5,462 research outputs found
Clustering features of N nuclei in relativistic multifragmentation process
Progress in the study of the peripheral nuclear interactions in
dissociation at in nuclear emulsion is outlined. The leading role of
the multiple fragmentations in the most peripheral nucleus interactions is
discussed. The production of unusual states, for which a regrouping of nucleons
beyond the -particle clustering is needed, is identified for this
channel.Comment: 6 pages, 4 figures, International Conference "Current Problems in
Nuclear Physics and Atomic Energy" (NPAE-Kyiv2008), 9-15 June, 2008, Ukrain
Dissociation of relativistic nuclei in peripheral interactions in nuclear track emulsion
Possibilities of the nuclear emulsion technique for the study of the systems
of several relativistic fragments produced in the peripheral interactions of
relativistic nuclei are discussed. The interactions of the B and
Be nuclei in emulsion are taken as an example to show the manifestation
of the cluster degrees of freedom in relativistic fragmentation. For the case
of the relativistic Be nucleus dissociation it is shown that exact
angular measurements play a crucial role in the restoration of the excitation
spectrum of the alpha particle fragments. The energy calibration of the angular
measurements by the Be nucleus enables one to conclude reliably about the
features of internal velocity distributions in more complicated systems of
relativistic particles.Comment: 7 pages, 10 figures, conference: NATO ARW & INTAS Summer School,
Kurpaty, Yalta, Ukraine, September 10-17, 200
Unstable nuclei in dissociation of light stable and radioactive nuclei in nuclear track emulsion
A role of the unstable nuclei Be, Be and B in the
dissociation of relativistic nuclei Be, B and C
is under study on the basis of nuclear track emulsion exposed to secondary
beams of the JINR Nuclotron. Contribution of the configuration Be +
\mit{n} to the Be nucleus structure is 8 1% which is near the
value for the configuration Li + \mit{p}. Distributions over the
opening angle of -particle pairs indicate to a simultaneous presence of
virtual Be and Be states in the ground states
of the Be and C nuclei. The core B is manifested in
the {C} nucleus with a probability of 30 4%. Selection of the
C "white" stars accompanied by Be (B) leads
to appearance in the excitation energy distribution of 22\mit{p}
"quartets" of the distinct peak with a maximum at 4.1 0.3 MeV.
Be decays are presented in 24 7% of 2He + 2H events of
the C coherent dissociation and 27 11% of the 3He ones. The
channel B + H amounts 14 3%. The Be nucleus is
manifested in the coherent dissociation B 2He + H with a
probability of 25 5% including 14 3% of B decays. A
probability ratio of the mirror channels B + \mit{n} and Be +
\mit{p} is estimated to be 6 1.Comment: To be published in Physics of Particles in Nuclei (in press
Secondary nuclear fragment beams for investigations of relativistic fragmentation of light radioactive nuclei using nuclear photoemulsion at Nuclotron
Slowly extracted relativistic beams of light nuclei and a beam transportation
line net system constitute a good base for secondary nuclear beams forming at
the LHE accelerator facility. A recent years activity in the field at the
Laboratory is connected with a project on study light nuclei structure by means
the emulsion technique [1,2]. The paper shortly summarizes results of the work
Manifestation of Jet Quenching in the Total Transverse Energy Distributions in the Nucleus-Nucleus Collisions
In the framework of the HIJING model global characteristics of nucleus-
nucleus collisions are studied for a Large Hadron Collider energy scale. An
interesting model prediction is the presence of a central bump over a
pseudorapidity plateau of a total transverse energy distribution. The bump is
induced by a jet quenching effect in a dense nuclear matter. It is shown that
on a wide acceptance calorimeter with a pseudorapidity coverage
-5 < \eta < 5 allow to obtain experimental confirmation of such an effect.Comment: 9 pages, 5 figure
Global Features of Nucleus-Nucleus Collisions in the Ultrarelativistic Domain
HIJING generator simulation of nucleus-nucleus collisions at
ultrarelativistic energies are presented. Is shown, that the global
characteristics of nucleus-nucleus collisions, such as of distribution of a
charge multiplicity, total and electromagnetic transverse energy over
pseudorapidity are rather sensitive to some predictions of formation models of
high-exited nuclear medium, namely parton energy losses in dense nuclear
matter. This losses results to appearance of a broad maximum in global variable
distributions over pseudorapidity. The most profound of this effect occurs at
central heavy ion collisions at LHC energy.Comment: 7 pages, 5 figure
Rapidity distribution of jet quenching: effects on global observables
We discuss modification in the rapidity distribution of the transverse energy flow as a signal of medium-induced partonic energy loss in ultrarelativistic heavy ion collisions. A scan of the global energy flow and jet rates in the wide rapidity region might provide the important information about the pseudo-rapidity size of a dense medium created in heavy ion collisions at the LHC
The Hoyle state in relativistic dissociation of light nuclei
In the context of the search for triples of relativistic -particles
in the Hoyle state, the analysis of available data on the dissociation of the
nuclei C, O and Ne in the nuclear emulsion was
carried out. The Hoyle state is identified by the invariant mass calculated
from pair angles of expansion in -triples in the approximation of the
conservation of the momentum per nucleon of the parent nucleus. The
contribution of the Hoyle state to the dissociation of C
3 is 11\%. In the case of the coherent dissociation of O
4 it reaches 22\% when the portion of the channel O
2Be is equal to 5\%.Comment: Submitted to Physics of Atomic Nucle
Clustering features of the Be nucleus in relativistic fragmentation
Charge topology of fragmentation of 1.2 A GeV Be nuclei in nuclear track
emulsion is presented.The dissociation channels He + He, 2He+ n,
He + 2H are considered in detail. It is established that the events
Be + n amount about to 27 % in the channel He + 2H.Comment: 5 pages, 3 figures, conference: The 22nd European Conference on Few
Body Problems in Physics, Krak\'ow, Poland, 9 - 13 September 201
Estimation of Collision Impact Parameter
We demonstrate that the nuclear collision geometry (i.e. impact parameter) can be determined with 1.5 fm accuracy in an event-by-event analysis by measuring the transverse energy flow in the pseudorapidity region with a minimal dependence on collision dynamics details at the LHC energy scale. Using the HIJING model we have illustrated our calculation by a simulation of events of nucleus-nucleus interactions at the c.m.s energy from 1 up to 5.5 TeV per nucleon and various type of nuclei
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