Evidence for top quark production in $\bar{p}p$ collisions at $\sqrt{s} = 1.8$ TeV

We present the results of a search for the top quark in 19.3 pb−1 of p¯p collisions at √s =1.8 TeV. The data were collected at the Fermilab Tevatron collider using the Collider Detector at Fermilab (CDF). The search includes standard model tt¯ decays to final states eeνν¯, eμνν¯, and μμνν¯ as well as e+ν+jets or μ+ν+jets. In the (e,μ)+ν+jets channel we search for b quarks from t decays via secondary vertex identification and via semileptonic decays of the b and cascade c quarks. In the dilepton final states we find two events with a background of 0.56−0.13+0.25 events. In the e,μ+ν+jets channel with a b identified via a secondary vertex, we find six events with a background of 2.3±0.3. With a b identified via a semileptonic decay, we find seven events with a background of 3.1±0.3. The secondary vertex and semileptonic-decay samples have three events in common. The probability that the observed yield is consistent with the background is estimated to be 0.26%. The statistics are too limited to firmly establish the existence of the top quark; however, a natural interpretation of the excess is that it is due to tt¯ production. We present several cross-checks. Some support this hypothesis; others do not. Under the assumption that the excess yield over background is due to tt¯, constrained fitting on a subset of the events yields a mass of 174±10−12+13 GeV/c2 for the top quark. The tt¯ cross section, using this top quark mass to compute the acceptance, is measured to be 13.9−4.8+6.1 pb.

anti-p p: colliding beams
colliding beams: anti-p p
anti-p p: inclusive reaction
top
quark: pair production
pair production: quark
quark: semileptonic decay
semileptonic decay: quark
quark: cascade decay
cascade decay: quark

References(62)

Figures(0)

Partial Symmetries of Weak Interactions

S.L. Glashow
(
- Copenhagen U.
)

- Nucl.Phys. 22 (1961) 579-588,
- Also in *Lai, C. H. (Ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 171-180
•
DOI:
- 10.1016/0029-5582(61)90469-2

A Model of Leptons

Steven Weinberg
(
- MIT, LNS
)

- Phys.Rev.Lett. 19 (1967) 1264-1266,
- Also in *Lichtenberg, D. B. (ed.), Rosen, S. P. (ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 157-159,
- In *Lai, C. H. (ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 185-187,
- In *Rosner, J. L. (ed.): New Particles*, 26-28
•
DOI:
- 10.1103/PhysRevLett.19.1264

Weak and Electromagnetic Interactions

Abdus Salam
(
- Imperial Coll., London and
- ICTP, Trieste
)

- Conf.Proc.C 680519 (1968) 367-377,
- Reprinted in *Lichtenberg, D. B. (ed.), Rosen, S. P. (ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 160-170, and in *Lai, C. H. (ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 188-198,
- Also in *Rosner, J.L. (ed.): New particles* 29-39,
- Also in *Ali, A. (ed.) et al.: Selected papers of Abdus Salam* 244-254
•
DOI:
- 10.1142/9789812795915_0034

Weak Interactions with Lepton-Hadron Symmetry

- Phys.Rev.D 2 (1970) 1285-1292,
- Also in *Lai, C. H. (ed.): Gauge Theory Of Weak and Electromagnetic Interactions*, 203-210,
- In *Rosner, J.L. (ed.): New Particles*, 18-25,
- In *Lichtenberg, D. B. (Ed.), Rosen, S. P. (Ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 193-200.,
- In *Bologna 1984, Proceedings, Fifty Years of Weak-Interaction Physics* 687-694
•
DOI:
- 10.1103/PhysRevD.2.1285

CP Violation in the Renormalizable Theory of Weak Interaction

Makoto Kobayashi
(
- Kyoto U.
)
,
Toshihide Maskawa
(
- Kyoto U.
)

- Prog.Theor.Phys. 49 (1973) 652-657,
- Also in *Lichtenberg, D. B. (Ed.), Rosen, S. P. (Ed.): Developments In The Quark Theory Of Hadrons, Vol. 1*, 218-223.
•
DOI:
- 10.1143/PTP.49.652

A Lower limit on the top quark mass from events with two leptons in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

CDF

Collaboration

•

F. Abe

et al.

- Phys.Rev.Lett. 68 (1992) 447-451
•
DOI:
- 10.1103/PhysRevLett.68.447

A Limit on the Top Quark Mass from $p\bar{p}$ Collisions at $\sqrt{s} = 1.8$ TeV

CDF

Collaboration

•

F. Abe
(
- KEK, Tsukuba
)

et al.

- Phys.Rev.D 45 (1992) 3921-3948
•
DOI:
- 10.1103/PhysRevD.45.3921

Search for the top quark in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

D0

Collaboration

•

S. Abachi

et al.

- Phys.Rev.Lett. 72 (1994) 2138-2142
•
DOI:
- 10.1103/PhysRevLett.72.2138

Direct measurement of the W - gamma coupling at the CERN anti-p p collider

UA2

Collaboration

•

J. Alitti
(
- IRFU, Saclay
)

et al.

- Phys.Lett.B 277 (1992) 194-202
•
DOI:
- 10.1016/0370-2693(92)90979-E

The Total Cross-Section for the Production of Heavy Quarks in Hadronic Collisions

- Nucl.Phys.B 303 (1988) 607-633
•
DOI:
- 10.1016/0550-3213(88)90422-1

QCD Corrections to Heavy Quark Production in p anti-p Collisions

- Phys.Rev.D 40 (1989) 54-82
•
DOI:
- 10.1103/PhysRevD.40.54

Total Cross-Sections for Heavy Flavor Production in Hadronic Collisions and QCD

Guido Altarelli
(
- CERN
)
,
M. Diemoz
(
- Rome U. and
- INFN, Rome
)
,
G. Martinelli
(
- CERN
)
,
P. Nason
(
- Zurich, ETH
)

- Nucl.Phys.B 308 (1988) 724-752
•
DOI:
- 10.1016/0550-3213(88)90126-5

All order resummation of soft gluon contributions to heavy quark production in hadron hadron collisions

- Nucl.Phys.B 369 (1992) 543-599
•
DOI:
- 10.1016/0550-3213(92)90279-K

Top quark production cross-section

- Phys.Lett.B 321 (1994) 254-258
•
e-Print:
- hep-ph/9310233
•
DOI:
- 10.1016/0370-2693(94)90473-1

Top quark production by W gluon fusion

R.Keith Ellis
(
- Fermilab
)
,
Stephen J. Parke
(
- Fermilab
)

- Phys.Rev.D 46 (1992) 3785-3788
•
DOI:
- 10.1103/PhysRevD.46.3785

Studying the top quark via the W - gluon fusion process

Douglas O. Carlson
(
- Michigan State U.
)
,
C.P. Yuan
(
- Michigan State U.
)

- Phys.Lett.B 306 (1993) 386-390
•
e-Print:
- hep-ph/9211289
•
DOI:
- 10.1016/0370-2693(93)90095-Y

On the search for the top quark in the hadronic decay channel

- Phys.Rev.D 48 (1993) 5226-5232
•
DOI:
- 10.1103/PhysRevD.48.5226

Production of $W$ plus heavy quark pairs in hadronic collisions

Michelangelo L. Mangano
(
- INFN, Pisa and
- Pisa U.
)

- Nucl.Phys.B 405 (1993) 536-554
•
DOI:
- 10.1016/0550-3213(93)90558-7

The CDF Detector: An Overview

CDF

Collaboration

•

F. Abe

et al.

- Nucl.Instrum.Meth.A 271 (1988) 387-403
•
DOI:
- 10.1016/0168-9002(88)90298-7

A Measurement of $\sigma B (W \to e \nu)$ and $\sigma B (Z^0 \to e^+ e-)$ in $\bar{p}p$ collisions at $\sqrt{s} = 1800$ GeV

CDF

Collaboration

•

F. Abe
(
- KEK, Tsukuba
)

et al.

- Phys.Rev.D 44 (1991) 29-52
•
DOI:
- 10.1103/PhysRevD.44.29

The Topology of three jet events in $\bar{p}p$ collisions at $\sqrt{s} = 1.8$ TeV

CDF

Collaboration

•

F. Abe
(
- KEK, Tsukuba
)

et al.

- Phys.Rev.D 45 (1992) 1448-1458
•
DOI:
- 10.1103/PhysRevD.45.1448

Study of four jet events and evidence for double parton interactions in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

CDF

Collaboration

•

F. Abe
(
- KEK, Tsukuba
)

et al.

- Phys.Rev.D 47 (1993) 4857-4871,
- Phys. Rev. D47 (1993) 4857-4871. and Fermilab Batavia - FERMILAB-Pub-93-003 (93/01,rec.Nov.) 52 p. C
•
DOI:
- 10.1103/PhysRevD.47.4857