Name Type√

s (GeV) Lint (pb−1) Years of Detectors Location

operation

LEP e+e− 91.2 (LEP-1) ≈ 200 (LEP-1) 1989-95 (LEP-1) ALEPH, L3, CERN

161-209 (LEP-2) ≈ 600 (LEP-2) 1996-2000 (LEP-2) DELPHI, OPAL

SLC e+e− 91.2 20 1992-98 SLD SLAC

HERA e±p 320 500 1992-2007 ZEUS, H1 DESY

Tevatron pp̄ 1800 (Run-1) 160 (Run-1) 1987-96 (Run-1) CDF, DØ FNAL

1960 (Run-2) 6 K (Run-2, 06/09) 2000-??? (Run-2)

LHC (design) pp 14000 10 K/yr (”low-L”) 2010? - 2013? ATLAS, CMS CERN

100 K/yr (”high-L”) 2013?? - 2016???

LHC-2009 7000 ≈ 50? 11/09- 05/10?

ILC e+e− 500-1000 1 M??? ??? ??? ???

Table 1: Recent and future energy-frontier particle colliders.

2

ALEPH Collaboration/Physics Letters B 399 (1997) 329-341 337

dbb) ALEPH

Table 3

Results obtained for the S-matrix parameters from a maximum like-

lihood fit to the events selected in the inclusive analysis. The SM

predictions are computed with MZ = 9 1.1863 GeV, a-l (M$) =

128.896, Mt = 175 GeV and MH = 150 GeV.

SM predictions Fit results Correlation matrix

r? 0.14298 0.14186f0.00080 1.00 0.04 0.04 0.11

JCL ‘L”t 0.004 -0.033 f 0.022 1.00 -0.04 -0.34

r$ 0.00278 0.00273 f 0.00054 1.00 0.13

j,” 0.800 0.807 f 0.026 1 .oo

the interval & > @ 2 fi when the expected

number is fl. The x2/d.o.f. for the fit shown in

Table 3 is 193.71187, corresponding to a confidence

level of 35%. The results are in agreement with the

SM, and the statistical precision of the measurements

of j,” and j: is improved by a factor 1.4 compared

with the results obtained using the convolved cross

sections of Ref. [ 141. A direct comparison with the

predictions of the fit as a function of the fi interval

is shown in Table 4.

From the definitions

a measurement of the total cross section and forward-

backward asymmetry is obtained over a wide range

of energies, where the effect of the ISR has been de-

convolved. The results are shown in Tables 5 and 6

for the exclusive and inclusive analyses, respectively.

In Figs. 2 and 3 one can compare also these measure-

ments with previous measurements made at PEP [ lo],

PETRA [ 111 and TRISTAN [ 121 at lower energies.

The low energy data from these experiments are cor-

rected to include the effect of the running of the fine

structure constant cz.

Different sources of possible systematic errors on

the measured S-matrix parameters have been investi-

gated and reported in Table 7:

- The statistical uncertainty due to the finite number

of MC events used to determine E&(~) has been

propagated in the fit.

- The uncertainty associated with the calculation at

O(a) of the ISR-FSR interference corrections has

. LEP (AL.EPH)

1

-I IO

-2 10

20 40 60 80 100 120 140

4.9’ (c&v)

Fig. 2. Measured cross sections of muon-pair production compared

with the fit results. The ALEPH measurements below 60 GeV

correspond to the exclusive hard ISR selection that are not used in

the fit. For comparison the measurements at lower energies from

PEP, PETRA and TRISTAN are included.

ALEPH

0.8 . I,!2 (ALEP” )

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

-1 ,,“‘,‘1’,“,,,1,,,‘,“‘, 20 40 60 80 100 120 140

ds. (Gev)

Fig. 3. Measured forward-backward asymmetries of muon-pair

production compared with the fit results. The ALEPH measure-

ments below 60 GeV correspond to the exclusive hard ISR selec-

tion that are not used in the fit. For comparison the measurements

at lower energies from PEP, PETRA and TRISTAN are included.

ALEPH Collaboration/Physics Letters B 399 (1997) 329-341 337

dbb) ALEPH

Table 3

Results obtained for the S-matrix parameters from a maximum like-

lihood fit to the events selected in the inclusive analysis. The SM

predictions are computed with MZ = 9 1.1863 GeV, a-l (M$) =

128.896, Mt = 175 GeV and MH = 150 GeV.

SM predictions Fit results Correlation matrix

r? 0.14298 0.14186f0.00080 1.00 0.04 0.04 0.11

JCL ‘L”t 0.004 -0.033 f 0.022 1.00 -0.04 -0.34

r$ 0.00278 0.00273 f 0.00054 1.00 0.13

j,” 0.800 0.807 f 0.026 1 .oo

the interval & > @ 2 fi when the expected

number is fl. The x2/d.o.f. for the fit shown in

Table 3 is 193.71187, corresponding to a confidence

level of 35%. The results are in agreement with the

SM, and the statistical precision of the measurements

of j,” and j: is improved by a factor 1.4 compared

with the results obtained using the convolved cross

sections of Ref. [ 141. A direct comparison with the

predictions of the fit as a function of the fi interval

is shown in Table 4.

From the definitions

a measurement of the total cross section and forward-

backward asymmetry is obtained over a wide range

of energies, where the effect of the ISR has been de-

convolved. The results are shown in Tables 5 and 6

for the exclusive and inclusive analyses, respectively.

In Figs. 2 and 3 one can compare also these measure-

ments with previous measurements made at PEP [ lo],

PETRA [ 111 and TRISTAN [ 121 at lower energies.

The low energy data from these experiments are cor-

rected to include the effect of the running of the fine

structure constant cz.

Different sources of possible systematic errors on

the measured S-matrix parameters have been investi-

gated and reported in Table 7:

- The statistical uncertainty due to the finite number

of MC events used to determine E&(~) has been

propagated in the fit.

- The uncertainty associated with the calculation at

O(a) of the ISR-FSR interference corrections has

. LEP (AL.EPH)

1

-I IO

-2 10

20 40 60 80 100 120 140

4.9’ (c&v)

Fig. 2. Measured cross sections of muon-pair production compared

with the fit results. The ALEPH measurements below 60 GeV

correspond to the exclusive hard ISR selection that are not used in

the fit. For comparison the measurements at lower energies from

PEP, PETRA and TRISTAN are included.

ALEPH

0.8 . I,!2 (ALEP” )

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

-1 ,,“‘,‘1’,“,,,1,,,‘,“‘, 20 40 60 80 100 120 140

ds. (Gev)

Fig. 3. Measured forward-backward asymmetries of muon-pair

production compared with the fit results. The ALEPH measure-

ments below 60 GeV correspond to the exclusive hard ISR selec-

tion that are not used in the fit. For comparison the measurements

at lower energies from PEP, PETRA and TRISTAN are included.

ATLAS, PLB 399, 329 (1997)