| Records |
| Author |
Wimmer, K. et al; Algora, A.; Rubio, B. |
| Title |
Shape coexistence revealed in the N = Z isotope Kr-72 through inelastic scattering |
Type |
Journal Article |
| Year |
2020 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
| Volume |
56 |
Issue |
6 |
Pages |
159 - 12pp |
| Keywords |
|
| Abstract |
The N = Z = 36 nucleus Kr-72 has been studied by inelastic scattering at intermediate energies. Two targets, Be-9 and Au-197, were used to extract the nuclear deformation length, delta(N), and the reduced E2 transition probability, B(E2). The previously unknown non-yrast 2(+) and 4(+) states as well as a new candidate for the octupole 3(-) state have been observed in the scattering on the Be target and placed in the level scheme based on gamma – gamma coincidences. The second 2(+) state was also observed in the scattering on the Au target and the B(E2; 2(2)(+) -> 0(1)(+)) value could be determined for the first time. Analyzing the results in terms of a two-band mixing model shows clear evidence for a oblate-prolate shape coexistence and can be explained by a shape change from an oblate ground state to prolate deformed yrast band from the first 2+ state. This interpretation is corroborated by beyond mean field calculations using the Gogny D1S interaction. |
Address  |
[Wimmer, K.; Ando, T.; Koyama, S.; Nagamine, S.; Niikura, M.; Saito, T. Y.; Sakurai, H.; Taniuchi, R.] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan, Email: k.wimmer@csic.es |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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 |
1434-6001 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000540063900002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4428 |
| Permanent link to this record |
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| Author |
Wilson, J.N. et al; Algora, A. |
| Title |
Angular momentum generation in nuclear fission |
Type |
Journal Article |
| Year |
2021 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
590 |
Issue |
7847 |
Pages |
566-570 |
| Keywords |
|
| Abstract |
When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning(1); this phenomenon has been a mystery in nuclear physics for over 40 years(2,3). The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum(4-12). Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the gamma-ray heating problem in nuclear reactors(13,14), for the study of the structure of neutron-rich isotopes(15,16), and for the synthesis and stability of super-heavy elements(17,18). gamma-ray spectroscopy experiments on the origin of spin in the products of nuclear fission of spin-zero nuclei suggest that the fission fragments acquire their spin after scission, rather than before. |
| Address |
[Wilson, J. N.; Thisse, D.; Lebois, M.; Jovancevic, N.; Adsley, P.; Babo, M.; Chakma, R.; Delafosse, C.; Haefner, G.; Hauschild, K.; Ibrahim, F.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I; Nemer, J.; Popovitch, Y.; Qi, L.; Tocabens, G.; Verney, D.] Univ Paris Saclay, IJC Lab, CNRS, IN2P3, Orsay, France, Email: jonathan.wilson@ijclab.in2p3.fr |
| Corporate Author |
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Thesis |
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| Publisher |
Nature Research |
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 |
0028-0836 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000621583600006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4717 |
| Permanent link to this record |
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| Author |
Wilkinson, C.; Garcia Soto, A. |
| Title |
Low-ν method with LHC neutrinos |
Type |
Journal Article |
| Year |
2024 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
109 |
Issue |
3 |
Pages |
033010 - 19pp |
| Keywords |
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| Abstract |
The Forward Physics Facility (FPF) plans to use neutrinos produced at the Large Hadron Collider to make a variety of measurements at previously unexplored TeV energies. Its primary goals include precision measurements of the neutrino cross section and using the measured neutrino flux both to uncover information about far-forward hadron production and to search for various beyond standard model scenarios. However, these goals have the potential to conflict: Extracting information about the flux or cross section relies upon an assumption about the other. In this paper, we demonstrate that the FPF can use the low-nu method-a technique for constraining the flux shape by isolating neutrino interactions with low energy transfer to the nucleus-to break this degeneracy. We show that the low-nu method is effective for extracting the nu μflux shape, in a model-independent way. We discuss its application for extracting the nu over bar μflux shape but find that this is significantly more model dependent. Finally, we explore the precision to which the nu μflux shape could be constrained at the FPF for a variety of proposed detector options. We find that the precision would be sufficient to discriminate between various realistic flux models. |
| Address |
[Wilkinson, C.] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA, Email: cwilkinson@lbl.gov; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical 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 |
|
| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001183228500009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5986 |
| Permanent link to this record |
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| Author |
CALICE Collaboration (White, A. et al); Irles, A. |
| Title |
Design, construction and commissioning of a technological prototype of a highly granular SiPM-on-tile scintillator-steel hadronic calorimeter |
Type |
Journal Article |
| Year |
2023 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
18 |
Issue |
11 |
Pages |
P11018 - 39pp |
| Keywords |
Calorimeters; Detector alignment and calibration methods (lasers, sources, par ticle- beams); Detector design and construction technologies and materials |
| Abstract |
The CALICE collaboration is developing highly granular electromagnetic and hadronic calorimeters for detectors at future energy frontier electron-positron colliders. After successful tests of a physics prototype, a technological prototype of the Analog Hadron Calorimeter has been built, based on a design and construction techniques scalable to a collider detector. The prototype consists of a steel absorber structure and active layers of small scintillator tiles that are individually read out by directly coupled SiPMs. Each layer has an active area of 72 x 72 cm2 and a tile size of 3 x 3 cm2. With 38 active layers, the prototype has nearly 22, 000 readout channels, and its total thickness amounts to 4.4 nuclear interaction lengths. The dedicated readout electronics provide time stamping of each hit with an expected resolution of about 1 ns. The prototype was constructed in 2017 and commissioned in beam tests at DESY. It recorded muons, hadron showers and electron showers at different energies in test beams at CERN in 2018. In this paper, the design of the prototype, its construction and commissioning are described. The methods used to calibrate the detector are detailed, and the performance achieved in terms of uniformity and stability is presented. |
| Address |
[White, A.; Yu, J.] Univ Texas Arlington, Dept Phys, Arlington, TX 76019 USA |
| 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 |
|
| ISSN |
1748-0221 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001127235400003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5874 |
| Permanent link to this record |
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| Author |
ATLAS Collaboration (Abat, E. et al); Bernabeu Verdu, J.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Garcia, C.; Gonzalez-Sevilla, S.; Higon-Rodriguez, E.; Lacasta, C.; Marti-Garcia, S.; Mitsou, V.A.; Ruiz, A.; Solans, C.; Valero, A.; Valls Ferrer, J.A. |
| Title |
A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
6 |
Issue |
|
Pages |
P06001 - 35pp |
| Keywords |
Calorimeter methods; Pattern recognition, cluster finding, calibration and fitting methods; Calorimeters; Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) |
| Abstract |
A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20 GeV and 180 GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale. |
| Address |
[Wheeler, S] Univ Alberta, Dept Phys, Ctr Particle Phys, Edmonton, AB T6G 2G7, Canada[Bernabeu, J; Castillo, MV; Costa, MJ; Escobar, C; Ferrer, A; Garcia, C; Gonzalez-Sevilla, S; Higon, E; Lacasta, C; Garcia, SMI; Mitsou, VA; Ruiz, A; Solans, C; Valero, A; Valls, JA] Ctr Mixto UVEG CSIC, Inst Fis Corpuscular IFIC, ES-46071 Valencia, Spain, Email: kjg@particle.kth.se |
| 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 |
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Conference |
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| Notes |
WOS:000294492600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
744 |
| Permanent link to this record |
