scholarly journals Off-shell pairing correlations from meson-exchange theory of nuclear forces

2003 ◽  
Vol 68 (6) ◽  
Author(s):  
Armen Sedrakian
Keyword(s):  
Exchange Theory ◽  
Meson Exchange ◽  
Nuclear Forces ◽  
Pairing Correlations

scholarly journals On the nuclear forces and the magnetic moments of the neutron and the proton

1938 ◽  
Vol 166 (924) ◽  
pp. 154-177 ◽  
Keyword(s):  
Cosmic Radiation ◽  
Decay Constant ◽  
Magnetic Moments ◽  
Cosmic Ray ◽  
Exchange Theory ◽  
Approximate Theory ◽  
Nuclear Forces ◽  
Hard Component ◽  
Heavy Particles ◽  
Upper Limit

It was first suggested by Heisenberg that the forces between a proton and a neutron are connected with an exchange of charge between the two heavy particles. This exchange nature of the neutron-proton forces is now generally accepted. It would follow from this assumption that in suitable circumstances a proton (neutron) could emit a positively (negatively) charged particle transforming itself into a neutron (proton). At first sight it seemed that the emission of positive or negative electrons in the β -decay could in this way be made responsible for the nuclear forces. This was, in fact, suggested by Iwanenko (1934) and Tamm (1934). It has also been pointed out by Wick (1935) that the virtual emission of β -electrons might explain the values of the magnetic moments of the proton and the neutron. These theories, however, were not successful. The nuclear forces, for instance, turn out to be too small by a factor of more than 10 10 and have far too small a range; this is due to the fact that the β -decay constant is extremely small. Since the β -decay is a process which, in nuclear dimensions, takes “geological ages”, one might think that the ordinary properties of the heavy particles have no direct connexion with this process and that an approximate theory of the nuclear forces should be possible without the inclusion of the β -decay. A new hope for such an “exchange theory” of the properties of nuclei is offered by the probable existence of a hitherto unknown type of particle constituting the hard component of cosmic radiation. Since these particles do not lose much energy by radiation, it has been suggested by Neddermeyer and Anderson (1937) that they are (positive and negative) “heavy electrons” with a mass between that of an electron and a proton. From cosmic-ray data the mass of these particles can hardly be determined yet, but it can be limited to values between 3 and 300 electron masses. There are, however, some arguments favouring a mass nearer to the upper limit of 100-200 electron masses.

Nuclear Strategy in the Modern Era

2014 ◽  
Author(s):  
Vipin Narang
Keyword(s):  
Deterrent Effect ◽  
Regional Power ◽  
Nuclear Forces ◽  
Regional Powers ◽  
Nuclear Strategy ◽  
Weak Institutions ◽  
Nuclear Age ◽  
International Stability ◽  
The World ◽  
Modern Era

The world is in a second nuclear age in which regional powers play an increasingly prominent role. These states have small nuclear arsenals, often face multiple active conflicts, and sometimes have weak institutions. How do these nuclear states—and potential future ones—manage their nuclear forces and influence international conflict? Examining the reasoning and deterrence consequences of regional power nuclear strategies, this book demonstrates that these strategies matter greatly to international stability and it provides new insights into conflict dynamics across important areas of the world such as the Middle East, East Asia, and South Asia. The book identifies the diversity of regional power nuclear strategies and describes in detail the posture each regional power has adopted over time. Developing a theory for the sources of regional power nuclear strategies, the book offers the first systematic explanation of why states choose the postures they do and under what conditions they might shift strategies. It then analyzes the effects of these choices on a state's ability to deter conflict. Using both quantitative and qualitative analysis, the book shows that, contrary to a bedrock article of faith in the canon of nuclear deterrence, the acquisition of nuclear weapons does not produce a uniform deterrent effect against opponents. Rather, some postures deter conflict more successfully than others. This book considers the range of nuclear choices made by regional powers and the critical challenges they pose to modern international security.

British Nuclear Forces, 2001

2001 ◽  
Vol 57 (6) ◽  
pp. 78-79
Author(s):  
Robert S. Norris ◽  
William M. Arkin ◽  
Hans M. Kristensen ◽  
Joshua Handler
Keyword(s):  
Nuclear Forces

Pakistan's Nuclear Forces, 2001

2002 ◽  
Vol 58 (1) ◽  
pp. 70-71
Author(s):  
Robert S. Norris ◽  
William M. Arkin ◽  
Hans M. Kristensen ◽  
Joshua Handler
Keyword(s):  
Nuclear Forces

Pakistan's nuclear forces, 2007

2007 ◽  
Vol 63 (3) ◽  
pp. 71-74 ◽  
Author(s):  
Robert S. Norris ◽  
Hans M. Kristensen
Keyword(s):  
Nuclear Forces
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