Measurements of hadron production in p + C interactions at 31 GeV/
c
are performed using the NA61/SHINE spectrometer at the CERN SPS. The analysis is based on the full set of data collected in 2009 ...using a graphite target with a thickness of 4 % of a nuclear interaction length. Inelastic and production cross sections as well as spectra of
π
±
,
K
±
, p,
K
S
0
and
Λ
are measured with high precision. These measurements are essential for improved calculations of the initial neutrino fluxes in the T2K long-baseline neutrino oscillation experiment in Japan. A comparison of the NA61/SHINE measurements with predictions of several hadroproduction models is presented.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The production of
K
S
0
mesons in inelastic
p+p
collisions at beam momentum 158
GeV
/
c
(
s
NN
=
17.3
GeV
) was measured with the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. ...Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicity of
K
S
0
was determined to be
0.162
±
0.001
(
s
t
a
t
.
)
±
0.011
(
s
y
s
.
)
. The results on
K
S
0
production are compared with model predictions (
EPOS 1.99
, SMASH 2.0, PHSD and UrQMD 3.4 models) as well as with published world data.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of ...nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of
π
±
,
K
±
,
p
and
p
¯
produced in
40
Ar+
45
Sc
collisions at beam momenta of 13
A
, 19
A
, 30
A
, 40
A
, 75
A
and 150
A
Ge
V
/
c
. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the
K
±
/
π
±
ratios as well as of inverse slope parameters of the
K
±
transverse mass distributions are placed in between those found in inelastic
p
+
p
and central Pb + Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Interaction cross sections and charged pion spectra in p+C interactions at 31 GeV/c were measured with the large-acceptance NA61/SHINE spectrometer at the CERN SPS. These data are required to improve ...predictions of the neutrino flux for the T2K long-baseline neutrino oscillation experiment in Japan. A set of data collected during the first NA61/SHINE run in 2007 with an isotropic graphite target with a thickness of 4% of a nuclear interaction length was used for the analysis. The measured p+C inelastic and production cross sections are 257.2 {+-} 1.9 {+-} 8.9 and 229.3 {+-} 1.9 {+-} 9.0 mb, respectively. Inclusive production cross sections for negatively and positively charged pions are presented as functions of laboratory momentum in ten intervals of the laboratory polar angle covering the range from 0 up to 420 mrad. The spectra are compared with predictions of several hadron production models.
The properties of the strongly intensive variable characterizing correlations between the number of particles in two separated rapidity interval in pp interactions at LHC energies are studied in the ...framework of the string fusion model. We perform the MC simulations of string distributions in the impact parameter plane to take into account the experimental conditions of pp collisions. We account the string fusion processes, leading to the formation of string clusters, embedding a finite lattice (a grid) in the impact parameter plane. As a result, we found the dependence of this variable both on the distance between the centers of the observation windows and their width for the minbias pp collisions at several initial energies. Analyzing these dependencies we can extract the important information on the properties of string clusters. We show that in pp collisions at LHC energies the string fusion effects have a significant impact on the behavior of this strongly intensive variable. The role of these effects is increasing with the initial energy and centrality of collisions. In particular, we found that the increase of this variable with initial energy takes place due to the growth of the portion of the fused string clusters in string configurations arising in pp interactions.
The experiment of the NA61/SHINE Collaboration at the CERN SPS is performing a unique study of the phase diagram of strongly interacting matter by varying collision energy and nuclear mass number of ...colliding nuclei. In central Pb + Pb collisions, the experiment of the NA49 Collaboration found structures in the energy dependence of several observables in the energy range of the CERN SPS that had been predicted for the transition to a deconfined phase. New measurements of the NA61/SHINE Collaboration find intriguing similarities in $p + p$ interactions for which no deconfinement transition is expected at the energies of the SPS. Possible implications will be discussed.
This paper presents multiplicity measurements of charged hadrons produced in 120 GeV/$c$ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment ...during two different data-taking periods, with increased phase space coverage in the second configuration due to the addition of new subdetectors. Particle identification via $dE/dx$ was employed to obtain double-differential production multiplicities of $\pi^+$, $\pi^-$, $p$, $\bar{p}$, $K^+$ and $K^-$. These measurements are presented as a function of laboratory momentum in intervals of laboratory polar angle covering the range from 0 to 450 mrad. They provide crucial inputs for current and future long-baseline neutrino experiments, where they are used to estimate the initial neutrino flux.
The yields of
K
S
0
mesons have been measured in inelastic
p+p
interactions at incident projectile momenta of 31, 40 and 80
Ge
V
/
c
(
s
NN
=
7.7
,
8.8
and 12.3
Ge
V
, respectively). The data were ...recorded by the NA61
/
SHINE spectrometer at the CERN Super Proton Synchrotron and the
K
S
0
mesons identified via their decays into
π
+
π
-
pairs. Double-differential distributions are presented as function of transverse momentum and rapidity. The mean multiplicities of
K
S
0
mesons were determined to be
(
5.95
±
0.19
(
s
t
a
t
)
±
0.30
(
s
y
s
)
)
×
10
-
2
at 31
Ge
V
/
c
,
(
7.61
±
0.13
(
s
t
a
t
)
±
0.43
(
s
y
s
)
)
×
10
-
2
at 40
Ge
V
/
c
and
(
11.58
±
0.12
(
s
t
a
t
)
±
0.55
(
s
y
s
)
)
×
10
-
2
at 80
Ge
V
/
c
. The results on
K
S
0
production are compared with the production of charged kaons in corresponding reactions and with model calculations (
Epos1.99
, SMASH 2.0 and PHSD) as well as with published data from other experiments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central
40
Ar +
45
Sc collisions at 13
A
, 19
A
, 30
A
, 40
A
, and 75
A
GeV/
...c
. The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central $$^{40}$$ 40 Ar + $$^{45}$$ 45 Sc collisions at 13 A , 19 A , 30 ...A , 40 A , and 75 A GeV/ c . The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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