Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV

K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K. Ametewee, K. J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A. H. Ball, E. Barberio, R. J. Barlow, R. Bartoldus, J. R. Batley, J. Bechtluft, C. Beeston, T. Behnke, A. N. Bell & 311 others K. W. Bell, G. Bella, S. Bentvelsen, P. Berlich, S. Bethke, O. Biebel, V. Blobel, I. J. Bloodworth, J. E. Bloomer, M. Bobinski, P. Bock, H. M. Bosch, M. Boutemeur, B. T. Bouwens, S. Braibant, R. M. Brown, H. J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R. Carter, C. Y. Chang, D. G. Charlton, D. Chrisman, P. E.L. Clarke, I. Cohen, J. E. Conboy, O. C. Cooke, M. Cuffiani, S. Dado, C. Dallapiccola, G. M. Dallavalle, S. de Jong, L. A. del Pozo, K. Desch, M. S. Dixit, E. do Couto e Silva, M. Doucet, E. Duchovni, G. Duckeck, I. P. Duerdoth, J. E.G. Edwards, P. G. Estabrooks, H. G. Evans, M. Evans, F. Fabbri, P. Fath, F. Fiedler, M. Fierro, H. M. Fischer, R. Folman, D. G. Fong, M. Foucher, A. Fürtjes, P. Gagnon, J. W. Gary, J. Gascon, S. M. Gascon-Shotkin, N. I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W. R. Gibson, D. M. Gingrich, D. Glenzinski, J. Goldberg, M. J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G. G. Hanson, M. Hansroul, M. Hapke, C. K. Hargrove, PA Hart, C. Hartmann, M. Hauschild, C. M. Hawkes, R. Hawkings, R. J. Hemingway, M. Herndon, G. Herten, R. D. Heuer, M. D. Hildreth, J. C. Hill, S. J. Hillier, T. Hilse, P. R. Hobson, R. J. Homer, A. K. Honma, D. Horváth, R. Howard, R. E. Hughes-Jones, D. E. Hutchcroft, P. Igo-Kemenes, D. C. Imrie, M. R. Ingram, K. Ishii, A. Jawahery, P. W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C. R. Jones, G. Jones, M. Jones, R. W.L. Jones, U. Jost, P. Jovanovic, T. R. Junk, D. Karlen, K. Kawagoe, T. Kawamoto, R. K. Keeler, R. G. Kellogg, B. W. Kennedy, B. J. King, J. Kirk, S. Kluth, T. Kobayashi, M. Kobel, D. S. Koetke, T. P. Kokott, M. Kolrep, Sachio Komamiya, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G. D. Lafferty, R. Lahmann, W. P. Lai, D. Lanske, J. Lauber, S. R. Lautenschlager, J. G. Layter, D. Lazic, A. M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, C. Lewis, S. L. Lloyd, F. K. Loebinger, G. D. Long, M. J. Losty, J. Ludwig, M. Mannelli, S. Marcellini, C. Markus, A. J. Martin, J. P. Martin, G. Martinez, T. Mashimo, W. Matthews, P. Mättig, W. J. McDonald, J. McKenna, E. A. Mckigney, T. J. McMahon, A. I. McNab, R. A. McPherson, F. Meijers, S. Menke, F. S. Merritt, H. Mes, J. Meyer, A. Michelini, G. Mikenberg, D. J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, M. Morii, U. Müller, K. Nagai, I. Nakamura, H. A. Neal, B. Nellen, B. Nijjhar, R. Nisius, S. W. O'Neale, F. G. Oakham, F. Odorici, H. O. Ogren, N. J. Oldershaw, T. Omori, M. J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J. R. Pater, G. N. Patrick, J. Patf, M. J. Pearce, S. Petzold, P. Pfeifenschneider, J. E. Pilcher, J. Pinfold, D. E. Plane, P. Poffenberger, B. Poli, A. Posthaus, H. Przysiezniak, D. L. Rees, D. Rigby, S. Robertson, S. A. Robins, N. Rodning, J. M. Roney, A. Rooke, E. Ros, A. M. Rossi, M. Rosvick, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D. R. Rust, R. Rylko, K. Sachs, E. K.G. Sarkisyan, M. Sasaki, C. Sbarra, A. D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, B. Schmitt, S. Schmitt, M. Schroder, H. C. Schultz-Coulon, M. Schulz, M. Schumacher, P. Schütz, W. G. Scott, T. G. Shears, B. C. Shen, C. H. Shepherd-Themistocleous, P. Sherwood, G. P. Siroli, A. Sittler, A. Skillman, A. Skuja, A. M. Smith, TJ Smith, G. A. Snow, R. Sobie, S. Söldner-Rembold, R. W. Springer, M. Sproston, A. Stahl, M. Steiert, K. Stephens, J. Steuerer, B. Stockhausen, D. Strom, F. Strumia, P. Szymanski, R. Tafirout, S. D. Talbot, S. Tanaka, P. Taras, S. Tarem, M. Thiergen, M. A. Thomson, E. von Törne, S. Towers, I. Trigger, T. Tsukamoto, E. Tsur, A. S. Turcot, M. F. Turner-Watson, P. Utzat, R. van Kooten, M. Verzocchi, P. Vikas, M. Vincter, E. H. Vokurka, F. Wäckerle, A. Wagner, C. P. Ward, D. R. Ward, J. J. Ward, P. M. Watkins, A. T. Watson, N. K. Watson, P. S. Wells, N. Wermes, J. S. White, B. Wilkens, G. W. Wilson, J. A. Wilson, G. Wolf, S. Wotton, T. R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Searches for unstable neutral and charged heavy leptons (L0, L±) have been performed using a data sample of 10.0 pb-1 at a centre-of-mass energy of √s = 161.3 GeV collected with the OPAL detector at LEP during July and August 1996. Two candidate events were observed after the selection, which is consistent with the expected total background of 1.57 events, and lower limits have been derived on heavy lepton masses for various models. If an unstable Dirac neutral heavy lepton, L0, decays only into eW*, μW* or τW*, the lower limits on its mass at the 95% C.L. are 69.3 GeV, 72.0 GeV and 66.0 GeV, respectively. The limits are modified for a Majorana L0 to 59.5 GeV, 60.5 GeV and 55.7 GeV, respectively. If an unstable heavy charged lepton, L±, decays into a stable heavy neutrino, and if mL± - mvL > 13 GeV, a lower limit on its mass of 73.5 GeV is obtained. If the L± decays through lepton flavour mixing into a massless neutrino vℓ and W*±, the lower limit on mL± was determined to be 76.7 GeV at 95% C.L.

Original languageEnglish
Pages (from-to)217-230
Number of pages14
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume393
Issue number1-2
DOIs
Publication statusPublished - 1997 Feb 6
Externally publishedYes

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leptons
collisions
decay
neutrinos
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detectors
energy

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV. / Ackerstaff, K.; Alexander, G.; Allison, J.; Altekamp, N.; Ametewee, K.; Anderson, K. J.; Anderson, S.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Ball, A. H.; Barberio, E.; Barlow, R. J.; Bartoldus, R.; Batley, J. R.; Bechtluft, J.; Beeston, C.; Behnke, T.; Bell, A. N.; Bell, K. W.; Bella, G.; Bentvelsen, S.; Berlich, P.; Bethke, S.; Biebel, O.; Blobel, V.; Bloodworth, I. J.; Bloomer, J. E.; Bobinski, M.; Bock, P.; Bosch, H. M.; Boutemeur, M.; Bouwens, B. T.; Braibant, S.; Brown, R. M.; Burckhart, H. J.; Burgard, C.; Bürgin, R.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Chrisman, D.; Clarke, P. E.L.; Cohen, I.; Conboy, J. E.; Cooke, O. C.; Cuffiani, M.; Dado, S.; Dallapiccola, C.; Dallavalle, G. M.; de Jong, S.; del Pozo, L. A.; Desch, K.; Dixit, M. S.; do Couto e Silva, E.; Doucet, M.; Duchovni, E.; Duckeck, G.; Duerdoth, I. P.; Edwards, J. E.G.; Estabrooks, P. G.; Evans, H. G.; Evans, M.; Fabbri, F.; Fath, P.; Fiedler, F.; Fierro, M.; Fischer, H. M.; Folman, R.; Fong, D. G.; Foucher, M.; Fürtjes, A.; Gagnon, P.; Gary, J. W.; Gascon, J.; Gascon-Shotkin, S. M.; Geddes, N. I.; Geich-Gimbel, C.; Geralis, T.; Giacomelli, G.; Giacomelli, P.; Giacomelli, R.; Gibson, V.; Gibson, W. R.; Gingrich, D. M.; Glenzinski, D.; Goldberg, J.; Goodrick, M. J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwé, M.; Hajdu, C.; Hanson, G. G.; Hansroul, M.; Hapke, M.; Hargrove, C. K.; Hart, PA; Hartmann, C.; Hauschild, M.; Hawkes, C. M.; Hawkings, R.; Hemingway, R. J.; Herndon, M.; Herten, G.; Heuer, R. D.; Hildreth, M. D.; Hill, J. C.; Hillier, S. J.; Hilse, T.; Hobson, P. R.; Homer, R. J.; Honma, A. K.; Horváth, D.; Howard, R.; Hughes-Jones, R. E.; Hutchcroft, D. E.; Igo-Kemenes, P.; Imrie, D. C.; Ingram, M. R.; Ishii, K.; Jawahery, A.; Jeffreys, P. W.; Jeremie, H.; Jimack, M.; Joly, A.; Jones, C. R.; Jones, G.; Jones, M.; Jones, R. W.L.; Jost, U.; Jovanovic, P.; Junk, T. R.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R. K.; Kellogg, R. G.; Kennedy, B. W.; King, B. J.; Kirk, J.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D. S.; Kokott, T. P.; Kolrep, M.; Komamiya, Sachio; Kress, T.; Krieger, P.; von Krogh, J.; Kyberd, P.; Lafferty, G. D.; Lahmann, R.; Lai, W. P.; Lanske, D.; Lauber, J.; Lautenschlager, S. R.; Layter, J. G.; Lazic, D.; Lee, A. M.; Lefebvre, E.; Lellouch, D.; Letts, J.; Levinson, L.; Lewis, C.; Lloyd, S. L.; Loebinger, F. K.; Long, G. D.; Losty, M. J.; Ludwig, J.; Mannelli, M.; Marcellini, S.; Markus, C.; Martin, A. J.; Martin, J. P.; Martinez, G.; Mashimo, T.; Matthews, W.; Mättig, P.; McDonald, W. J.; McKenna, J.; Mckigney, E. A.; McMahon, T. J.; McNab, A. I.; McPherson, R. A.; Meijers, F.; Menke, S.; Merritt, F. S.; Mes, H.; Meyer, J.; Michelini, A.; Mikenberg, G.; Miller, D. J.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Morii, M.; Müller, U.; Nagai, K.; Nakamura, I.; Neal, H. A.; Nellen, B.; Nijjhar, B.; Nisius, R.; O'Neale, S. W.; Oakham, F. G.; Odorici, F.; Ogren, H. O.; Oldershaw, N. J.; Omori, T.; Oreglia, M. J.; Orito, S.; Pálinkás, J.; Pásztor, G.; Pater, J. R.; Patrick, G. N.; Patf, J.; Pearce, M. J.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J. E.; Pinfold, J.; Plane, D. E.; Poffenberger, P.; Poli, B.; Posthaus, A.; Przysiezniak, H.; Rees, D. L.; Rigby, D.; Robertson, S.; Robins, S. A.; Rodning, N.; Roney, J. M.; Rooke, A.; Ros, E.; Rossi, A. M.; Rosvick, M.; Routenburg, P.; Rozen, Y.; Runge, K.; Runolfsson, O.; Ruppel, U.; Rust, D. R.; Rylko, R.; Sachs, K.; Sarkisyan, E. K.G.; Sasaki, M.; Sbarra, C.; Schaile, A. D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schenk, P.; Schmitt, B.; Schmitt, S.; Schroder, M.; Schultz-Coulon, H. C.; Schulz, M.; Schumacher, M.; Schütz, P.; Scott, W. G.; Shears, T. G.; Shen, B. C.; Shepherd-Themistocleous, C. H.; Sherwood, P.; Siroli, G. P.; Sittler, A.; Skillman, A.; Skuja, A.; Smith, A. M.; Smith, TJ; Snow, G. A.; Sobie, R.; Söldner-Rembold, S.; Springer, R. W.; Sproston, M.; Stahl, A.; Steiert, M.; Stephens, K.; Steuerer, J.; Stockhausen, B.; Strom, D.; Strumia, F.; Szymanski, P.; Tafirout, R.; Talbot, S. D.; Tanaka, S.; Taras, P.; Tarem, S.; Thiergen, M.; Thomson, M. A.; von Törne, E.; Towers, S.; Trigger, I.; Tsukamoto, T.; Tsur, E.; Turcot, A. S.; Turner-Watson, M. F.; Utzat, P.; van Kooten, R.; Verzocchi, M.; Vikas, P.; Vincter, M.; Vokurka, E. H.; Wäckerle, F.; Wagner, A.; Ward, C. P.; Ward, D. R.; Ward, J. J.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Wells, P. S.; Wermes, N.; White, J. S.; Wilkens, B.; Wilson, G. W.; Wilson, J. A.; Wolf, G.; Wotton, S.; Wyatt, T. R.; Yamashita, S.; Yekutieli, G.; Zacek, V.

In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 393, No. 1-2, 06.02.1997, p. 217-230.

Research output: Contribution to journalArticle

Ackerstaff, K, Alexander, G, Allison, J, Altekamp, N, Ametewee, K, Anderson, KJ, Anderson, S, Arcelli, S, Asai, S, Axen, D, Azuelos, G, Ball, AH, Barberio, E, Barlow, RJ, Bartoldus, R, Batley, JR, Bechtluft, J, Beeston, C, Behnke, T, Bell, AN, Bell, KW, Bella, G, Bentvelsen, S, Berlich, P, Bethke, S, Biebel, O, Blobel, V, Bloodworth, IJ, Bloomer, JE, Bobinski, M, Bock, P, Bosch, HM, Boutemeur, M, Bouwens, BT, Braibant, S, Brown, RM, Burckhart, HJ, Burgard, C, Bürgin, R, Capiluppi, P, Carnegie, RK, Carter, AA, Carter, JR, Chang, CY, Charlton, DG, Chrisman, D, Clarke, PEL, Cohen, I, Conboy, JE, Cooke, OC, Cuffiani, M, Dado, S, Dallapiccola, C, Dallavalle, GM, de Jong, S, del Pozo, LA, Desch, K, Dixit, MS, do Couto e Silva, E, Doucet, M, Duchovni, E, Duckeck, G, Duerdoth, IP, Edwards, JEG, Estabrooks, PG, Evans, HG, Evans, M, Fabbri, F, Fath, P, Fiedler, F, Fierro, M, Fischer, HM, Folman, R, Fong, DG, Foucher, M, Fürtjes, A, Gagnon, P, Gary, JW, Gascon, J, Gascon-Shotkin, SM, Geddes, NI, Geich-Gimbel, C, Geralis, T, Giacomelli, G, Giacomelli, P, Giacomelli, R, Gibson, V, Gibson, WR, Gingrich, DM, Glenzinski, D, Goldberg, J, Goodrick, MJ, Gorn, W, Grandi, C, Gross, E, Grunhaus, J, Gruwé, M, Hajdu, C, Hanson, GG, Hansroul, M, Hapke, M, Hargrove, CK, Hart, PA, Hartmann, C, Hauschild, M, Hawkes, CM, Hawkings, R, Hemingway, RJ, Herndon, M, Herten, G, Heuer, RD, Hildreth, MD, Hill, JC, Hillier, SJ, Hilse, T, Hobson, PR, Homer, RJ, Honma, AK, Horváth, D, Howard, R, Hughes-Jones, RE, Hutchcroft, DE, Igo-Kemenes, P, Imrie, DC, Ingram, MR, Ishii, K, Jawahery, A, Jeffreys, PW, Jeremie, H, Jimack, M, Joly, A, Jones, CR, Jones, G, Jones, M, Jones, RWL, Jost, U, Jovanovic, P, Junk, TR, Karlen, D, Kawagoe, K, Kawamoto, T, Keeler, RK, Kellogg, RG, Kennedy, BW, King, BJ, Kirk, J, Kluth, S, Kobayashi, T, Kobel, M, Koetke, DS, Kokott, TP, Kolrep, M, Komamiya, S, Kress, T, Krieger, P, von Krogh, J, Kyberd, P, Lafferty, GD, Lahmann, R, Lai, WP, Lanske, D, Lauber, J, Lautenschlager, SR, Layter, JG, Lazic, D, Lee, AM, Lefebvre, E, Lellouch, D, Letts, J, Levinson, L, Lewis, C, Lloyd, SL, Loebinger, FK, Long, GD, Losty, MJ, Ludwig, J, Mannelli, M, Marcellini, S, Markus, C, Martin, AJ, Martin, JP, Martinez, G, Mashimo, T, Matthews, W, Mättig, P, McDonald, WJ, McKenna, J, Mckigney, EA, McMahon, TJ, McNab, AI, McPherson, RA, Meijers, F, Menke, S, Merritt, FS, Mes, H, Meyer, J, Michelini, A, Mikenberg, G, Miller, DJ, Mir, R, Mohr, W, Montanari, A, Mori, T, Morii, M, Müller, U, Nagai, K, Nakamura, I, Neal, HA, Nellen, B, Nijjhar, B, Nisius, R, O'Neale, SW, Oakham, FG, Odorici, F, Ogren, HO, Oldershaw, NJ, Omori, T, Oreglia, MJ, Orito, S, Pálinkás, J, Pásztor, G, Pater, JR, Patrick, GN, Patf, J, Pearce, MJ, Petzold, S, Pfeifenschneider, P, Pilcher, JE, Pinfold, J, Plane, DE, Poffenberger, P, Poli, B, Posthaus, A, Przysiezniak, H, Rees, DL, Rigby, D, Robertson, S, Robins, SA, Rodning, N, Roney, JM, Rooke, A, Ros, E, Rossi, AM, Rosvick, M, Routenburg, P, Rozen, Y, Runge, K, Runolfsson, O, Ruppel, U, Rust, DR, Rylko, R, Sachs, K, Sarkisyan, EKG, Sasaki, M, Sbarra, C, Schaile, AD, Schaile, O, Scharf, F, Scharff-Hansen, P, Schenk, P, Schmitt, B, Schmitt, S, Schroder, M, Schultz-Coulon, HC, Schulz, M, Schumacher, M, Schütz, P, Scott, WG, Shears, TG, Shen, BC, Shepherd-Themistocleous, CH, Sherwood, P, Siroli, GP, Sittler, A, Skillman, A, Skuja, A, Smith, AM, Smith, TJ, Snow, GA, Sobie, R, Söldner-Rembold, S, Springer, RW, Sproston, M, Stahl, A, Steiert, M, Stephens, K, Steuerer, J, Stockhausen, B, Strom, D, Strumia, F, Szymanski, P, Tafirout, R, Talbot, SD, Tanaka, S, Taras, P, Tarem, S, Thiergen, M, Thomson, MA, von Törne, E, Towers, S, Trigger, I, Tsukamoto, T, Tsur, E, Turcot, AS, Turner-Watson, MF, Utzat, P, van Kooten, R, Verzocchi, M, Vikas, P, Vincter, M, Vokurka, EH, Wäckerle, F, Wagner, A, Ward, CP, Ward, DR, Ward, JJ, Watkins, PM, Watson, AT, Watson, NK, Wells, PS, Wermes, N, White, JS, Wilkens, B, Wilson, GW, Wilson, JA, Wolf, G, Wotton, S, Wyatt, TR, Yamashita, S, Yekutieli, G & Zacek, V 1997, 'Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 393, no. 1-2, pp. 217-230. https://doi.org/10.1016/S0370-2693(96)01633-4
Ackerstaff, K. ; Alexander, G. ; Allison, J. ; Altekamp, N. ; Ametewee, K. ; Anderson, K. J. ; Anderson, S. ; Arcelli, S. ; Asai, S. ; Axen, D. ; Azuelos, G. ; Ball, A. H. ; Barberio, E. ; Barlow, R. J. ; Bartoldus, R. ; Batley, J. R. ; Bechtluft, J. ; Beeston, C. ; Behnke, T. ; Bell, A. N. ; Bell, K. W. ; Bella, G. ; Bentvelsen, S. ; Berlich, P. ; Bethke, S. ; Biebel, O. ; Blobel, V. ; Bloodworth, I. J. ; Bloomer, J. E. ; Bobinski, M. ; Bock, P. ; Bosch, H. M. ; Boutemeur, M. ; Bouwens, B. T. ; Braibant, S. ; Brown, R. M. ; Burckhart, H. J. ; Burgard, C. ; Bürgin, R. ; Capiluppi, P. ; Carnegie, R. K. ; Carter, A. A. ; Carter, J. R. ; Chang, C. Y. ; Charlton, D. G. ; Chrisman, D. ; Clarke, P. E.L. ; Cohen, I. ; Conboy, J. E. ; Cooke, O. C. ; Cuffiani, M. ; Dado, S. ; Dallapiccola, C. ; Dallavalle, G. M. ; de Jong, S. ; del Pozo, L. A. ; Desch, K. ; Dixit, M. S. ; do Couto e Silva, E. ; Doucet, M. ; Duchovni, E. ; Duckeck, G. ; Duerdoth, I. P. ; Edwards, J. E.G. ; Estabrooks, P. G. ; Evans, H. G. ; Evans, M. ; Fabbri, F. ; Fath, P. ; Fiedler, F. ; Fierro, M. ; Fischer, H. M. ; Folman, R. ; Fong, D. G. ; Foucher, M. ; Fürtjes, A. ; Gagnon, P. ; Gary, J. W. ; Gascon, J. ; Gascon-Shotkin, S. M. ; Geddes, N. I. ; Geich-Gimbel, C. ; Geralis, T. ; Giacomelli, G. ; Giacomelli, P. ; Giacomelli, R. ; Gibson, V. ; Gibson, W. R. ; Gingrich, D. M. ; Glenzinski, D. ; Goldberg, J. ; Goodrick, M. J. ; Gorn, W. ; Grandi, C. ; Gross, E. ; Grunhaus, J. ; Gruwé, M. ; Hajdu, C. ; Hanson, G. G. ; Hansroul, M. ; Hapke, M. ; Hargrove, C. K. ; Hart, PA ; Hartmann, C. ; Hauschild, M. ; Hawkes, C. M. ; Hawkings, R. ; Hemingway, R. J. ; Herndon, M. ; Herten, G. ; Heuer, R. D. ; Hildreth, M. D. ; Hill, J. C. ; Hillier, S. J. ; Hilse, T. ; Hobson, P. R. ; Homer, R. J. ; Honma, A. K. ; Horváth, D. ; Howard, R. ; Hughes-Jones, R. E. ; Hutchcroft, D. E. ; Igo-Kemenes, P. ; Imrie, D. C. ; Ingram, M. R. ; Ishii, K. ; Jawahery, A. ; Jeffreys, P. W. ; Jeremie, H. ; Jimack, M. ; Joly, A. ; Jones, C. R. ; Jones, G. ; Jones, M. ; Jones, R. W.L. ; Jost, U. ; Jovanovic, P. ; Junk, T. R. ; Karlen, D. ; Kawagoe, K. ; Kawamoto, T. ; Keeler, R. K. ; Kellogg, R. G. ; Kennedy, B. W. ; King, B. J. ; Kirk, J. ; Kluth, S. ; Kobayashi, T. ; Kobel, M. ; Koetke, D. S. ; Kokott, T. P. ; Kolrep, M. ; Komamiya, Sachio ; Kress, T. ; Krieger, P. ; von Krogh, J. ; Kyberd, P. ; Lafferty, G. D. ; Lahmann, R. ; Lai, W. P. ; Lanske, D. ; Lauber, J. ; Lautenschlager, S. R. ; Layter, J. G. ; Lazic, D. ; Lee, A. M. ; Lefebvre, E. ; Lellouch, D. ; Letts, J. ; Levinson, L. ; Lewis, C. ; Lloyd, S. L. ; Loebinger, F. K. ; Long, G. D. ; Losty, M. J. ; Ludwig, J. ; Mannelli, M. ; Marcellini, S. ; Markus, C. ; Martin, A. J. ; Martin, J. P. ; Martinez, G. ; Mashimo, T. ; Matthews, W. ; Mättig, P. ; McDonald, W. J. ; McKenna, J. ; Mckigney, E. A. ; McMahon, T. J. ; McNab, A. I. ; McPherson, R. A. ; Meijers, F. ; Menke, S. ; Merritt, F. S. ; Mes, H. ; Meyer, J. ; Michelini, A. ; Mikenberg, G. ; Miller, D. J. ; Mir, R. ; Mohr, W. ; Montanari, A. ; Mori, T. ; Morii, M. ; Müller, U. ; Nagai, K. ; Nakamura, I. ; Neal, H. A. ; Nellen, B. ; Nijjhar, B. ; Nisius, R. ; O'Neale, S. W. ; Oakham, F. G. ; Odorici, F. ; Ogren, H. O. ; Oldershaw, N. J. ; Omori, T. ; Oreglia, M. J. ; Orito, S. ; Pálinkás, J. ; Pásztor, G. ; Pater, J. R. ; Patrick, G. N. ; Patf, J. ; Pearce, M. J. ; Petzold, S. ; Pfeifenschneider, P. ; Pilcher, J. E. ; Pinfold, J. ; Plane, D. E. ; Poffenberger, P. ; Poli, B. ; Posthaus, A. ; Przysiezniak, H. ; Rees, D. L. ; Rigby, D. ; Robertson, S. ; Robins, S. A. ; Rodning, N. ; Roney, J. M. ; Rooke, A. ; Ros, E. ; Rossi, A. M. ; Rosvick, M. ; Routenburg, P. ; Rozen, Y. ; Runge, K. ; Runolfsson, O. ; Ruppel, U. ; Rust, D. R. ; Rylko, R. ; Sachs, K. ; Sarkisyan, E. K.G. ; Sasaki, M. ; Sbarra, C. ; Schaile, A. D. ; Schaile, O. ; Scharf, F. ; Scharff-Hansen, P. ; Schenk, P. ; Schmitt, B. ; Schmitt, S. ; Schroder, M. ; Schultz-Coulon, H. C. ; Schulz, M. ; Schumacher, M. ; Schütz, P. ; Scott, W. G. ; Shears, T. G. ; Shen, B. C. ; Shepherd-Themistocleous, C. H. ; Sherwood, P. ; Siroli, G. P. ; Sittler, A. ; Skillman, A. ; Skuja, A. ; Smith, A. M. ; Smith, TJ ; Snow, G. A. ; Sobie, R. ; Söldner-Rembold, S. ; Springer, R. W. ; Sproston, M. ; Stahl, A. ; Steiert, M. ; Stephens, K. ; Steuerer, J. ; Stockhausen, B. ; Strom, D. ; Strumia, F. ; Szymanski, P. ; Tafirout, R. ; Talbot, S. D. ; Tanaka, S. ; Taras, P. ; Tarem, S. ; Thiergen, M. ; Thomson, M. A. ; von Törne, E. ; Towers, S. ; Trigger, I. ; Tsukamoto, T. ; Tsur, E. ; Turcot, A. S. ; Turner-Watson, M. F. ; Utzat, P. ; van Kooten, R. ; Verzocchi, M. ; Vikas, P. ; Vincter, M. ; Vokurka, E. H. ; Wäckerle, F. ; Wagner, A. ; Ward, C. P. ; Ward, D. R. ; Ward, J. J. ; Watkins, P. M. ; Watson, A. T. ; Watson, N. K. ; Wells, P. S. ; Wermes, N. ; White, J. S. ; Wilkens, B. ; Wilson, G. W. ; Wilson, J. A. ; Wolf, G. ; Wotton, S. ; Wyatt, T. R. ; Yamashita, S. ; Yekutieli, G. ; Zacek, V. / Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV. In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 1997 ; Vol. 393, No. 1-2. pp. 217-230.
@article{e1e856c03e6b4cca8441f192407379bc,
title = "Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV",
abstract = "Searches for unstable neutral and charged heavy leptons (L0, L±) have been performed using a data sample of 10.0 pb-1 at a centre-of-mass energy of √s = 161.3 GeV collected with the OPAL detector at LEP during July and August 1996. Two candidate events were observed after the selection, which is consistent with the expected total background of 1.57 events, and lower limits have been derived on heavy lepton masses for various models. If an unstable Dirac neutral heavy lepton, L0, decays only into eW*, μW* or τW*, the lower limits on its mass at the 95{\%} C.L. are 69.3 GeV, 72.0 GeV and 66.0 GeV, respectively. The limits are modified for a Majorana L0 to 59.5 GeV, 60.5 GeV and 55.7 GeV, respectively. If an unstable heavy charged lepton, L±, decays into a stable heavy neutrino, and if mL± - mvL > 13 GeV, a lower limit on its mass of 73.5 GeV is obtained. If the L± decays through lepton flavour mixing into a massless neutrino vℓ and W*±, the lower limit on mL± was determined to be 76.7 GeV at 95{\%} C.L.",
author = "K. Ackerstaff and G. Alexander and J. Allison and N. Altekamp and K. Ametewee and Anderson, {K. J.} and S. Anderson and S. Arcelli and S. Asai and D. Axen and G. Azuelos and Ball, {A. H.} and E. Barberio and Barlow, {R. J.} and R. Bartoldus and Batley, {J. R.} and J. Bechtluft and C. Beeston and T. Behnke and Bell, {A. N.} and Bell, {K. W.} and G. Bella and S. Bentvelsen and P. Berlich and S. Bethke and O. Biebel and V. Blobel and Bloodworth, {I. J.} and Bloomer, {J. E.} and M. Bobinski and P. Bock and Bosch, {H. M.} and M. Boutemeur and Bouwens, {B. T.} and S. Braibant and Brown, {R. M.} and Burckhart, {H. J.} and C. Burgard and R. B{\"u}rgin and P. Capiluppi and Carnegie, {R. K.} and Carter, {A. A.} and Carter, {J. R.} and Chang, {C. Y.} and Charlton, {D. G.} and D. Chrisman and Clarke, {P. E.L.} and I. Cohen and Conboy, {J. E.} and Cooke, {O. C.} and M. Cuffiani and S. Dado and C. Dallapiccola and Dallavalle, {G. M.} and {de Jong}, S. and {del Pozo}, {L. A.} and K. Desch and Dixit, {M. S.} and {do Couto e Silva}, E. and M. Doucet and E. Duchovni and G. Duckeck and Duerdoth, {I. P.} and Edwards, {J. E.G.} and Estabrooks, {P. G.} and Evans, {H. G.} and M. Evans and F. Fabbri and P. Fath and F. Fiedler and M. Fierro and Fischer, {H. M.} and R. Folman and Fong, {D. G.} and M. Foucher and A. F{\"u}rtjes and P. Gagnon and Gary, {J. W.} and J. Gascon and Gascon-Shotkin, {S. M.} and Geddes, {N. I.} and C. Geich-Gimbel and T. Geralis and G. Giacomelli and P. Giacomelli and R. Giacomelli and V. Gibson and Gibson, {W. R.} and Gingrich, {D. M.} and D. Glenzinski and J. Goldberg and Goodrick, {M. J.} and W. Gorn and C. Grandi and E. Gross and J. Grunhaus and M. Gruw{\'e} and C. Hajdu and Hanson, {G. G.} and M. Hansroul and M. Hapke and Hargrove, {C. K.} and PA Hart and C. Hartmann and M. Hauschild and Hawkes, {C. M.} and R. Hawkings and Hemingway, {R. J.} and M. Herndon and G. Herten and Heuer, {R. D.} and Hildreth, {M. D.} and Hill, {J. C.} and Hillier, {S. J.} and T. Hilse and Hobson, {P. R.} and Homer, {R. J.} and Honma, {A. K.} and D. Horv{\'a}th and R. Howard and Hughes-Jones, {R. E.} and Hutchcroft, {D. E.} and P. Igo-Kemenes and Imrie, {D. C.} and Ingram, {M. R.} and K. Ishii and A. Jawahery and Jeffreys, {P. W.} and H. Jeremie and M. Jimack and A. Joly and Jones, {C. R.} and G. Jones and M. Jones and Jones, {R. W.L.} and U. Jost and P. Jovanovic and Junk, {T. R.} and D. Karlen and K. Kawagoe and T. Kawamoto and Keeler, {R. K.} and Kellogg, {R. G.} and Kennedy, {B. W.} and King, {B. J.} and J. Kirk and S. Kluth and T. Kobayashi and M. Kobel and Koetke, {D. S.} and Kokott, {T. P.} and M. Kolrep and Sachio Komamiya and T. Kress and P. Krieger and {von Krogh}, J. and P. Kyberd and Lafferty, {G. D.} and R. Lahmann and Lai, {W. P.} and D. Lanske and J. Lauber and Lautenschlager, {S. R.} and Layter, {J. G.} and D. Lazic and Lee, {A. M.} and E. Lefebvre and D. Lellouch and J. Letts and L. Levinson and C. Lewis and Lloyd, {S. L.} and Loebinger, {F. K.} and Long, {G. D.} and Losty, {M. J.} and J. Ludwig and M. Mannelli and S. Marcellini and C. Markus and Martin, {A. J.} and Martin, {J. P.} and G. Martinez and T. Mashimo and W. Matthews and P. M{\"a}ttig and McDonald, {W. J.} and J. McKenna and Mckigney, {E. A.} and McMahon, {T. J.} and McNab, {A. I.} and McPherson, {R. A.} and F. Meijers and S. Menke and Merritt, {F. S.} and H. Mes and J. Meyer and A. Michelini and G. Mikenberg and Miller, {D. J.} and R. Mir and W. Mohr and A. Montanari and T. Mori and M. Morii and U. M{\"u}ller and K. Nagai and I. Nakamura and Neal, {H. A.} and B. Nellen and B. Nijjhar and R. Nisius and O'Neale, {S. W.} and Oakham, {F. G.} and F. Odorici and Ogren, {H. O.} and Oldershaw, {N. J.} and T. Omori and Oreglia, {M. J.} and S. Orito and J. P{\'a}link{\'a}s and G. P{\'a}sztor and Pater, {J. R.} and Patrick, {G. N.} and J. Patf and Pearce, {M. J.} and S. Petzold and P. Pfeifenschneider and Pilcher, {J. E.} and J. Pinfold and Plane, {D. E.} and P. Poffenberger and B. Poli and A. Posthaus and H. Przysiezniak and Rees, {D. L.} and D. Rigby and S. Robertson and Robins, {S. A.} and N. Rodning and Roney, {J. M.} and A. Rooke and E. Ros and Rossi, {A. M.} and M. Rosvick and P. Routenburg and Y. Rozen and K. Runge and O. Runolfsson and U. Ruppel and Rust, {D. R.} and R. Rylko and K. Sachs and Sarkisyan, {E. K.G.} and M. Sasaki and C. Sbarra and Schaile, {A. D.} and O. Schaile and F. Scharf and P. Scharff-Hansen and P. Schenk and B. Schmitt and S. Schmitt and M. Schroder and Schultz-Coulon, {H. C.} and M. Schulz and M. Schumacher and P. Sch{\"u}tz and Scott, {W. G.} and Shears, {T. G.} and Shen, {B. C.} and Shepherd-Themistocleous, {C. H.} and P. Sherwood and Siroli, {G. P.} and A. Sittler and A. Skillman and A. Skuja and Smith, {A. M.} and TJ Smith and Snow, {G. A.} and R. Sobie and S. S{\"o}ldner-Rembold and Springer, {R. W.} and M. Sproston and A. Stahl and M. Steiert and K. Stephens and J. Steuerer and B. Stockhausen and D. Strom and F. Strumia and P. Szymanski and R. Tafirout and Talbot, {S. D.} and S. Tanaka and P. Taras and S. Tarem and M. Thiergen and Thomson, {M. A.} and {von T{\"o}rne}, E. and S. Towers and I. Trigger and T. Tsukamoto and E. Tsur and Turcot, {A. S.} and Turner-Watson, {M. F.} and P. Utzat and {van Kooten}, R. and M. Verzocchi and P. Vikas and M. Vincter and Vokurka, {E. H.} and F. W{\"a}ckerle and A. Wagner and Ward, {C. P.} and Ward, {D. R.} and Ward, {J. J.} and Watkins, {P. M.} and Watson, {A. T.} and Watson, {N. K.} and Wells, {P. S.} and N. Wermes and White, {J. S.} and B. Wilkens and Wilson, {G. W.} and Wilson, {J. A.} and G. Wolf and S. Wotton and Wyatt, {T. R.} and S. Yamashita and G. Yekutieli and V. Zacek",
year = "1997",
month = "2",
day = "6",
doi = "10.1016/S0370-2693(96)01633-4",
language = "English",
volume = "393",
pages = "217--230",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Search for unstable neutral and charged heavy leptons in e+e- collisions at √s = 161 GeV

AU - Ackerstaff, K.

AU - Alexander, G.

AU - Allison, J.

AU - Altekamp, N.

AU - Ametewee, K.

AU - Anderson, K. J.

AU - Anderson, S.

AU - Arcelli, S.

AU - Asai, S.

AU - Axen, D.

AU - Azuelos, G.

AU - Ball, A. H.

AU - Barberio, E.

AU - Barlow, R. J.

AU - Bartoldus, R.

AU - Batley, J. R.

AU - Bechtluft, J.

AU - Beeston, C.

AU - Behnke, T.

AU - Bell, A. N.

AU - Bell, K. W.

AU - Bella, G.

AU - Bentvelsen, S.

AU - Berlich, P.

AU - Bethke, S.

AU - Biebel, O.

AU - Blobel, V.

AU - Bloodworth, I. J.

AU - Bloomer, J. E.

AU - Bobinski, M.

AU - Bock, P.

AU - Bosch, H. M.

AU - Boutemeur, M.

AU - Bouwens, B. T.

AU - Braibant, S.

AU - Brown, R. M.

AU - Burckhart, H. J.

AU - Burgard, C.

AU - Bürgin, R.

AU - Capiluppi, P.

AU - Carnegie, R. K.

AU - Carter, A. A.

AU - Carter, J. R.

AU - Chang, C. Y.

AU - Charlton, D. G.

AU - Chrisman, D.

AU - Clarke, P. E.L.

AU - Cohen, I.

AU - Conboy, J. E.

AU - Cooke, O. C.

AU - Cuffiani, M.

AU - Dado, S.

AU - Dallapiccola, C.

AU - Dallavalle, G. M.

AU - de Jong, S.

AU - del Pozo, L. A.

AU - Desch, K.

AU - Dixit, M. S.

AU - do Couto e Silva, E.

AU - Doucet, M.

AU - Duchovni, E.

AU - Duckeck, G.

AU - Duerdoth, I. P.

AU - Edwards, J. E.G.

AU - Estabrooks, P. G.

AU - Evans, H. G.

AU - Evans, M.

AU - Fabbri, F.

AU - Fath, P.

AU - Fiedler, F.

AU - Fierro, M.

AU - Fischer, H. M.

AU - Folman, R.

AU - Fong, D. G.

AU - Foucher, M.

AU - Fürtjes, A.

AU - Gagnon, P.

AU - Gary, J. W.

AU - Gascon, J.

AU - Gascon-Shotkin, S. M.

AU - Geddes, N. I.

AU - Geich-Gimbel, C.

AU - Geralis, T.

AU - Giacomelli, G.

AU - Giacomelli, P.

AU - Giacomelli, R.

AU - Gibson, V.

AU - Gibson, W. R.

AU - Gingrich, D. M.

AU - Glenzinski, D.

AU - Goldberg, J.

AU - Goodrick, M. J.

AU - Gorn, W.

AU - Grandi, C.

AU - Gross, E.

AU - Grunhaus, J.

AU - Gruwé, M.

AU - Hajdu, C.

AU - Hanson, G. G.

AU - Hansroul, M.

AU - Hapke, M.

AU - Hargrove, C. K.

AU - Hart, PA

AU - Hartmann, C.

AU - Hauschild, M.

AU - Hawkes, C. M.

AU - Hawkings, R.

AU - Hemingway, R. J.

AU - Herndon, M.

AU - Herten, G.

AU - Heuer, R. D.

AU - Hildreth, M. D.

AU - Hill, J. C.

AU - Hillier, S. J.

AU - Hilse, T.

AU - Hobson, P. R.

AU - Homer, R. J.

AU - Honma, A. K.

AU - Horváth, D.

AU - Howard, R.

AU - Hughes-Jones, R. E.

AU - Hutchcroft, D. E.

AU - Igo-Kemenes, P.

AU - Imrie, D. C.

AU - Ingram, M. R.

AU - Ishii, K.

AU - Jawahery, A.

AU - Jeffreys, P. W.

AU - Jeremie, H.

AU - Jimack, M.

AU - Joly, A.

AU - Jones, C. R.

AU - Jones, G.

AU - Jones, M.

AU - Jones, R. W.L.

AU - Jost, U.

AU - Jovanovic, P.

AU - Junk, T. R.

AU - Karlen, D.

AU - Kawagoe, K.

AU - Kawamoto, T.

AU - Keeler, R. K.

AU - Kellogg, R. G.

AU - Kennedy, B. W.

AU - King, B. J.

AU - Kirk, J.

AU - Kluth, S.

AU - Kobayashi, T.

AU - Kobel, M.

AU - Koetke, D. S.

AU - Kokott, T. P.

AU - Kolrep, M.

AU - Komamiya, Sachio

AU - Kress, T.

AU - Krieger, P.

AU - von Krogh, J.

AU - Kyberd, P.

AU - Lafferty, G. D.

AU - Lahmann, R.

AU - Lai, W. P.

AU - Lanske, D.

AU - Lauber, J.

AU - Lautenschlager, S. R.

AU - Layter, J. G.

AU - Lazic, D.

AU - Lee, A. M.

AU - Lefebvre, E.

AU - Lellouch, D.

AU - Letts, J.

AU - Levinson, L.

AU - Lewis, C.

AU - Lloyd, S. L.

AU - Loebinger, F. K.

AU - Long, G. D.

AU - Losty, M. J.

AU - Ludwig, J.

AU - Mannelli, M.

AU - Marcellini, S.

AU - Markus, C.

AU - Martin, A. J.

AU - Martin, J. P.

AU - Martinez, G.

AU - Mashimo, T.

AU - Matthews, W.

AU - Mättig, P.

AU - McDonald, W. J.

AU - McKenna, J.

AU - Mckigney, E. A.

AU - McMahon, T. J.

AU - McNab, A. I.

AU - McPherson, R. A.

AU - Meijers, F.

AU - Menke, S.

AU - Merritt, F. S.

AU - Mes, H.

AU - Meyer, J.

AU - Michelini, A.

AU - Mikenberg, G.

AU - Miller, D. J.

AU - Mir, R.

AU - Mohr, W.

AU - Montanari, A.

AU - Mori, T.

AU - Morii, M.

AU - Müller, U.

AU - Nagai, K.

AU - Nakamura, I.

AU - Neal, H. A.

AU - Nellen, B.

AU - Nijjhar, B.

AU - Nisius, R.

AU - O'Neale, S. W.

AU - Oakham, F. G.

AU - Odorici, F.

AU - Ogren, H. O.

AU - Oldershaw, N. J.

AU - Omori, T.

AU - Oreglia, M. J.

AU - Orito, S.

AU - Pálinkás, J.

AU - Pásztor, G.

AU - Pater, J. R.

AU - Patrick, G. N.

AU - Patf, J.

AU - Pearce, M. J.

AU - Petzold, S.

AU - Pfeifenschneider, P.

AU - Pilcher, J. E.

AU - Pinfold, J.

AU - Plane, D. E.

AU - Poffenberger, P.

AU - Poli, B.

AU - Posthaus, A.

AU - Przysiezniak, H.

AU - Rees, D. L.

AU - Rigby, D.

AU - Robertson, S.

AU - Robins, S. A.

AU - Rodning, N.

AU - Roney, J. M.

AU - Rooke, A.

AU - Ros, E.

AU - Rossi, A. M.

AU - Rosvick, M.

AU - Routenburg, P.

AU - Rozen, Y.

AU - Runge, K.

AU - Runolfsson, O.

AU - Ruppel, U.

AU - Rust, D. R.

AU - Rylko, R.

AU - Sachs, K.

AU - Sarkisyan, E. K.G.

AU - Sasaki, M.

AU - Sbarra, C.

AU - Schaile, A. D.

AU - Schaile, O.

AU - Scharf, F.

AU - Scharff-Hansen, P.

AU - Schenk, P.

AU - Schmitt, B.

AU - Schmitt, S.

AU - Schroder, M.

AU - Schultz-Coulon, H. C.

AU - Schulz, M.

AU - Schumacher, M.

AU - Schütz, P.

AU - Scott, W. G.

AU - Shears, T. G.

AU - Shen, B. C.

AU - Shepherd-Themistocleous, C. H.

AU - Sherwood, P.

AU - Siroli, G. P.

AU - Sittler, A.

AU - Skillman, A.

AU - Skuja, A.

AU - Smith, A. M.

AU - Smith, TJ

AU - Snow, G. A.

AU - Sobie, R.

AU - Söldner-Rembold, S.

AU - Springer, R. W.

AU - Sproston, M.

AU - Stahl, A.

AU - Steiert, M.

AU - Stephens, K.

AU - Steuerer, J.

AU - Stockhausen, B.

AU - Strom, D.

AU - Strumia, F.

AU - Szymanski, P.

AU - Tafirout, R.

AU - Talbot, S. D.

AU - Tanaka, S.

AU - Taras, P.

AU - Tarem, S.

AU - Thiergen, M.

AU - Thomson, M. A.

AU - von Törne, E.

AU - Towers, S.

AU - Trigger, I.

AU - Tsukamoto, T.

AU - Tsur, E.

AU - Turcot, A. S.

AU - Turner-Watson, M. F.

AU - Utzat, P.

AU - van Kooten, R.

AU - Verzocchi, M.

AU - Vikas, P.

AU - Vincter, M.

AU - Vokurka, E. H.

AU - Wäckerle, F.

AU - Wagner, A.

AU - Ward, C. P.

AU - Ward, D. R.

AU - Ward, J. J.

AU - Watkins, P. M.

AU - Watson, A. T.

AU - Watson, N. K.

AU - Wells, P. S.

AU - Wermes, N.

AU - White, J. S.

AU - Wilkens, B.

AU - Wilson, G. W.

AU - Wilson, J. A.

AU - Wolf, G.

AU - Wotton, S.

AU - Wyatt, T. R.

AU - Yamashita, S.

AU - Yekutieli, G.

AU - Zacek, V.

PY - 1997/2/6

Y1 - 1997/2/6

N2 - Searches for unstable neutral and charged heavy leptons (L0, L±) have been performed using a data sample of 10.0 pb-1 at a centre-of-mass energy of √s = 161.3 GeV collected with the OPAL detector at LEP during July and August 1996. Two candidate events were observed after the selection, which is consistent with the expected total background of 1.57 events, and lower limits have been derived on heavy lepton masses for various models. If an unstable Dirac neutral heavy lepton, L0, decays only into eW*, μW* or τW*, the lower limits on its mass at the 95% C.L. are 69.3 GeV, 72.0 GeV and 66.0 GeV, respectively. The limits are modified for a Majorana L0 to 59.5 GeV, 60.5 GeV and 55.7 GeV, respectively. If an unstable heavy charged lepton, L±, decays into a stable heavy neutrino, and if mL± - mvL > 13 GeV, a lower limit on its mass of 73.5 GeV is obtained. If the L± decays through lepton flavour mixing into a massless neutrino vℓ and W*±, the lower limit on mL± was determined to be 76.7 GeV at 95% C.L.

AB - Searches for unstable neutral and charged heavy leptons (L0, L±) have been performed using a data sample of 10.0 pb-1 at a centre-of-mass energy of √s = 161.3 GeV collected with the OPAL detector at LEP during July and August 1996. Two candidate events were observed after the selection, which is consistent with the expected total background of 1.57 events, and lower limits have been derived on heavy lepton masses for various models. If an unstable Dirac neutral heavy lepton, L0, decays only into eW*, μW* or τW*, the lower limits on its mass at the 95% C.L. are 69.3 GeV, 72.0 GeV and 66.0 GeV, respectively. The limits are modified for a Majorana L0 to 59.5 GeV, 60.5 GeV and 55.7 GeV, respectively. If an unstable heavy charged lepton, L±, decays into a stable heavy neutrino, and if mL± - mvL > 13 GeV, a lower limit on its mass of 73.5 GeV is obtained. If the L± decays through lepton flavour mixing into a massless neutrino vℓ and W*±, the lower limit on mL± was determined to be 76.7 GeV at 95% C.L.

UR - http://www.scopus.com/inward/record.url?scp=0040565277&partnerID=8YFLogxK

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U2 - 10.1016/S0370-2693(96)01633-4

DO - 10.1016/S0370-2693(96)01633-4

M3 - Article

VL - 393

SP - 217

EP - 230

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

SN - 0370-2693

IS - 1-2

ER -