Search

Acknowledgments We thank the participants of the FPF meetings and the Snowmass working groups for discussions that have contributed both directly and indirectly to this study. We gratefully acknowledge the invaluable support of the CERN Physics Beyond Colliders study group and the work of CERN technical teams related to civil engineering studies (SCE-DOD), safety discussions (HSE-OHS, HSE-RP, EP-DI-SO), integration (EN-ACE), and discussions on services (EN-CV, EN-EL, EN-AA) and simulations (SY-STI). The work by J Alameddine, W Rhode, T Ruhe, and A Sandrock has been supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Collaborative Research Center SFB 876 and SFB 1491. L A Anchordoqui is supported by the US National Science Foundation (NSF) Grant PHY-2112527. T Araki is supported by JP18H01210. A Ariga is supported by JSPS KAKENHI Grant JP20K23373 and the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant 101002690). T Ariga acknowledges support from JSPS KAKENHI Grant JP19H01909. K Asai is supported by JSPS KAKENHI Grant JP19J13812 and JP21K20365. A Bacchetta and F G Celiberto acknowledge support from the INFN/NINPHA project. P Bakhti and M Rajaee are supported by the National Research Foundation of Korea (NRF-2020R1I1A3072747). B Barman received funding from the Patrimonio Autónomo—Fondo Nacional de Financiamiento para la Ciencia, la Tecnología y la Innovación Francisco José de Caldas (MinCiencias—Colombia) Grant 80740-465-2020 and the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 860881-HIDDeN. The work of B Batell is supported by the US Department of Energy (DOE) Grant DE–SC0007914. The work of A Berlin, T J Hobbs, S Hoeche, and J G Morfín was supported by the Fermi National Accelerator Laboratory (Fermilab), a US DOE, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract DE-AC02-07CH11359. M Becker, E Copello and J Harz acknowledge support from the DFG Emmy Noether Grant HA 8555/1-1. E Copello acknowledges also support from the DFG Collaborative Research Centre 'Neutrinos and Dark Matter in Astro- and Particle Physics' (SFB 1258). E Bertuzzo acknowledges financial support from FAPESP Contracts 2015/25884-4 and 2019/15149-6 and is indebted to the Theoretical Particle Physics and Cosmology group at King's College London for hospitality. The work of J Bian and W Wu is supported in part by US DOE Grant DE-SC0009920 and Heising-Simons Foundation Grant 2022-3319. The work of A Boyarsky and M Ovchynnikov is supported by the ERC under the European Union's Horizon 2020 Research and Innovation Programme (GA 694896). A Carmona acknowledges funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant Agreement No. 754446 and UGR Research and Knowledge Transfer Found—Athenea3i. A Carmona also acknowledges partial support by the Ministry of Science and Innovation and SRA (10.13039/501100011033) Grant PID2019-106087GB-C22 and by the Junta de Andalucía Grant A-FQM-472-UGR20. F G Celiberto thanks the Università degli Studi di Pavia for the warm hospitality. The work of G Chachamis was supported by the Fundação para a Ciência e a Tecnologia (Portugal) under Project CERN/FIS-PAR/0024/2019 and Contract 'Investigador auxiliar FCT—Individual Call/03216/2017'. The work of M Citron and D Stuart is supported by US DOE Grant DE-SC0011702. The work of L Darme is supported by the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement 101028626. P B Denton acknowledges support from the US DOE Grant Contract DE-SC0012704. The work of P S Bhupal Dev was supported in part by the US DOE Grant DE-SC0017987. The research activities of K R Dienes were supported in part by the US DOE Grant DE-FG02-13ER41976/DE-SC0009913 and also by the US NSF through its employee IR/D program. M V Diwan acknowledges support from the US DOE Grant Contract DE-SC0012704. Y Du and J H Yu are supported in part by National Key Research and Development Program of China Grant 2020YFC2201501, and the National Science Foundation of China (NSFC) under Grants 12022514, 11875003 and 12047503, and CAS Project for Young Scientists in Basic Research YSBR-006, and the Key Research Program of the CAS Grant XDPB15. The work of B Dutta and S Ghosh are supported in part by the US DOE Grant DE-SC0010813. The work of S Ghosh is also supported in part by National Research Foundation of Korea (NRF)'s Grants, Grant 6N021413. Y Farzan has received financial support from Saramadan Contract ISEF/M/400279 as well as from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant Agreement 860881-HIDDeN. The work of J L Feng is supported in part by US NSF Grants PHY-1915005 and PHY-2111427, Simons Investigator Award #376204, Simons Foundation Grant 623683, and Heising-Simons Foundation Grants 2019-1179 and 2020-1840. M Fieg is supported in part by US NSF Grant PHY-1915005 and by NSF Graduate Research Fellowship Award DGE-1839285. A L Foguel is supported by FAPESP Contract 2020/00174-2. The work of P Foldenauer is supported by the UKRI Future Leaders Fellowship DARKMAP. The work of S Foroughi-Abari and A Ritz is supported in part by NSERC, Canada. The work of J-F Fortin is supported in part by NSERC, Canada. A Friedland is supported by the US DOE Grant DE-AC02-76SF00515. E Fuchs acknowledges support by the DFG Germany's Excellence Strategy—EXC-2123 'QuantumFrontiers'—390837967. M Fucilla, M M A Mohammed, and A Papa acknowledge support from the INFN/QFT@COLLIDERS project. A Garcia acknowledges support from the European Union's H2020-MSCA Grant Agreement 101025085. C A García Canal and S J Sciutto acknowledge support from CONICET and ANPCyT M V Garzelli acknowledges support the from German BMBF Contract 05H21GUCCA. V P Goncalves was partially financed by the Brazilian funding agencies CNPq, CAPES, FAPERGS and INCT-FNA (Process Number 464898/2014-5). S Goswami acknowledges the J C Bose Fellowship (JCB/2020/000011) of Science and Engineering Research Board of Department of Science and Technology, Government of India. The work of M Guzzi is supported by US NSF Grant PHY-2112025. L Harland-Lang thanks the Science and Technology Facilities Council (STFC) for support via Grant Award ST/L000377/1. The work of S P Harris is supported by the US DOE Grant DE-FG02-00ER41132 as well as the US NSF Grant PHY-1430152 (JINA Center for the Evolution of the Elements). J C Helo acknowledge support from Grant ANID FONDECYT-Chile 1201673 and ANID—Millennium Science Initiative Program ICN2019-044. The work of M Hirsch is supported by the Spanish Grants PID2020-113775GB-I00 (AEI/10.13039/501100011033) and PROMETEO/2018/165 (Generalitat Valenciana). The work of A Hryczuk and M Laletin is supported by the National Science Centre, Poland, research Grant 2018/31/D/ST2/00813. The research activities of F Huang are supported by the International Postdoctoral Exchange Fellowship Program and in part by US NSF Grant PHY-1915005. A Ismail is supported by NSERC (Reference Number 557763) and by US NSF Grant PHY-2014071. Y S Jeong acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government through Ministry of Science and ICT Grant 2021R1A2C1009296. K Jodlowski and L Roszkowski are supported by the National Science Centre, Poland, research Grant 2015/18/A/ST2/00748. S R Klein is supported in part by the US NSF Grant PHY-1307472 and the US DOE Contract DE-AC-76SF00098. F Kling and P Quílez are supported by the DFG under Germany's Excellence Strategy—EXC 2121 Quantum Universe—390833306. P Ko is supported in part by KIAS Individual Grant PG021403 and by National Research Foundation of Korea (NRF) Grant NRF-2019R1A2C3005009. S Kulkarni is supported by the Austrian Science Fund Elise-Richter Grant V592-N27. The work of J Kumar is supported in part by US DOE Grant DE-SC0010504. J-L Kuo is supported by US NSF Theoretical Physics Program, Grant PHY-1915005. The work of C Le Roux and K Zapp is part of a project that has received funding from the ERC under the European Union's Horizon 2020 Research and Innovation Programme (Grant Agreement 803183, collectiveQCD). The work of H-S Lee was supported in part by the National Research Foundation of Korea (NRF-2021R1A2C2009718). S J Lee was supported by the Samsung Science and Technology Foundation. Ji Li is supported by the National Natural Science Foundation of China Grant 11905149. K-F Lyu and Z Liu are supported in part by the US DOE Grant DE-SC0022345. The work of R Maciula and A Szczurek was partially supported by the Polish National Science Centre under Grant 2018/31/B/ST2/03537. R Mammen Abraham and A Ismail acknowledge support from the US DOE Grant DE-SC0016013. M R Masouminia is supported by the UK Science and Technology Facilities Council (Grant ST/P001246/1). The work of J McFayden was supported by the Royal Society Fellowship Grant URF R1 201519. The work of O Mikulenko is supported by the NWO Physics Vrij Programme 'The Hidden Universe of Weakly Inter-acting Particles' with Project Number 680.92.18.03 (NWO Vrije Programma), which is (partly) financed by the Dutch Research Council (NWO). P Nadolsky and F Olness acknowledge support through US DOE Grant DE-SC0010129. E R Nocera thanks the STFC for support by the Grant Awards ST/P000630/1and ST/T000600/1. The work of N Okada is supported by the US DOE Grant DE-SC0012447. V Pandey acknowledges the support from US DOE Grant DE-SC0009824. The work of D Raut is supported by the US DOE Grant DE-SC0013880. P Reimitz acknowledges financial support from FAPESP Contract 2020/10004-7. M H Reno is supported in part by US DOE Grant DE-SC-0010113. The work of J Rojo is partly supported by the Dutch Research Council (NWO). L Roszkowski and S Trojanowski are supported by the grant 'AstroCeNT: Particle Astrophysics Science and Technology Centre' carried out within the International Research Agendas programme of the Foundation for Polish Science financed by the European Union under the European Regional Development Fund. S Trojanowski is also supported in part by the Polish Ministry of Science and Higher Education through its scholarship for young and outstanding scientists (Decision No. 1190/E-78/STYP/14/2019). S Trojanowski is also supported in part from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No. 952480 (DarkWave 24 project). I Sarcevic is supported by US DOE Grant DOE DE-SC-0009913. The work of L Shchutska is supported by the ERC under the European Union's Horizon 2020 Research and Innovation Programme (GA 758316). The work of T Shimomura is supported by JSPS KAKENHI Grants JP18H01210, JP18K03651, and MEXT KAKENHI Grant JP18H05543. The work of K Sinha is supported in part by US DOE Grant DE-SC0009956. The work of T Sjöstrand is supported by the Swedish Research Council, Contract 2016-05996. J T Sobczyk acknowledges support from NCN Grant UMO-2021/41/B/ST2/02778. D Soldin acknowledges support from the US NSF Grant PHY-1913607. H Song is supported by the International Postdoctoral Exchange Fellowship Program. Y Soreq is supported by grants from the NSF-BSF, BSF, the ISF and by the Azrieli foundation. A Stasto acknowledges support from US DOE Grant DE-SC-0002145. S Su is supported by the US DOE Grant DE-FG02-13ER41976/DE-SC0009913. W Su is supported by a KIAS Individual Grant (PG084201) at Korea Institute for Advanced Study. Y Takubo is supported by JP20K04004. M Taoso acknowledges support from the INFN Grant 'LINDARK', the research grant 'The Dark Universe: A Synergic Multimessenger Approach 2017X7X85' funded by MIUR, and the project 'Theoretical Astroparticle Physics (TAsP)' funded by the INFN. The research activities of B Thomas are supported in part by US NSF Grant PHY-2014104. The work of Y-D Tsai is supported in part by US NSF Grant PHY-1915005. The work of A Sabio Vera has been supported by the Spanish Research Agency (Agencia Estatal de Investigación) through the Grant IFT Centro de Excelencia Severo Ochoa SEV-2016-0597, by the Spanish Government Grant FPA2016-78022-P and from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement 824093. The work of Yongchao Zhang is supported by the National Natural Science Foundation of China Grant 12175039, the 2021 Jiangsu Shuangchuang (Mass Innovation and Entrepreneurship) Talent Program JSSCBS20210144, and the 'Fundamental Research Funds for the Central Universities'. Yue Zhang is supported by the Arthur B McDonald Canadian Astroparticle Physics Research Institute. R Zukanovich Funchal is partially supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Ciência e Tecnologia (CNPq). The opinions and conclusions expressed herein are those of the authors and do not represent any funding agencies., High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF's physics potential., German Research Foundation (DFG) SFB 876 SFB 1491, National Science Foundation (NSF) PHY2112527, Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research (KAKENHI) JP18H01210 JSPS KAKENHI JP20K23373 JP19H01909 JSPS KAKENHI JP19J13812 JP21K20365 JSPS KAKENHI JP18K03651, European Research Council (ERC) 101002690, National Research Foundation of Korea NRF-2020R1I1A3072747, Patrimonio Autónomo-Fondo Nacional de Financiamiento para la Ciencia Tecnología y la Innovación Francisco José de Caldas (MinCiencias-Colombia) 80740-465-2020, European Commission Joint Research Centre 860881-HIDDeN European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant 754446, United States Department of Energy (DOE) DE-SC0007914, Fermi National Accelerator Laboratory (Fermilab), a US DOE, Office of Science, HEP User Facility, Fermi Research Alliance, LLC (FRA) DE-AC02-07CH11359, German Research Foundation (DFG) HA 8555/1-1, DFG Collaborative Research Centre 'Neutrinos and Dark Matter in Astro-and Particle Physics' SFB 1258, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2015/25884-4 2019/15149-6, United States Department of Energy (DOE) DE-SC0009920, Heising-Simons Foundation 2022-3319 2019-1179 2020-1840, ERC under the European Union's Horizon 2020 Research and Innovation Programme 694896 803183, UGR Research and Knowledge Transfer Found-Athenea3i, Ministry of Science and Innovation, Spain (MICINN) Spanish Government, SRA Grant PID2019-106087GB-C22, Junta de Andalucía A-FQM-472-UGR20, Fundacao para a Ciencia e a Tecnologia (FCT) CERN/FIS-PAR/0024/2019 03216/2017, United States Department of Energy (DOE) DE-SC0011702 DE-SC0017987 DE-FG02-13ER41976/DE-SC0009913 DE-SC0012704 DE-SC0010813 DE-AC02-76SF00515 DE-FG02-00ER41132 DE-AC-76SF00098 DE-SC0010504 DE-SC0022345 DE-SC0010129, US NSF through its employee IR/D program, National Key Research and Development Program of China 2020YFC2201501, National Natural Science Foundation of China (NSFC) 12022514 11875003 12047503, CAS Project for Young Scientists in Basic Research YSBR-006, Key Research Program of the CAS XDPB15, National Research Foundation of Korea (NRF)'s Grants 6N021413, Saramadan Contract ISEF/M/400279, National Science Foundation (NSF) PHY-1915005 PHY-2111427 PHY1430152 PHY-2014071 PHY-1307472 PHY-2014104, Simons Investigator Award 376204, Simons Foundation 623683, National Science Foundation (NSF) DGE-1839285, FAPESP Contract 2020/00174-2, UKRI Future Leaders Fellowship DARKMAP, Natural Sciences and Engineering Research Council of Canada (NSERC), German Research Foundation (DFG) EXC-2123 390837967, INFN/QFT@COLLIDERS project, European Union's H2020-MSCA Grant Agreement 101025085, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), ANPCyT, Federal Ministry of Education & Research (BMBF) 05H21GUCCA, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ), Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Fundacao de Amparo a Ciencia e Tecnologia do Estado do Rio Grande do Sul (FAPERGS), INCT-FNA 464898/2014-5, J C Bose Fellowship of Science and Engineering Research Board of Department of Science and Technology, Government of India JCB/2020/000011, National Science Foundation (NSF) PHY-2112025, UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) Science and Technology Development Fund (STDF) ST/L000377/1, Grant ANID FONDECYT-Chile 1201673, ANID-Millennium Science Initiative Program ICN2019-044, Spanish Grant (AEI) PID2020-113775GBI00, Center for Forestry Research & Experimentation (CIEF) PROMETEO/2018/165, National Science Centre, Poland 2018/31/D/ST2/00813, International Postdoctoral Exchange Fellowship Program, KIAS Individual Grant PG021403, National Research Foundation of Korea NRF-2019R1A2C3005009, Austrian Science Fund Elise-Richter Grant V592-N27, US NSF Theoretical Physics Program PHY-1915005, Samsung, National Natural Science Foundation of China (NSFC) 11905149, Polish National Science Centre 2018/31/B/ST2/03537, UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ST/P001246/1, Royal Society of London URF R1 201519, Netherlands Organization for Scientific Research (NWO) 680.92.18.03 Physics Vrij Programme .The Hidden Universe of Weakly Inter-acting Particles' - Dutch Research Council (NWO), UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ST/T000600/1 ST/P000630/1, Netherlands Organization for Scientific Research (NWO), European Union under the European Regional Development Fund, Polish Ministry of Science and Higher Education through its scholarship for young and outstanding scientists 1190/E-78/STYP/14/2019, European Commission 952480, ERC under the European Union 758316, Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (KAKENHI) JP18H05543 MEXT KAKENHI, Swedish Research Council 2016-05996, NCN UMO-2021/41/B/ST2/02778, NSF-BSF, US-Israel Binational Science Foundation, Israel Science Foundation, Azrieli foundation, KIAS Individual Grant at Korea Institute for Advanced Study PG084201, Istituto Nazionale di Fisica Nucleare (INFN), Ministry of Education, Universities and Research (MIUR) 2017X7X85', Spanish Government SEV-2016-0597 Spanish Research Agency (Agencia Estatal de Investigacion) through the Grant IFT Centro de Excelencia Severo Ochoa FPA2016-78022-P, European Union's Horizon 2020 Research and Innovation Programme 824093, National Natural Science Foundation of China (NSFC) 12175039, 2021 Jiangsu Shuangchuang (Mass Innovation and Entrepreneurship) Talent Program JSSCBS20210144, Fundamental Research Funds for the Central Universities, Arthur B McDonald Canadian Astroparticle Physics Research Institute, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), United States Department of Energy (DOE) DE-SC0012447 DE-SC0009824 DE-SC0013880 :The US DOE DE-SC-0010113 DOE DE-SC-0009913 US DOE DE-SC0009956 DE-FG02-13ER41976/DESC0009913 US DOE JP20K04004

Due to collision singularities, the Lagrange action functional of the N-body problem in general is not differentiable. Because of this, the usual critical point theory cannot be applied to this problem directly. Following ideas from Arioli et al (2006 Commun. Math. Phys. 268 439–63); Bahri and Rabinowitz (1991 Ann. Inst. Henri Poincare Anal. Non Lineaire 8 561–649); Tanaka (1993 Ann. Inst. Henri Poincare Anal. Non Lineaire 10 215–38), we introduce a notion called weak critical point for such an action functional, as a generalization of the usual critical point. A corresponding definition of Morse index for such a weak critical point will also be given. Moreover it will be shown that the Morse index gives an upper bound of the number of possible binary collisions in a weak critical point of the N-body problem with weak force potentials including the Newtonian potential.

The process of turning a proton into a neutron, positron and electron-neutrino in a strong plane-wave electromagnetic field is studied. This process is forbidden in vacuum and is seen to feature an exponential suppression factor which is non-perturbative in the field amplitude. The suppression is alleviated when the proton experiences a field strength of about ten times the Schwinger critical field in its rest frame or larger. Around this threshold the lifetime of the proton, in its rest frame, is comparable to the conventional neutron decay lifetime. As the field strength is increased, the proton lifetime becomes increasingly short. We investigate possible scenarios where this process may be observed in the laboratory using an ultra-intense laser and a high-energy proton beam with the conclusion, however, that it would be very challenging to observe this effect in the near future., 22 pages, 2 figures. To appear in the Focus issue "Strong Field Quantum Electrodynamics with high power lasers and particle beams" of New Journal of Physics

We calculate and discuss the implications of neutrino self-interactions for the physics of weak decoupling and big bang nucleosynthesis (BBN) in the early universe. In such neutrino-sector extensions of the standard model, neutrinos may not free-stream, yet can stay thermally coupled to one another. Nevertheless, the neutrinos exchange energy and entropy with the photon, electron-positron, and baryon component of the early universe only through the ordinary weak interaction. We examine the effects of neutrino self-interaction for the primordial helium and deuterium abundances and $N_{\rm eff}$, a measure of relativistic energy density at photon decoupling. These quantities are determined in, or may be influenced by, the physics in the weak decoupling epoch. Self interacting neutrinos have been invoked to address a number of anomalies, including as a possible means of ameliorating tension in the Hubble parameter. Our calculations show that surprisingly subtle changes in BBN accompany some of these neutrino self-interaction schemes. Such minute signals require high-precision measurements, making deuterium the best abundance for BBN constraints in the models explored here., Comment: Version accepted by JCAP. 26 pages, 5 figures; mistakes in Sec. 5 corrected; model clarified in Sec. 1

Weak values are traditionally obtained using a weak interaction between the measured system and a pointer state. It has, however, been pointed out that weak coupling can be replaced by a carefully tailored strong interaction. This paper provides a direct comparison of two strong interaction-based approaches (strong interaction accompanied by either a suitably prepared pointer state or quantum erasure) and the traditional weak interaction-based method. Presented theoretical derivations explicitly prove analytical equivalence of these approaches which was subsequently certified by an experiment implemented on the platform of linear optics. We find that strong-interaction-based measurements are experimentally less demanding on this platform., 9 pages, 3 figures

This study presents an effective scheme for estimating the weak Coulomb force through a hybrid optomechanical system. In this scheme, information regarding the weak Coulomb force can be transferred to the cavity field through the coupling between the cavity field and the mechanical oscillator, and it can be fully extracted from the cavity field when the cavity field and the mechanical oscillator are disentangled. We employed the quantum Fisher information and the error propagation formula to analyse the effects of the coupling strength, the cavity average photon number and the Coulomb force on the estimation precision. We observed that the estimation precision can be improved by increasing the coupling strength. In addition, when choosing the proper value of average photon number and the proper range of the Coulomb force, we can approach the theoretical-attainable precision determined by quantum Fisher information. Particularly, the magnitude of the estimated weak Coulomb force in this scheme is up to 10ڨ10N or even smaller, which is better than the results obtained from previously conducted studies. Moreover, the decoherence of the mechanical oscilator and that of the cavity field are considered by solving the master equation. We show that the leakage of photons from the cavity greatly influences the measurement precision.

We propose a scheme for detecting time-varying weak forces using quantum probe consisting of single spin and quantum oscillator under the effect of collective dissipation. We study the force estimation in the steady-state regime where the information of the force is extracted by measuring observable of the oscillator such as quadrature and mean phonon excitation. We quantify the force sensitivity in terms of quantum Fisher information and show that it diverges approaching the critical spin-boson coupling making the system sensitive to very small force perturbation. We show that close to the critical coupling the measurement of the oscillator quadrature is optimal in a sense that saturates the fundamental Cramer-Rao bound. Furthermore, we study the force estimation in the presence of phonon squeezing and show that it can significantly improve the sensitivity reaching minimal detectable force of order of xN (1${\rm xN=10^{-27}{\rm N}}$)., 7 pages, 5 figures

The penetration and diffusion of metal atoms in self-assembled monolayers (SAMs) and pentacene solids were studied by first-principles calculations. It was shown in the case of SAM that metal atoms easily penetrate and diffuse in solids, reflecting the weak interaction between metal atoms and molecules. Even when diffusing metal atoms produce a cluster, such a cluster can easily diffuse in solids. In the case of pentacene, on the other hand, since the interaction between metal atoms and molecules is attractive and strong, metal atoms actively enter into solids and are tightly bonded to molecules. We found that Au atoms prefer to produce a cluster at the molecule edge and such a cluster is difficult to move, while Al atoms are scatteringly distributed and last the diffusion owing to the repulsive interaction between Al atoms. We showed that the difference in metal-atom behavior comes from the difference in electronic structure between SAM and pentacene, which are, respectively, σ- and π-orbital molecular systems.

Dark matter (DM) plays a major role in the large-scale structure formation of the universe. The leading candidate for DM particle is generally called Weakly Interacting Massive Particles (WIMPs) for its properties inferred from astronomical observations. Such DM particle would only interact via weak interaction and could decay or self-annihilate into other standard model particles such as , uū, e - e +, ν. In this work, we have simulated the final-state neutrino particles resulting from DM annihilations inside the Sun's core. The neutrino propagations and oscillations to Earth and expected signals at the Jiangmen Underground Neutrino Observatory (JUNO) are then calculated. We will present the preliminary results of our study, including comparisons with various other neutrino sources to be detected at JUNO.

We study the spectral properties of two-particle operators with weak interaction for spatial dimension . We show that such an operator is unitarily equivalent to the two-particle operator obtained from by omitting the interaction terms. This is done using a special diagrammatic technique developed in this paper.

With the recent discovery of a new particle at the CERN Large Hadron Collider (LHC) the Higgs boson could be about to be discovered. This paper provides a brief summary of the standard model of particle physics and the importance of the Higgs boson and field in that model for non-specialists. The role of Feynman diagrams in making predictions for interactions via the electromagnetic, strong and weak forces is also discussed. Finally, an educational tool (Minerva), which provides access to LHC collision data from the ATLAS experiment, is briefly described.

Employing phenomenological density-dependent critical temperatures of strong singlet-state proton pairing and of moderate triplet-state neutron pairing, we investigate the effects of rotochemical heating on the thermal evolution of superfluid neutron stars whose cores consist of npe matter with the Akmal-Pandharipande-Ravenhall equation of state. Since the star is not quite in the weak interaction equilibrium state during spin-down, the departure from the chemical equilibrium leads to the rotochemical heating in a rotating NS which will increase the stellar's temperature. Our calculations show that the rotochemical heating delays the cooling of superfluid neutron stars considerably and makes the previous classification of NS cooling ambiguous. What's more, our model is currently consistent with all the observational data, and in particular some middle-aged and cold NSs (PRS J0205+6449 in 3C 58, PRS J1357-6429, RX J007.0+7303 in CTA 1, Vela) can be better explained when taking into account rotochemical heating.

The measurement of parity-violating (PV) observables in few-nucleon system can shed light on our current understanding of the weak interaction between nucleons. Theoretical models describe the nucleon-nucleon weak interaction at low energies use a series of undetermined parameters. Two parity violating measurements have been considered: the capture of polarized slow neutrons on hydrogen ( + p ? d + ?) at Los Alamos National Laboratory for first phase and Oka Ridge National Laboratory for second phase and the helicity dependence of the deuteron photodisintegration cross section using circularly polarized photons ( + d ? n + p) at Shanghai Institute of Applied Physics. The goal of both experiments is to constraint the weak meson-nucleon couplings to a precision of 1 ? 10?8. The introduction of both experiments is presented.

The MiniBooNE experiment reported results from the analysis of νe and appearance searches, which showed an excess of signal-like events at low reconstructed neutrino energies with respect to the expected background. The origin of this anomaly could reside in poorly understood neutrino interactions in the detector, leading to unaccounted backgrounds. We discuss photon emission in neutral current interactions with nucleons and nuclei, finding it insufficient to explain the observed event excess. A proposed alternative scenario in which photons arise from the radiative decay of heavy (~ 50 MeV) sterile neutrinos produced by νµ electromagnetic and weak interactions in the detector is also considered. We have calculated the expected signal at MicroBooNE. The distinctive shape and total number of photon events from this mechanism makes its experimental investigation appealing.

Collective effects in deformed atomic nuclei present possible avenues of study on the non-spherical distribution of neutrons and the violation of the local Lorentz invariance. We introduce the weak quadrupole moment of nuclei, related to the quadrupole distribution of the weak charge in the nucleus. The weak quadrupole moment produces tensor weak interaction between the nucleus and electrons and can be observed in atomic and molecular experiments measuring parity nonconservation. The dominating contribution to the weak quadrupole is given by the quadrupole moment of the neutron distribution, therefore, corresponding experiments should allow one to measure the neutron quadrupoles. Using the deformed oscillator model and the Schmidt model we calculate the quadrupole distributions of neutrons, $Q_{n}$, the weak quadrupole moments ,$Q_{W}^{(2)}$, and the Lorentz Innvariance violating energy shifts in $^{9}$Be, $^{21}$Ne , $^{27}$Al, $^{131}$Xe, $^{133}$Cs, $^{151}$Eu, $^{153}$Eu, $^{163}$Dy, $^{167}$Er, $^{173}$Yb, $^{177}$Hf, $^{179}$Hf, $^{181}$Ta, $^{201}$Hg and $^{229}$Th.

The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η − χ parameter space. By representing the weak measurement on the Poincare sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques' capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

A new formalism is introduced to treat problems in quantum field theory, using coherent functional expansions rather than path integrals. The basic results and identities of this approach are developed. In the case of a Bose gas with point-contact interactions, this leads to a soluble functional equation in the weak interaction limit, where the perturbing term is part of the kinetic energy. This approach has the potential to prevent the Dyson problem of divergence in perturbation theory.

A new improved nuclear partition function is employed to calculate the nuclear statistical equilibrium (NSE) in core-collapse supernova environment. The results show that the change of nucleus abundance is slight even though the temperature is higher than 1011 K when shock propagates, which indicates that the effect of the nuclear partition function is not so important as shown in the previous calculations, but it can also be considered in detailed simulation if it is sensitive to weak interaction rates in core-collapse supernova.

The nuclear structure in regions of the Segre chart which are of astrophysical importance is reviewed. The main emphasis is put on those nuclei that are relevant for stellar nucleosynthesis in fusion processes, and in slow neutron capture, both located close to stability, rapid neutron capture close to the neutron dripline and rapid proton capture near the proton dripline. The basic features of modern nuclear structure, their importance and future potential for astrophysics and their level of predictibility are critically discussed. Recent experimental and theoretical results for shell evolution far off the stability line and consequences for weak interaction processes, proton and neutron capture are reviewed.

The effect of isospin terms of weak interaction on the main nonmesonic hypernuclear weak decay observables, the total rate, ?NM, the neutron-to-proton branching ratio, ?n/p, and the proton asymmetry parameter, a?, is evaluated. A general shell-model formalism for finite hypernuclei recently developed has been used. A strangeness-changing weak ?N ? NN transition potential including the exchange of pseudoscalar mesons (?, ?, K) is adopted. The effects of isospin changes have been added through an adequate modification of the weak coupling constants and a comparison with contribution is made both for 12?C and 5?He. Numerical computations show that the effect on the decay rates is very small and the neutron-to-proton ratio is reduced to ~4%. The asymmetry parameter a? is increased in the same percentage. We conclude that the effect of terms helps to enhance the a? value but diminishes ?n/p, both by a few per cent. In this regard, contribution of pseudoscalar mesons is not enough to reproduce the experimental data. The necessity of a detailed analysis including vector-meson exchange is suggested.

We extend the chiral hadronic model (FST) with an inclusion of Λ hyperon to investigate the properties of multi-Λ hypernuclei. With such an effective hadronic model in the relativistic mean-field approximation, we accomplish the calculations with both the conventional strong Λ–Λ interaction and the weak Λ–Λ interaction determined from recent experiment. Our calculations indicate that not only the strong but also the weak Λ–Λ interaction provide tighter binding for multi-Λ hypernuclei than the ones with only nucleons. However the strong interaction generates a binding slightly tighter than the weak interaction.

Nuclear and Particle Physics provides an introductory course on nuclear and particle physics for undergraduate and early-graduate students, which the author has taught for several years at the University of Zurich. It contains fundamentals on both nuclear and particle physics, giving emphasis to the discovery and history of developments in the field, and is experimentally/phenomenologically oriented. It contains detailed derivations of formulae such as 2–3 body phase space, the Weinberg-Salam model, and neutrino scattering. Originally published in German as Kern- und Teilchenphysik, several sections have been added to this new English version to cover modern topics, including updates on neutrinos, the Higgs boson, the top quark and bottom quark physics.

From the history of the $\theta$-$\tau$ puzzle and the discovery of parity non-conservation in 1956, we review the current status of discrete symmetry violations in the weak interaction. Possible origin of these symmetry violations are discussed., Comment: 16 pages, 3 figures

We discuss the properties of the lifetime or the time-delay matrix Q(E) for multichannel scattering, which is related to the scattering matrix S(E) by Q = iS(dS†/dE). For two overlapping resonances occurring at energies Eν with widths Γν(ν = 1, 2), with an energy-independent background, only two eigenvalues of Q(E) are proved to be different from zero and to show typical avoided-crossing behaviour. These eigenvalues are expressible in terms of the four resonance parameters (Eν, Γν) and a parameter representing the strength of the interaction of the resonances. An example of the strong and weak interaction in an overlapping double resonance is presented for the positronium negative ion. When more than two resonances overlap (ν = 1, ..., N), no simple representation of each eigenvalue has been found. However, the formula for the trace of the Q-matrix leads to the expression δ(E) = −∑arctan[(Γν/2)/(E − Eν)] + δb(E) for the eigenphase sum δ(E) and the background eigenphase sum δb(E), in agreement with the known form of the state density. The formulae presented in this paper are useful in a parameter fitting of overlapping resonances.

Francium is a candidate for atomic parity non-conservation (PNC) experiments. Its simple atomic structure has been the subject of extensive experimental research facilitated by the ability to trap and cool significant numbers of atoms. The studies include the location of energy levels, their hyperfine splittings and their lifetime. All of these levels are close to the ground state. The results show a remarkable agreement with calculated ab initio properties to a degree that is comparable with other stable alkali atoms. The quantitative understanding of francium has made possible the exploration of avenues for a PNC measurement in the optical and the microwave regimes. These precision experiments have the potential to enhance our understanding of the weak coupling constants between electrons and nucleons, as well as between nucleons.

High-resolution γ-ray spectroscopy is essential to fully exploit the unique, high-quality beams available at the next generation of radioactive ion beam facilities such as the TRIUMF isotope separator and accelerator (ISAC). The 8π spectrometer, which consists of 20 Compton-suppressed HPGe detectors, has recently been reconfigured for a vigorous research programme in weak interaction and nuclear structure physics. With the addition of a variety of ancillary detectors it has become the world's most powerful device dedicated to β-decay studies. This paper provides a brief overview of the apparatus and highlights from recent experiments.

The unexpectedly large transverse polarization measured in the B-to-phi K* decay poses the question whether it is accounted for as a strong interaction effect or possibly points to a hidden nonstandard weak interaction. We extend here the perturbative argument to the helicity structure of the two-body baryonic decay and discuss qualitatively on how the baryonic B decay modes might help us in understanding the issue raised by the B-to-VV decays. We find among others that the helicity +1/2 amplitude dominates in the leading order in the B (b-bar q) decay and that the dominant amplitude is sensitive to the right-handed penguin interaction., Comment: References added and typos corrected

A basic nonlinear two-state model generic in classical and bosonic field theories with a cubic nonlinearity is considered. For the class of models with constant external field amplitude a general strategy for attacking the problem is developed based on the reduction of the initial system of equations for the semi-classical atom–molecule amplitudes to a nonlinear Volterra integral equation for the molecular probability. A uniformly convergent series solution to the problem is constructed for the weak interaction limit. The Landau–Zener model is considered as a specific example. The first approximation term is derived and an asymptotic expression for the nonlinear transition probability is established in the weak interaction regime.

There are several proposals to build facilities similar to the neutron spallation source (SNS) under construction at the Oak Ridge National Laboratory (ORNL). These are also prolific sources of intermediate energy neutrinos. We have used the parameters of the SNS to compute the spectra, flux and time structure of neutrinos from stopped-pions and muons from protons impinging on a high-Z target. We demonstrate the feasibility of a broad programme of measurements of neutrino–nucleus cross-sections, important in weak interaction nuclear physics and nuclear astrophysics that could be carried out at such facilities.

Accurate masses of radioactive nuclides are important for a better understanding of nuclear structure, as input for the modelling of element synthesis in nuclear astrophysics and for fundamental tests of the weak interaction. Today, a variety of techniques exists for direct mass measurements of unstable nuclides. A very powerful approach is the employment of Penning traps. Penning trap mass spectrometry offers unprecedented accuracy, and is now applied to nuclides with half-lives well below a tenth of a second and produced only in minute quantities. This paper discusses specific aspects of Penning trap mass spectrometry on rare isotopes and gives an overview of on-going activities. This includes LEBIT, a new project at the National Superconducting Cyclotron Laboratory at Michigan State University.

A variation of the valence electron wave function inside a nucleus induced by a perturbative potential is expressed in terms of the potential momenta. As an application we consider QED vacuum polarization corrections due to the Uehling and Wichmann-Kroll potentials to the weak interaction matrix elements., Comment: 16 pages, Latex, IOP stile

The triplet character of doubly excited 2lnl' resonances close to the He+ (N = 2) ionization threshold has been seen to affect the angular distribution of photoelectrons associated with the He+ (1s) state: a peak has been observed at a photon energy just below the N = 2 threshold when the photoelectrons are detected at 90° with respect to the photon polarization direction. This is forbidden in pure LS-coupling and therefore the observation immediately indicates the presence of triplet configurations due to spin–orbit interactions. Such weak interaction effects are usually overwhelmed by LS-allowed processes, particularly in such a low-Z atom, but the choice of observation angle in this case desensitizes the measurements to the dominant ionization processes. The results have been reproduced by R-matrix MQDT calculations which also indicate that all seven relativistically allowed Rydberg series are present.

Parity-violating interactions between nucleons are the manifestation of an interplay of strong and weak interactions between quarks in the nucleons. Compared to the dominant parity-conserving part, the parity-violating component of the nuclear force is typically suppressed by approximately 6 to 7 orders of magnitude or more. Due to the short range of the weak interactions, however, it provides a unique probe of the strong dynamics that confine quarks into nucleons. An ongoing experimental program is mapping out this weak component of the nuclear force in few-nucleon systems. I will discuss recent theoretical progress based on effective field theory methods to analyze and interpret hadronic parity violation in few-nucleon systems, with a particular focus on two- and three-nucleon systems.

Lattice dynamical calculations of ice VIII have been carried out by using a slightly modified set of force constants obtained recently for ice Ih (Li J C and Ross D K 1993 Nature 365 327). A weak interaction was introduced between the two interpenetrated sublattices in the ice VIII structure. The calculated results for H2O and D2O ice VIII are in reasonable agreement with the measured inelastic neutron scattering spectra. The eigenvectors of phonon modes in the range of translational and librational bands have been studied in order to understand the properties of the vibrational modes. It is found that the third peak at 26.7meV in the translation results from weak hydrogen bond interactions and the first peak (14.7meV) is much higher than it is in ice Ih (~7.1meV), which is partially due to the interactions between the two sublattices.

The properties of strange hadronic matter are studied in the context of the modified quark-meson coupling model using two substantially different sets of hyperon-hyperon ($YY$) interactions. The first set is based on the Nijmegen hard core potential model D with slightly attractive $YY$ interactions. The second potential set is based on the recent SU(3) extension of the Nijmegen soft-core potential NSC97 with strongly attractive $YY$ interactions which may allow for deeply bound hypernuclear matter. The results show that, for the first potential set, the $\Sigma$ hyperon does not appear at all in the bulk at any baryon density and for all strangeness fractions. The binding energy curves of the resulting $N\Lambda\Xi$ system vary smoothly with density and the system is stable (or metastable if we include the weak force). However, the situation is drastically changed when using the second set where the $\Sigma$ hyperons appear in the system at large baryon densities above a critical strangeness fraction. We find strange hadronic matter undergoes a first order phase transition from a $N\Lambda\Xi$ system to a $N\Sigma\Xi$ for strangeness fractions $f_S>1.2$ and baryonic densities exceeding twice ordinary nuclear matter density. Furthermore, it is found that the system built of $N\Sigma\Xi$ is deeply bound. This phase transition affects significantly the equation of state which becomes much softer and a substantial drop in energy density and pressure are detected as the phase transition takes place., Comment: 25 pages latex and 12 figures in postscript format

AFM force curve measurements have been performed on layers of entangled multiwall carbon nanotubes, produced by chemical vapor deposition, to measure the nanotubes adhesive and elastic properties. AFM tip radius and nanotube diameter being comparable, these layers are a discrete medium for the force curve measurements. Controlling the tip-layer interaction, we can specifically probe the response of one or several nanotubes. If the tip is strongly pressed against the layer, it interacts with several nanotubes; for a weak interaction, it interacts with only one nano-object. Non-linear behavior in force curves is an evidence for an inelastic response of the nanotubes. Numerical simulations of the layer-AFM tip system mechanical analysis reproduce all the nanotubes adhesion and mechanical experimental features.

Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing.

The exchange coupling energy for two magnetized monolayers embedded symmetrically in a metal and polarized in an arbitrary direction has been investigated in contact interaction approximation. Since the model can be solved exactly in particular for free-electron case, the coupling energy contributed from both extended state electrons and bound state electrons is calculated rigorously. For weak interaction, it is found that the leading term in the power-series expansion of density of states can give a correct coupling energy compared with rigorous one while extended state electrons give a much larger coupling energy. Furthermore, the relevant problems such as phase shift, 90° coupling and lattice effects have been discussed; an asymptotic expression of the interlayer coupling has been derived in a different way and used to calculate the exchange energy between magnetic layers in copper with Fermi surface obtained from de Haas-van Alphen effect.

Parity conserving weak-interaction corrections to energy levels of highly charged few-electron ions are considered in the framework of the standard model. The corresponding effective potentials in coordinate space are derived. Due to the Z3 dependence on the nuclear charge number Z and due to the strong enhancement of the Dirac wavefunctions at the nuclear origin these corrections are strongly amplified for heavy few-electron ions. Their contribution to the Lamb shift and to the hyperfine splitting are of the order of 10-5 and 10-7 eV, respectively. This is much smaller than the recent experimental accuracy for the Lamb shift but not too far away from the expected accuracy for future hyperfine structure measurements.

At weak force range the two-well Duffing equation has a closed bifurcation region in the parameter plane, inside which there are many different periodic windows. By means of one-dimensional and two-dimensional symbolic dynamics, these periodic windows and the dynamical behavior of chaotic attractors are analyzed systematically.

The transition from bound exciton to free exciton and exciton–phonon interaction in an AlN epilayer have been investigated by time resolved deep ultraviolet photoluminescence spectroscopy. Based on the analysis of the energy position (S-shaped dependence with temperature), integrated intensity as well as decay time, the main X peak located at 6.06 eV at 7.7 K is assigned to originate from radiative recombination of excitons bound to some unintentionally doped Si or O impurities. While the other two peaks on the lower energy side should be from the bound exciton's phonon replicas. The corresponding small Huang–Rhys factor indicates weak interaction between phonon and bound excitons, in comparison to the case of free exciton, for which our experimental results are in good agreement with the theoretical calculation of the Huang–Rhys factors.

We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for $^{56}$Fe and $^{208}$Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons $\mathrm{p}(\bar{\nu}_\mathrm{e},\mathrm{e}^{+})\mathrm{n}$ are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of $\nu_\mathrm{e}$- and $\bar{\nu}_\mathrm{e}$-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei ($^{208}$Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice., Comment: 22 pages, 7 figures, 3 tables

A microscopic theory of the neutron, which consists in a neutron model constructed using key relevant experimental observations as input information and the first principles solutions for the basic properties of the model neutron, is proposed within a framework consistent with the Standard Model. The neutron is composed of an electron e and a proton p that are separated at a distance r1 of the order 10-18 m, and are in relative orbital angular motion and Thomas precession highly relativistically, with their reduced mass moving along a quantised circular orbit l = 1, j = ½ of radius vector r1½ = r1rˆ1½ about their mass centre. The associated rotational energy flux has a spin ½ and resembles a confined antineutrino. The particles e, p are attracted with one another predominantly by a central magnetic force produced as result of the particles' relative precessional-orbital and intrinsic angular motions. The interaction force (resembling the weak force), potential (resembling the Higgs' field), and a corresponding excitation Hamiltonian (HI), among others, are derived based directly on first principles laws of electromagnetism, quantum mechanics and relativistic mechanics within a unified framework. In particular, the equation for 4/3πr13HI, which is directly comparable with the Fermi constant GF, is predicted as GF = 4/3πr13HI = AoC0 ½/γeγp, where Ao = e22/12π𝜖0m0em0pc2, m0em0p are the e, p rest masses, C0½ is a geo-magnetic factor, and γe, γp are the Lorentz factors. Quantitative solution for a stationary meta-stable neutron is found to exist at the extremal point r1m = 2.537 × 10-18 m, at which the GF is a minimum (whence the neutron lifetime is a maximum) and is equal to the experimental value. Solutions for the magnetic moment, effective spin (½), fine structure constant, and intermediate vector boson masses of the neutron are also given in this paper.

In this review lifetime measurements of ions with at most two electrons are summarized. Such highly ionized systems have been studied - until now - only in the Experimental Storage Ring of the GSI in Darmstadt. Emphasis is put on decays via the weak interaction. The first observations of beta-decay into bound atomic states are described as well as its time mirrored counterpart, the electron-capture decay. In the latter case the decays of hydrogen- and helium-like ions are compared with a surprising result. Further on, the observation of sinusoidal modulations of the decay rate in two-body decays is summarized. As a possible cause an interference due to the emission of neutrinos with different rest mass is discussed., Comment: Proceedings of the 9th International Conference on Nuclear Physics at Storage Rings STORI'14

The production of light photons during beta decay in condensed media is investigated. The internal and external bremsstrahlung processes are considered as mechanisms for the light emission. It has been found that the total number of photons depends on the end-point of the beta spectrum and on the media characteristics. The degree of circular polarization (CP) of the bremsstrahlung light photons emitted during beta decay is analysed. It is suggested that CP of light bremsstrahlung may serve as an additional source of information about the features of the weak interaction in nuclei.

Mossbauer spectra of Fe-8.0 at.%C, Fe-10.9 at.%Al-8.2 at.%C, Fe-1.4 at.%Mn-7.9 at.%C, Fe-2.4 at.%Mn-7.8 at%C and Fe-14.6 at.%Ni-6.2 at.%C FCC gamma -irons have been measured in order to investigate the distribution and the local interactions of C in the lattice. The local interaction energies in nearest and second-nearest C-C and M-C (M: Al, Mn, Ni) atomic pairs have been determined by a Monte Carlo method simulating the distribution obtained. The interaction energies in nearest and second-nearest C-C pairs are strongly repulsive, in contrast to the weak interaction in second-nearest N-N pairs. The results are compared with the interaction energies derived from activity data. The interaction in nearest Al-C pairs is repulsive but that in second-nearest pairs is strongly attractive, which can lead to the formation of the perovskite Fe3AlC-type ordering. The interaction between nearest Mn and C atoms is strongly attractive, while between Ni and C the interaction is very weak.

Some of the problems related to the evaluation of binding energies (masses) and weak-interaction rates in nuclei of astrophysical interest are briefly discussed by way of a few selected examples of those arising in stellar evolution and nucleosynthesis studies.

The authors investigate the kinetics of a generalized monomer-monomer surface reaction model in which there is a variable excluded-volume interaction between same species particles (As and Bs). For no interaction, this system reduces to the monomer-monomer model for which there is a first-order transition between A- and B-saturated phases. As a function of the excluded volume interaction, the first-order transition line for weak interaction terminates at a tricritical point where two second-order transitions meet. These transitions, which appear to be in the Reggeon field theory universality class, separate the A-saturated, reactive, and B-saturated phases. Series expansions and various time-dependent Monte Carlo simulations are used to estimate the critical parameters and exponents associated with these transitions.