Abstract
Measurements of ep scattering with squared 4—momentum transfer Q2 up to 35000 GeV2 are compared with the expectation of the standard deep-inelastic model of lepton—nucleon scattering (DIS). For Q2 > 15000 GeV2, N obs = 12 neutral current candidate events are observed where the expectation is N DIS = 4.71 ± 0.76 events. In the same Q2 range, N obs = 4 charged current candidates are observed where the expectation is N DIS = 1.77 ± 0.87 events. The probability P(N ≥ N obs) that the DIS model signal N fluctuates to N ≥ N obs in a random set of experiments is 6 × 10−3 for neutral current and 0.14 for charged current. The difference in the observed and expected number of Neutral Current events is mostly due to events at large masses \(M = \sqrt {xs}\) in which the positron is backscattered at large y = Q2/M2.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
ZEUS Collaboration, M. Derrick et al., Z. Phys. C67 (1995) 81; H1 Collaboration, S. Aid et al., Phys. Lett. B353 (1995) 578; ZEUS Collaboration, M. Derrick et al., Z. Phys. C72 (1996) 47
H1 Collaboration, S. Aid et al., Z. Phys. C67 (1995) 565
H1 Collaboration, S. Aid et al., Phys. Lett. B379 (1996) 319
H1 Collaboration, I. Abt et al., Nucl. Phys. B396 (1993) 3; ZEUS Collaboration, M. Derrick et al., Phys. Lett. B306 (1993) 173; H1 Collaboration, T. Ahmed et al., Z. Phys. C64 (1994) 545; H1 Collaboration, S. Aid et al., Phys. Lett. B369 (1996) 173; H1 Collaboration, S. Aid et al., Z. Phys. C71 (1996) 211; ZEUS Collaboration, M. Derrick et al., DESY preprint 96-161 (August 1996) 31pp., to be published in Z. Phys. C
H1 Collaboration, I. Abt et al., Nucl. Instr. and Meth. A386 (1997) 310 and 348
H1 Calorimeter Group, B. Andrieu et al., Nucl. Instr. and Meth. A336 (1993) 460
H1 Calorimeter Group, B. Andrieu et al., Nucl. Inst. and Meth. A344 (1994) 492
H1 Calorimeter Group, B. Andrieu et al., Nucl. Instr. and Meth. A350 (1994) 57; idem, Nucl. Instr. and Meth. A336 (1993) 499
H1 SPACAL Group, R.D. Appuhn et al., DESY preprint 96-171 (August 1996) 24pp., to be published in Nucl. Instr. and Meth.
H1 BEMC Group, J. Ban et al., Nucl. Instr. and Meth. A372 (1996) 399
S. Bentvelsen, J. Engelen and P. Kooijman, Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 1 p. 25; K.C. Hoeger, ibid. p. 43; and references therein
A.D. Martin, R.G. Roberts and W.J. Stirling, Durham Univ. preprint DTP-93-86 and Rutherford Appleton Lab. preprint RAL-93-077 (October 1993) 16pp.; A. D. Martin, R. G. Roberts and W. J. Stirling, Proc. of the Workshop on Quantum Field Theoretical Aspects of High Energy Physics, ed. B. Geyser and E.M. Ilgenfritz (1993), p. 11; from [13] MRS (H): Ntype=1, Ngroup=3, Nset=36, DIS-scheme
H. Plothow-Besch, PDFLIB Version 7.07 - W5051, CERN-PPE (December 1996)
BCDMS Collaboration, A. C. Benvenuti et al., Phys. Lett. B223 (1989) 485; CERN preprint CERN-EP/89-06
NMC Collaboration, P. Amaudruz et al., Phys. Lett. B295 (1992) 159
CCFR Collaboration, A.O. Bazarko et al., Proc. of the XXVIIIth Renc. de Moriond, J. Trân Thanh Vân (Editor), (March 1993) 4pp
EMC Collaboration, J. J. Aubert et al., Nucl. Phys. B213 (1982) 31
WA70 Collaboration, M. Bonesini et al., Z. Phys. C38 (1988) 371
E605 Collaboration, C. N. Brown et al., Phys. Rev. Lett. 63 (1989) 2637
CDF Collaboration, F. Abe et al., Phys. Rev. Lett. 68 (1992) 2734; idem Phys. Rev. D48 (1993) 2998; Phys. Rev. Lett. 69 (1992) 28; idem Phys. Rev. D50 (1994) 5550; Phys. Rev. D50 (1994) 2966; A. Bodek, CDF Collaboration, Proc. of the Int. Workshop on Deep-Inelastic Scattering, Eilat, Israel (1994)
UA6 Collaboration, G. Sozzi et al., Phys. Lett. B317 (1993) 243
H1 Collaboration, I. Abt et al., Nucl. Phys. B407 (1993) 515
ZEUS Collaboration, M. Derrick et al., Phys. Lett. B316 (1993) 412
Yu. L. Dokshitzer, JETP 46 (1977) 641; V. N. Gribov and L. N. Lipatov, Sov. Journ. Nucl. Phys. 15 (1972) 78; G. Altarelli and G. Parisi, Nucl. Phys. B126 (1977) 298
G. Altarelli, R.K. Ellis and G. Martinelli, Nucl. Phys. B143 (1978) 521; idem Nucl. Phys. B157 (1979) 461
DJANGO 6.2; G.A. Schuler and H. Spiesberger, Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 3 p. 1419
HERACLES 4.4; A. Kwiatkowski, H. Spiesberger and H.-J. Möhring, Comput. Phys. Commun. 69 (1992) 155
LEPTO 6.5; G. Ingelman, Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 3 p. 1366
ARIADNE 4.08; L. Lönnblad, Comput. Phys. Commun. 71 (1992) 15
G. Gustafson and U. Pettersson, Nucl. Phys. B306 (1988) 746; idem, addendum Lund University preprint LU-TP-87-19, (October 1987) 4pp.; B. Andersson et al., Z. Phys. C43 (1989) 625
JETSET 7.3 and 7.4; T. Sjöstrand, Lund Univ. preprint LU-TP-95-20 (August 1995) 321pp; idem, CERN preprint TH-7112-93 (February 1994) 305pp
HECTOR 1.00; A. Arbuzov et al., Comput. Phys. Comm. 94 (1996) 128
A.D. Martin, W.J. Stirling and R.G. Roberts, Phys. Lett B387 (1996) 419; from [13] MRS (R1): Ntype=1,Ngroup=3,Nset=53, \(\overline {MS}\) scheme; MRS (R2): Ntype=1,Ngroup=3,Nset=54, \(\overline {MS}\) scheme
H. L. Lai et al., Phys. Rev. D55 (1997) 1280; from [13] CTEQ4M: Ntype=1, Ngroup=4, Nset=34, $⩈erline {MS}$ scheme; CTEQ4HJ: Ntype=1, Ngroup=4, Nset=40, $⩈erline {MS}$ scheme
M. Glück, E. Reya and A. Vogt, Z. Phys. C67 (1995) 433; from [13] GRV94HO: Ntype=1, Ngroup=5, Nset=6, $⩈erline {MS}$ scheme
W.A. Bardeen et al., Phys. Rev. D18 (1978) 3998
H. L. Lai et al., Phys. Rev. D55 (1997) 1280 from [13] Ntype=1, Ngroup=4, $⩈erline {MS}$ scheme; Nset=35, CTEQ (4A1); Nset=36, CTEQ (4A2); Nset=37, CTEQ (4A3); Nset=38, CTEQ4 (A4); Nset=39, CTEQ (4A5)
HELIOS 1.0; J. Blümlein, Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) ol. 3 p. 1272; Z. Phys. C65 (1995) 293
TERAD 91; A. Akhundov et al., Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 3 p. 1285, Fortschritte d. Physik 44 (1996) 373
H1 generator based on EPVEC 1.0; U. Baur, J.A.M. Vermaseren and D. Zeppenfeld, Nucl. Phys. B375 (1992) 3
T. Sjöstrand, CERN-TH-6488 (1992), Comp. Phys. Comm. 82 (1994) 74
M. Glück, E. Reya and A. Vogt, Phys. Rev. D45 (1992) 3986; idem, Phys. Rev. D46 (1992) 1973
S. Baranov et al., Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 3, p. 1478; J.A.M. Vermaseren, Nucl. Phys. B229 (1983) 347
C. F. v. Weizsäcker, Z. Phys. 88 (1934) 612; E. J. Williams, Phys. Rev. 45 (1934) 729; P. Kessler, Nuovo Cim., 17 (1960) 809; C. Carimalo et al., Phys. Rev. D10 (1974) 1561; Phys. Rev. D18 (1978) 2443; P. Bussey, Proc. of the Workshop Physics at HERA, W. Buchmüller and G. Ingelman (Editors), (October 1991, DESY-Hamburg) Vol. 1, p. 629
CDF Collaboration, F. Abe et al., Phys. Rev. Lett. 77 (1996) 438; G.C. Blazey, D0 Collaboration, Proc. of the XXXIst Renc. de Moriond, J. Trân Thanh Vân (Editor), (March 1996) 11pp
E.W.N. Glover et al., Phys. Lett. B381 (1996) 353
W. Buchmüller, R. Rückl and D. Wyler, Phys. Lett. B191 (1987) 442
H. Fritzsch and G. Mandelbaum, Phys. Lett. B102 (1981) 319; U. Baur and K.H. Streng, Z. Phys. C30 (1986) 325
J. Butterworth and H. Dreiner, Nucl. Phys. B397 (1993) 3, and references therein
LEGO 0.02; K. Rosenbauer, thesis RWTH Aachen, PITHA preprint 95/16 (July 1995)
Author information
Authors and Affiliations
Consortia
Rights and permissions
About this article
Cite this article
H1 Collaboration., Adloff, C., Aid, S. et al. Observation of events at very high Q2 in ep collisions at HERA. Z Phys C - Particles and Fields 74, 191–205 (1997). https://doi.org/10.1007/s002880050383
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002880050383