0 c , and Ξ + cc are discussed.

Physics Letters B, 2000

Using data recorded at centre-of-mass energies around 183 GeV and 189 GeV with the OPAL detector at LEP, the fundamental coupling of the charm quark to the W boson has been studied. The ratio R W c ≡ Γ (W → c X)/Γ (W → hadrons) has been measured from jet properties, lifetime information, and leptons produced in charm decays. A value compatible with the Standard Model expectation of 0.5 is obtained: R W c = 0.481±0.042 (stat.) ±0.032 (syst.). By combining this result with measurements of the W boson total width and hadronic branching ratio, the magnitude of the CKM matrix element |V cs | is determined to be |V cs | = 0.969 ± 0.058.

Physics Reports, 1997

Introduction 4 4.4. Sample selection 2. Theoretical treatment of charm and beauty 4.5. Lifetime determination lifetimes 5 4.6. S-/I?' lifetimes 2.1. Phenomenology: Legends with truths 5 4.7. B, lifetime 2.2. From phenomenology to theory 8 4.8. Ah and the generic b-Baryon lifetime 2.3. Methodology of the heavy quark expansion 4.9. zh lifetime for fully integrated rates 10 4. IO. Inclusive measurements 3. The lifetimes of weakly decaying charm 4.11. Overall summary of current lifetime hadrons 17 values 3.1. Experimental devices 18 4.12. Predictions and interpretation of existing 3.2. Vertex reconstruction 38 relevant data 3.3. Lifetimes of the charmed mesons 49 5. Summary and outlook 3.4. Lifetimes of charmed baryons 55 5.1. Comments on the underlying concepts 3.5. Theoretical evaluation of the results 68 5.2. What have we learned and 4. The lifetimes of weakly decaying beauty what will we learn? hadrons 81 5.3. Future prospects for further experimental 4.1. Formation of B states in e+e-and pp 83 data 4.2. Identification of B decays 84 References 4.3. Detector requirements 87

Physical review letters, 2007

Using 230.2 fb -1 of e + e - annihilation data collected with the BABAR detector at and near the peak of the Υ(4S) resonance, 489±55 events containing the pure leptonic decay D s + →μ + ν μ have been isolated in charm-tagged events. The ratio of partial widths Γ(D s + →μ + ν ...

Physics Letters B, 2004

Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report on the measurement of the ratio of semileptonic rates Γ(D + →Kπµ + νµ)

Annals of the New York Academy of Sciences, 1988

Since the first Symposium on Heavy Flavors, in May, 1986, there have been many important new experimental results in charm physics. Among these have been precise D, and Ac lifetimes, new absolute branching ratios, many 0, branching ratios, confirmation of an excited charmed resonance in the D*u system, and observation of a similar state in the Du system. Discussions of these topics are included in the review that follows. Other&portant results included in other reviews at this conference are new limits on Do-Do mixing' and a new limit on f D from D+-p+ur decays.* CHARM LIFETIMES The basic ideas behind the present picture of charm decays are discussed extensively in the theoretical review.' For reference, FIGURE 1 shows four quark diagrams representing the Cabibbo-allowed decays of charmed mesons. The first two are spectator diagrams in which the light quark is not one of the four fermions at the weak vertex. The last two are nonspectator diagrams-Wexchange for the Do and W annihilation for the 0 , '. Much theoretical effort has been expended in trying to investigate the relative strength of the nonspectator amplitudes. The central experimental fact that must be explained is T(D+)/T(DO) = 2.6. The most obvious candidate to explain the large lifetime ratio is a large contribution from the W-exchange and V-annihilation diagrams because these contribute to Do and D,+, but not D' decays. Theoretically, these diagrams were expected to make rather small contributions to charmed meson decay because of helicity suppression. Experimentally, Mark I11 sets a limit,f, 5 290 MeV, from a search for the decay, D +-p+u,. Unlessjb, the effective decay constant for nonleptonic decays, is much larger than this, the W-exchange diagram should account for a small fraction of the total Do decay rate? The only direct way to measure the contribution of nonspectator diagrams to hadronic decay rates is to look foidecay modes that should be very small for the spectator diagrams. One of these is Do-K04, for which a rather large branching ratio of about 18 has been mea~ured.~ It is not clear, though, to what extent final state interactions are responsible for any single final state. Another decay of this type is 0,'-POT+, which will be discussed later. The second possible cause of the large difference in D lifetimes is suppression of the D

Nuclear Physics B-proceedings Supplements, 2011

In this paper, the potential to study hadroproduction of charmonium via pp decay at the LHC is discussed. The branching ratio of h c → pp is estimated to be about 0.6 × 10 −3 . The studies of charmonium hadroproduction using cc → pp and cc → + − are compared. The yield of J/ψ → pp is estimated to be about 60 events/pb −1 at √ s = 7 TeV.

1996

Recent results on Dalitz analysis of three-pseudoscalar decays are discussed in the context of probing charm hadronic-decay mechanisms: the role of FSI effects, which create phase shifts between the interfering resonant channels, can be studied in the different decay modes and the annihilation contribution measured in the charm sector through the $D^+_s \to \pi^+\pi^-\pi^+$ decay.