| Records |
| Author |
Pierre Auger Collaboration (Abreu, P. et al); Pastor, S. |
| Title |
The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
6 |
Issue |
|
Pages |
P01003 - 16pp |
| Keywords |
Cherenkov detectors; Large detector systems for particle and astroparticle physics; Particle detectors |
| Abstract |
Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found. |
| Address |
[Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1748-0221 |
ISBN |
|
Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
ISI:000291345600003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
646 |
| Permanent link to this record |
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| Author |
Linhart, V.; Burdette, D.; Chessi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Honscheid, K.; Kagan, H.; Lacasta, C.; Llosa, G.; Mikuz, M.; Stankova, V.; Studen, A.; Weilhammer, P.; Zontar, D. |
| Title |
Spectroscopy study of imaging devices based on silicon Pixel Array Detector coupled to VATAGP7 read-out chips |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
6 |
Issue |
|
Pages |
C01092 - 8pp |
| Keywords |
Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA); Compton imaging |
| Abstract |
Spectroscopic and timing response studies have been conducted on a detector module consisting of a silicon Pixel Array Detector bonded on two VATAGP7 read-out chips manufactured by Gamma-Medica Ideas using laboratory gamma sources and the internal calibration facilities (the calibration system of the read-out chips). The performed tests have proven that the chips have (i) non-linear calibration curves which can be approximated by power functions, (ii) capability to measure the energy of photons with energy resolution better than 2 keV (exact range and resolution depend on experimental setup), (iii) the internal calibration facility which provides 6 out of 16 available internal calibration charges within our region of interest (spanning the Compton edge of 511 keV photons). The peaks induced by the internal calibration facility are suitable for a fit of the calibration curves. However, they are not suitable for measurements of equivalent noise charge because their full width at half maximum varies with their amplitude. These facts indicate that the VATAGP7 chips are useful and precise tools for a wide variety of spectroscopic devices. We have also explored time walk of the module and peaking time of the spectroscopy signals provided by the chips. We have observed that (iv) the time walk is caused partly by the peaking time of the signals provided by the fast shaper of the chips and partly by the timing uncertainty related to the varying position of the photon interaction, (v) the peaking time of the spectroscopy signals provided by the chips increases with increasing pulse height. |
| Address |
[Linhart, V.; Lacasta, C.; Llosa, G.; Stankova, V.] UVEG, CSIC, IFIC, Expt Phys Dept,Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Vladimir.Linhart@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1748-0221 |
ISBN |
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Medium |
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| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:000291345600097 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
645 |
| Permanent link to this record |
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| Author |
Marco-Hernandez, R. |
| Title |
Development of a beam test telescope based on the Alibava readout system |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
6 |
Issue |
|
Pages |
C01002 - 7pp |
| Keywords |
Particle tracking detectors; Data acquisition circuits; Front-end electronics for detector readout; Digital electronic circuits |
| Abstract |
A telescope for a beam test have been developed as a result of a collaboration among the University of Liverpool, Centro Nacional de Microelectronica (CNM) of Barcelona and Instituto de Fisica Corpuscular (IFIC) of Valencia. This system is intended to carry out both analogue charge collection and spatial resolution measurements with different types of microstrip or pixel silicon detectors in a beam test environment. The telescope has four XY measurement as well as trigger planes (XYT board) and it can accommodate up to twelve devices under test (DUT board). The DUT board uses two Beetle ASICs for the readout of chilled silicon detectors. The board could operate in a self-triggering mode. The board features a temperature sensor and it can be mounted on a rotary stage. A peltier element is used for cooling the DUT. Each XYT board measures the track space points using two silicon strip detectors connected to two Beetle ASICs. It can also trigger on the particle tracks in the beam test. The board includes a CPLD which allows for the synchronization of the trigger signal to a common clock frequency, delaying and implementing coincidence with other XYT boards. An Alibava mother board is used to read out and to control each XYT/DUT board from a common trigger signal and a common clock signal. The Alibava board has a TDC on board to have a time stamp of each trigger. The data collected by each Alibava board is sent to a master card by means of a local data/address bus following a custom digital protocol. The master board distributes the trigger, clock and reset signals. It also merges the data streams from up to sixteen Alibava boards. The board has also a test channel for testing in a standard mode a XYT or DUT board. This board is implemented with a Xilinx development board and a custom patch board. The master board is connected with the DAQ software via 100M Ethernet. Track based alignment software has also been developed for the data obtained with the DAQ software. |
| Address |
[Marco-Hernandez, R.; Alibava Collaboration] CSIC UV, Inst Fis Corpuscular, E-46980 Paterna, Valencia, Spain, Email: rmarco@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1748-0221 |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
ISI:000291345600007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
644 |
| Permanent link to this record |
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| Author |
Ancilotto, F.; Barranco, M.; Navarro, J.; Pi, M. |
| Title |
Cavitation of electron bubbles in liquid parahydrogen |
Type |
Journal Article |
| Year |
2011 |
Publication |
Molecular Physics |
Abbreviated Journal |
Mol. Phys. |
| Volume |
109 |
Issue |
23-24 |
Pages |
2757-2762 |
| Keywords |
liquid parahydrogen; electron bubbles; density functional theory; capillary approximation |
| Abstract |
Within a finite-temperature density functional approach, we have investigated the structure of electron bubbles in liquid parahydrogen below the saturated vapour pressure, determining the critical pressure at which electron bubbles explode as a function of temperature. The electron-parahydrogen interaction has been modelled by a Hartree-type local potential fitted to the experimental value of the conduction band-edge for a delocalized electron in pH(2). We have found that the pressure for bubble explosion is, in absolute value, about a factor of two smaller than that of the homogeneous cavitation pressure in the liquid. Comparison with the results obtained within the capillary model shows the limitations of this approximation, especially as temperature increases. |
| Address |
[Barranco, Manuel; Pi, Marti] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain, Email: manuel@ecm.ub.es |
| Corporate Author |
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Thesis |
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| Publisher |
Taylor & Francis Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0026-8976 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000299109300007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
930 |
| Permanent link to this record |
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| Author |
Guardiola, R.; Navarro, J. |
| Title |
On the Lindemann Criterion for Quantum Clusters at Very Low Temperature |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Physical Chemistry A |
Abbreviated Journal |
J. Phys. Chem. A |
| Volume |
115 |
Issue |
25 |
Pages |
6843-6850 |
| Keywords |
|
| Abstract |
The Lindemann criterion to discern the solid-like or liquid-like nature of a quantum cluster at T = 0 is discussed. A critical analysis of current Lindemann parameters is presented and a new parameter is proposed that is appropriate to study quantum clusters made of identical particles. A simple model wave function is introduced to fix the range of variation of these parameters. The model presents two extreme limits that correspond to either a liquid-like or a solid-like system; besides, it fulfills the Bose symmetry and also permits evaluations without symmetrization. Variational and diffusion Monte Carlo calculations are also performed for clusters of spinless bosons interacting through Lennard-Jones potentials. It is shown that the liquid-like or solid-like character of quantum clusters at zero temperature cannot be simply established in terms of a single parameter. |
| Address |
[Guardiola, R.; Navarro, J.] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain, Email: navarro@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Chemical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1089-5639 |
ISBN |
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Medium |
|
| Area |
|
Expedition |
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Conference |
|
| Notes |
ISI:000291895500012 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
669 |
| Permanent link to this record |
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| Author |
Pino, F.; Roe, N.; Orero, A.; Falcon, C.; Rojas, S.; Benlloch, J.M.; Ros, D.; Pavia, J. |
| Title |
Development of a variable-radius pinhole SPECT system with a portable gamma camera |
Type |
Journal Article |
| Year |
2011 |
Publication |
Revista Española de Medicina Nuclear |
Abbreviated Journal |
Rev. Esp. Med. Nucl. |
| Volume |
30 |
Issue |
5 |
Pages |
286-291 |
| Keywords |
SPECT; Small animal; Pinhole; Portable gamma camera; Continuous scintillator |
| Abstract |
Objective: To develop a small-animal SPECT system using a low cost commercial portable gamma camera equipped with a pinhole collimator, a continuous scintillation crystal and a position-sensitive photomultiplier tube. Material and methods: The gamma camera was attached to a variable radius system, which enabled us to optimize sensitivity and resolution by adjusting the radius of rotation to the size of the object. To investigate the capability of the SPECT system for small animal imaging, the dependence of resolution and calibration parameters on radius was assessed and acquisitions of small phantoms and mice were carried out. Results: Resolution values, ranging from 1.0 mm for a radius of 21.4 mm and 1.4 mm for a radius of 37.2 mm were obtained, thereby justifying the interest of a variable radius SPECT system. Conclusions: The image quality of phantoms and animals were satisfactory, thus confirming the usefulness of the system for small animal SPECT imaging. |
| Address |
[Pino, F; Roe, N; Ros, D] Univ Barcelona, Fac Med, Unitat Biofis, Barcelona 7, Spain, Email: fpino@iconcologia.net |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Inc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0212-6982 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000294659400004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
753 |
| Permanent link to this record |
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| |
| Author |
Fujita, Y.; Rubio, B.; Gelletly, W. |
| Title |
Spin-isospin excitations probed by strong, weak and electro-magnetic interactions |
Type |
Journal Article |
| Year |
2011 |
Publication |
Progress in Particle and Nuclear Physics |
Abbreviated Journal |
Prog. Part. Nucl. Phys. |
| Volume |
66 |
Issue |
3 |
Pages |
549-606 |
| Keywords |
Gamow-Teller transitions; beta decay; Charge-exchange reactions; Isospin symmetry; High resolution; Proton-rich nuclei |
| Abstract |
Gamow-Teller (GT) transitions are the most common weak interaction processes of spin-isospin (sigma tau) type in atomic nuclei. They are of interest not only in nuclear physics but also in astrophysics; they play an important role in supernovae explosions and nucleosynthesis. The direct study of weak decay processes, however, gives relatively limited information about GT transitions and the states excited via GT transitions (GT states); beta decay can only access states at excitation energies lower than the decay Q-value, and neutrino-induced reactions have very small cross-sections. However, one should note that beta decay has a direct access to the absolute GT transition strengths B(GT) from a study of half-lives, Q(beta)-values and branching ratios. They also provide information on GT transitions in nuclei far-from-stability. Studies of M1 gamma transitions provide similar information. In contrast, the complementary charge-exchange (CE) reactions, such as the (p, n) or ((3)He, t) reactions at intermediate beam energies and 0 degrees, can selectively excite GT states up to high excitation energies in the final nucleus. It has been found empirically that there is a close proportionality between the cross-sections at 0 degrees and the transition strengths B(GT) in these CE reactions. Therefore, CE reactions are useful tools to study the relative values of B(GT) strengths up to high excitation energies. In recent ((3)He, t) measurements, one order-of-magnitude improvement in the energy resolution has been achieved. This has made it possible to make one-to-one comparisons of GT transitions studied in CE reactions and beta decays. Thus GT strengths in ((3)He, t) reactions can be normalised by the beta-decay values. In addition, comparisons with closely related M1 transitions studied in gamma decay or electron inelastic scattering [(e, e')1, and furthermore with “spin” M I transitions that can be studied by proton inelastic scattering [(p, p')[ have now been made possible. In these comparisons, the isospin quantum number T and associated symmetry structure in the same mass A nuclei (isobars) play a key role. Isospin symmetry can extend our scope even to the structures of unstable nuclei that are far from reach at present unstable beam factories. |
| Address |
[Fujita, Y] Osaka Univ, Dept Phys, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0146-6410 |
ISBN |
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Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000292473100003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
692 |
| Permanent link to this record |
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| Author |
Fernandez-Carames, T.; Valcarce, A.; Vijande, J. |
| Title |
Doubly charmed exotic mesons: A gift of nature? |
Type |
Journal Article |
| Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
699 |
Issue |
4 |
Pages |
291-295 |
| Keywords |
Exotic mesons; Quark model; Multiquark states |
| Abstract |
We study doubly charmed exotic states by solving the scattering problem of two D mesons. Our results point to the existence of a stable isoscalar doubly charmed meson with quantum numbers (I)J(P) = (0)1(+). We perform a thorough comparison to the results obtained within the hyperspherical harmonic formalism. Such exotic states could be measured at LHC and RHIC. Their experimental observation would, for the first time, confirm the contribution of multiquark structures to hadron spectroscopy. |
| Address |
[Carames, T. F.; Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: valcarce@usal.es |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Medium |
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| Area |
|
Expedition |
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Conference |
|
| Notes |
ISI:000291073200016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
634 |
| Permanent link to this record |
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| Author |
Montanari, D. et al; Gadea, A. |
| Title |
Probing the nature of particle-core couplings in Ca-49 with gamma spectroscopy and heavy-ion transfer reactions |
Type |
Journal Article |
| Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
697 |
Issue |
4 |
Pages |
288-293 |
| Keywords |
Multi-nucleon transfer; Gamma spectroscopy; Magnetic spectrometer; Particle-core coupling |
| Abstract |
Neutron rich nuclei around Ca-48 have been measured with the CLARA-PRISMA setup, making use of Ca-48 on Ni-64 binary reactions, at 5.9 MeV/A. Angular distributions of gamma rays give evidence, in several transfer channels, for a large spin alignment (approximate to 70%) perpendicular to the reaction plane, making it possible to firmly establish spin and parities of the excited states. In the case of Ca-49, states arising from different types of particle-core couplings are, for the first time, unambiguously identified on basis of angular distribution, polarization and lifetime measurements. Shell model and particle-vibration coupling calculations are used to pin down the nature of the states. Evidence is found for the presence, in the same excitation energy region, of two types of coupled states, i.e. single particle coupled to either Ca-48 or Ca-50 simple configurations, and particle-vibration coupled states based on the 3- phonon of Ca-48. |
| Address |
[Montanari, D.; Leoni, S.; Bocchi, G.; Bortignon, P. F.; Bracco, A.; Camera, F.; Colo, G.; Corsi, A.; Crespi, F. C. L.; Nicolini, R.] Univ Milan, Dipartimento Fis, Milan, Italy, Email: silvia.leoni@mi.infn.it |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
ISI:000288300400005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
542 |
| Permanent link to this record |
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| Author |
Langer, C.; Algora, A.; Couture, A.; Csatlos, M.; Gulyas, J.; Heil, M.; Krasznahorkay, A.; O'Donnell, J.M.; Plag, R.; Reifarth, R.; Stuhl, L.; Sonnabend, K.; Tornyi, T.; Tovesson, F. |
| Title |
Simulations and developments of the Low Energy Neutron detector Array LENA |
Type |
Journal Article |
| Year |
2011 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
659 |
Issue |
1 |
Pages |
411-418 |
| Keywords |
Monte Carlo simulations; Charge-exchange reactions; Scintillation detectors; Neutron detector |
| Abstract |
Prototypes of the Low Energy Neutron detector Array (LENA) have been tested and compared with detailed GEANT simulations. LENA will consist of plastic scintillation bars with the dimensions 1000 x 45 x 10 mm(3). The tests have been performed with gamma-ray sources and neutrons originating from the neutron-induced fission of (235)U. The simulations agreed very well with the measured response and were therefore used to simulate the response to mono-energetic neutrons with different detection thresholds. LENA will be used to detect low-energy neutrons from (p,n)-type reactions with low momentum transfer foreseen at the R(3)B and EXL setups at FAIR, Darmstadt. |
| Address |
[Langer, C.; Heil, M.; Plag, R.; Reifarth, R.] GSI Helmholtzzentrum Schwerionenforsch GmbH, D-64291 Darmstadt, Germany, Email: c.langer@gsi.de |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0168-9002 |
ISBN |
|
Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000297826100057 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
833 |
| Permanent link to this record |
