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Objectives Pulmonary adenocarcinomas (ADC) can be sub-grouped based on dominant oncogenic drivers. EGFR mutations define an entity of metastatic ADC with favorable prognosis and high susceptibility to EGFR tyrosine kinase inhibition. In contrast, the clinical impact of additional ERBB family members in ADC is less defined. To this end we prospectively studied HER2 expression, gene amplification, and mutation in relation to outcome of patients with advanced or metastatic ADC. Materials and methods Diagnostic tumor biopsies from 193 sequential patients with stage III/IV ADC were prospectively studied for HER2 expression by immunohistochemistry (IHC). Cases with IHC scores 2+ or 3+ were analyzed by HER2 chromogenic in situ hybridization (CISH), and sequencing of HER2 exons 20 and 23. Additional prospectively determined biomarkers included PTEN, cMET, pAKT, and pERK expression, KRAS , EGFR , BRAF and PIK3CA mutations, and ALK fluorescence ISH (FISH) . Results and conclusion HER2–IHC was feasible in 176 (91.2%) cases. Of 53 (30%) cases with IHC scores 2+/3+, 45 (85%) could be studied by CISH and 34 (64%) by sequencing. The lower number of HER2 -mutational analyses resulted from exhaustion of tumor tissue and DNA following mutational analysis of KRAS , EGFR , BRAF and PIK3CA . HER2 amplification was detected in 4 cases (2.3%), while no mutation was found. HER2 expression correlated with expression of pAKT and cMET. Expression of HER2 and pAKT was associated with favorable overall survival in stage IV disease. HER2-expressing ADC more frequently harbored KRAS mutations, while HER2 expression was absent in all 4 cases with BRAF mutation. HER2–IHC was not predictive of HER2 gene amplification or mutation, which both were rare events in prospectively studied patients with advanced or metastatic ADC. Expression of HER2 and pAKT define a population of patients with stage IV ADC with a distinct disease course, who could benefit from specifically tailored pharmacotherapies.

The Gamow–Teller strength distributions for the β decay of the ground state as well as the lowest excited states of the rp-process waiting point nuclei 68Se and 72Kr are obtained within the complex Excited Vampir variational approach using realistic effective interactions and a rather large model space. The shape mixing is consistently described for both the states in the even–even parent and the states in the odd–odd daugther nucleus. The influence of the shape mixing accounted by the different effective interactions used and comparison with the available data are presented. The possible influence of the decay of the lowest excited states of the parent nuclei in the astrophysical environment of X-ray bursts is discussed. Gamow–Teller strength distributions, β -decay half-lives, and β -delayed neutron emission probabilities for neutron-rich Zr nuclei are investigated for the first time within the complex Excited Vampir approach using a large model space. Comparison with available data and predictions relevant for the astrophysical r process are presented.

We study the influence of shape mixing on the Gamow–Teller β decay of the nucleus 74Kr using the complex EXCITED VAMPIR variational approach for the description of the ground state of 74Kr and the 1 + states appearing within the β + -decay window in the daughter nucleus 74Br. The Gamow–Teller strength is obtained describing consistently the shape mixing in both parent and daughter nucleus. The theoretical results for the Gamow–Teller strength distribution as well as accumulated strength are compared with the available experimental data.

We study the influence of Coulomb-induced isospin-mixing on the superallowed Fermi β decay using the complex EXCITED VAMPIR variational approach for the description of the lowest excited 0 + states in the two isovector triplets of nuclei 70 Se, 70 Br, 70 Kr and 74 Kr, 74 Rb, 74 Sr, respectively. As expected, the effects are small but nevertheless non-negligible. The calculated strength for the 74 Rb → 74 Kr Fermi β decay to the first excited 0 + state turns out to be very weak, in agreement with the experimentally given upper limit. However, particular non-analog Fermi branches to excited 0 + states with considerable strength are predicted to coexist with the superallowed decay in some of the presently investigated nuclei. This may give some hope for possible experimental detection.

Various variational approaches to the nuclear many-body problem are reviewed, which all use general symmetry-projected Hartree–Fock–Bogoliubov determinants as test configurations. The different approaches vary, however, in the degree of sophistication with which the underlying mean-fields as well as the configuration mixing are determined. The methods are explained in detail and their limitations are discussed. Special attention is payed to the particular symmetry restrictions made in the earlier applications and their consequences. Illustrative examples for some selected applications will be given, and the results, where possible, will be compared to those of alternative approaches. A calculational procedure, which allows one to use phenomenological density-dependent interactions, is reported and its merits and shortcomings are discussed. Finally, the problem of restoring Galilei invariance in the variational and similar approaches is adressed in some detail.

Results are presented on shape coexistence at low and high spins in the mirror nuclei 70 Se and 70 Kr obtained within the complex version of the Excited Vampir variational approach. Effects of oblate–prolate coexistence and mixing at low, intermediate and high spins are discussed. Strong M1, ΔI=0 transitions are predicted. A detailed comparison with the available experimental information is performed.

Results are presented concerning shape coexistence and shape transition at low and intermediate spins in the N = Z nuclei 72 Kr, 76 Sr and 80 Zr obtained within the complex version of the Excited Vampir variational approach. The effects of possible contaminations due to the center-of-mass motion are discussed using a rough method to eliminate them at least approximately. The results indicate maximum influence on the observables depending on band mixing. Detailed illustration of the effects on the oblate–prolate mixing and the electromagnetic properties, as well as the alignments and particle occupations of the 0 g 9/2 spherical orbital is presented for the 72 Kr nucleus.

The ground state of the mid pf -shell nucleus 56 Ni is described in the framework of a symmetry-projected complex mean-field theory in which the desired symmetry properties are exactly projected from the most general Hartree–Fock–Bogoliubov type determinants. This few determinant method is applied for the first time in a full 1 p 0 f -shell model space. In the calculations the FPD6 effective interaction was used. It turns out that the use of only a few such generalized determinants is sufficient to give an excellent result. We compare the result with that of the quantum Monte Carlo approach, as well as with recently performed exact shell-model diagonalizations.

Results are presented concerning shape coexistence and neutron–proton correlations at low and high spins in the N=Z nucleus 56Ni obtained within the complex version of the Excited Vampir variational approach. The coexistence of small and moderately deformed oblate and prolate configurations, strongly mixed in some cases, may explain the irregularities observed for the yrast line, as well as the presence of other nonyrast states connected with them by E2 or Ml transitions. The first deformed band is well reproduced and predictions on the structure of next deformed bands are presented. These are the first microscopic calculations for 56Ni including in the model space the 0g9/2 and 1d5/2 spherical orbitals besides the full pf-shell. Contaminations due to the center of momentum motion are discussed and a rough method to eliminate them at least approximately is presented.

Results are presented on shape coexistence, shape transition and neutron–proton correlations at low and high spin states in the nuclei 72 Kr and 74 Kr. They have been obtained within the complex version of the Excited Vampir variational approach. Oblate–prolate coexistence and mixing at low spin is found to be responsible for the irregular sequence of states identified at low excitation energy. At high spins the coexistence of states with different prolate deformations results in complex multiple band structures. The present investigation indicates furthermore that particular neutron–proton matrix elements of the effective interaction play an essential role for the shape mixing.

The pair structure and the average pairing gaps of realistic wave functions obtained within the complex Excited Vampir variational approach are investigated in order to evaluate the neutron-proton pairing correlations at low and high spins in medium mass N ∼- Z nuclei. The number of isovector Jπ = 0+ pairs is calculated for the lowest few 0+ states in two chains of nuclei in the A ∼- 70 mass region. The results indicate the dominant role played by the isovector neutron-proton pairing correlations in the structure of odd-odd N = Z nuclei and the reduction of their importance with increasing neutron excess in even-even nuclei. The evolution of particular isovector and isoscalar pairs with increasing angular momentum is analyzed for the odd-odd N = Z nucleus 74Rb and the even-even N = Z nucleus 72Kr. It turns out that in the nucleus 74Rb the neutron-proton correlations play an essential role for the alignment of the yrast positive-parity even-spin band.

We review the theoretical interpretation of experimental results on low and high spin states in some even mass A=60−80 nuclei within the complex versions of the Excited Vampir and Fed Vampir variational approaches. The coexistence of oblate and prolate deformed configurations and their mixing at low spin are found to be responsible for the irregular sequences of states and the isomeric decays identified at low excitation energy in even-even nuclei. This behaviour is determined essentially by the isoscalar neutron-proton interaction. At higher spins the coexistence of states with different deformations causes complicated multiple band structures and strong fragmentation of the B(E2) strengths. It also influences the occurence of almost identical bands at normal deformation in some even mass nuclei. In some odd-odd nuclei the shape coexistence furthermore suggests a possible mechanism to populate high spin isomeric states. For the ground state properties of N=Z nuclei the competition between neutron-proton and like-nucleon isovector pairing plays an important role. With increasing angular momentum the neutron-proton alignment dominates the like-nucleon one in the ground bands of odd-odd N=Z nuclei while in the doubly even N=Z nuclei both types of alignment are of comparable importance.

The recent investigations of the shape coexistence phenomena dominating the structure of even-even and odd-odd nuclei in the A ∼ 70 mass region are extended to N ⋍ Z nuclei ranging from krypton to molybdenum. Positive-parity states with even angular momenta in 72 Kr, 76 Sr, 78 Sr, 80 Zr and 84 Mo are investigated within the EXCITED VAMPIR approximation using essentially complex Hartree-Fock-Bogoliubov transformations and a relatively large model space. The results are compared with the available experimental data. We obtain an oblate ground band and strong oblate-prolate mixing for N = Z = 36, almost pure prolate and oblate bands, with the yrast one being prolate in 76 Sr, maximum prolate deformation in 76,78 Sr and 80 Zr with very high-lying non-yrast bands and decreased prolate quadrupole deformation for the N = Z = 42 system. Predictions for the electromagnetic properties of the investigated states are presented, too.

In a previous study immunocytochemically detectable metallothionein (MT) expression in tumor cells of invasive duct carcinoma of the breast was shown to be associated with a more aggressive behavior and these findings have been subsequently confirmed by others. The aim of this study was to examine the prevalence and significance of MT positivity in preinvasive duct carcinoma in situ (DCIS). Fifty-five specimens of pure screen-detected DCIS were stained immunocytochemically for MT using the antibody E9. The intensity and distribution of MT staining were assessed using a semi-quantitative method resulting in intensity distribution (ID) scores allowing duct by duct analysis in relation to architectural and cytological features of the DCIS. In general, myoepithelial cells around benign and malignant structures stained uniformly strongly for MT. Staining in DCIS was analyzed by architecture irrespective of cytology and by nuclear grade irrespective of architecture. The results showed that MT staining was significantly greater in comedo (ducts with necrosis) DCIS (ID = 97) compared with noncomedo (ducts without necrosis) DCIS (ID = 56) ( P = .05 by Mann Whitney U statistic) and that low cytological grade (ID = 50) was associated with less MT staining than was high cytological grade (ID = 92) ( P = .05 by Mann Whitney U statistic). These observations thus are consistent with the previously observed association between MT positivity and more aggressive behavior in invasive duct carcinoma of the breast.

Translational and Galilean invariant approaches to the charge form factor for elastic electron scattering from nuclei as well as to the longitudinal and transverse response functions for inclusive electron scattering are presented. The results indicate that the proper treatment of these invariances is rather essential for the analysis of such experiments.

A microscopic description of the yrast states in the odd-odd nucleus 72 As is presented. The investigation is based on the FED VAMPIR approach, which for each yrast state under consideration solves the general Hartree-Fock-Bogoliubov problem with symmetry-projection before variation first for the dominant and then successively for the most important correlating configurations. Energies as well as electromagnetic properties of the resulting bands are analysed and, where possible, compared to the experimental data. Unfortunately, the overall agreement with the latter is not very satisfying. Reasons for this deficiency are discussed.

The recent investigations of the shape-coexistence phenomena dominating the structure of the even-even nuclei in the A ∼ 70 mass region are extended by introducing neutron-proton and unnatural-parity correlations in the mean field, while keeping the time-reversal invariance and the axial-symmetry restrictions. Selected low-lying states in 68Ge, 72Ge and 72Kr nuclei are investigated within the FED VAMPIR or EXCITED FED VAMPIR approaches. The results obtained using real and complex mean fields in a relatively large model space are compared with the experimental data. Similar qualitative features are obtained with both real and complex calculations concerning the evolution of the shape transition and shape coexistence with increasing spin and excitation energy. The results obtained indicate the importance of the new type of correlations introduced by the complex mean fields.

We discuss the relation between K -mixing and gamma-decay branching ratios (BR) for dipole excitations using a microscopic, number and spin-projected mean-field model and two phenomenological approaches based on the former: a generalized two-level rotational model and a model with general projected matrix elements. The microscopic model shows that most of the unnatural parity excitations with strong ground state B (MI)↑ strength are associated with BR's to the 0 + and 2 + members of the ground band in agreement with the Alaga-rule. However, BR's calculated for other states do not correlate with the intrinsic K -values in a manner, which would allow one to predict K -mixing from them. The phenomenological models, with randomly selected, intrinsic transition matrix elements, reproduce qualitatively the experimental distribution of the BR's with no decisive information about the K -content of the initial states.

A set of deformed states generated with the VAMPIR approach is used for a generator coordinate method description of the 0 + states in 28 Si. As model space the 1s0d shell was used, and as effective hamiltonian the Chung-Wildenthal interaction. Thus a comparison with the “exact” shell-model solutions was possible. Potential-energy functions, overlaps between different deformation points and the hamiltonian matrices are discussed for three different types of VAMPIR solutions: with full symmetry projection, with particle-number projection only and without any projection. The validity of the “horizontal expansion” of the hamiltonian matrix is examined.

We investigate the effects of center-of-mass projection on the nuclear charge density resulting from self-consistent calculations using the effective Skyrme interaction. We compare the full projection with the widely used standard recipe which corrects for the spurious center-of-mass motion by unfolding a harmonic oscillation. We find that full projection is necessary for a quantitative description in light nuclei at least up to the Ca isotopes. The variations of the effect with varying Skyrme forces are studies. A microscopic derivation of the standard recipe, the oscillator correction is given.

The status of the microscopic explanation of the ground-state properties of finite nuclei (in a non-relativistic framework) is updated, and compared to the corresponding situation in nuclear matter. In addition, modifications of the meson exchange parameters in the nuclear medium are explored. It is demonstrated that a change of the effective meson mass for the scalar and vector mesons yields quite different effects on the saturation properties of nuclear matter and finite nuclei than a change of e.g. the effective mass of the pion. The origin of such differences are explored.

The shape coexistence phenomena dominating the structure of the nucleus 68 Ge are reinvestigated by taking the dominant correlations on top of the symmetry-projected quasiparticle mean-field solutions of the earlier EXCITED VAMPIR description into account. It turns out that in spite of some quantitative changes the main qualitative features of the older description like, e.g., the occurrence of multiple band structures, the coexistence of many differently deformed configurations, the high level density for medium and high spin values, and the corresponding complex feeding pattern do persist. Qualitatively these features are confirmed by recent experimental data. In addition an EXCITED VAMPIR description of the positive-parity states with even angular momenta in the nucleus 70 Se is reported. The results for this nucleus are besides a few peculiarities qualitatively rather similar to those of our earlier calculations for the nucleus 72 Se.

The convergence of the expansion for the effective interaction is studied considering as examples the shell model for the nuclei 18 O and 18 F. In this work the effective interaction is computed through third order in the Brueckner G matrix using both a harmonic-oscillator (HO) basis and a Brueckner-Hartree-Fock (BHF) basis. We report significant differences in the convergence behavior of the effective interaction in these two cases. Our results indicate that the choice of the BHF single-particle potential seems to facilitate the convergence of the effective interaction in low orders of the expansion, whereas the HO results exhibit a non-convergent behavior. The implications for the HO approach are discussed. All calculations have been performed considering a modern version of the Bonn one-boson-exchange potential for the nucleon-nucleon interaction.

Introduction Monoclonal antibodies and tyrosine kinase inhibitors (TKI) targeting the EGFR are approved or under investigation for the systemic treatment of patients with HNSCC. However, primary and acquired resistance against EGFR-targeted therapies are frequently observed. Mutational activation of the EGFR signaling cascade as well as molecular changes caused by HPV infection are the most abundant oncogenic alterations in HNSCC. Against this background we have used preclinical cancer models to study the impact of activated PI3K/AKT and RAS/RAF/MAPK pathways or HPV16 oncoprotein expression on the response to anti-EGFR therapies. Materia and methods Cetuximab- and erlotinib-sensitive cancer cells were retrovirally transduced to express HPV16 oncoproteins E6 or E7, conditionally active AKT and RAF-1 or a RASG12V mutant. HPV16-positive cancer cells and cells harboring endogenously mutated PIK3CA or RAS were used as alternative models. Cell proliferation, induction of apoptosis, clonogenic survival and tumor growth in immune-compromised mice were analyzed in relation to treatment with anti-EGFR antibodies. In support, tumor samples from cetuximab-treated patients with recurrent or metastatic HNSCC were probed for p16INK4a expression, an established biomarker of HPV infection and retrospectively analyzed concerning the response rates (RR) and progression free survival (PFS) in relation to HPV status. Results Activation of the PI3K/AKT and the RAS/RAF/MAPK pathways strongly protected HNSCC cells against anti-EGFR therapies. Mechanistically, this resistance was mediated by changes in the expression of anti-apoptotic proteins and could be overcome by co-treatment with specific inhibitors of EGFR downstream signaling. In contrast, the endogenous HPV status of HNSCC cells or the expression of HPV oncogenes had no significant impact on cetuximab-mediated suppression of EGFR signaling and proliferation in vitro. In addition, response rates (45.5% versus 45.5%) and median progression-free survival (97 versus 92 days) following cetuximab-based therapy were similar in patients with p16INK4A-positive and p16INK4A-negative tumors. Conclusion Activation of the PI3K/AKT and the RAS/RAF/MAPK pathways functionally interfere with the activity of anti-EGFR therapies. In contrast, HPV status of HNSCC did not influence the response to cetuximab in our retrospective analyses and in our preclinical models. In conclusion, cetuximab treatment should be administered independently of HPV status.

Background The reversible EGFR tyrosine kinase inhibitors E and G are effective treatments for advanced NSCLC, but most pts acquire resistance. Currently, the benefit from sustained EGFR blockade during subsequent salvage therapy is unclear. LUX-Lung 5 is an international, multicenter phase III trial studying the efficacy of BIBW2992 (Afatinib®, A), an irreversible erbB family blocker, in NSCLC pts progressing after treatment with ctx and E or G irrespective of their EGFR mutation status. Here we report the outcome of NSCLC pts treated within LUX-Lung 5 at a single center in relation to EGFR and KRAS mutation status. Methods Pts with stage IV (UICC 7) NSCLC progressing after ctx and E or G were enrolled into LUX-Lung 5. In part A of the study pts received A (starting dose 50 mg/d) until progression. In part B pts with clinical benefit ≥12 wks were randomized between A plus weekly paclitaxel vs investigator's choice mono ctx. Following microdissection, tumor DNA was extracted and analyzed by PCR and Sanger sequencing. Results Between May 2010 and February 2011 39 pts (20 f, 19 m; median age 61 y, 38-83 y) were enrolled at the West German Cancer Center. Median number of pretreatments was 3 (1-8) including E or G. So far, tumor biopsies were retrieved from 25 pts (64%). Somatic EGFR mutations were detected in 11 pts (44% of analyzed tumors, 28% of entire cohort), whereas 14 pts (56%/36%) exhibited EGFR wild type (wt) sequences. EGFR mutation status remains unknown in 14 pts (36%). KRAS mutation analysis was performed in 20 pts (51% of entire cohort) and 4 mutations were observed (20%/10%), 3 in EGFR wt and one in an EGFR mutant tumor. Median survival time from initiation of A was 432 d in EGFR mutant pts, 189 d in EGFR wt pts, and 255 d in KRAS mutant pts. Median survival time of pts with unknown EGFR mutation status was 191 d. Safety of A was manageable. Conclusions A can achieve disease control in heavily pretreated NSCLC pts. Pts with EGFR mutant tumors experience prolonged survival as compared to EGFR wt tumors (HR 0.29; 95% CI 0.07–0.64; p = 0.0058). This argues for sustained tumor dependency on EGFR signaling despite progression after E or G. Disclosure J. Kohler: J. Kohler received financial support from Boehringer Ingelheim for writing a review article. T.C. Gauler: T.C. Gauler is principle investigator of the BI1200.43 trial testing Afatinib in HNSCC. D. Theegarten: D. Theegarten is member of the Lilly Advisory Board. W. Eberhardt: W. Eberhardt received honoraries for advisory board functions from Boehringer Ingelheim, Astra Zeneca, Roche, OSi Pharmaceuticals, Pfizer and honoraries for lectures from Boehringer Ingelheim, Astra Zeneca, Roche and Pfizer. M. Schuler: M. Schuler received research funding from Boehringer Ingelheim and travel support from Lilly. All other authors have declared no conflicts of interest.

Aim: Mutations and/or amplifications of HER2 can be found in approximately 4% of patients with NSCLC. In patients with NSCLC and amplification of HER2, identified by immunohistochemistry (IHC3+) or positive fluorescence in situ hybridization (FISH), preliminary clinical data suggests efficacy of trastuzumab. AUY922 is an inhibitor of the heat shock protein HSP90. This protein acts as molecular chaperone for processing and transport of various intracellular proteins including HER2. AUY922 has shown single agent activity in patients suffering from HER2 amplified breast cancer. This trial investigates the efficacy of trastuzumab combined with AUY922 in patients with NSCLC. Methods: Patients with metastatic NSCLC and overexpression or amplification of HER2 (IHC DAKO 3+ or positive FISH) or activating mutation after failure of at least one standard treatment are enrolled for combination treatment with trastuzumab and AUY922 in this bicentric phase II study (study centers Cologne and Essen). Treatment starts as monotherapy with trastuzumab, restaging is performed every 6 weeks by CT scan. AUY922 is added at 70mg/m2 once weekly once progression occurs. The primary endpoint is response rate of combination therapy. Results: We screened 3,863 patients with NSCLC within the Network of Genomic Medicine for amplification or mutation of HER2 in Cologne; patients in Essen were screened separately. An amplification was detected in 4% of these patients, mutations occurred in 1.6%. So far, 5 patients have been treated within the ongoing trial. One patient is currently being treated with trastuzumab monotherapy and has shown stable disease in the third restaging after 18 weeks of treatment. The preliminary best response to combination therapy is disease stabilization for 12 weeks until progression, the maximum reduction in tumor volume is -29.3%, six weeks after start of combination therapy. Conclusions: Patients with NSCLC and amplified/mutated HER2 are treated with trastuzumab and AUY922 in this ongoing study. We will present preliminary data of clinical outcome and tolerability of this treatment. Disclosure: L. Nogova: Honoraria by Roche, Travel grant by Novartis; M. Schuler: Advisory Board/Consultant: AstraZeneca, Boehringer Ingelheim, Novartis, Pfizer Research grants: Boehringer Ingelheim, Novartis Honoraries: Alexion, Boehringer Ingelheim, Celgene, GlaxoSmithKline, Lilly, Novartis, Pfizer; J. Wolf: Advisory boards (compensated) and lecture fees: AstraZeneca, BMS, Boehringer-Ingelheim, Clovis, Novartis, Pfizer, Roche Research support: Bayer, Boehringer-Ingelheim, Novartis, Pfizer, Roche. All other authors have declared no conflicts of interest.

Aims To present wide-ranging clinicopathological data of papillary thyroid cancer in children and adolescents who have no apparent link to previous irradiation or other aetiological cause (genetic predisposition or contact with any well-known canceri-genic agent). Ninety-four consecutive surgically treated patients aged 4–18 years were investigated. Results In the majority of patients the carcinoma had already broken through the organ’s capsule and afflicted lymph nodes of both paratracheal (level VI) and parajugular (level II–IV, in a few cases level V) zones (pT3bN1bM0, n = 27; 28.4%). Median tumour size was 12 (range 1–100) mm. Classical variant of papillary thyroid carcinoma was the most common subtype (43; 45.7%) followed by follicular (20; 21.3%) and tall cell (10; 10.7%) variants. Incidence of lymph node metastases at presentation was 71.3% (N1a 20.2%, N1b 51.1%) and 9.6% of patients had bilateral N1b involvement. Classical architectonic ( p p p p Conclusion Papillary thyroid carcinoma in childhood and adolescence was most commonly diagnosed in patients aged 12–17 years and was usually >10 mm in size (53; 56.4%). Infiltration of soft tissues (36; 38.3%) and intrathyroid lymphatic vessels by tumour complexes and psammoma bodies (59; 62.8%) was common. It is also typical that the tumour undergoes secondary scarring located mostly in central parts (massive fibrosis involves 30–70% of neoplasm volume observed in 25 cases; 26.6%). The tumours spread regionally. Finally, autoimmune thyroiditis appears to play a role in the background pathology (26; 27.6%).

First results of a recently developed nuclear structure approach are reported. The model diagonalizes the Hamiltonian in the space of the symmetry-projected Hartree-Fock-Bogoliubov (HFB) vacuum and symmetry-projected quasiparticle excitations with respect to it. The underlying HFB transformation, which is assumed to be time-reversal and axially symmetric, is determined by variation after the projection. The model allows the use of large basis systems. The first investigation has been performed in the sd shell, using the Chung-Wildenthal interaction. Good agreement with the exact shell model diagonalization and a considerable improvement on the previous more restricted approach is obtained.

The angular momentum fluctuations of cranked Hartree-Fock-Bogoliubov wave functions are shown to be quite large and strongly varying in the regions of band crossing. The distribution of angular momenta is explicitly calculated using angular momentum projection. The peculiar behaviour of those distributions around the band crossing is discussed.

A Hartree-Fock calculation with parity-mixed orbitals is used in an effort to describe the ground state and O+ excited state of 16O. Parity projection and orthogonality between the ground state and the excited state are imposed as constraints in the variational procedure. It is found that there exists a stable ground state with parity-mixed orbitals. However, the only non spurious excited state which orthogonal to the ground state does not contain parity-mixing.

This article is intended as a review of models describing high and very high spin states in nuclei. It further gives examples of the application of these models to data. (i) First, an outline of the cranked Hartree-Fock-Bogoliubov (CHFB) theory is given. It is applied to the first and the second anomaly of the moment of inertia normally called backbending (bb). (ii) The CHFB approach is extended to n quasi-particle (q.p.) states. The role of the odd protons for bb is investigated. (iii) The difficulties of the cranking model with the total angular momentum conserved only on the average are studied. (iv) An exact angular momentum conserving model in which valence nucleons in a vi 13 2 (or πh 11 2 ) shell are coupled to a core is introduced. It explains the oscillating behaviour of bb as a function of the neutron (or for second bb of the proton) number. (v) The decay of a highly excited and rapidly rotating compound nucleus after a heavy ion (HI) fusion reaction into particles and γ rays is described by the Monte Carlo method. Special attention is paid to the competition between collective and single particle γ ray decay. (vi) Different methods for calculating the deformation energy surface (DES) at high spins are discussed. The occurrence of yrast isomers is investigated. Furthermore, the nuclear stability against fission, particle emission and large scale shape changes is discussed.

Recent theoretical investigations revealed two different mechanisms for the backbending in 130Ce and 128Ba. While in 130Ce the well-known alignment of two nucleons at the beginning of the π h 11 2 shell is found, in 128Ba the effect is produced by the particles in the more than half-filled ν h 11 2 orbit and hence is preceded by the scattering of a nucleon pair in the nearby ν g 7 2 shell in order to increase the available alignment energy. The present paper is devoted to the possible experimental fingerprints of these different mechanisms. Using the wave functions already obtained, the total spin of each state is decomposed into the individual contributions from the different shells. Furthermore g-factors, static and dynamic quadrupole and also static hexadecapole moments are calculated. It turns out that the only decisive measurable quantities are the occupations of the relevant shells before and after the backbend, which are hardly accessible experimentally, at least at present.

The Hartree-Fock-Bogoliubov approach with spin and number projection before the variation extended to the description of nonyrast states (EXCITED VAMPIR) is used to describe simultaneously many properties of the 68,70,72,74Ge and 72,74Se nuclei. Low-lying spectra, neutron and proton occupation numbers for the spherical-basis orbitals, E0 and E2 transitions, and quadrupole moments are calculated and a fairly good agreement is obtained with experiment. The analysis of the EXCITED VAMPIR mean fields reveals that a strong mixing of prolate and oblate intrinsic quasiparticle determinants is responsible for the complex behaviour of the nuclei in A=70 region.

The solution of the Hartree-Fock-Bogoliubov problem with restoration of the broken symmetries before the variation, as it has been formulated within the VAMPIR and EXCITED VAMPIR approaches yields a description of each state of the nucleus by essentially one single symmetry-projected quasi-particle determinant. In the present paper we propose a procedure which allows to go beyond this mean-field approximation and to include the most important additional correlations in a systematic way. In this new approach each state is approximated by a linear combination of several symmetry-projected quasi-particle determinants, and the corresponding quasi-particle transformations are determined successively together with the configuration mixing via a chain of variational calculations. In this way the selection of the relevant configurations for each state is entirely left to the dynamics of the considered system. The method is applied to some selected examples within the 1sOd shell (the lowest three I π = 1 + states in 20 Ne and the 0 + , 2 + , 4 + members of the 28 Si ground-state band). The results are compared to the exact as well as to the VAMPIR and EXCITED VAMPIR results. Considerable improvements with respect to the latter approaches are obtained.

We have calculated the neutrinoless double beta decay rate of 76Ge. We take into account for the first time a relativistic correction to the nuclear current including weak magnetism. Its effect is to cancel a considerable part of the decay amplitude and we obtain less stringent upper limits on the neutrino Majorana mass and the right-handed weak leptonic current compared with previous calculations.

Two main shortcomings of the cranking model in band crossing regions, namely the possible occurrence of discontinuities and the strongly varying angular momentum fluctuations, are investigated. It is found that because of these drawbacks the reliability of the cranking approximation in regions of band crossing is more than doubtful, and that even the suggestions to overcome the difficulties by including the so-called physical parts of the 2qp trajectory do not improve the situation, at least as far as the wave functions are considered.

In this first of two successive papers we present a microscopic model for nuclear reactions. It allows the description of elastic and inelastic nucleon scattering as well as photonuclear reactions with real and virtual photons. The model is based on a particular classification scheme of the many-body Hilbert space according to the number of continuum nucleons. By its very definition it is restricted to processes with at most one continuum particle in the entrance and/or exit channel. In a large model space, containing all single-particle resonances as bound states, nuclear wave functions are calculated by means of the structure model MONSTER(VAMPIR). Arbitrary general effective two-body forces may be used for the structure calculations as well as for the coupling of the resulting highly correlated wave functions to the continuum. It is the coupling to a modified resonance free continuum in the framework of a general coupled-channel calculation which allows the description of the intermediate structure of the nuclear continuum. In the second paper results obtained from an application to the reaction /sup 29/Si(e,e'x/sub i/)/sup 27/Al will be presented, while in a forthcoming paper the particular role of a fifth response function arising from polarized electron scattering will be discussed. copyrightmore » 1988 Academic Press, Inc.« less