-
K.-H. Ackermann,
M. Agostini,
M. Allardt,
M. Altmann,
E. Andreotti,
A. M. Bakalyarov,
M. Balata,
I. Barabanov,
M. Barnabé Heider,
N. Barros, [......],
M. Walter,
A. Wegmann,
M. Wojcik,
E. Yanovich,
P. Zavarise,
I. Zhitnikov,
S. V. Zhukov,
D. Zinatulina,
K. Zuber,
G. Zuzel
[show abstract]
[hide abstract]
ABSTRACT: The Gerda collaboration is performing a search for neutrinoless double beta decay of 76Ge with the eponymous detector. The experiment has been installed and commissioned at the Laboratori Nazionali del Gran Sasso and has started operation in November 2011. The design, construction and first operational results are described, along with detailed information from the R&D phase.
European Physical Journal C 03/2013; 73(3). · 3.63 Impact Factor
-
GERDA Collaboration,
K. -H. Ackermann,
M. Agostini,
M. Allardt,
M. Altmann,
E. Andreotti,
A. M. Bakalyarov,
M. Balata,
I. Barabanov,
M. Barnabe Heider, [......],
M. Walter,
A. Wegmann,
M. Wojcik,
E. Yanovich,
P. Zavarise,
I. Zhitnikov,
S. V. Zhukov,
D. Zinatulina,
K. Zuber,
G. Zuzel
[show abstract]
[hide abstract]
ABSTRACT: The GERDA collaboration is performing a search for neutrinoless double beta
decay of ^{76}Ge with the eponymous detector. The experiment has been installed
and commissioned at the Laboratori Nazionali del Gran Sasso and has started
operation in November 2011. The design, construction and first operational
results are described, along with detailed information from the R&D phase.
12/2012;
-
GERDA Collaboration,
M. Agostini,
M. Allardt,
E. Andreotti,
A. M. Bakalyarov,
M. Balata,
I. Barabanov,
M. Barnabe Heider,
N. Barros,
L. Baudis, [......],
M. Walter,
A. Wegmann,
M. Wojcik,
E. Yanovich,
P. Zavarise,
I. Zhitnikov,
S. V. Zhukov,
D. Zinatulina,
K. Zuber,
G. Zuzel
[show abstract]
[hide abstract]
ABSTRACT: The primary goal of the GERmanium Detector Array (Gerda) experiment at the
Laboratori Nazionali del Gran Sasso of INFN is the search for the neutrinoless
double beta decay of Ge-76. High-purity germanium detectors made from material
enriched in Ge-76 are operated directly immersed in liquid argon, allowing for
a substantial reduction of the background with respect to predecessor
experiments. The first 5.04 kg yr of data collected in Phase I of the
experiment have been analyzed to measure the half-life of the
neutrino-accompanied double beta decay of Ge-76. The observed spectrum in the
energy range between 600 and 1800 keV is dominated by the double beta decay of
Ge-76. The half-life extracted from Gerda data is T(1/2) = (1.84 +0.14 -0.10)
10^{21} yr.
12/2012;
-
[show abstract]
[hide abstract]
ABSTRACT: An experiment on studying the 28Si(p, p′ γ
0
X)24Mg semicoherent reaction is carried out at the MAG setup on the 1-GeV proton beam of the U-10 ITEP accelerator. Two particles,
proton and γ-ray photon, which accompanies the transition of the 24Mg* nucleus from the first excited state to the ground state, are detected. When the events with the proton emission angle
from 3° to 6.5° are selected, the following four processes are observed: the direct knockout of a nuclear α cluster by a proton, the formation of a ΔSi isobaric nucleus, the formation of a Δ1232 isobar, and the production of a π
0 meson at rest in the nuclear coordinate system. The cross sections for the indicated processes are obtained.
Physics of Atomic Nuclei 06/2007; 70(7):1160-1169. · 0.57 Impact Factor
-
S Schoenert,
I Abt,
M Altmann,
A M Bakalyarov,
I Barabanov,
C Bauer,
M Bauer,
E Bellotti,
S Belogurov,
S T Belyaev, [......],
A A Vasenko,
S Vasiliev,
D Weisshaar,
M Wojcik,
E Yanovich,
J Yurkowski,
S V Zhukov,
F Zocca,
G Zuzel,
GERDA Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The Germanium Detector Array (GERDA) in the search for neutrinoless beta beta decays of Ge-76 at LNGS will operate bare germanium diodes enriched in Ge-76 in an (optional active) cryogenic (76) shield to investigate neutrinoless beta beta decay with a sensitivity of T-1/ 2 > 2 x 10(26) yr after an exposure of 100 kg yr. Recent progress includes the installation of the underground infrastructures at Gran Sasso, the completion of the enrichment of 37.5 kg of germanium material for detector construction, prototyping of low-mass detector support and contacts, and front-end and DAQ electronics, as well as the preparation for construction of the cryogenic vessel and water tank.
Physics of Atomic Nuclei 12/2006; 69(12):2101-2108. · 0.57 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The 28Si(p, p' gamma)24Mg reaction has been studied at the ITEP accelerator by the hadron-gamma coincidence method for a proton energy of 1 GeV. Two reaction products are detected: a 1368.6-keV gamma-ray photon accompanying the transition of the 24Mg* nucleus from the first excited state to the ground state and a proton p' whose momentum is measured in a magnetic spectrometer. The measured distribution in the energy lost by the proton in interaction is attributed to five processes: the direct knockout of a nuclear alpha cluster, the knockout of four nucleons with a total charge number of 2, the formation of the DeltaSi isobaric nucleus, the formation of the Delta isobar in the interaction of the incident proton with a nuclear nucleon, and the production of a pi meson, which is at rest in the nuclear reference frame. The last process likely corresponds to the reaction of the formation of a deeply bound pion state in the 28P nucleus. Such states were previously observed only on heavy nuclei. The cross sections for the listed processes have been estimated.
10/2006;
-
[show abstract]
[hide abstract]
ABSTRACT: The 28Si(p, p′γ0
X)24Mg reaction has been studied at the ITEP accelerator by the hadron-gamma coincidence method for a proton energy of 1 GeV.
Two reaction products are detected: a 1368.6-keV γ-ray photon accompanying the transition of the 24Mg* nucleus from the first excited state to the ground state and a proton p′ whose momentum is measured in a magnetic spectrometer. The measured distribution in the energy lost by the proton in interaction
is attributed to five processes: the direct knockout of a nuclear α cluster, the knockout of four nucleons with a total charge
number of 2, the formation of the ΔSi isobaric nucleus, the formation of the Δ isobar in the interaction of the incident proton with a nuclear nucleon, and the
production of a π meson, which is at rest in the nuclear reference frame. The last process likely corresponds to the reaction
of the formation of a deeply bound pion state in the 28P nucleus. Such states were previously observed only on heavy nuclei. The cross sections for the listed processes have been
estimated.
JETP Letters 01/2006; 83(10):433-438. · 1.35 Impact Factor
-
GERDA Collaboration,
I. Abt,
M. Altmann,
A. M. Bakalyarov,
I. Barabanov,
C. Bauer,
M. Bauer,
E. Bellotti,
S. Belogurov,
S. T. Belyaev, [......],
C. Tomei,
C. A. Ur,
A. A. Vasenko,
S. Vasiliev,
D. Weißhaar,
M. Wojcik,
E. Yanovich,
J. Yurkowski,
S. V. Zhukov,
G. Zuzel
[show abstract]
[hide abstract]
ABSTRACT: This paper describes the proposed GERDA experiment, the GERMANIUM
DETECTOR ARRAY for the search of neutrinoless ββ decays of
76Ge at LNGS. The goal of the GERDA project is to operate
bare germanium diodes enriched in 76Ge in an (optional
active) cryogenic fluid shield with a sensitivity for neutrinoless
ββ decay of T1/2>2ṡ1026 years
after an exposure of 100 kg ṡ years.
Nuclear Physics B - Proceedings Supplements 07/2005; 145:242-245. · 0.88 Impact Factor
-
C. E. Aalseth,
III F. T. Avignone,
R. L. Brodzinski,
S. Cebrian,
E. Garcia,
D. Gonzales,
W. K. Hensley,
I. G. Irastorza, I. V. Kirpichnikov,
A. A. Klimenko, [......],
V. S. Pogosov,
J. Puimedon,
J. H. Reeves,
M. L. Sarsa,
A. A. Smolnikov,
A. S. Starostin,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: This paper is a response to the preceding Comment by Klapdor-Kleingrothaus, Dietz, and Krivosheina. The criticisms are confronted, and the questions raised are answered. We demonstrate that the lower limit quoted by IGEX, T1/20ν(76Ge)≥1.57×1025 yr, is correct and that there was no “arithmetical error” as claimed in the “Critical View” article.
Phys. Rev. D. 10/2004; 70(7).
-
I Abt,
M. Altmann,
A. Bakalyarov,
I. Barabanov,
C Bauer,
E Bellotti,
S T Belyaev,
L. Bezrukov,
V. Brudanin,
C. Buettner, [......],
H. Simgen,
A. Smolnikov,
A. Tikhomirov,
A. A. Vasenko,
S. Vasiliev,
D. Weisshaar,
E. Yanovich,
J. Yurkowski,
S. Zhukov,
G. Zuzel
[show abstract]
[hide abstract]
ABSTRACT: This Letter of Intent has been submitted to the Scientific Committee of the INFN Laboratori Nazionali del Gran Sasso (LNGS) in March 2004. It describes a novel facility at the LNGS to study the double beta decay of 76Ge using an (optionally active) cryogenic fluid shield. The setup will allow to scrutinize with high significance on a short time scale the current evidence for neutrinoless double beta decay of 76Ge using the existing 76Ge diodes from the previous Heidelberg-Moscow and IGEX experiments. An increase in the lifetime limit can be achieved by adding more enriched detectors, remaining thereby background-free up to a few 100 kg-years of exposure.
05/2004;
-
A. A. Vasenko,
N. D. Galanina,
K. E. Gusev,
V. S. Demidov,
E. V. Demidova, I. V. Kirpichnikov,
V. A. Kuznetsov,
B. N. Pavlov,
A. Yu. Sokolov,
A. S. Starostin,
N. A. Khaldeeva
[show abstract]
[hide abstract]
ABSTRACT: The cross sections for the production of excited nuclei were measured in the reaction 28Si(p, xpyn)A* followed by a gamma transition to a state of lower excitation energy or to the ground state. The experiment was performed
in an extracted proton beam from the accelerator of the Institute of Theoretical and Experimental Physics (ITEP, Moscow).
The reaction in question was identified by a Ge(Li)-NaI(Tl) anticoincidence spectrometer that recorded prompt gamma radiation
emitted by the excited final nucleus. The sensitivity of the experiment was 1.5 mb. The cross-section values were obtained
for 24 gamma transitions in 17 nuclear products. The cross sections for spallation reactions were estimated. A comparison
was performed with known experimental data and with the results of calculations by a semiempirical formula, as well as with
the results obtained by simulating hadron interactions on the basis of the GEANT and INUCL codes.
Physics of Atomic Nuclei 01/2004; 67(8):1505-1512. · 0.57 Impact Factor
-
D. Gonzalez,
J Morales,
S. Cebrian,
E. Garcia,
I. G. Irastorza,
A Morales,
A. Ortiz de Solorzano,
J. Puimedon,
M. L. Sarsa,
J. A. Villar, [......],
H. S. Miley,
J. H. Reeves, I. V. Kirpichnikov,
A. A. Klimenko,
S. B. Osetrov,
A. A. Smolnikov,
A. A. Vasenko,
S. I. Vasiliev,
V. S. Pogosov,
A. G. Tamanyan
[show abstract]
[hide abstract]
ABSTRACT: The IGEX experiment has been operating enriched germanium detectors in the Canfranc Underground Laboratory (Spain) in a search for the neutrinoless double decay of 76Ge. The implementation of Pulse Shape Discrimination techniques to reduce the radioactive background is described in detail. This analysis has been applied to a fraction of the IGEX data, leading to a rejection of ~60 % of their background, in the region of interest (from 2 to 2.5 MeV), down to ~0.09 c/(keV kg y).
03/2003;
-
I. G. Irastorza,
A Morales,
C. E. Aalseth,
F. T. Avignone III,
R. L. Brodzinski,
J. M. Carmona,
S. Cebrian,
E. Garcia, I. V. Kirpichnikov,
A. A. Klimenko, [......],
S. B. Osetrov,
V. S. Pogosov,
J. Puimedon,
J. H. Reeves,
M. L. Sarsa,
A. A. Smolnikov,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory in a search for dark matter WIMPs, through the Ge nuclear recoil produced by the WIMP elastic scattering. In this talk we report on the on-going efforts to understand and eventually reject the background at low energy. These efforts have led to the improvement of the neutron shielding and to partial reduction of the background, but still the remaining events are not totally identified. A tritium contamination or muon-induced neutrons are considered as possible sources, simulations and experimental test being still under progress. According to the success of this study we comment the prospects of the experiment as well as those of its future extension, the GEDEON dark matter experiment.
12/2002;
-
C. E. Aalseth,
F. T. Avignone III,
R. L. Brodzinski,
S. Cebrian,
E. Garcia,
D. Gonzalez,
W. K. Hensley,
I. G. Irastorza, I. V. Kirpichnikov,
A. A. Klimenko, [......],
V. S. Pogosov,
J. Puimedon,
J. H. Reeves,
M. L. Sarsa,
A. A. Smolnikov,
A. S. Starostin,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: The International Germanium Experiment (IGEX) has analyzed 117 mole yr of 76Ge data from its isotopically enriched (86% 76Ge) germanium detectors. Applying pulse-shape discrimination (PSD) to the more recent data, the lower bound on the half-life for neutrinoless double-beta decay of 76Ge is: $T_{1/2}(0\nu)> 1.57 \times 10^{25}$ yr (90% C.L.). This corresponds to an upper bound in the Majorana neutrino mass parameter,$<m_{\nu}>$, between 0.33 eV and 1.35 eV, depending on the choice of theoretical nuclear matrix elements used in the analysis.
03/2002;
-
M. P. Bezuglov,
E. T. Bogdanov,
E. V. Bystritskaya,
A. A. Vasenko,
M. E. Vishnevskii,
M. O. Vlasova,
N. D. Galanina,
K. E. Gusev,
V. S. Demidov,
E. V. Demidova,
V. V. Zhurkin, I. V. Kirpichnikov,
V. A. Kuznetsov,
V. N. Markizov,
B. N. Pavlov,
V. A. Sadykov,
A. Yu. Sokolov,
A. S. Starostin,
N. A. Khaldeeva,
Yu. P. Shkurenko
[show abstract]
[hide abstract]
ABSTRACT: A combined spectrometer is composed of a wide-aperture magnetic spectrometer with proportional chambers and a -spectrometer based on a Ge(Li) detector. The respective momentum and the angular resolutions of the magnetic spectrometer are FWHM/p(%) = 0.59p (GeV/c) + 1.1 and 0.5–1 mrad; its average efficiency for 0–5 angles is 85%. The energy resolution of the -spectrometer is 8 and 16 keV for 0.5- and 2.0-MeV photons, respectively; the average angular acceptance is 1.5 msr.
Instruments and Experimental Techniques 12/2001; 45(1):9-19. · 0.36 Impact Factor
-
I. G. Irastorza,
A Morales,
C. E. Aalseth,
F. T. Avignone III,
R. L. Brodzinski,
S. Cebrian,
E. Garcia, I. V. Kirpichnikov,
A. A. Klimenko,
H. S. Miley, [......],
S. B. Osetrov,
V. S. Pogosov,
J. Puimedon,
J. H. Reeves,
M. L. Sarsa,
A. A. Smolnikov,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory in a search for dark matter WIMPs, through the Ge nuclear recoil produced by the WIMP elastic scattering. A new exclusion plot has been derived for WIMP-nucleon spin-independent interactions. To obtain this result, 40 days of data from the IGEX detector (energy threshold 4 keV), recently collected, have been analyzed. These data improve the exclusion limits derived from all the other ionization germanium detectors in the mass region from 20 GeV to 200 GeV, where a WIMP supposedly responsible for the annual modulation effect reported by the DAMA experiment would be located. The new IGEX exclusion contour enters, by the first time, the DAMA region by using only raw data, with no background discrimination, and excludes its upper left part. It is also shown that with a moderate improvement of the detector performances, the DAMA region could be fully explored.
12/2001;
-
A Morales,
C. E. Aalseth,
F. T. Avignone III,
R. L. Brodzinski,
S. Cebrian,
E. Garcia,
I. G. Irastorza, I. V. Kirpichnikov,
A. A. Klimenko,
H. S. Miley, [......],
S. B. Osetrov,
V. S. Pogosov,
J. Puimedon,
J. H. Reeves,
M. L. Sarsa,
A. A. Smolnikov,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory in a search for dark matter WIMPs, through the Ge nuclear recoil produced by the WIMP elastic scattering. A new exclusion plot, has been derived for WIMP-nucleon spin-independent interactions. To obtain this result, 40 days of data from the IGEX detector (energy threshold E \~ 4 keV), recently collected, have been analyzed. These data improve the exclusion limits derived from all the other ionization germanium detectors in the mass region from 20 GeV to 200 GeV, where a WIMP supposedly responsible for the annual modulation effect reported by the DAMA experiment would be located. The new IGEX exclusion contour enters, by the first time, the DAMA region by using only raw data, with no background discrimination, and excludes its upper left part. It is also shown that with a moderate improvement of the detector performances, the DAMA region could be fully explored.
11/2001;
-
M. P. Besuglov,
B. M. Bobchenko,
E. V. Byistritskaya,
A. A. Vasenko,
M. E. Vishnevsky,
N. D. Galanina,
K. E. Gusev,
V. S. Demidov,
E. V. Demidova,
V. V. Zchurkin, I. V. Kirpichnikov,
V. A. Kuznetsov,
V. N. Markizov,
M. A. Martemianov,
A. A. Nedosekin,
B. N. Pavlov,
V. A. Sadyukov,
A. Yu. Sokolov,
A. S. Starostin,
N. A. Khaldeeva
[show abstract]
[hide abstract]
ABSTRACT: The total, elastic and inelastic cross-sections for quasi-coherent interactions of protons with Si28 have been measured using hadron-gamma coincidence method at the energy 1 GeV. The limits for the existence of long-lived excited states of the Si28 nucleus have been obtained in the range of energies from 0 to 0.8 GeV.
10/2000;
-
C. E. Aalseth,
F. T. Avignone,
R. L. Brodzinski,
S. Cebrian,
D. Gonzáles,
E. García,
W. K. Hensley,
I. G. Irastorza, I. V. Kirpichnikov,
A. A. Klimenko, [......],
J. Puimedón,
J. H. Reeves,
M. L. Sarsa,
S. Scopel,
A. A. Smolnikov,
A. S. Starostin,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: The International Germanium Experiment (IGEX) has now analyzed 117 mol yr of data from its isotopically enriched (86% 76Ge) germanium detectors. Applying pulse shape discrimination (PSD) to the more recent data, the lower bound on the half-life
for neutrinoless double-beta decay of 76Ge is deduced: T
1/2(0ν)>1.57×1025 yr (90% C.L.). This corresponds to an upper bound on the Majorana neutrino mass parameter, 〈m
ν〉, between 0.33 eV and 1.35 eV depending on the choice of theoretical nuclear matrix elements used in the analysis.
Physics of Atomic Nuclei 06/2000; 63(7):1225-1228. · 0.57 Impact Factor
-
C. E. Aalseth,
F. T. Avignone,
R. L. Brodzinski,
S. Cebrian,
D. Gonzáles,
E. García,
W. K. Hensley,
I. G. Irastorza, I. V. Kirpichnikov,
A. A. Klimenko, [......],
J. Puimedón,
J. H. Reeves,
M. L. Sarsa,
S. Scopel,
A. A. Smolnikov,
A. S. Starostin,
A. G. Tamanyan,
A. A. Vasenko,
S. I. Vasiliev,
J. A. Villar
[show abstract]
[hide abstract]
ABSTRACT: To search for cold dark matter (CDM) particles, the data from two (Ge-76 and Ge-natural) detectors, fabricated in the first
phase of the IGEX collaboration, were accumulated and analyzed for a period from May 1995 to May 1999. The use of effective
passive and active shielding together with pulse shape discrimination allowed us to perform long-term measurements with an
energy threshold of 2 keV at a level of the residual background 0.1 counts/(kg keV d). New restrictions on masses of weakly
interacting massive particles and the cross section of their elastic scattering on nuclei have been obtained from the data
corresponding to 810 d of live time. The derived exclusion plots compete with the best bounds obtained so far. Annual modulations
of the CDM signal have been also investigated. It is shown that the planned operation of all IGEX detectors (at Canfranc and
Baksan) with the recently achieved low-energy thresholds gives a chance to achieve the DAMA annual modulation sensitivity
region in a nearest future.
Physics of Atomic Nuclei 06/2000; 63(7):1268-1271. · 0.57 Impact Factor
