Estimation of charm production cross section in hadronic

Report
Estimation of charm production cross
section in hadronic interactions
at high energies s > 1.8 TeV
Yu.F. Novoseltsev1, G.M. Vereshkov1,2
1Institute
for Nuclear Research of RAS
2Physics Research Institute of Rostov State University
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The analysis is carried out within the frame of phenomenological
model of diffractive production and quark statistics based on additive
quark model (AQM)
We make use of low energy data on charm production and collider
data on diffractive dissociation
At collider energies 200, 540, 900, 1800 GeV , the values of σppccX
(s) were obtained by a quark statistics method
It is established, that logarithmic function with universal numerical
parameters describes the whole set of low-energy and high-energy
data with high accuracy
The expected values of cross section are σppccX =
250 ± 15 µb at TEVATRON energy s = 1.96 TeV and
355 ± 22 µb at LHC energy s = 14 TeV
Discussion
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The estimation of the total charm production cross section is based on
processing of collider data on diffractive dissociation with use of
phenomenological model of diffractive charm production and quark
statistics.
Cross section of diffractive dissociation in pp-interactons:
SPS --- √s = 200 GeV, 900 GeV
(Ansorge et al., 1986)
TEVATRON --- √s = 546 GeV, 1800 Gev (Abe et al., 1994)
σDD(pp  X) = CDD ln(s/so)
The basic assumptions consist in the following:
1) charm production occurs in process of diffractive
dissociation;
2) charm production cross section is extracted from
total cross section by quark statistics rules:
σtot( pp  cc + X) ≈ kcc× σDD(pp  X),
kcc ≈ 0.025 ± 0.004
uu : dd : ss : cc = 1 : 1 : (0.38 ± 0.07) : (0.06 ± 0.01)
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Data on total cross section of charm production
at s = 20 − 40 GeV
To begin with, we clear up the
opportunities of AQM and
logarithmic dependence for
cross section in the description
of data on charm production in
pN and N interactions at low
energies:
σNcc+X(s) = ⅔ σpNcc+X(3s/2)
σpNcc+X(s) = CpN ln(s/so)
CpN = 28.84 ± 2.10 μb, √so = 18.51 ± 0.36 GeV , 2 = 0.89
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(1)
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σ(pp  cc +X) at collider energies
√s, GeV
σDD, mb
200
546
900
4.8 ± 0.5 7.89 ± 0.33 7.8 ± 0.5 9.46 ± 0.44
σ(pp  cc +X) = kcc × σDD ,
σpp  cc +X, μb
1800
120 ± 21 197 ± 32
(2)
195 ± 32
236 ± 38
The obtained values of charm production cross section have the status
of model dependent processing collider data
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Joint fit of low-energy and high-energy data
on charm production
The strip corresponds
to 90 % CL
Values of C and so in
(1) and (3) coincide
within the limits of
statistical errors
(3 )
√
The charm production cross section in hadronic interaction is described
by universal logarithmic dependence
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Ideas of phenomenological models of diffractive production
and quark statistics were repeatedly tested at processing
most various experimental data.
These models give reliable quantitative predictions at the
accuracy level 10 - 20 % after fixing several parameters by
experimental data.
Therefore we consider possible to use the results (3) for
forecasting cross section of charm production in pp/pp
interactions in overaccelerating energy range.
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Forecast of charm production cross section
at √s > 1.8 TeV
These results mean the flux of “prompt” muons becomes equal to the flux
of “conventional” (from ,K-mesons) muons of CR at Eμ = 500 − 600 TeV
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There are three possible (and alternative) variants of
results, each of which represents the certain interest.
The measured flux of CR muons within the limits of measurement errors
coincides with calibration flux calculated according to the estimation (4).
In this case the estimation (4) can be used for testing microscopic models.
The measured flux of CR muons will exceed noticeably the calibration value,
but the σpp  ccX at energies in the region of a break of CR energy spectrum
will stay essentially smaller 10 mb. In this case it will be necessary to
recognize, that either quark statistics rules become incorrect in the area of
high energies, or the new mechanism of charm production, distinct from the
diffractive one, is included at these energies.
The measured flux of CR muons will correspond formally to σpp  ccX > 10
mb This result will mean that VHE muons carry away the energy from EAS
forming an observable break of CR spectrum. It is necessary to note, that
sources of such big numbers of VHE muons, most likely, are not reduced to
charmed particles − a New physics will required for interpretation of such
effect.
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