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1.
We investigate inclusive
photoproduction off complex nuclei, concentrating on the feasibility to examine a possible in-medium change of the
properties by observing the
invariant-mass spectrum. The simulations are performed by means of a BUU transport model including a full coupled-channel treatment of the final-state interactions. In-medium changes of the
spectral density are found to yield a moderate modification of the observables as compared to the situa tion in free space. Also the effects of a momentum dependence of the strong
potential are discussed.Received: 28 October 2003, Revised: 26 November 2003, Published online: 8 June 2004PACS:
25.20.-x Photonuclear reactions - 13.60.-r Photon and charged-lepton interactions with hadrons - 13.60.Le Meson production - 14.40.-n Mesons 相似文献
2.
Isomeric states in 210-215Ra have been populated by the decay of the compound nuclei 216,220Ra produced in irradiations of 204,208Pb with 12C at
MeV. Published values for
-ray energies and half-lives were confirmed for
Ra. Our data for
Ra agree with the
-energies and the half-life measured at the RITU separator, University of Jyväskylä (Finland). Its decay pattern is complex. Two series of
-rays of
keV and
keV were observed. A half-life of
s was measured. The isomeric state is attributed to an 8 + state at E
* = 2053.8keV. A previously unknown isomeric state was assigned to
Ra. It has a half-life of (
)
and it decays by emission of
-rays with energies of 396.1keV and 802.0keV. It is attributed to a 13/2 + state at E
* = 1198.1 keV.PACS:
23.60. + e
decay - 27.90. + b
相似文献
3.
J. G. Messchendorp 《The European Physical Journal A - Hadrons and Nuclei》2003,18(2-3):417-419
Preliminary differential cross-sections of the reactions
and
with A = 1
H, 12
C, and
nat
Pb are presented. A significant nuclear-mass dependence of the
invariant-mass distribution is found in the
channel. The dependence is not observed in the
channel. The in-medium observation in the
channel is consistent with an in-medium modification of the
interaction in the I = J = 0 channel, changing width and pole position of a
resonant state.Received: 30 September 2002, Published online: 22 October 2003PACS:
13.60.Le Meson production - 21.65. + f Nuclear matterJ.G. Messchendorp: For the TAPS and A2 Collaborations 相似文献
4.
A. N. Andreyev D. Ackermann F. P. Heßberger S. Hofmann M. Huyse I. Kojouharov B. Kindler B. Lommel G. Münzenberg R. D. Page K. Van de Vel P. Van Duppen K. Heyde 《The European Physical Journal A - Hadrons and Nuclei》2003,18(1):55-64
Alpha-decay of the new nuclide 184Bi has been studied in the complete-fusion reaction 93Nb(94Mo, 3n)184Bi at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-
, recoil-
-
analysis and excitation functions measurements. Two
-decaying isomeric states in 184Bi with half-life values of 13(2) ms and 6.6(1.5) ms were identified. The
-branching ratio of 180Tl was deduced for the first time as
. Improved data on the fine-structure
-decay of 186Bi were obtained in the 93Nb(95Mo, 2n)186Bi reaction. A similarity of the decay energies and half-life values of 184,186Bi is pointed out and a possible explanation for this effect is suggested.Received: 14 March 2003, Revised: 29 April 2003, Published online: 2 September 2003PACS:
23.60.+e
decay - 27.70.+q
- 27.80.+w
K. Heyde: Present address: EP-ISOLDE, CERN, CH-1211, Geneva 23, Switzerland. 相似文献
5.
Exotic, neutron-rich proton-induced spallation products of 232Th and 238U obtained from the PS Booster ISOLDE facility have been investigated by
-
,
-
coincidence and spectrum-multiscaling measurements. A new method for the reduction of isobaric contamination enabled to study the unknown region beyond 208Pb for the decay chain A = 217. A new isotope 217Bi with a half-life of
s was discovered and its
-decay studied. For the first time, a half-life value of
s for the
-decay of 217Po was measured.Received: 3 March 2003, Revised: 13 May 2003, Published online: 30 September 2003PACS:
23.20.Lv
transitions and level energies - 23.60.+e
decay - 27.80.+w 190
A
219 - 29.30.Kv X- and
-ray spectroscopyV. Fedoseyev: Present address: ISOLDE, CERN-PPE, CH-1211, Geneva 23, Switzerland.M. Górska: Present address: GSI, Darmstadt, D-64220, Germany.M. Huhta: Present address: Nokia, Tampere, Finland. 相似文献
6.
A. Sibirtsev 《The European Physical Journal A - Hadrons and Nuclei》2003,18(2-3):475-478
We investigate the
decay width of excited charmonium states at finite nuclear density with simultaneous modification of both D- and
-mesons in nuclear matter. The strongest effect is found for the
-meson. The medium modification can be detected by dilepton spectroscopy as substantial
broadening and anomalous
absorption.Received: 30 September 2002, Published online: 22 October 2003PACS:
13.25.Gv Decays of
,
, and other quarkonia - 14.40.Lb Charmed mesons - 14.65.Dw Charmed quarks - 24.85. + p Quarks, gluons, and QCD in nuclei and nuclear processes 相似文献
7.
Ts Venkova R. M. Lieder W. Gast D. Bazzacco G. de Angelis E. Podsvirova H. M. Jäger L. Mihailescu R. Menegazzo S. Lunardi C. Rossi Alvarez C. Ur T. Martinez M. Axiotis D. Napoli W. Urban T. Rzaca-Urban 《The European Physical Journal A - Hadrons and Nuclei》2003,18(4):577-581
High-spin states in the odd-proton nucleus 173Lu have been populated in a 170Er(7Li,4n) reaction and the emitted
-radiation was detected with the GASP array. The favoured and unfavoured sequences of the
band have been considerably extended. The favoured sequence does not show any indication of a band crossing up to a rotational frequency of
0.45 MeV. This is the largest crossing frequency ever observed for 1/2- [541] bands of odd-proton nuclei with
and
. Previous Cranked Shell Model (CSM) calculations underestimate the crossing frequency by 100 keV.Received: 19 May 2003, Published online: 11 November 2003PACS:
21.10.-k Properties of nuclei; nuclear energy levels - 21.10.Re Collective levels - 23.20.Lv
transitions and level energies - 27.70. + q
相似文献
8.
P. Kowina M. Wolke H. -H. Adam A. Budzanowski R. Czyżykiewicz D. Grzonka J. Haidenbauer M. Janusz L. Jarczyk A. Khoukaz K. Kilian P. Moskal W. Oelert C. Piskor-Ignatowicz J. Przerwa C. Quentmeier T. Rożek R. Santo G. Schepers T. Sefzick M. Siemaszko J. Smyrski S. Steltenkamp A. Strzałkowski P. Winter P. Wüstner W. Zipper 《The European Physical Journal A - Hadrons and Nuclei》2004,22(2):293-299
The production of the
- and
-hyperons has been measured via the
reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the
cross-section ratio from about 28 at
MeV to the high-energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy. Effects from the final-state interactions in the p-
channel seem to be much smaller than in the p-
channel. Estimates of the effective range parameters are given for the
and the
systems.PACS:
13.75.-n Hadron-induced low- and intermediate-energy reactions and scattering (energy
GeV) - 13.75.Ev Hyperon-nucleon interactions - 13.85.Lg Total cross-sections - 25.40.Ep Inelastic proton scattering 相似文献
9.
A. N. Andreyev D. Ackermann S. Antalic H. J. Boardman P. Cagarda J. Gerl F. P. Heßberger S. Hofmann M. Huyse D. Karlgren A. Keenan H. Kettunen A. Kleinböhl B. Kindler I. Kojouharov A. Lavrentiev C. D. O’Leary M. Leino B. Lommel M. Matos C. J. Moore G. Münzenberg R. D. Page S. Reshitko S. Saro H. Schaffner C. Schlegel M. J. Taylor K. Van de Vel P. Van Duppen L. Weissman K. Heyde 《The European Physical Journal A - Hadrons and Nuclei》2003,18(1):39-54
Detailed fine-structure
-decay studies of 188,190Bi were performed using the complete-fusion reactions of 50,52Cr ions with a 142Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-
, recoil-
-
/X-ray and excitation function measurements. Improved data on the
-decay of 188,190Bi were obtained and a number of new low-lying excited states in the daughters 184,186Tl were observed. An intruder, presumably 10- state was identified in 184Tl, extending the systematics of such states in the odd-odd Tl nuclei beyond the neutron mid-shell at N = 104. Some technical aspects of experiment at recoil separators are also discussed.Received: 14 March 2003, Revised: 1 May 2003, Published online: 2 September 2003PACS:
23.60.+e
decay - 27.70.+q
- 27.80.+w
C.D. OLeary: Present address: Department of Physics, University of York, York, UK.M.J. Taylor: Present address: Department of Physics and Astronomy, Rutgers Univesity, NJ, USA.L. Weissman: Present address: NSCL, Michigan State University, East Lansing, MI 48824-1321 USA.K. Heyde: Present address: EP-ISOLDE, CERN, CH-1211, Geneva 23, Switzerland. 相似文献
10.
Ph Dessagne M. J. G. Borge J. Giovinazzo A. Huck A. Jokinen A. Knipper C. Longour G. Marguier M. Ramdhane V. Rauch O. Tengblad G. Walter Ch. Miehé 《The European Physical Journal A - Hadrons and Nuclei》2004,20(3):405-411
Challenged by recent theoretical work, a study of the
-EC decay of the N = Z even-even nucleus 76
Sr has been undertaken in order to assign the parent ground-state deformation. In this study 13 levels with
have been located in 76
Rb. The beta-delayed proton emission has been observed for the first time in an N = Z even-even nucleus. The
p branching ratio has been determined to be
. The 76
Sr half-life has been remeasured and a more precise value of
s has been obtained. On the basis of the comparison of measured Gamow-Teller strength with calculated strength distributions for both oblate and prolate deformation, it is concluded that the 76
Sr has strong prolate deformation in the ground state.Received: 26 June 2003, Revised: 5 November 2003, Published online: 18 June 2004PACS:
21.10.Hw Spin, parity, and isobaric spin - 23.20.Lv
transitions and level energies - 23.40.Hc Relation with nuclear matrix elements and nuclear structure - 27.50. + e
J. Giovinazzo: Present address: Centre d Etudes Nucléaires de Bordeaux-Gradignan, Le Haut Vigneau, F-33175 Gradignan Cedex, France.M. Ramdhane: Present address: University Mentouri, 25000 Constantine, Algeria. 相似文献
11.
Gyürky Gy. Fülöp Zs. Somorjai E. Kiss G. Rolfs C. 《The European Physical Journal A - Hadrons and Nuclei》2004,20(2):355-358
The absolute strengths of the
keV resonance in the
reaction and of the
keV resonance in the
reaction have been measured to
meV and
meV, respectively, in good agreement with previous values. These resonances can be used to measure the absolute acceptance of the recoil separator ERNA to a precision of about 10%.Received: 12 December 2003, Revised: 10 February 2004, Published online: 3 August 2004PACS:
24.30.-v Resonance reactions - 25.40.Lw Radiative capture - 26.20. + f Hydrostatic stellar nucleosynthesis 相似文献
12.
A. Khoukaz I. Geck C. Quentmeier H.-H. Adam A. Budzanowski R. Czyżykiewicz D. Grzonka L. Jarczyk K. Kilian P. Kowina N. Lang T. Lister P. Moskal W. Oelert C. Piskor-Ignatowicz T. Rożek R. Santo G. Schepers T. Sefzick S. Sewerin M. Siemaszko J. Smyrski A. Strzałkowski A. Täschner P. Winter M. Wolke P. Wüstner W. Zipper 《The European Physical Journal A - Hadrons and Nuclei》2004,20(2):345-350
The
-meson production in the reaction
has been studied at excess energies of Q = 26.5, 32.5 and 46.6 MeV using the internal beam facility COSY-11 at the cooler synchrotron COSY. The total cross-sections as well as one angular distribution for the highest Q-value are presented. The excitation function of the near-threshold data can be described by a pure s-wave phase space distribution with the inclusion of the proton-proton final-state interaction and Coulomb effects. The obtained angular distribution of the
-mesons is also consistent with pure s-wave production.Received: 11 August 2003, Revised: 14 November 2003, Published online: 6 April 2004PACS:
13.60.Le Meson production - 13.75.-n Hadron-induced low- and intermediate-energy reactions and scattering (energy
GeV) - 13.85.Lg Total cross-sections - 25.40.-h Nucleon-induced reactions 相似文献
13.
X. Z. Cai C. Zhong W. Q. Shen Y. G. Ma H. Y. Zhang Y. B. Wei J. G. Chen W. Guo K. Wang G. L. Ma X. F. Zhou 《The European Physical Journal A - Hadrons and Nuclei》2004,20(2):263-267
,
and
have been calculated via the BUU model with soft EOS and 0.8 times of
. The density distribution without any adjustable parameters which comes from the RMF model has been introduced into the BUU calculation to replace the normally used one-parameter square-type distribution. The calculated results can reproduce the experimental data well for both halo- and stable-nuclei-induced reactions. Here
or
is calculated as the difference between
of halo nucleus and core nucleus, by assuming
. It indicates that this assumption works very well at high energy in the BUU calculation. More experimental measurements are necessary to test the validity of this assumption at intermediate energy.Received: 12 June 2003, Revised: 29 September 2003, Published online: 27 April 2004PACS:
24.10.-i Nuclear reaction models and methods - 25.60.Dz Interaction and reaction cross-sections - 25.60.Gc Breakup and momentum distributions - 27.20. + n
相似文献
14.
J. Kurpeta A. Plochocki A. N. Andreyev J. Äystö A. De Smet H. De Witte A.-H. Evensen V. Fedoseyev S. Franchoo M. Górska H. Grawe M. Huhta M. Huyse Z. Janas A. Jokinen M. Karny E. Kugler W. Kurcewicz U. Köster J. Lettry A. Nieminen K. Partes M. Ramdhane H. L. Ravn K. Rykaczewski J. Szerypo K. Van de Vel P. Van Duppen L. Weissman G. Walter A. Wöhr 《The European Physical Journal A - Hadrons and Nuclei》2003,18(1):31-37
A new high-spin isomer in 215Bi, with a half-life of 36.9(6) s, has been identified at the PSB-ISOLDE on-line mass separator using the pulsed-release technique combined with the element selective RILIS source. A decay scheme of
Bi was constructed and complemented with the low-spinstructure observed in
Bi decay. The population of a cascade on top of the
level in 215Poprovides evidence for Gamow-Teller
-decay of the high-spin 215Bi isomer.Received: 3 March 2003, Revised: 10 June 2003, Published online: 9 October 2003PACS:
23.20.Lv
transitions and level energies - 27.80.+w
- 29.30.Kv X- and
-ray spectroscopyV. Fedoseyev: Present address: ISOLDE, CERN-PPE, CH-1211, Geneva 23, Switzerland.M. Górska: Present address: GSI, Darmstadt, D-64220, Germany.M. Huhta: Present address: Nokia, Tampere, Finland. 相似文献
16.
C. Y. Xie X. H. Zhou Y. Zheng Y. H. Zhang Z. Liu Z. G. Gan T. Hayakawa M. Oshima T. Toh T. Shizuma J. Katakura Y. Hatsukawa M. Matsuda H. Kusakari M. Sugawara K. Furuno T. Komatsubara 《The European Physical Journal A - Hadrons and Nuclei》2004,19(1):7-9
The level structure of the doubly odd nucleus 146Tb has been studied via the 118Sn(32S, 1p3n) reaction using techniques of in-beam
-ray spectroscopy. Measurements of
-ray anisotropies, X-
and
-
-t coincidences were performed with 12 BGO(AC)HPGe detectors. Based on the measured results, the level scheme of 146Tb has been revised significantly and extended up to an excitation energy of 8.39 MeV. The level structure has been interpreted qualitatively by coupling an h
11/2 proton-particle and an h
11/2 neutron-hole to the excited states in the 146Gd core.Received: 3 July 2003, Published online: 26 November 2003PACS:
23.20.Lv
transitions and level energies - 27.60. + j
相似文献
17.
F. P. Heßberger S. Hofmann D. Ackermann P. Cagarda R. -D. Herzberg I. Kojouharov P. Kuusiniemi M. Leino R. Mann 《The European Physical Journal A - Hadrons and Nuclei》2004,22(3):417-427
The isotopes 251No and 253No were produced in nuclear reactions 206Pb(48Ca,3n)251No and 207Pb (48Ca,2n)253No. Radioactive decay of these isotopes and their daughter products has been investigated by means of
- and
-
- spectroscopy. An isomeric state 251m
No, having a half-life of
s and decaying by emission of
particles of
keV was identified. The measured decay data allowed for the construction of partial level schemes for 251No, 247,249Fm and 243,245Cf and an extrapolation of energy systematics of single particle levels of N = 145, 147 and 149 isotones with even Z towards higher atomic numbers up to Z = 102.PACS:
23.60. + e
decay - 27.90. + b
- 21.10.-k Properties of nuclei; nuclear energy levels 相似文献
18.
The
-decay of 149Ba to 149La has been investigated by means of
- and X-ray spectroscopy, and a partial level scheme of 149La has been constructed for the first time. It includes thirteen
-rays and ten excited states. The exotic 149La is the heaviest lanthanum for which spectroscopic information is now available. We have applied the shell correction approach with the axially deformed Woods-Saxon potential in order to calculate the deformation energy for the 149La ground state. The deformed ground state was found at
0.23,
0 and
0.12.Received: 18 July 2003, Revised: 12 January 2004, Published online: 26 May 2004PACS:
27.60. + j
- 29.30.Kv X- and
-ray spectroscopy 相似文献
19.
G. Martens C. Greiner S. Leupold U. Mosel 《The European Physical Journal A - Hadrons and Nuclei》2003,18(2-3):223-226
We calculate color electric fields of quark/antiquark (
) and 3-quark (qqq) systems within the Chromodielectric Model (CDM). We explicitly evaluate the string tension of flux tubes in the
-system and analyze their profile. To reproduce results of lattice calculations we use a bag pressure
from which an effective strong-coupling constant
follows. With these parameters we get a Y-shaped configuration for large qqq-systems.Received: 30 September 2002, Published online: 22 October 2003PACS:
11.10.Lm Field theory: Nonlinear or nonlocal theories and models - 11.15.Kc Gauge field theories: Classical and semiclassical techniques - 12.39.Ba Phenomenological quark models: Bag model 相似文献
20.
A high-quality double-polarization data set for the helicity dependence of the total and differential cross-sections for both
channels in the
region has been obtained in the framework of the GDH experiment. The experiment, performed at the Mainz microtron MAMI, used a 4
detection system, a circularly polarized photon beam, and a longitudinally polarized frozen-spin target. These data are included in the database to perform a multipole analysis to determine the properties of the
-resonance. For the resonant
(1232) multipoles we find a very good agreement with previous analyses, while the nonresonant ones show significant deviations.Received: 11 July 2003, Revised: 16 January 2004, Published online: 17 August 2004PACS:
13.60.Le Meson production - 14.20.Gk Baryon resonances with S = 0 - 25.20.Lj Photoproduction reactions 相似文献