The scaling violation within the pionization region in the energy range of 0.2 to 2.0 TeV is shown on the basis of the analysis of angular characteristics in the interactions of the cosmic radiation hadrons with the nuclei of various substances (CH2, Al, Cu, Pb)

Garsevanishvili, L. P.

Kotlyarevski, D. M.

Ladaria, N. K.

Shabelski, Y. M.

Sherer, N. I.

Stemanetyan, G. Z.

Tatalashvili, N. G.

Tsomaya, P. V.

Verbetski, Y. G.

English

NASA Technical Reports Server

H_ 3.2-8
2S8
SCALING VIOLATION IN HADRON-NUCLEUS
INTERACTION
Yu.G.Verbetski, L.P,Garsevanishvili, D.M.Kotlya-
revski, N.KoLadaria, NoGoTatalashvili, P.V.Tso -
maya, N.I.Sherer, Yu.M.Shabel'ski, G.Z.Stemanetyan
Institute of Physics, Academy of Sciences of the
Georgian SSR, Tbilisi, USSR
Summary. The scaling violation within the pionization re-
gion in the energy range of o.2 - 2.0 TeV is shown on the
basis of the analysis of angular characteristics in the in-
teractions of the cosmic radiation hadrons with the nuclei
of various substances (CH2, A1, Cu, Pb).
The investigation of multiple processes in hadren-nuc-
leus interactions allows to obtain the information on the
space-time structure of strong interactions.
It is rather paradoxical, but at present, the so called
soft processes of particle generation makind the overwhel-
ming contribution to the inelastic interaction cross-section,
remain the most obscure.
The most natural method to the understanding of the struc
ture of such interactions is the investigation of hadron-
-nucleus interactions at high energies using nuclei of va-
rious atomic numbers A.
The experimental data presented in this work have been
obtained at Chikovani Tskhra-Tskaro Station at the height
of 2500 m above the sea level by means of the instalation
consisting of the magnetic spark spectrometer and the ioni-
zation calorimeter /q /.
• .The targets of A1, CH_, Cu! Pb with the _hickness of
0.1A int. were exposed, dome _nteresting results have been
obtained in the energy region of O,q + 5.0 TeV using the
data of several thousand of events. °
Here the results of the investigation of interactions
with the energy above 0.9 TeV are presented. The selected
events have been generated, mainly, by primary protons which
have had passed through the atmosphere without any interacti-
ons° That condition has been achieved by means of selection
of showers without of other particles accompanying ( _c_¢_
o.31__ 161.
The aim of the present investigation is to reveal the
dominating mechanism of the secondary particle generation.
In the present paper the e_perimental data are analyzed with
respect to the variable _c ._ • _ _ O_n_is the pr jection of the s ondarg_y_r_l/_ esc_p_h le
the photography plane.
The experimental data have been corrected for the effi-
ciency of secondary particle recording in wide-gap spark
https://ntrs.nasa.gov/search.jsp?R=19850027603 2020-03-20T17:21:09+00:00Z
259 HE 3.2-8
chambers (dependin_ on the track direction with respect to
the electric field) and for the conversion of _ -quanta
due to _o -meson decay /7,_, The resolution of the appa-
tus does not allow us to make some definite conclusions on
the particles generated within the angle interval narrower
than O.1 ° (i.e. at _i_ 6.5). The experimental distributions
given in Fig.1 take into account the corrections over the
whole rapidity region excluding (0° . 0.1 °) where the uncer-
tainty in the estimations may be significant.
The experimental distributions have been compared with
the predictions of additive quark model /9/. According to
the latter, the component interact independently with the
cross-section equal to I/3 of nucleon-nucleon one, while the
generated objects do not interact within the nucleus. In
addition, the comparison has been made with the active lea-
der model, according to which the leading object interacts
with nucleons, while the newly-generated particles do not
interact in the nucleus: as it follows from Fig.l, a consi-
derable discrepancy with the experimental data takes place.
To achieve the agreement of theoretical predictions with the
experimental data, one may: assume 1) a significant viola-
tion of scaling laws within the fragmentation region or a
significant decrease of the cross-section of secondary inte-
ractions of the leading object (quarks, diquarks) with the
nucleons in the nucleus; and 2) take into account the cas-
cade of particles generated in the nucleus, which is, appa-
rently, growing with increasing E. Table and Fig.2 present
the data on the extent of the scaling violation increasing
with the growth of A within the pionization region in hadron-
-hadron and hadron-nucleus interactions.
I I I I i --
dn____h Fig.1 Inclusive dist_bu-
CH_ AL tions over _ of secon-
& _ d_' <E°>=II00GeV < E°>=I60QG_ dary particles in hadron-
6_ <ns_=14'3 <n_>_Q4 -hadron interactions. The
- histogram corresponds to
the corrected data (see
___, .\\ - the text). Dotted line -
_-_ _\ _ -L, + \\ the active leader model.
2 _ L_._\I z_ _+ \_ Crosses-additive quark
J#_. _ +_ L+ model with the shifts ino._ , i . distribution due to the
Cu <E_=ISQOGeV errors in the determina-tion of the primary patti-
O- _go>=i_00@V <n.>=28_ cle direction, introduced
6 <n_>=_L3 r_\ P_ by means of Monte-Carlo
;+ i J , d
0 £ 4 6 O _ 4 6 _'
_ 3.2-8
2@0 Table
Reaction _ _s in the interval _a = 2
in the vicinity ........of q'= 4 _ _A _ ('_'_)0.2 TeV 2.0 TeV
i , m,,, , i , ii i
pH 2.8 -+0.I 4.o + 0.I 1.42 + o.o8
pCH 2 3.9 _-0.3 5.4 ! 0.6 1.38 + 0.28
pH 4.2 + o.4 8.1 + 1.0 1;93 +-o.42
pc 4.0 + 0.4 10.3+-1.1 2.58 + 0.53
_b 4.8 +-0.5 12.1 +-1.2 2.52 +-0.51
i
, I , l l
// /
iiii j,. _..CH,
5 _!iI _ "_ I Fig.2 The multiplicity
_-- .-.-.-._-.---Ha of the charge_ particles
._ _a_ within the central
"'" _'= 4.0 - 1.0 region "
of the distribution over
I I I I I
o,l o,z q@ l,O P.,O 5,0 E.,Tev
HE 3.2-8
261
References
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(1976)
9. Yu.M.Shabel'ski, Proc XIII School of the LNPI, Leningrad,
90 (1978)


Scaling violation in hadron-nucleus interaction

Scaling violation in hadron-nucleus interaction

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