Observation of the Cabibbo-suppressed decay Xi_c+ -> p K- pi+

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi_c+ -> p K- pi+. We observe 150 +- 22 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma- beam. The branching fractions of the decay relative to the Cabibbo-favored Xi_c+ -> Sigma+ K- pi+ and Xi_c+ -> X- pi+ pi+ are measured to be B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> Sigma+ K- pi+) = 0.22 +- 0.06 +- 0.03 and B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> X- pi+ pi+) = 0.20 +- 0.04 +- 0.02, respectively.Comment: 5 pages, RevTeX, 3 figures (postscript), Submitted to Phys. Rev. Let

Total Cross Section Measurements With π- , Σ- And Protons On Nuclei And Nucleons Around 600 Gev/c

Total cross sections for Σ- and π- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c . These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for σtot(Σ-N) and σtot(π-N) , which were deduced from nuclear cross sections. © 2000 Elsevier Science B.V.57901/02/15277312Langland, J.L., (1995) Ph.D. Thesis, , University of IowaKleinfelder, S.A., (1988) IEEE Trans. Nucl. Sci., 35 (1)Dersch, U., (1998) Ph.D. Thesis, HeidelbergBiagi, S.F., (1981) Nucl. Phys. B, 186, pp. 1-21Bellettini, G., (1966) Nucl. Phys., 79, pp. 609-624Schiz, A.M., (1980) Phys. Rev. D, 21, pp. 3010-3022Murthy, P.V.R., (1975) Nucl. Phys. B, 92, pp. 269-308Caso, C., (1998) Eur. Phys. J. C, 3. , http://pdg.lbl.gov/1998/contents_plots.html, and data on total cross sections from computer readable filesSchiz, A.M., (1979) Ph.D. Thesis, , Yale University(1973) Landolt Börnstein Tables, 7. , Springer editionEngler, J., (1970) Phys. Lett. B, 32, pp. 716-719Babaev, A., (1974) Phys. Lett. B, 51, pp. 501-504Glauber, R.J., (1959) Boulder Lectures, pp. 315-413Franco, V., (1972) Phys. Rev. C, 6, pp. 748-757Karmanov, V.A., Kondratyuk, L.A., (1973) JETP Lett., 18, pp. 266-268Burq, J.P., (1983) Nucl. Phys. B, 217, pp. 285-335Gross, D., (1978) Phys. Rev. Lett., 41, pp. 217-220Beznogikh, G.G., (1972) Phys. Lett. B, 39, pp. 411-413Vorobyov, A.A., (1972) Phys. Lett. B, 41, pp. 639-641Foley, K.J., (1967) Phys. Rev. Lett., 19, pp. 857-859Fajardo, L.A., (1981) Phys. Rev. D, 24, pp. 46-65Jenni, P., (1977) Nucl. Phys. B, 129, pp. 232-252Breedon, R.E., (1989) Phys. Rev. Lett. B, 216, pp. 459-465Amos, N., (1983) Phys. Rev. Lett. B, 128, pp. 343-348Amaldi, U., (1977) Phys. Rev. Lett. B, 66, pp. 390-394Amos, N., (1985) Nucl. Phys. B, 262, pp. 689-714Akopin, V.D., (1977) Sov. J. Nucl. Phys., 25, pp. 51-55Amirkhanov, I.V., (1973) Sov. J. Nucl. Phys., 17, pp. 636-637Foley, K.J., (1969) Phys. Rev., 181, pp. 1775-1793Apokin, V.D., (1976) Nucl. Phys. B, 106, pp. 413-429Burq, J.P., (1982) Phys. Lett. B, 109, pp. 124-127Dakhno, L.G., (1983) Sov. J. Nucl. Phys., 37, pp. 590-598Kazarinov, M., (1976) Sov. Phys. JETP, 43, pp. 598-606De Jager, C.W., (1974) At. Data Nucl. Data Tables, 14, pp. 479-508Donnachie, A., Landshoff, P.V., (1992) Phys. Lett. B, 296, pp. 227-232Lipkin, H., (1975) Phys. Rev. D, 11, pp. 1827-1831Barnett, R.M., (1996) Phys. Rev. D, 54, pp. 191-192Carroll, A.S., (1979) Phys. Lett. B, 80, pp. 423-427Badier, J., (1972) Phys. Lett. B, 41, pp. 387-39

Total Cross Section Measurements with pi-, Sigma- and Protons on Nuclei and Nucleons around 600 GeV/c

Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.Comment: 42 pages, submitted to Nucl.Phys.

Observation of the Cabibbo-suppressed decay Xi(+)(c) -> pK(-)pi(+)

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi(c)(+) --> pK(-)pi(+) We observe 150 +/- 22 +/- 5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma(-) beam. The branching fractions of the decay relative to the Cabibbo-favored Xi(c)(+) --> Sigma(+)K(-)pi(+) and Xi(c)(+) --> Xi(-)pi(+)pi(+) are measured to be B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Sigma(+)K(-)pi(+)) = 0.22 +/- 0.06 +/- 0.03 and B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Xi(-)pi(+)pi(+)) = 0.20 +/- 0.04 +/- 0.02, respectively

Total cross section measurements with π- , Σ- and protons on nuclei and nucleons around 600 GeV/c

Total cross sections for Σ- and π- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c . These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for σtot(Σ-N) and σtot(π-N) , which were deduced from nuclear cross sections. © 2000 Elsevier Science B.V.Ball State University, Muncie, IN 47306Bogazici University, Bebek 80815 IstanbulCarnegie-Mellon University, Pittsburgh, PA 15213Centro Brasiliero de Pesquisas Físicas, Rio de JaneiroFermilab, Batavia, IL 60510Institute for High Energy Physics, ProtvinoInstitute of High Energy Physics, BeijingInstitute of Theoretical and Experimental Physics, MoscowMax-Planck-Institut für Kernphysik, 69117 HeidelbergMoscow State University, MoscowPetersburg Nuclear Physics Institute, St. PetersburgTel Aviv University, 69978 Ramat AvivUniversidad Autónoma de San Luis Potosí, San Luis PotosíUniversidade Federal da Paraíba, ParaíbaUniversity of Bristol, Bristol BS8 1TLUniversity of Iowa, Iowa City, IA 52242University of Michigan-Flint, Flint, MI 48502University of Rome 'La Sapienza' and INFN, RomeUniversity of São Paulo, São PauloUniversity of Trieste and INFN, TriesteNow at Imperial College, London SW7 2BZInstituto de Física da Universidade Estadual de Campinas UNICAMP, SPDept. of Physics Wayne State University, Detroit, MI 48201Universität Freiburg, 79104 FreiburgPhysik-Department Technische Universität München, 85748 GarchingInstituto de Física Teórica da Universidade Estadual Paulista, São PauloLucent Technologies, Naperville, ILNow at Max-Planck-Institut für Physik, MünchenMotorola Inc, Schaumburg, ILDeutsche Bank AG, 65760 EschbornInstituto de Física Teórica da Universidade Estadual Paulista, São Paul

Observation Of The Cabibbo-suppressed Decay ξc+ π K- π+

We report the first observation of the Cabihbo-suppressed charm baryon decay ξc+ → pK- π+. We observe 150 ± 22 ± 5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Σ- beam. The branching fractions of the decay relative to the Cabibbo-favored ξc+ → Σ + K- π and ξ+ →c+ →- ξ+ π+ π+ are measured to he B(ξc+ → pK- π+)/B(ξc+ → Σ- π+ K π+) = 0.22 ± 0.06 ± 0.03 and B(ξc+ → ξ π+π+pK- π+)/B(ξc+ →- π+ π+) = 0.20 ± 0.04 ± 0.02, respectively.84918571861Körner, J.G., Krämer, M., (1992) Z. Phys. C, 55, p. 659Bauer, M., Stech, B., Wirbel, M., (1987) Z. Phys. C, 34, p. 103Alexander, J.P., (1996) Phys. Rev. D, 53, pp. R1013Frabetti, P.L., (1993) Phys. Lett. B, 314, p. 477Russ, J.S., Proceedings of the 29th International Conference on High Energy Physics, 1998, 2, p. 1259. , edited by A. Astbury et al. (World Scientific, Singapore, 1998), hep-ex/9812031Engelfried, J., (1999) Nucl. Instrum. Methods Phys. Res., Sect. A, 431, p. 53Caso, C., (1998) Eur. Phys. J., C3, p. 1Bergfeld, T., (1996) Phys. Lett. B, 365, p. 43