Abstract
A study of the channel e
+
e
- → μ
+
μ
γ
ISR, where γ
ISR is an initial state radiation photon, is presented using data collected by the DELPHI experiment from 1991 to 1994. The total cross-section at effective annihilation energies (√s') below the Z
0 peak is obtained by using the events with relatively hard initial state radiative photon(s) (E
γ > 1 GeV). The differential cross-section as a function of the muon polar production angle is also determined in order to extract the forward-backward asymmetries for the reaction e
+
e
- → μ
+
μ
- at energies √s' between 20 and 87 GeV. The ratio of the helicity cross-sections 
, where the two subscripts stand for the helicities of the incoming e
- and outgoing μ
- respectively, is extracted from the differential cross-sections in order to test the Standard Model and to look for new physics near 80 GeV. No deviations from the Standard Model were found.
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References
ALEPH Collab., R. Barate et al., Phys. Lett. B399 (1997), 329; L3 Collab., M. Acciari et al., Phys. Lett. B374 (1996) 331; OPAL Collab., P.D. Acton et al., Phys. Lett. B273 (1991) 338
J.-M. Frêre, V.A. Novikov, M.I. Vysotsky, Phys. Lett. B386 (1996) 437
K. Miyabayashi, Recent electroweak results from TRISTAN, Proc. of the XXXth Rencontres de Moriond, Les Arcs, March 1995, ed. J. Trân Thanh Vân
DELPHI Collab., P. Abreu et al., Z. Phys. C65 (1995) 603
D. Schaile, Precision tests of the electroweak interaction, Proc. of the XXVIIth Int. Conf. on High Energy Physics, Glasgow, July 1994, ed. P.J. Bussey and I.G. Knowles, IOP publishing (1995) 27
F. Berends, Z lineshape, in Z Physics at LEP I, CERN 89-08, Volume 1 (1989)
D. Bardin et al., Nucl. Phys. B351 (1991) 1; DELPHI Collab., P. Abreu et al., Z. Phys. C72 (1996) 31
D. Bardin et al., ZFITTER, An Analytical Program for Fermion Pair Production in e + e - Annihilation, CERN-TH. 6443/92 and hepph/ 9412201
DELPHI Collab., P. Aarnio et al., Nucl. Instr. & Meth. A303 (1991) 233; DELPHI Collab., P. Abreu et al., Nucl. Instr. & Meth. A378 (1996) 57
J.E. Campagne and R. Zitoun, Z. Phys. C43 (1989) 469; and Proc. of the Brighton Workshop on Radiative Corrections, Sussex, July 1989
S. Jadach and Z. Was, Comp. Phys. Com. 36 (1985) 191; S. Jadach, B.F. Ward and Z. Was, Comp. Phys. Com. 66 (1991) 276
J. Hilgart, R. Kleis, Comp. Phys. Com. 75 (1993) 191
DELPHI Collab., P. Abreu et al., Nucl. Phys. B417 (1994) 3
Z. Was and S. Jadach, Phys. Rev. D41 (1990) 1425
DELPHI Collab., P. Abreu et al., Nucl. Phys. B418 (1994) 403
HRS Collab., M. Derrick et al., Phys. Rev. D31 (1985) 2352; MAC Collab., W. W. Ash et al., Phys. Rev. Lett. 55 (1985) 1831; TASSO Collab., W. Braunschweig et al., Z. Phys. C40 (1988) 163; CELLO Collab., H.-J. Behrend et al., Phys. Lett. B191 (1987) 209; JADE Collab., W. Bartel et al., Z. Phys. C26 (1985) 507; MARK J Collab., B. Adeva et al., Phys. Rev. D38 (1988) 2665; AMY Collab., A. Bacala et al., Phys. Lett. B218 (1989) 112; AMY Collab., C. Velissaris et al., Phys. Lett. B331 (1994) 227; TOPAZ Collab., B. Howell et al., Phys. Lett. B291 (1992) 206
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DELPHI Collaboration. A study of the reaction e + e - - → μ + μ - γ ISR at LEP and search for new physics at annihilation energies near 80 GeV. Z Phys C - Particles and Fields 75, 581–592 (1997). https://doi.org/10.1007/s002880050504
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DOI: https://doi.org/10.1007/s002880050504