Measurement of single photon production in e+e- collisions near the Z0 resonance

R. Akers, G. Alexander, J. Allison, K. J. Anderson, S. Arcelli, S. Asai, A. Astbury, D. Axen, G. Azuelos, A. H. Ball, E. Barberio, R. J. Barlow, R. Bartoldus, J. R. Batley, G. Beaudoin, A. Beck, G. A. Beck, J. Becker, C. Beeston, T. Behnke & 302 others K. W. Bell, G. Bella, P. Bentkowski, S. Bentvelsen, P. Berlich, S. Bethke, O. Biebel, I. J. Bloodworth, P. Bock, H. M. Bosch, M. Boutemeur, S. Braibant, P. Bright-Thomas, R. M. Brown, A. Buijs, H. J. Burckhart, C. Burgard, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R. Carter, C. Y. Chang, C. Charlesworth, D. G. Charlton, S. L. Chu, P. E.L. Clarke, J. C. Clayton, S. G. Clowes, I. Cohen, J. E. Conboy, M. Coupland, M. Cuffiani, S. Dado, C. Dallapiccola, G. M. Dallavalle, C. Darling, S. De Jong, H. Deng, M. Dittmar, M. S. Dixit, E. do Couto e Silva, J. E. Duboscq, E. Duchovni, G. Duckeck, I. P. Duerdoth, U. C. Dunwoody, P. A. Elcombe, P. G. Estabrooks, E. Etzion, H. G. Evans, F. Fabbri, B. Fabbro, M. Fanti, M. Fierro, M. Fincke-Keeler, H. M. Fischer, P. Fischer, R. Folman, D. G. Fong, M. Foucher, H. Fukui, A. Fürtjes, P. Gagnon, A. Gaidot, J. W. Gary, J. Gascon, N. I. Geddes, C. Geich-Gimbel, S. W. Gensler, F. X. Gentit, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W. R. Gibson, J. D. Gillies, J. Goldberg, D. M. Gingrich, M. J. Goodrick, W. Gorn, C. Grandi, P. Grannis, E. Gross, J. Hagemann, G. G. Hanson, M. Hansroul, C. K. Hargrove, J. Hart, P. A. Hart, M. Hauschild, C. M. Hawkes, E. Heflin, R. J. Hemingway, G. Herten, R. D. Heuer, J. C. Hill, S. J. Hillier, T. Hilse, D. A. Hinshaw, P. R. Hobson, D. Hochman, A. Höcker, R. J. Homer, A. K. Honma, R. Howard, R. E. Hughes-Jones, R. Humbert, P. Igo-Kemenes, H. Ihssen, D. C. Imrie, A. Jawahery, P. W. Jeffreys, H. Jeremie, M. Jimack, M. Jones, R. W.L. Jones, P. Jovanovic, C. Jui, D. Karlen, K. Kawagoe, T. Kawamoto, R. K. Keeler, R. G. Kellogg, B. W. Kennedy, B. King, J. King, S. Kluth, T. Kobayashi, M. Kobel, D. S. Koetke, T. P. Kokott, Sachio Komamiya, R. Kowalewski, P. Krieger, J. von Krogh, P. Kyberd, G. D. Lafferty, H. Lafoux, R. Lahmann, J. Lauber, J. G. Layter, P. Leblanc, P. Le Du, A. M. Lee, E. Lefebvre, M. H. Lehto, D. Lellouch, C. Leroy, J. Letts, L. Levinson, Z. Li, F. Liu, S. L. Lloyd, F. K. Loebinger, G. D. Long, B. Lorazo, M. J. Losty, X. C. Lou, J. Ludwig, A. Luig, M. Mannelli, S. Marcellini, C. Markus, A. J. Martin, J. P. Martin, T. Mashimo, P. Mättig, U. Maur, J. McKenna, T. J. McMahon, A. I. McNab, J. R. McNutt, F. Meijers, F. S. Merrit, H. Mes, A. Michelini, R. P. Middleton, G. Mikenberg, J. Mildenberger, D. J. Miller, R. Mir, W. Mohr, C. Moisan, A. Montanari, T. Mori, M. Morii, U. MÜller, B. Nellen, B. Nijjhar, S. W. O'Neale, F. G. Oakham, F. Odorici, H. O. Ogren, C. J. Oram, M. J. Oreglia, S. Orito, J. P. Pansart, G. N. Patrick, M. J. Pearce, P. Pfister, P. D. Phillips, J. E. Pilcher, J. Pinfold, D. Pitman, D. E. Plane, P. Poffenberger, B. Poli, A. Posthaus, T. W. Pritchard, H. Przysiezniak, M. W. Redmond, D. L. Rees, D. Rigby, M. Rison, S. A. Robins, D. Robinson, J. M. Roney, E. Ros, S. Rossberg, A. M. Rossi, M. Rosvick, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, D. R. Rust, M. Sasaki, C. Sbarra, A. D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, B. Schmitt, H. von der Schmitt, M. Schröder, H. C. Schultz-Coulon, P. Schütz, M. Schulz, C. Schwick, J. Schwiening, W. G. Scott, M. Settles, T. G. Shears, B. C. Shen, C. H. Shepherd-Themistocleous, P. Sherwood, G. P. Siroli, A. Skillman, A. Skuja, A. M. Smith, T. J. Smith, G. A. Snow, R. Sobie, R. W. Springer, M. Sproston, A. Stahl, C. Stegmann, K. Stephens, B. Stochausen, R. Ströhmer, D. Strom, P. Szymanski, H. Takeda, T. Takeshita, S. Tarem, M. Tecchio, P. Teixeira-Dias, N. Tesch, M. A. Thomson, S. Towers, T. Tsukamoto, M. F. Turner-Watson, D. Van den plas, R. Van Kooten, G. Vasseur, M. Vincter, A. Wagner, D. L. Wagner, C. P. Ward, D. R. Ward, J. J. Ward, P. M. Watkins, A. T. Watson, N. K. Watson, P. Weber, P. S. Wells, N. Wermes, B. Wilkens, G. W. Wilson, J. A. Wilson, V. H. Winterer, T. Wlodek, G. Wolf, S. Wotton, T. R. Wyatt, A. Yeaman, G. Yekutieli, M. Yurko, W. Zeuner, G. T. Zorn

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

A measurement of the single photon production cross-section is presented based on a data-sample of 40.5 pb-1 collected with the OPAL detector at centre-of-mass energies within 3 GeV of the Z0 mass. Single photon events arise from initial state radiation and the production of an "invisible" final state consisting of neutrinos or possibly particles such as sneutrinos or photinos. The single photon topology is also sensitive to new Z0 decays such as {Mathematical expression} or Z0→γX, X→invisible particles. A total of 447 single photon candidates were observed with energy exceeding 1.75 GeV in the polar angle region |cosθ|<0.7. The estimated background from processes with visible reaction products, mainly e+e-→e+e-γ, is 37±6 events. Interpreting the cross-sections as being solely due to Z0 decay to invisible particles and the expected W-contributions, the Z0 invisible with is determined to be 539±26±17 MeV corresponding to Nv=3.23±0.16±0.10 light neutrino generations. The differential cross-section with photon energy is presented. Upper limits are set on additional invisible contributions to the Z0 width, on possible non-resconant processes, and on Z0 decays to single photons. The energy spectra are used to constrain exotic sources of high energy single photons. In particular, the radiative twobody decay of the Z0 to a new particle X, with mass below 64 GeV and an invisible signature, has a Z0 branching ratio of less than 4.3×10-6 at 95% confidence level.

Original languageEnglish
Pages (from-to)47-65
Number of pages19
JournalZeitschrift für Physik C Particles and Fields
Volume65
Issue number1
DOIs
Publication statusPublished - 1995 Mar 1
Externally publishedYes

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Photons
collisions
photons
decay
cross sections
neutrinos
energy
Reaction products
reaction products
center of mass
confidence
energy spectra
topology
signatures
Topology
Detectors
Radiation
detectors
radiation

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Akers, R., Alexander, G., Allison, J., Anderson, K. J., Arcelli, S., Asai, S., ... Zorn, G. T. (1995). Measurement of single photon production in e+e- collisions near the Z0 resonance. Zeitschrift für Physik C Particles and Fields, 65(1), 47-65. https://doi.org/10.1007/BF01571303

Measurement of single photon production in e+e- collisions near the Z0 resonance. / Akers, R.; Alexander, G.; Allison, J.; Anderson, K. J.; Arcelli, S.; Asai, S.; Astbury, A.; Axen, D.; Azuelos, G.; Ball, A. H.; Barberio, E.; Barlow, R. J.; Bartoldus, R.; Batley, J. R.; Beaudoin, G.; Beck, A.; Beck, G. A.; Becker, J.; Beeston, C.; Behnke, T.; Bell, K. W.; Bella, G.; Bentkowski, P.; Bentvelsen, S.; Berlich, P.; Bethke, S.; Biebel, O.; Bloodworth, I. J.; Bock, P.; Bosch, H. M.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brown, R. M.; Buijs, A.; Burckhart, H. J.; Burgard, C.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlesworth, C.; Charlton, D. G.; Chu, S. L.; Clarke, P. E.L.; Clayton, J. C.; Clowes, S. G.; Cohen, I.; Conboy, J. E.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallapiccola, C.; Dallavalle, G. M.; Darling, C.; De Jong, S.; Deng, H.; Dittmar, M.; Dixit, M. S.; do Couto e Silva, E.; Duboscq, J. E.; Duchovni, E.; Duckeck, G.; Duerdoth, I. P.; Dunwoody, U. C.; Elcombe, P. A.; Estabrooks, P. G.; Etzion, E.; Evans, H. G.; Fabbri, F.; Fabbro, B.; Fanti, M.; Fierro, M.; Fincke-Keeler, M.; Fischer, H. M.; Fischer, P.; Folman, R.; Fong, D. G.; Foucher, M.; Fukui, H.; Fürtjes, A.; Gagnon, P.; Gaidot, A.; Gary, J. W.; Gascon, J.; Geddes, N. I.; Geich-Gimbel, C.; Gensler, S. W.; Gentit, F. X.; Geralis, T.; Giacomelli, G.; Giacomelli, P.; Giacomelli, R.; Gibson, V.; Gibson, W. R.; Gillies, J. D.; Goldberg, J.; Gingrich, D. M.; Goodrick, M. J.; Gorn, W.; Grandi, C.; Grannis, P.; Gross, E.; Hagemann, J.; Hanson, G. G.; Hansroul, M.; Hargrove, C. K.; Hart, J.; Hart, P. A.; Hauschild, M.; Hawkes, C. M.; Heflin, E.; Hemingway, R. J.; Herten, G.; Heuer, R. D.; Hill, J. C.; Hillier, S. J.; Hilse, T.; Hinshaw, D. A.; Hobson, P. R.; Hochman, D.; Höcker, A.; Homer, R. J.; Honma, A. K.; Howard, R.; Hughes-Jones, R. E.; Humbert, R.; Igo-Kemenes, P.; Ihssen, H.; Imrie, D. C.; Jawahery, A.; Jeffreys, P. W.; Jeremie, H.; Jimack, M.; Jones, M.; Jones, R. W.L.; Jovanovic, P.; Jui, C.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R. K.; Kellogg, R. G.; Kennedy, B. W.; King, B.; King, J.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D. S.; Kokott, T. P.; Komamiya, Sachio; Kowalewski, R.; Krieger, P.; von Krogh, J.; Kyberd, P.; Lafferty, G. D.; Lafoux, H.; Lahmann, R.; Lauber, J.; Layter, J. G.; Leblanc, P.; Le Du, P.; Lee, A. M.; Lefebvre, E.; Lehto, M. H.; Lellouch, D.; Leroy, C.; Letts, J.; Levinson, L.; Li, Z.; Liu, F.; Lloyd, S. L.; Loebinger, F. K.; Long, G. D.; Lorazo, B.; Losty, M. J.; Lou, X. C.; Ludwig, J.; Luig, A.; Mannelli, M.; Marcellini, S.; Markus, C.; Martin, A. J.; Martin, J. P.; Mashimo, T.; Mättig, P.; Maur, U.; McKenna, J.; McMahon, T. J.; McNab, A. I.; McNutt, J. R.; Meijers, F.; Merrit, F. S.; Mes, H.; Michelini, A.; Middleton, R. P.; Mikenberg, G.; Mildenberger, J.; Miller, D. J.; Mir, R.; Mohr, W.; Moisan, C.; Montanari, A.; Mori, T.; Morii, M.; MÜller, U.; Nellen, B.; Nijjhar, B.; O'Neale, S. W.; Oakham, F. G.; Odorici, F.; Ogren, H. O.; Oram, C. J.; Oreglia, M. J.; Orito, S.; Pansart, J. P.; Patrick, G. N.; Pearce, M. J.; Pfister, P.; Phillips, P. D.; Pilcher, J. E.; Pinfold, J.; Pitman, D.; Plane, D. E.; Poffenberger, P.; Poli, B.; Posthaus, A.; Pritchard, T. W.; Przysiezniak, H.; Redmond, M. W.; Rees, D. L.; Rigby, D.; Rison, M.; Robins, S. A.; Robinson, D.; Roney, J. M.; Ros, E.; Rossberg, S.; Rossi, A. M.; Rosvick, M.; Routenburg, P.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D. R.; Sasaki, M.; Sbarra, C.; Schaile, A. D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schenk, P.; Schmitt, B.; von der Schmitt, H.; Schröder, M.; Schultz-Coulon, H. C.; Schütz, P.; Schulz, M.; Schwick, C.; Schwiening, J.; Scott, W. G.; Settles, M.; Shears, T. G.; Shen, B. C.; Shepherd-Themistocleous, C. H.; Sherwood, P.; Siroli, G. P.; Skillman, A.; Skuja, A.; Smith, A. M.; Smith, T. J.; Snow, G. A.; Sobie, R.; Springer, R. W.; Sproston, M.; Stahl, A.; Stegmann, C.; Stephens, K.; Stochausen, B.; Ströhmer, R.; Strom, D.; Szymanski, P.; Takeda, H.; Takeshita, T.; Tarem, S.; Tecchio, M.; Teixeira-Dias, P.; Tesch, N.; Thomson, M. A.; Towers, S.; Tsukamoto, T.; Turner-Watson, M. F.; Van den plas, D.; Van Kooten, R.; Vasseur, G.; Vincter, M.; Wagner, A.; Wagner, D. L.; Ward, C. P.; Ward, D. R.; Ward, J. J.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Weber, P.; Wells, P. S.; Wermes, N.; Wilkens, B.; Wilson, G. W.; Wilson, J. A.; Winterer, V. H.; Wlodek, T.; Wolf, G.; Wotton, S.; Wyatt, T. R.; Yeaman, A.; Yekutieli, G.; Yurko, M.; Zeuner, W.; Zorn, G. T.

In: Zeitschrift für Physik C Particles and Fields, Vol. 65, No. 1, 01.03.1995, p. 47-65.

Research output: Contribution to journalArticle

Akers, R, Alexander, G, Allison, J, Anderson, KJ, Arcelli, S, Asai, S, Astbury, A, Axen, D, Azuelos, G, Ball, AH, Barberio, E, Barlow, RJ, Bartoldus, R, Batley, JR, Beaudoin, G, Beck, A, Beck, GA, Becker, J, Beeston, C, Behnke, T, Bell, KW, Bella, G, Bentkowski, P, Bentvelsen, S, Berlich, P, Bethke, S, Biebel, O, Bloodworth, IJ, Bock, P, Bosch, HM, Boutemeur, M, Braibant, S, Bright-Thomas, P, Brown, RM, Buijs, A, Burckhart, HJ, Burgard, C, Capiluppi, P, Carnegie, RK, Carter, AA, Carter, JR, Chang, CY, Charlesworth, C, Charlton, DG, Chu, SL, Clarke, PEL, Clayton, JC, Clowes, SG, Cohen, I, Conboy, JE, Coupland, M, Cuffiani, M, Dado, S, Dallapiccola, C, Dallavalle, GM, Darling, C, De Jong, S, Deng, H, Dittmar, M, Dixit, MS, do Couto e Silva, E, Duboscq, JE, Duchovni, E, Duckeck, G, Duerdoth, IP, Dunwoody, UC, Elcombe, PA, Estabrooks, PG, Etzion, E, Evans, HG, Fabbri, F, Fabbro, B, Fanti, M, Fierro, M, Fincke-Keeler, M, Fischer, HM, Fischer, P, Folman, R, Fong, DG, Foucher, M, Fukui, H, Fürtjes, A, Gagnon, P, Gaidot, A, Gary, JW, Gascon, J, Geddes, NI, Geich-Gimbel, C, Gensler, SW, Gentit, FX, Geralis, T, Giacomelli, G, Giacomelli, P, Giacomelli, R, Gibson, V, Gibson, WR, Gillies, JD, Goldberg, J, Gingrich, DM, Goodrick, MJ, Gorn, W, Grandi, C, Grannis, P, Gross, E, Hagemann, J, Hanson, GG, Hansroul, M, Hargrove, CK, Hart, J, Hart, PA, Hauschild, M, Hawkes, CM, Heflin, E, Hemingway, RJ, Herten, G, Heuer, RD, Hill, JC, Hillier, SJ, Hilse, T, Hinshaw, DA, Hobson, PR, Hochman, D, Höcker, A, Homer, RJ, Honma, AK, Howard, R, Hughes-Jones, RE, Humbert, R, Igo-Kemenes, P, Ihssen, H, Imrie, DC, Jawahery, A, Jeffreys, PW, Jeremie, H, Jimack, M, Jones, M, Jones, RWL, Jovanovic, P, Jui, C, Karlen, D, Kawagoe, K, Kawamoto, T, Keeler, RK, Kellogg, RG, Kennedy, BW, King, B, King, J, Kluth, S, Kobayashi, T, Kobel, M, Koetke, DS, Kokott, TP, Komamiya, S, Kowalewski, R, Krieger, P, von Krogh, J, Kyberd, P, Lafferty, GD, Lafoux, H, Lahmann, R, Lauber, J, Layter, JG, Leblanc, P, Le Du, P, Lee, AM, Lefebvre, E, Lehto, MH, Lellouch, D, Leroy, C, Letts, J, Levinson, L, Li, Z, Liu, F, Lloyd, SL, Loebinger, FK, Long, GD, Lorazo, B, Losty, MJ, Lou, XC, Ludwig, J, Luig, A, Mannelli, M, Marcellini, S, Markus, C, Martin, AJ, Martin, JP, Mashimo, T, Mättig, P, Maur, U, McKenna, J, McMahon, TJ, McNab, AI, McNutt, JR, Meijers, F, Merrit, FS, Mes, H, Michelini, A, Middleton, RP, Mikenberg, G, Mildenberger, J, Miller, DJ, Mir, R, Mohr, W, Moisan, C, Montanari, A, Mori, T, Morii, M, MÜller, U, Nellen, B, Nijjhar, B, O'Neale, SW, Oakham, FG, Odorici, F, Ogren, HO, Oram, CJ, Oreglia, MJ, Orito, S, Pansart, JP, Patrick, GN, Pearce, MJ, Pfister, P, Phillips, PD, Pilcher, JE, Pinfold, J, Pitman, D, Plane, DE, Poffenberger, P, Poli, B, Posthaus, A, Pritchard, TW, Przysiezniak, H, Redmond, MW, Rees, DL, Rigby, D, Rison, M, Robins, SA, Robinson, D, Roney, JM, Ros, E, Rossberg, S, Rossi, AM, Rosvick, M, Routenburg, P, Rozen, Y, Runge, K, Runolfsson, O, Rust, DR, Sasaki, M, Sbarra, C, Schaile, AD, Schaile, O, Scharf, F, Scharff-Hansen, P, Schenk, P, Schmitt, B, von der Schmitt, H, Schröder, M, Schultz-Coulon, HC, Schütz, P, Schulz, M, Schwick, C, Schwiening, J, Scott, WG, Settles, M, Shears, TG, Shen, BC, Shepherd-Themistocleous, CH, Sherwood, P, Siroli, GP, Skillman, A, Skuja, A, Smith, AM, Smith, TJ, Snow, GA, Sobie, R, Springer, RW, Sproston, M, Stahl, A, Stegmann, C, Stephens, K, Stochausen, B, Ströhmer, R, Strom, D, Szymanski, P, Takeda, H, Takeshita, T, Tarem, S, Tecchio, M, Teixeira-Dias, P, Tesch, N, Thomson, MA, Towers, S, Tsukamoto, T, Turner-Watson, MF, Van den plas, D, Van Kooten, R, Vasseur, G, Vincter, M, Wagner, A, Wagner, DL, Ward, CP, Ward, DR, Ward, JJ, Watkins, PM, Watson, AT, Watson, NK, Weber, P, Wells, PS, Wermes, N, Wilkens, B, Wilson, GW, Wilson, JA, Winterer, VH, Wlodek, T, Wolf, G, Wotton, S, Wyatt, TR, Yeaman, A, Yekutieli, G, Yurko, M, Zeuner, W & Zorn, GT 1995, 'Measurement of single photon production in e+e- collisions near the Z0 resonance', Zeitschrift für Physik C Particles and Fields, vol. 65, no. 1, pp. 47-65. https://doi.org/10.1007/BF01571303
Akers, R. ; Alexander, G. ; Allison, J. ; Anderson, K. J. ; Arcelli, S. ; Asai, S. ; Astbury, A. ; Axen, D. ; Azuelos, G. ; Ball, A. H. ; Barberio, E. ; Barlow, R. J. ; Bartoldus, R. ; Batley, J. R. ; Beaudoin, G. ; Beck, A. ; Beck, G. A. ; Becker, J. ; Beeston, C. ; Behnke, T. ; Bell, K. W. ; Bella, G. ; Bentkowski, P. ; Bentvelsen, S. ; Berlich, P. ; Bethke, S. ; Biebel, O. ; Bloodworth, I. J. ; Bock, P. ; Bosch, H. M. ; Boutemeur, M. ; Braibant, S. ; Bright-Thomas, P. ; Brown, R. M. ; Buijs, A. ; Burckhart, H. J. ; Burgard, C. ; Capiluppi, P. ; Carnegie, R. K. ; Carter, A. A. ; Carter, J. R. ; Chang, C. Y. ; Charlesworth, C. ; Charlton, D. G. ; Chu, S. L. ; Clarke, P. E.L. ; Clayton, J. C. ; Clowes, S. G. ; Cohen, I. ; Conboy, J. E. ; Coupland, M. ; Cuffiani, M. ; Dado, S. ; Dallapiccola, C. ; Dallavalle, G. M. ; Darling, C. ; De Jong, S. ; Deng, H. ; Dittmar, M. ; Dixit, M. S. ; do Couto e Silva, E. ; Duboscq, J. E. ; Duchovni, E. ; Duckeck, G. ; Duerdoth, I. P. ; Dunwoody, U. C. ; Elcombe, P. A. ; Estabrooks, P. G. ; Etzion, E. ; Evans, H. G. ; Fabbri, F. ; Fabbro, B. ; Fanti, M. ; Fierro, M. ; Fincke-Keeler, M. ; Fischer, H. M. ; Fischer, P. ; Folman, R. ; Fong, D. G. ; Foucher, M. ; Fukui, H. ; Fürtjes, A. ; Gagnon, P. ; Gaidot, A. ; Gary, J. W. ; Gascon, J. ; Geddes, N. I. ; Geich-Gimbel, C. ; Gensler, S. W. ; Gentit, F. X. ; Geralis, T. ; Giacomelli, G. ; Giacomelli, P. ; Giacomelli, R. ; Gibson, V. ; Gibson, W. R. ; Gillies, J. D. ; Goldberg, J. ; Gingrich, D. M. ; Goodrick, M. J. ; Gorn, W. ; Grandi, C. ; Grannis, P. ; Gross, E. ; Hagemann, J. ; Hanson, G. G. ; Hansroul, M. ; Hargrove, C. K. ; Hart, J. ; Hart, P. A. ; Hauschild, M. ; Hawkes, C. M. ; Heflin, E. ; Hemingway, R. J. ; Herten, G. ; Heuer, R. D. ; Hill, J. C. ; Hillier, S. J. ; Hilse, T. ; Hinshaw, D. A. ; Hobson, P. R. ; Hochman, D. ; Höcker, A. ; Homer, R. J. ; Honma, A. K. ; Howard, R. ; Hughes-Jones, R. E. ; Humbert, R. ; Igo-Kemenes, P. ; Ihssen, H. ; Imrie, D. C. ; Jawahery, A. ; Jeffreys, P. W. ; Jeremie, H. ; Jimack, M. ; Jones, M. ; Jones, R. W.L. ; Jovanovic, P. ; Jui, C. ; Karlen, D. ; Kawagoe, K. ; Kawamoto, T. ; Keeler, R. K. ; Kellogg, R. G. ; Kennedy, B. W. ; King, B. ; King, J. ; Kluth, S. ; Kobayashi, T. ; Kobel, M. ; Koetke, D. S. ; Kokott, T. P. ; Komamiya, Sachio ; Kowalewski, R. ; Krieger, P. ; von Krogh, J. ; Kyberd, P. ; Lafferty, G. D. ; Lafoux, H. ; Lahmann, R. ; Lauber, J. ; Layter, J. G. ; Leblanc, P. ; Le Du, P. ; Lee, A. M. ; Lefebvre, E. ; Lehto, M. H. ; Lellouch, D. ; Leroy, C. ; Letts, J. ; Levinson, L. ; Li, Z. ; Liu, F. ; Lloyd, S. L. ; Loebinger, F. K. ; Long, G. D. ; Lorazo, B. ; Losty, M. J. ; Lou, X. C. ; Ludwig, J. ; Luig, A. ; Mannelli, M. ; Marcellini, S. ; Markus, C. ; Martin, A. J. ; Martin, J. P. ; Mashimo, T. ; Mättig, P. ; Maur, U. ; McKenna, J. ; McMahon, T. J. ; McNab, A. I. ; McNutt, J. R. ; Meijers, F. ; Merrit, F. S. ; Mes, H. ; Michelini, A. ; Middleton, R. P. ; Mikenberg, G. ; Mildenberger, J. ; Miller, D. J. ; Mir, R. ; Mohr, W. ; Moisan, C. ; Montanari, A. ; Mori, T. ; Morii, M. ; MÜller, U. ; Nellen, B. ; Nijjhar, B. ; O'Neale, S. W. ; Oakham, F. G. ; Odorici, F. ; Ogren, H. O. ; Oram, C. J. ; Oreglia, M. J. ; Orito, S. ; Pansart, J. P. ; Patrick, G. N. ; Pearce, M. J. ; Pfister, P. ; Phillips, P. D. ; Pilcher, J. E. ; Pinfold, J. ; Pitman, D. ; Plane, D. E. ; Poffenberger, P. ; Poli, B. ; Posthaus, A. ; Pritchard, T. W. ; Przysiezniak, H. ; Redmond, M. W. ; Rees, D. L. ; Rigby, D. ; Rison, M. ; Robins, S. A. ; Robinson, D. ; Roney, J. M. ; Ros, E. ; Rossberg, S. ; Rossi, A. M. ; Rosvick, M. ; Routenburg, P. ; Rozen, Y. ; Runge, K. ; Runolfsson, O. ; Rust, D. R. ; Sasaki, M. ; Sbarra, C. ; Schaile, A. D. ; Schaile, O. ; Scharf, F. ; Scharff-Hansen, P. ; Schenk, P. ; Schmitt, B. ; von der Schmitt, H. ; Schröder, M. ; Schultz-Coulon, H. C. ; Schütz, P. ; Schulz, M. ; Schwick, C. ; Schwiening, J. ; Scott, W. G. ; Settles, M. ; Shears, T. G. ; Shen, B. C. ; Shepherd-Themistocleous, C. H. ; Sherwood, P. ; Siroli, G. P. ; Skillman, A. ; Skuja, A. ; Smith, A. M. ; Smith, T. J. ; Snow, G. A. ; Sobie, R. ; Springer, R. W. ; Sproston, M. ; Stahl, A. ; Stegmann, C. ; Stephens, K. ; Stochausen, B. ; Ströhmer, R. ; Strom, D. ; Szymanski, P. ; Takeda, H. ; Takeshita, T. ; Tarem, S. ; Tecchio, M. ; Teixeira-Dias, P. ; Tesch, N. ; Thomson, M. A. ; Towers, S. ; Tsukamoto, T. ; Turner-Watson, M. F. ; Van den plas, D. ; Van Kooten, R. ; Vasseur, G. ; Vincter, M. ; Wagner, A. ; Wagner, D. L. ; Ward, C. P. ; Ward, D. R. ; Ward, J. J. ; Watkins, P. M. ; Watson, A. T. ; Watson, N. K. ; Weber, P. ; Wells, P. S. ; Wermes, N. ; Wilkens, B. ; Wilson, G. W. ; Wilson, J. A. ; Winterer, V. H. ; Wlodek, T. ; Wolf, G. ; Wotton, S. ; Wyatt, T. R. ; Yeaman, A. ; Yekutieli, G. ; Yurko, M. ; Zeuner, W. ; Zorn, G. T. / Measurement of single photon production in e+e- collisions near the Z0 resonance. In: Zeitschrift für Physik C Particles and Fields. 1995 ; Vol. 65, No. 1. pp. 47-65.
@article{1378f916c49a4fff936ffb801795f3bb,
title = "Measurement of single photon production in e+e- collisions near the Z0 resonance",
abstract = "A measurement of the single photon production cross-section is presented based on a data-sample of 40.5 pb-1 collected with the OPAL detector at centre-of-mass energies within 3 GeV of the Z0 mass. Single photon events arise from initial state radiation and the production of an {"}invisible{"} final state consisting of neutrinos or possibly particles such as sneutrinos or photinos. The single photon topology is also sensitive to new Z0 decays such as {Mathematical expression} or Z0→γX, X→invisible particles. A total of 447 single photon candidates were observed with energy exceeding 1.75 GeV in the polar angle region |cosθ|<0.7. The estimated background from processes with visible reaction products, mainly e+e-→e+e-γ, is 37±6 events. Interpreting the cross-sections as being solely due to Z0 decay to invisible particles and the expected W-contributions, the Z0 invisible with is determined to be 539±26±17 MeV corresponding to Nv=3.23±0.16±0.10 light neutrino generations. The differential cross-section with photon energy is presented. Upper limits are set on additional invisible contributions to the Z0 width, on possible non-resconant processes, and on Z0 decays to single photons. The energy spectra are used to constrain exotic sources of high energy single photons. In particular, the radiative twobody decay of the Z0 to a new particle X, with mass below 64 GeV and an invisible signature, has a Z0 branching ratio of less than 4.3×10-6 at 95{\%} confidence level.",
author = "R. Akers and G. Alexander and J. Allison and Anderson, {K. J.} and S. Arcelli and S. Asai and A. Astbury 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 G. Beaudoin and A. Beck and Beck, {G. A.} and J. Becker and C. Beeston and T. Behnke and Bell, {K. W.} and G. Bella and P. Bentkowski and S. Bentvelsen and P. Berlich and S. Bethke and O. Biebel and Bloodworth, {I. J.} and P. Bock and Bosch, {H. M.} and M. Boutemeur and S. Braibant and P. Bright-Thomas and Brown, {R. M.} and A. Buijs and Burckhart, {H. J.} and C. Burgard and P. Capiluppi and Carnegie, {R. K.} and Carter, {A. A.} and Carter, {J. R.} and Chang, {C. Y.} and C. Charlesworth and Charlton, {D. G.} and Chu, {S. L.} and Clarke, {P. E.L.} and Clayton, {J. C.} and Clowes, {S. G.} and I. Cohen and Conboy, {J. E.} and M. Coupland and M. Cuffiani and S. Dado and C. Dallapiccola and Dallavalle, {G. M.} and C. Darling and {De Jong}, S. and H. Deng and M. Dittmar and Dixit, {M. S.} and {do Couto e Silva}, E. and Duboscq, {J. E.} and E. Duchovni and G. Duckeck and Duerdoth, {I. P.} and Dunwoody, {U. C.} and Elcombe, {P. A.} and Estabrooks, {P. G.} and E. Etzion and Evans, {H. G.} and F. Fabbri and B. Fabbro and M. Fanti and M. Fierro and M. Fincke-Keeler and Fischer, {H. M.} and P. Fischer and R. Folman and Fong, {D. G.} and M. Foucher and H. Fukui and A. F{\"u}rtjes and P. Gagnon and A. Gaidot and Gary, {J. W.} and J. Gascon and Geddes, {N. I.} and C. Geich-Gimbel and Gensler, {S. W.} and Gentit, {F. X.} and T. Geralis and G. Giacomelli and P. Giacomelli and R. Giacomelli and V. Gibson and Gibson, {W. R.} and Gillies, {J. D.} and J. Goldberg and Gingrich, {D. M.} and Goodrick, {M. J.} and W. Gorn and C. Grandi and P. Grannis and E. Gross and J. Hagemann and Hanson, {G. G.} and M. Hansroul and Hargrove, {C. K.} and J. Hart and Hart, {P. A.} and M. Hauschild and Hawkes, {C. M.} and E. Heflin and Hemingway, {R. J.} and G. Herten and Heuer, {R. D.} and Hill, {J. C.} and Hillier, {S. J.} and T. Hilse and Hinshaw, {D. A.} and Hobson, {P. R.} and D. Hochman and A. H{\"o}cker and Homer, {R. J.} and Honma, {A. K.} and R. Howard and Hughes-Jones, {R. E.} and R. Humbert and P. Igo-Kemenes and H. Ihssen and Imrie, {D. C.} and A. Jawahery and Jeffreys, {P. W.} and H. Jeremie and M. Jimack and M. Jones and Jones, {R. W.L.} and P. Jovanovic and C. Jui and D. Karlen and K. Kawagoe and T. Kawamoto and Keeler, {R. K.} and Kellogg, {R. G.} and Kennedy, {B. W.} and B. King and J. King and S. Kluth and T. Kobayashi and M. Kobel and Koetke, {D. S.} and Kokott, {T. P.} and Sachio Komamiya and R. Kowalewski and P. Krieger and {von Krogh}, J. and P. Kyberd and Lafferty, {G. D.} and H. Lafoux and R. Lahmann and J. Lauber and Layter, {J. G.} and P. Leblanc and {Le Du}, P. and Lee, {A. M.} and E. Lefebvre and Lehto, {M. H.} and D. Lellouch and C. Leroy and J. Letts and L. Levinson and Z. Li and F. Liu and Lloyd, {S. L.} and Loebinger, {F. K.} and Long, {G. D.} and B. Lorazo and Losty, {M. J.} and Lou, {X. C.} and J. Ludwig and A. Luig and M. Mannelli and S. Marcellini and C. Markus and Martin, {A. J.} and Martin, {J. P.} and T. Mashimo and P. M{\"a}ttig and U. Maur and J. McKenna and McMahon, {T. J.} and McNab, {A. I.} and McNutt, {J. R.} and F. Meijers and Merrit, {F. S.} and H. Mes and A. Michelini and Middleton, {R. P.} and G. Mikenberg and J. Mildenberger and Miller, {D. J.} and R. Mir and W. Mohr and C. Moisan and A. Montanari and T. Mori and M. Morii and U. M{\"U}ller and B. Nellen and B. Nijjhar and O'Neale, {S. W.} and Oakham, {F. G.} and F. Odorici and Ogren, {H. O.} and Oram, {C. J.} and Oreglia, {M. J.} and S. Orito and Pansart, {J. P.} and Patrick, {G. N.} and Pearce, {M. J.} and P. Pfister and Phillips, {P. D.} and Pilcher, {J. E.} and J. Pinfold and D. Pitman and Plane, {D. E.} and P. Poffenberger and B. Poli and A. Posthaus and Pritchard, {T. W.} and H. Przysiezniak and Redmond, {M. W.} and Rees, {D. L.} and D. Rigby and M. Rison and Robins, {S. A.} and D. Robinson and Roney, {J. M.} and E. Ros and S. Rossberg and Rossi, {A. M.} and M. Rosvick and P. Routenburg and Y. Rozen and K. Runge and O. Runolfsson and Rust, {D. R.} 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 {von der Schmitt}, H. and M. Schr{\"o}der and Schultz-Coulon, {H. C.} and P. Sch{\"u}tz and M. Schulz and C. Schwick and J. Schwiening and Scott, {W. G.} and M. Settles and Shears, {T. G.} and Shen, {B. C.} and Shepherd-Themistocleous, {C. H.} and P. Sherwood and Siroli, {G. P.} and A. Skillman and A. Skuja and Smith, {A. M.} and Smith, {T. J.} and Snow, {G. A.} and R. Sobie and Springer, {R. W.} and M. Sproston and A. Stahl and C. Stegmann and K. Stephens and B. Stochausen and R. Str{\"o}hmer and D. Strom and P. Szymanski and H. Takeda and T. Takeshita and S. Tarem and M. Tecchio and P. Teixeira-Dias and N. Tesch and Thomson, {M. A.} and S. Towers and T. Tsukamoto and Turner-Watson, {M. F.} and {Van den plas}, D. and {Van Kooten}, R. and G. Vasseur and M. Vincter and A. Wagner and Wagner, {D. L.} 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 P. Weber and Wells, {P. S.} and N. Wermes and B. Wilkens and Wilson, {G. W.} and Wilson, {J. A.} and Winterer, {V. H.} and T. Wlodek and G. Wolf and S. Wotton and Wyatt, {T. R.} and A. Yeaman and G. Yekutieli and M. Yurko and W. Zeuner and Zorn, {G. T.}",
year = "1995",
month = "3",
day = "1",
doi = "10.1007/BF01571303",
language = "English",
volume = "65",
pages = "47--65",
journal = "European Physical Journal C",
issn = "1434-6044",
publisher = "Springer New York",
number = "1",

}

TY - JOUR

T1 - Measurement of single photon production in e+e- collisions near the Z0 resonance

AU - Akers, R.

AU - Alexander, G.

AU - Allison, J.

AU - Anderson, K. J.

AU - Arcelli, S.

AU - Asai, S.

AU - Astbury, A.

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 - Beaudoin, G.

AU - Beck, A.

AU - Beck, G. A.

AU - Becker, J.

AU - Beeston, C.

AU - Behnke, T.

AU - Bell, K. W.

AU - Bella, G.

AU - Bentkowski, P.

AU - Bentvelsen, S.

AU - Berlich, P.

AU - Bethke, S.

AU - Biebel, O.

AU - Bloodworth, I. J.

AU - Bock, P.

AU - Bosch, H. M.

AU - Boutemeur, M.

AU - Braibant, S.

AU - Bright-Thomas, P.

AU - Brown, R. M.

AU - Buijs, A.

AU - Burckhart, H. J.

AU - Burgard, C.

AU - Capiluppi, P.

AU - Carnegie, R. K.

AU - Carter, A. A.

AU - Carter, J. R.

AU - Chang, C. Y.

AU - Charlesworth, C.

AU - Charlton, D. G.

AU - Chu, S. L.

AU - Clarke, P. E.L.

AU - Clayton, J. C.

AU - Clowes, S. G.

AU - Cohen, I.

AU - Conboy, J. E.

AU - Coupland, M.

AU - Cuffiani, M.

AU - Dado, S.

AU - Dallapiccola, C.

AU - Dallavalle, G. M.

AU - Darling, C.

AU - De Jong, S.

AU - Deng, H.

AU - Dittmar, M.

AU - Dixit, M. S.

AU - do Couto e Silva, E.

AU - Duboscq, J. E.

AU - Duchovni, E.

AU - Duckeck, G.

AU - Duerdoth, I. P.

AU - Dunwoody, U. C.

AU - Elcombe, P. A.

AU - Estabrooks, P. G.

AU - Etzion, E.

AU - Evans, H. G.

AU - Fabbri, F.

AU - Fabbro, B.

AU - Fanti, M.

AU - Fierro, M.

AU - Fincke-Keeler, M.

AU - Fischer, H. M.

AU - Fischer, P.

AU - Folman, R.

AU - Fong, D. G.

AU - Foucher, M.

AU - Fukui, H.

AU - Fürtjes, A.

AU - Gagnon, P.

AU - Gaidot, A.

AU - Gary, J. W.

AU - Gascon, J.

AU - Geddes, N. I.

AU - Geich-Gimbel, C.

AU - Gensler, S. W.

AU - Gentit, F. X.

AU - Geralis, T.

AU - Giacomelli, G.

AU - Giacomelli, P.

AU - Giacomelli, R.

AU - Gibson, V.

AU - Gibson, W. R.

AU - Gillies, J. D.

AU - Goldberg, J.

AU - Gingrich, D. M.

AU - Goodrick, M. J.

AU - Gorn, W.

AU - Grandi, C.

AU - Grannis, P.

AU - Gross, E.

AU - Hagemann, J.

AU - Hanson, G. G.

AU - Hansroul, M.

AU - Hargrove, C. K.

AU - Hart, J.

AU - Hart, P. A.

AU - Hauschild, M.

AU - Hawkes, C. M.

AU - Heflin, E.

AU - Hemingway, R. J.

AU - Herten, G.

AU - Heuer, R. D.

AU - Hill, J. C.

AU - Hillier, S. J.

AU - Hilse, T.

AU - Hinshaw, D. A.

AU - Hobson, P. R.

AU - Hochman, D.

AU - Höcker, A.

AU - Homer, R. J.

AU - Honma, A. K.

AU - Howard, R.

AU - Hughes-Jones, R. E.

AU - Humbert, R.

AU - Igo-Kemenes, P.

AU - Ihssen, H.

AU - Imrie, D. C.

AU - Jawahery, A.

AU - Jeffreys, P. W.

AU - Jeremie, H.

AU - Jimack, M.

AU - Jones, M.

AU - Jones, R. W.L.

AU - Jovanovic, P.

AU - Jui, C.

AU - Karlen, D.

AU - Kawagoe, K.

AU - Kawamoto, T.

AU - Keeler, R. K.

AU - Kellogg, R. G.

AU - Kennedy, B. W.

AU - King, B.

AU - King, J.

AU - Kluth, S.

AU - Kobayashi, T.

AU - Kobel, M.

AU - Koetke, D. S.

AU - Kokott, T. P.

AU - Komamiya, Sachio

AU - Kowalewski, R.

AU - Krieger, P.

AU - von Krogh, J.

AU - Kyberd, P.

AU - Lafferty, G. D.

AU - Lafoux, H.

AU - Lahmann, R.

AU - Lauber, J.

AU - Layter, J. G.

AU - Leblanc, P.

AU - Le Du, P.

AU - Lee, A. M.

AU - Lefebvre, E.

AU - Lehto, M. H.

AU - Lellouch, D.

AU - Leroy, C.

AU - Letts, J.

AU - Levinson, L.

AU - Li, Z.

AU - Liu, F.

AU - Lloyd, S. L.

AU - Loebinger, F. K.

AU - Long, G. D.

AU - Lorazo, B.

AU - Losty, M. J.

AU - Lou, X. C.

AU - Ludwig, J.

AU - Luig, A.

AU - Mannelli, M.

AU - Marcellini, S.

AU - Markus, C.

AU - Martin, A. J.

AU - Martin, J. P.

AU - Mashimo, T.

AU - Mättig, P.

AU - Maur, U.

AU - McKenna, J.

AU - McMahon, T. J.

AU - McNab, A. I.

AU - McNutt, J. R.

AU - Meijers, F.

AU - Merrit, F. S.

AU - Mes, H.

AU - Michelini, A.

AU - Middleton, R. P.

AU - Mikenberg, G.

AU - Mildenberger, J.

AU - Miller, D. J.

AU - Mir, R.

AU - Mohr, W.

AU - Moisan, C.

AU - Montanari, A.

AU - Mori, T.

AU - Morii, M.

AU - MÜller, U.

AU - Nellen, B.

AU - Nijjhar, B.

AU - O'Neale, S. W.

AU - Oakham, F. G.

AU - Odorici, F.

AU - Ogren, H. O.

AU - Oram, C. J.

AU - Oreglia, M. J.

AU - Orito, S.

AU - Pansart, J. P.

AU - Patrick, G. N.

AU - Pearce, M. J.

AU - Pfister, P.

AU - Phillips, P. D.

AU - Pilcher, J. E.

AU - Pinfold, J.

AU - Pitman, D.

AU - Plane, D. E.

AU - Poffenberger, P.

AU - Poli, B.

AU - Posthaus, A.

AU - Pritchard, T. W.

AU - Przysiezniak, H.

AU - Redmond, M. W.

AU - Rees, D. L.

AU - Rigby, D.

AU - Rison, M.

AU - Robins, S. A.

AU - Robinson, D.

AU - Roney, J. M.

AU - Ros, E.

AU - Rossberg, S.

AU - Rossi, A. M.

AU - Rosvick, M.

AU - Routenburg, P.

AU - Rozen, Y.

AU - Runge, K.

AU - Runolfsson, O.

AU - Rust, D. R.

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 - von der Schmitt, H.

AU - Schröder, M.

AU - Schultz-Coulon, H. C.

AU - Schütz, P.

AU - Schulz, M.

AU - Schwick, C.

AU - Schwiening, J.

AU - Scott, W. G.

AU - Settles, M.

AU - Shears, T. G.

AU - Shen, B. C.

AU - Shepherd-Themistocleous, C. H.

AU - Sherwood, P.

AU - Siroli, G. P.

AU - Skillman, A.

AU - Skuja, A.

AU - Smith, A. M.

AU - Smith, T. J.

AU - Snow, G. A.

AU - Sobie, R.

AU - Springer, R. W.

AU - Sproston, M.

AU - Stahl, A.

AU - Stegmann, C.

AU - Stephens, K.

AU - Stochausen, B.

AU - Ströhmer, R.

AU - Strom, D.

AU - Szymanski, P.

AU - Takeda, H.

AU - Takeshita, T.

AU - Tarem, S.

AU - Tecchio, M.

AU - Teixeira-Dias, P.

AU - Tesch, N.

AU - Thomson, M. A.

AU - Towers, S.

AU - Tsukamoto, T.

AU - Turner-Watson, M. F.

AU - Van den plas, D.

AU - Van Kooten, R.

AU - Vasseur, G.

AU - Vincter, M.

AU - Wagner, A.

AU - Wagner, D. L.

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 - Weber, P.

AU - Wells, P. S.

AU - Wermes, N.

AU - Wilkens, B.

AU - Wilson, G. W.

AU - Wilson, J. A.

AU - Winterer, V. H.

AU - Wlodek, T.

AU - Wolf, G.

AU - Wotton, S.

AU - Wyatt, T. R.

AU - Yeaman, A.

AU - Yekutieli, G.

AU - Yurko, M.

AU - Zeuner, W.

AU - Zorn, G. T.

PY - 1995/3/1

Y1 - 1995/3/1

N2 - A measurement of the single photon production cross-section is presented based on a data-sample of 40.5 pb-1 collected with the OPAL detector at centre-of-mass energies within 3 GeV of the Z0 mass. Single photon events arise from initial state radiation and the production of an "invisible" final state consisting of neutrinos or possibly particles such as sneutrinos or photinos. The single photon topology is also sensitive to new Z0 decays such as {Mathematical expression} or Z0→γX, X→invisible particles. A total of 447 single photon candidates were observed with energy exceeding 1.75 GeV in the polar angle region |cosθ|<0.7. The estimated background from processes with visible reaction products, mainly e+e-→e+e-γ, is 37±6 events. Interpreting the cross-sections as being solely due to Z0 decay to invisible particles and the expected W-contributions, the Z0 invisible with is determined to be 539±26±17 MeV corresponding to Nv=3.23±0.16±0.10 light neutrino generations. The differential cross-section with photon energy is presented. Upper limits are set on additional invisible contributions to the Z0 width, on possible non-resconant processes, and on Z0 decays to single photons. The energy spectra are used to constrain exotic sources of high energy single photons. In particular, the radiative twobody decay of the Z0 to a new particle X, with mass below 64 GeV and an invisible signature, has a Z0 branching ratio of less than 4.3×10-6 at 95% confidence level.

AB - A measurement of the single photon production cross-section is presented based on a data-sample of 40.5 pb-1 collected with the OPAL detector at centre-of-mass energies within 3 GeV of the Z0 mass. Single photon events arise from initial state radiation and the production of an "invisible" final state consisting of neutrinos or possibly particles such as sneutrinos or photinos. The single photon topology is also sensitive to new Z0 decays such as {Mathematical expression} or Z0→γX, X→invisible particles. A total of 447 single photon candidates were observed with energy exceeding 1.75 GeV in the polar angle region |cosθ|<0.7. The estimated background from processes with visible reaction products, mainly e+e-→e+e-γ, is 37±6 events. Interpreting the cross-sections as being solely due to Z0 decay to invisible particles and the expected W-contributions, the Z0 invisible with is determined to be 539±26±17 MeV corresponding to Nv=3.23±0.16±0.10 light neutrino generations. The differential cross-section with photon energy is presented. Upper limits are set on additional invisible contributions to the Z0 width, on possible non-resconant processes, and on Z0 decays to single photons. The energy spectra are used to constrain exotic sources of high energy single photons. In particular, the radiative twobody decay of the Z0 to a new particle X, with mass below 64 GeV and an invisible signature, has a Z0 branching ratio of less than 4.3×10-6 at 95% confidence level.

UR - http://www.scopus.com/inward/record.url?scp=0003008247&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0003008247&partnerID=8YFLogxK

U2 - 10.1007/BF01571303

DO - 10.1007/BF01571303

M3 - Article

VL - 65

SP - 47

EP - 65

JO - European Physical Journal C

JF - European Physical Journal C

SN - 1434-6044

IS - 1

ER -