Charmed Baryon Research Articles

Predictions for Charm Baryon Semileptonic Decays in the SU(4) Limit, the Non‐relativistic, and MIT Bag Quark Models

The predictions for charm baryon semileptonic decays (CBSD) are given in three different models: SU(4) symmetry limit, non-relativistic (NRQM), and the MIT Bag (MBM) quark models. The comparison with the only available data-the A: semileptonic decay-gives ample room for the existence of a fourth generation. Semileptonic decays of %+ charm baryons should be interesting to study experimentally and theoretically. On the one hand, the very large mass difference between the charm quark c and the s, u and d quarks guarantees a big phase space. This should make their observation easier and high statistic experiments should be attainable without too much effort. On the other hand, for %+ 5' decays the transition amplitude involves four relevant form factors when the emitted charged lepton is an electron. Because of the large momentum transfer, the four become almost equally important. Since they are all rich in information about strong interactions, their detailed measurement should give very important guidance to disentangle the theory of strong interactions at low energy, especially with respect to flavor symmetry breaking, which is now expected to be substan~ially large. The '12' are classified in the 20 representation whose SU(3) content is 8 + 6 + 3 + 3. The selection rules allow for 60 different decays among the 20 baryons. Of these, 12 correspond to the semileptonic decays between ordinary non-charm baryons described by the Cabbibo theory, which we do not discuss here. The processes A,+ Z and 2,' A have zero Clebsch-Gordan coefficients, they are forbidden by isospin because A,+ and A are singlets and 2,' and Z belong to triplets. We are, thus, left with 46

Predictions for Charm Baryon Semileptonic Decays in the SU(4) Limit, the Non-relativistic, and MIT Bag Quark Models

Predictions for Charm Baryon Semileptonic Decays in the SU(4) Limit, the Non-relativistic, and MIT Bag Quark Models

Predictions for semileptonic decays of charm baryons. I. SU(4)-symmetry limit.

We review the predictions of SU(4) symmetry and the Glashow-Iliopoulos-Maiani mechanism for the semileptonic decays of ${\mathrm{\textonehalf{}}}^{+}$ charm baryons. We use, wherever possible, the experimental masses of charm baryons; for the unknown masses we use the predictions of mass formulas. The ${q}^{2}$ dependence of form factors is taken to be either of monopole or of dipole form. For $\ensuremath{\Delta}S=\ensuremath{\Delta}Q=\ensuremath{-}1$ transitions, very large branching ratios are predicted---of the order of 10%.

Predictions for semileptonic decays of charm baryons. II. Nonrelativistic and MIT bag quark models.

Predictions for the semileptonic decays of charm baryons are given in two quark models: The nonrelativistic and the MIT bag models. We find that several processes have large branching ratios, of the order of few percent; these are very large in comparison with the strange-hyperon semileptonic-decay branching ratios. We also notice that the {ital q}{sup 2} dependence overwhelms other corrections and should be considered in the future with more emphasis. Finally, the predictions found for the {Lambda}{sub {ital c}}{sup +} decay---when compared with the corresponding experimental value---leave ample room for the existence of a fourth generation.

ISODOUBLET MASS SPLITTING OF CHARM BARYONS ON ONE GLUON EXCHANGE QCD MODEL WITH RELATIVISTIC CORRECTION

We apply a QCD motivated quark model, which was tested in the past for the calculation of isodoublet mass shift of several hadrons, to calculate isospin mass splitting of charm baryons. We find that the mass of [Formula: see text] is heavier than the mass of [Formula: see text] (an interesting as well as surprising result) when we compare the quark contents of these particles. Our theoretical value [Formula: see text] is also in agreement with recent experimental values [Formula: see text] by ARGUS.

Charmed Baryon Decaya

Annals of the New York Academy of SciencesVolume 518, Issue 1 p. 128-131 Charmed Baryon Decaya A. GARCIA, A. GARCIA Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, MéxicoSearch for more papers by this authorR. HUERTA, R. HUERTA Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, MéxicoSearch for more papers by this authorP. KIELANOWSKI, P. KIELANOWSKI Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, México The work of one of the authors (P. K.) was supported in part by Project MR-17 of the Polish Ministry of Science and Technology while the author was at the University of Warsaw, Warsaw, Poland.Search for more papers by this author A. GARCIA, A. GARCIA Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, MéxicoSearch for more papers by this authorR. HUERTA, R. HUERTA Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, MéxicoSearch for more papers by this authorP. KIELANOWSKI, P. KIELANOWSKI Departamento de Fisica, Centro de Investigatión y de Estudios Avanzados, Institute Politécnico National México City, México The work of one of the authors (P. K.) was supported in part by Project MR-17 of the Polish Ministry of Science and Technology while the author was at the University of Warsaw, Warsaw, Poland.Search for more papers by this author First published: December 1987 https://doi.org/10.1111/j.1749-6632.1987.tb48816.x a This work was supported in part by COSNET (Mexico). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume518, Issue1The Fourth Family of Quarks and Leptons: First International SymposiumDecember 1987Pages 128-131 RelatedInformation

Open-charm hadroproduction and perturbative quantum chromodynamics

We critically study the method and the validity of perturbative QCD in open-charm hadroproduction. We explain how the gluon-fusion process ($G+G\ensuremath{\rightarrow}c+\overline{c}$) and the flavor-excitation process ($q+c\ensuremath{\rightarrow}q+c$ or $G+c\ensuremath{\rightarrow}G+c$) should be calculated in line with a principle of perturbative QCD (absorption of mass singularities into parton distributions), and without causing double counting. In this framework it is rather unlikely that the cross section of the excitation process is as large as \ensuremath{\sim} 1 mb at CERN ISR energy $\sqrt{s}\ensuremath{\simeq}60$ GeV. We discuss how large the cross section can be through possible higher-order effects. The ${x}_{F}$ distribution of charmed hadrons is also analyzed. By using a simple model for the recombination of charm quarks with fast-moving valence quarks, we show that it is easy to explain the observed hard spectrum of charm baryons.

Remark on baryonic decays of B mesons

We point out that B mesons might possess significant baryonic decay modes like B → Λ c N . Invoking a simple-minded spectator ansatz for B decays we estimate BR(B → Λ c N +X) ≈ 2–13% while exclusive two-body channels might reach values of a few percent. Observation of such transitions could yield valuable information on the dynamics of weak decays and maybe even on charm baryons. The search for bottom baryons would, however, be made more difficult by a sizeable baryonic branching ratio of bottom mesons.

Weak annihilation in charm baryon decays ? A re-evaluation

We discuss weak decays of charm baryons taking the mode Λ c + →Δ++K− as the starting point of our analysis. This channel which can occur only due to weak annihilation has been seen at the ISR. Hence we conclude that weak annihilation is very significant for baryons. Further tests of this picture are listed, in particular concerning charm-strange baryons. We argue that τ(D°)~τ(Λ c + )<τ(D+) suggests that baryon and meson decays should be treated on an equal footing even when weak annihilation is included. We describe a framework based on evolution equations where this can be done.

Associated photoproduction of a charmed meson and a charmed baryon

Associated photoproduction of a charmed meson and a charmed baryon

Charmed-Baryon Production in High-Energy Neutrino-Deuterium Interactions

In a sample of approx.15 000 charged current ..nu..+d interactions from an exposure of the Fermilab 15-ft bubble chamber to a high-energy, wide-band neutrino beam, the production of the ..lambda../sub c/ /sup +/ charmed baryon decaying into ..lambda pi../sup +/ and K/sup 0/p is observed. The measured mass value is 2.275 +- 0.010 GeV. The products of the production rate and the branching ratio for these channels are (1.8 +- 0.9) x 10/sup -3/ and (3.5 +- 2.0) x 10/sup -3/, respectively.

Parity Violating Hadronic Decays of Charmed Baryons in SU(8) with Right-Handed Current

Parity Violating Hadronic Decays of Charmed Baryons in SU(8) with Right-Handed Current

Charmed baryons, their mass splitting, and weight diagrams

Sum rules relating the masses of the 1/2/sup +/ charmed and uncharmed baryons are derived using weight diagrams.

Regge Spectra of Charmed Baryons in Dual Resonance Amplitudes

Regge Spectra of Charmed Baryons in Dual Resonance Amplitudes

Selection of a dynamical group for the charmed baryons

Selection of a dynamical group for the charmed baryons