-
G. Agakishiev,
A. Balanda,
D. Belver,
A. Belyaev,
J. C. Berger-Chen,
A. Blanco,
M. Boehmer,
J. L. Boyard,
P. Cabanelas,
S. Chernenko, [......],
M. Traxler,
R. Trebacz,
H. Tsertos,
T. Vasiliev, V. Wagner,
M. Weber,
C. Wendisch,
J. Wuestenfeld,
S. Yurevich,
Y. Zanevsky
[show abstract]
[hide abstract]
ABSTRACT: Data on inclusive pion and eta production measured with the dielectron
spectrometer HADES in the reaction p+93Nb at a kinetic beam energy of 3.5 GeV
are presented. Our results, obtained with the photon conversion method,
supplement the rather sparse information on neutral meson production in
proton-nucleus reactions existing for this bombarding energy regime. The
reconstructed e+e-e+e- transverse-momentum and rapidity distributions are
confronted with transport model calculations which account fairly well for both
pi0 and eta production.
05/2013;
-
L. Fabbietti,
G. Agakishiev,
A. Balanda,
D. Belver,
A. V. Belyaev,
J-C Berger-Chen,
A. Blanco,
M. Böhmer,
J. L. Boyard,
P. Cabanelas, [......],
P. Tlusty,
M. Traxler,
R. Trebacz,
H. Tsertos, V. Wagner,
M. Weber,
C. Wendisch,
J. Wüstenfel,
S. Yurevich,
Y. V. Zanevsky
[show abstract]
[hide abstract]
ABSTRACT: The reaction p(@3.5\,GeV)+p -> p+\Lambda + K^+ can be studied to search for
the existence of kaonic bound states like ppK^- leading to this final state.
This effort has been motivated by the assumption that in p+p collisions the
\Lambda(1405) resonance can act as a doorway to the formation of the kaonic
bound states. The status of this analysis within the HADES collaboration, with
particular emphasis on the comparison to simulations, is shown in this work and
the deviation method utilized by the DISTO collaboration in a similar analysis
is discussed. The outcome suggests the employment of a partial wave analysis to
disentangle the different contributions to the measured pK^+\Lambda final
state.
05/2013;
-
B Abelev,
J Adam,
D Adamová,
A M Adare,
M M Aggarwal,
G Aglieri Rinella,
M Agnello,
A G Agocs,
A Agostinelli,
Z Ahammed, [......],
D Zhou,
X Zhu,
J Zhu,
H Zhu,
A Zichichi,
A Zimmermann,
G Zinovjev,
Y Zoccarato,
M Zynovyev,
M Zyzak
[show abstract]
[hide abstract]
ABSTRACT: The transverse momentum (p_{T}) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p+Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The p_{T} spectra measured near central rapidity in the range 0.5<p_{T}<20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor R_{pPb} is consistent with unity for p_{T} above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high p_{T} observed in Pb+Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations.
Physical Review Letters 02/2013; 110(8):082302. · 7.37 Impact Factor
-
B Abelev,
J Adam,
D Adamová,
A M Adare,
M M Aggarwal,
G Aglieri Rinella,
M Agnello,
A G Agocs,
A Agostinelli,
Z Ahammed, [......],
Y Zhou,
J Zhu,
H Zhu,
X Zhu,
A Zichichi,
A Zimmermann,
G Zinovjev,
Y Zoccarato,
M Zynovyev,
M Zyzak
[show abstract]
[hide abstract]
ABSTRACT: The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsingle-diffractive p+Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV is presented. The average value at midrapidity is measured to be 16.81±0.71 (syst), which corresponds to 2.14±0.17 (syst) per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsingle-diffractive pp collisions interpolated to the same collision energy and 84% higher than in d+Au collisions at sqrt[s_{NN}]=0.2 TeV. The measured pseudorapidity density in p+Pb collisions is compared to model predictions and provides new constraints on the description of particle production in high-energy nuclear collisions.
Physical Review Letters 01/2013; 110(3):032301. · 7.37 Impact Factor
-
B Abelev,
J Adam,
D Adamová,
A M Adare,
M M Aggarwal,
G Aglieri Rinella,
A G Agocs,
A Agostinelli,
S Aguilar Salazar,
Z Ahammed, [......],
D Zhou,
F Zhou,
J Zhu,
X Zhu,
A Zichichi,
A Zimmermann,
G Zinovjev,
Y Zoccarato,
M Zynovyev,
M Zyzak
[show abstract]
[hide abstract]
ABSTRACT: Measurements of charge-dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudorapidity range |η|<0.8 are presented as a function of the collision centrality, particle separation in pseudorapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge-dependent azimuthal correlations observed at RHIC and LHC energies.
Physical Review Letters 01/2013; 110(1):012301. · 7.37 Impact Factor
-
B Abelev,
J Adam,
D Adamová,
A M Adare,
M M Aggarwal,
G Aglieri Rinella,
A G Agocs,
A Agostinelli,
S Aguilar Salazar,
Z Ahammed, [......],
D Zhou,
F Zhou,
Y Zhou,
J Zhu,
X Zhu,
A Zichichi,
A Zimmermann,
G Zinovjev,
Y Zoccarato,
M Zynovyev
[show abstract]
[hide abstract]
ABSTRACT: The first measurement of neutron emission in electromagnetic dissociation of ^{208}Pb nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at sqrt[s_{NN}]=2.76 TeV with neutron emission are σ_{singleEMD}=187.4±0.2(stat)_{-11.2}^{+13.2}(syst) b and σ_{mutualEMD}=5.7±0.1(stat)±0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.
Physical Review Letters 12/2012; 109(25):252302. · 7.37 Impact Factor
-
B Abelev,
J Adam,
D Adamová,
A M Adare,
M M Aggarwal,
G Aglieri Rinella,
A G Agocs,
A Agostinelli,
S Aguilar Salazar,
Z Ahammed, [......],
Y Zhou,
F Zhou,
J Zhu,
X Zhu,
A Zichichi,
A Zimmermann,
G Zinovjev,
Y Zoccarato,
M Zynovyev,
M Zyzak
[show abstract]
[hide abstract]
ABSTRACT: In this Letter we report the first results on π^{±}, K^{±}, p, and p[over ¯] production at midrapidity (|y|<0.5) in central Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV, measured by the ALICE experiment at the LHC. The p_{T} distributions and yields are compared to previous results at sqrt[s_{NN}]=200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with sqrt[s_{NN}], which in hydrodynamic models is expected as a consequence of the increasing particle density. While the K/π ratio is in line with predictions from the thermal model, the p/π ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.
Physical Review Letters 12/2012; 109(25):252301. · 7.37 Impact Factor
-
G. Agakishiev,
A. Balanda,
D. Belver,
A. V. Belyaev,
J. C. Berger-Chen,
A. Blanco,
M. Böhmer,
J. L. Boyard,
P. Cabanelas,
S. Chernenko, [......],
M. Traxler,
R. Trebacz,
H. Tsertos,
T. Vasiliev, V. Wagner,
M. Weber,
C. Wendisch,
J. Wüstenfel,
S. Yurevich,
Y. V. Zanevsky
[show abstract]
[hide abstract]
ABSTRACT: We present an analysis of the Lambda(1405) resonance produced in the reaction
p+p->Sigma^{pm}+pi^{mp}+K+p at 3.5 GeV kinetic beam energy measured with HADES
at GSI. The two charged decay channels Lambda(1405) -> Sigma^{\pm}+pi^{\mp}
have been reconstructed for the first time in p+p collisions. The efficiency
and acceptance-corrected spectral shapes show a peak position clearly below
1400 MeV/c^2. We find a total production cross section of
sigma_{Lambda(1405)}=9.2 +- 0.9 +- 0.7 +3.3-1.0 mub. The analysis of its polar
angle distribution suggests that the Lambda(1405) is produced isotropically in
the p-p center of mass system.
08/2012;
-
ALICE Collaboration,
B. Abelev,
J. Adam,
D. Adamová,
A. M. Adare,
M. M. Aggarwal,
G. Aglieri Rinella,
A. G. Agocs,
A. Agostinelli,
S. Aguilar Salazar, [......],
X. Zhang,
Y. Zhou,
D. Zhou,
F. Zhou,
X. Zhu,
A. Zichichi,
A. Zimmermann,
G. Zinovjev,
Y. Zoccarato,
M. Zynovyev
[show abstract]
[hide abstract]
ABSTRACT: The ALICE Collaboration reports the measurement of the relative J/ψ
yield as a function of charged particle pseudorapidity density
dNch/dη in pp collisions at s=7 TeV at the LHC.
J/ψ particles are detected for pt>0, in the rapidity
interval |y|<0.9 via decay into e+e-, and
in the interval 2.5<y<4.0 via decay into
μ+μ- pairs. An approximately linear
increase of the J/ψ yields normalized to their event average
(dN/dy)/<dN/dy> with
(dNch/dη)/<dNch/dη> is observed in
both rapidity ranges, where dNch/dη is measured within
|η|<1 and pt>0. In the highest multiplicity
interval with <dNch/dη(bin)>=24.1, corresponding to
four times the minimum bias multiplicity density, an enhancement
relative to the minimum bias J/ψ yield by a factor of about 5 at
2.5<y<4 (8 at |y|<0.9) is observed.
Physics Letters B 05/2012; 712:165-175. · 3.95 Impact Factor
-
G. Agakishiev,
A. Balanda,
D. Belver,
A. Belyaev,
J. C. Berger-Chen,
A. Blanco,
M. Böhmer,
J. L. Boyard,
P. Cabanelas,
S. Chernenko, [......],
M. Traxler,
R. Trebacz,
H. Tsertos,
T. Vasiliev, V. Wagner,
M. Weber,
C. Wendisch,
J. Wüstenfeld,
S. Yurevich,
Y. Zanevsky
[show abstract]
[hide abstract]
ABSTRACT: We present data on dielectron emission in proton induced reactions on a Nb
target at 3.5 GeV kinetic beam energy measured with HADES installed at GSI. The
data represent the first high statistics measurement of proton-induced
dielectron radiation from cold nuclear matter in a kinematic regime, where
strong medium effects are expected. Combined with the good mass resolution of
2%, it is the first measurement sensitive to changes of the spectral functions
of vector mesons, as predicted by models for hadrons at rest or small relative
momenta. Comparing the e+e invariant mass spectra to elementary p+p data, we
observe for e+e momenta Pee < 0.8 GeV/c a strong modification of the shape of
the spectrum, which we attribute to an additional rho-like contribution and a
decrease of omega yield. These opposite trends are tentatively interpreted as a
strong coupling of the rho meson to baryonic resonances and an absorption of
the omega meson, which are two aspects of in-medium modification of vector
mesons.
05/2012;
-
The HADES Collaboration,
G. Agakishiev,
A. Balanda,
B. Bannier,
R. Bassini,
D. Belver,
A. V. Belyaev,
A. Blanco,
M. Böhmer,
J. L. Boyard, [......], V. Wagner,
M. Weber,
C. Wendisch,
M. Wisniowski,
T. Wojcik,
J. Wüstenfeld,
S. Yurevich,
Y. V. Zanevsky,
P. Zhou,
P. Zumbruch
[show abstract]
[hide abstract]
ABSTRACT: Results on pp, π+π+, and π−π− intensity interferometry are reported for collisions of Ar+KCl at 1.76A GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation
functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time
extent of the corresponding emission sources. The ππ source radii are found significantly larger than the pp emission radius.
The present radii do well complement the beam-energy dependences of Gaussian source radii of the collision system of size
A + A ≃ 40 + 40 . The pp source radius at fixed beam energy is found to increase linearly with the cube root of the number of participants.
From this trend, a lower limit of the pp correlation radius is deduced.
European Physical Journal A 04/2012; 47(5):1-8. · 2.19 Impact Factor
-
The HADES Collaboration,
S. Spataro,
G. Agakishiev,
C. Agodi,
A. Balanda,
G. Bellia,
D. Belver,
A. Belyaev,
A. Blanco,
M. Böhmer, [......],
I. Veretenkin, V. Wagner,
H. Wen,
M. Wisniowski,
T. Wojcik,
J. Wüstenfeld,
S. Yurevich,
Y. Zanevsky,
P. Zhou,
P. Zumbruch
[show abstract]
[hide abstract]
ABSTRACT: The HADES spectrometer at GSI (Darmstadt) is investigating the e
+
e
- pair production in p+p, p+A and A+A collisions. In this contribution we would like to highlight the physics motivations and the experiments performed so far,
focusing mainly on the first results coming from 12C + 12C collisions at 1 and 2AGeV, and on preliminary results from p+p/d+p collisions at 1.25AGeV.
European Physical Journal A 04/2012; 38(2):163-166. · 2.19 Impact Factor
-
The ALICE Collaboration,
K. Aamodt,
N. Abel,
U. Abeysekara,
A. Abrahantes Quintana,
A. Acero,
D. Adamová,
M. M. Aggarwal,
G. Aglieri Rinella,
A. G. Agocs, [......],
X. Zhang,
D. Zhou,
S. Zhou,
J. Zhu,
A. Zichichi,
A. Zinchenko,
G. Zinovjev,
M. Zinovjev,
Y. Zoccarato,
V. Zycháček
[show abstract]
[hide abstract]
ABSTRACT: On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton
bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450GeV per beam. Although
the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the
collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region
was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with
the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used
these events to measure the pseudorapidity density of charged primary particles in the central region. In the range |η|<0.5, we obtain dN
ch/dη=3.10±0.13(stat.)±0.22(syst.) for all inelastic interactions, and dN
ch/dη=3.51±0.15(stat.)±0.25(syst.) for non-single diffractive interactions. These results are consistent with previous measurements
in proton–antiproton interactions at the same centre-of-mass energy at the CERN Sp
[`(p)]\overline{\mathrm{p}}
S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware
and software of the ALICE experiment, in this early start-up phase.
European Physical Journal C 04/2012; 65(1):111-125. · 3.63 Impact Factor
-
The ALICE Collaboration,
K. Aamodt,
N. Abel,
U. Abeysekara,
A. Abrahantes Quintana,
A. Abramyan,
D. Adamová,
M. M. Aggarwal,
G. Aglieri Rinella,
A. G. Agocs, [......],
X. Zhang,
D. Zhou,
S. Zhou,
J. Zhu,
A. Zichichi,
A. Zinchenko,
G. Zinovjev,
Y. Zoccarato,
V. Zycháček,
M. Zynovyev
[show abstract]
[hide abstract]
ABSTRACT: The production of π
+, π
−, K+, K−, p, and [`(p)]\overline{\mathrm{p}} at mid-rapidity has been measured in proton-proton collisions at Ös = 900GeV\sqrt{s} = 900~\mathrm{GeV} with the ALICE detector. Particle identification is performed using the specific energy loss in the inner tracking silicon
detector and the time projection chamber. In addition, time-of-flight information is used to identify hadrons at higher momenta.
Finally, the distinctive kink topology of the weak decay of charged kaons is used for an alternative measurement of the kaon
transverse momentum (p
t) spectra. Since these various particle identification tools give the best separation capabilities over different momentum
ranges, the results are combined to extract spectra from p
t=100MeV/c to 2.5 GeV/c. The measured spectra are further compared with QCD-inspired models which yield a poor description. The total yields and
the mean p
t are compared with previous measurements, and the trends as a function of collision energy are discussed.
European Physical Journal C 04/2012; 71(6):1-22. · 3.63 Impact Factor
-
M. Sudol,
G. Agakishiev,
C. Agodi,
A. Balanda,
G. Bellia,
D. Belver,
A. Belyaev,
J. Bielcik,
A. Blanco,
A. Bortolotti, [......],
H. Tsertos, V. Wagner,
M. Weber,
M. Wisniowski,
T. Wojcik,
J. Wüstenfeld,
S. Yurevich,
Y. Zanevsky,
P. Zhou,
P. Zumbruch
[show abstract]
[hide abstract]
ABSTRACT: HADES is a secondary generation experiment operated at GSI Darmstadt with the main goal to study dielectron production in
proton, pion and heavy ion induced reactions. The first part of the HADES mission is to reinvestigate the puzzling pair excess
measured by the DLS collaboration in C + C and Ca + Ca collisions at 1 AGeV. For this purpose dedicated measurements with the C + C system at 1 and 2 AGeV were performed. The pair excess above a cocktail of free hadronic decays has been extracted and compared to the one measured
by DLS. Furthermore, the excess is confronted with predictions of various model calculations.
European Physical Journal C 04/2012; 62(1):81-84. · 3.63 Impact Factor
-
V. Wagner,
A. Krása,
M. Majerle,
F. Křížek,
O. Svoboda,
A. Kugler,
J. Adam,
V. M. Tsoupko-Sitnikov,
M. I. Krivopustov,
I. V. Zhuk,
W. Westmeier
[show abstract]
[hide abstract]
ABSTRACT: The set-up ‘energy plus transmutation’, consisting of a thick lead target and a natural uranium blanket, was irradiated by
relativistic proton beams with the energy from 0.7 GeV up to 2 GeV. Neutron field was measured in different places of this
set-up using different activation detectors. The possibilities of using the obtained data for benchmark studies are analyzed
in this paper. Uncertainties of experimental data are shown and discussed. The experimental data are compared with results
of simulation with MCNPX code.
Pramana 04/2012; 68(2):297-306. · 0.57 Impact Factor
-
K. Aamodt,
A. Abrahantes Quintana,
D. Adamová,
A. M. Adare,
M. M. Aggarwal,
G. Aglieri Rinella,
A. G. Agocs,
S. Aguilar Salazar,
Z. Ahammed,
N. Ahmad, [......],
P. Zelnicek,
A. Zenin,
I. Zgura,
M. Zhalov,
X. Zhang,
D. Zhou,
A. Zichichi,
G. Zinovjev,
Y. Zoccarato,
M. Zynovyev
[show abstract]
[hide abstract]
ABSTRACT: The production of mesons containing strange quarks ($\mbox {$\mbox {, φ) and both singly and doubly strange baryons ($\mbox {$\mbox {, $\mbox {$\mbox {, and $\mbox {$\mbox {) are measured at mid-rapidity in pp collisions at
_boxclose_boxclose_boxclose\sqrt{s}=0.9TeV{\rm TeV} with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250k minimum bias events recorded
in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at mid-rapidity for inelastic pp collisions are presented. For mesons, we report yields
(〈dN/dy〉) of 0.184±0.002(stat.)±0.006(syst.) for $\mbox {$\mbox { and 0.021±0.004(stat.)±0.003(syst.) forφ. For baryons, we find 〈dN/dy〉=0.048±0.001(stat.)±0.004(syst.) for $\mbox {$\mbox {, 0.047±0.002(stat.)±0.005(syst.) for $\mbox {$\mbox { and 0.0101±0.0020(stat.)±0.0009(syst.) for $\mbox {$\mbox {. The results are also compared with predictions for identified particle spectra from QCD-inspired models and provide a baseline
for comparisons with both future pp measurements at higher energies and heavy-ion collisions.
European Physical Journal C 04/2012; 71(3):1-24. · 3.63 Impact Factor
-
The HADES Collaboration,
G. Agakishiev,
A. Balanda,
B. Bannier,
R. Bassini,
D. Belver,
A. Belyaev,
A. Blanco,
M. Böhmer,
J. L. Boyard, [......], V. Wagner,
M. Weber,
C. Wendisch,
M. Wisniowski,
T. Wojcik,
J. Wüstenfeld,
S. Yurevich,
Y. Zanevsky,
P. Zhou,
P. Zumbruch
[show abstract]
[hide abstract]
ABSTRACT: We present transverse momentum spectra, rapidity distribution and multiplicity of L \Lambda -hyperons measured with the HADES spectrometer in the reaction Ar(1.76AGeV) + KCl . The yield of X- \Xi^{{-}}_{} is calculated from our previously reported X- \Xi^{{-}}_{}/(L \Lambda + S0 \Sigma^{{0}}_{}) ratio and compared to other strange particle multiplicities. Employing a strangeness balance equation the multiplicities
of the yet unmeasured S± \Sigma^{{\pm}}_{} -hyperons can be estimated. Finally a statistical hadronization model is used to fit the yields of p- \pi^{-}_{} , K+, K
0
s , K-, f \phi , L \Lambda and X- \Xi^{-}_{} . The resulting chemical freeze-out temperature of T = (76±2) MeV is compared to the measured slope parameters obtained from fits to the transverse mass distributions of the
different particles.
European Physical Journal A 04/2012; 47(2):1-9. · 2.19 Impact Factor
-
The ALICE Collaboration,
K. Aamodt,
N. Abel,
U. Abeysekara,
A. Abrahantes Quintana,
A. Abramyan,
D. Adamová,
M. M. Aggarwal,
G. Aglieri Rinella,
A. G. Agocs, [......],
X. Zhang,
D. Zhou,
S. Zhou,
J. Zhu,
A. Zichichi,
A. Zinchenko,
G. Zinovjev,
Y. Zoccarato,
V. Zycháček,
M. Zynovyev
[show abstract]
[hide abstract]
ABSTRACT: Charged-particle production was studied in proton–proton collisions collected at the LHC with the ALICE detector at centre-of-mass
energies 0.9TeV and 2.36TeV in the pseudorapidity range |η|<1.4. In the central region (|η|<0.5), at 0.9TeV, we measure charged-particle pseudorapidity density dNch/dh = 3.02±0.01(stat.)+0.08-0.05(syst.)\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=3.02\pm 0.01(\mathit{stat.})^{+0.08}_{-0.05}(\mathit{syst.}) for inelastic interactions, and dNch/dh = 3.58±0.01(stat.)+0.12-0.12(syst.)\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=3.58\pm0.01(\mathit{stat.})^{+0.12}_{-0.12}(\mathit{syst.}) for non-single-diffractive interactions. At 2.36TeV, we find dNch/dh = 3.77±0.01(stat.)+0.25-0.12(syst.)\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=3.77\pm0.01(\mathit{stat.})^{+0.25}_{-0.12}(\mathit{syst.}) for inelastic, and dNch/dh = 4.43±0.01(stat.)+0.17-0.12(syst.)\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=4.43\pm0.01(\mathit{stat.})^{+0.17}_{-0.12}(\mathit{syst.}) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy
is 24.7%±0.5%(stat.)+5.7-2.8%(syst.)24.7\%\pm0.5\%(\mathit{stat.})^{+5.7}_{-2.8}\%(\mathit{syst.}) for inelastic and 23.7%±0.5%(stat.)+4.6-1.1%(syst.)23.7\%\pm0.5\%(\mathit{stat.})^{+4.6}_{-1.1}\%(\mathit{syst.}) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive
events and larger than that found by a number of commonly used models. The multiplicity distribution was measured in different
pseudorapidity intervals and studied in terms of KNO variables at both energies. The results are compared to proton–antiproton
data and to model predictions.
European Physical Journal C 04/2012; 68(1):89-108. · 3.63 Impact Factor
-
The HADES Collaboration,
G. Agakichiev,
C. Agodi,
H. Alvarez-Pol,
E. Atkin,
E. Badura,
A. Balanda,
A. Bassi,
R. Bassini,
G. Bellia, [......],
M. Wisniowski,
T. Wojcik,
J. Wüstenfeld,
S. Yurevich,
Y. V. Zanevsky,
K. Zeitelhack,
A. Zentek,
P. Zhou,
D. Zovinec,
P. Zumbruch
[show abstract]
[hide abstract]
ABSTRACT: HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion-induced collisions.
Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting
of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger
array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events
containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and
dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from
18° to 85° , a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons
is achieved combining time-of-flight and energy loss measurements over a large momentum range ( 0.1 < p < 1.0 GeV/c . This paper describes the main features and the performance of the detector system.
European Physical Journal A 04/2012; 41(2):243-277. · 2.19 Impact Factor
