ترغب بنشر مسار تعليمي؟ اضغط هنا

The Past and Future of Coulomb Dissociation in Hadron- and Astrophysics

175   0   0.0 ( 0 )
 نشر من قبل Kai Hencken
 تاريخ النشر 2000
  مجال البحث
والبحث باللغة English
 تأليف G. Baur




اسأل ChatGPT حول البحث

Breakup reactions are generally quite complicated, they involve nuclear and electromagnetic forces including interference effects. Coulomb dissociation is an especially simple and important mechanism since the perturbation due to the electric field of the nucleus is exactly known. Therefore firm conclusions can be drawn from such measurements. Electromagnetic matrixelements, radiative capture cross-sections and astrophysical S-factors can be extracted from experiments. We describe the basic theory, give analytical results for higher order effects in the dissociation of neutron halo nuclei and briefly review the experimental results obtained up to now. Some new applications of Coulomb dissociation for nuclear astrophysics and nuclear structure physics are discussed.



قيم البحث

اقرأ أيضاً

NASAs Great Observatories have opened up the electromagnetic spectrum from space, providing sustained access to wavelengths not accessible from the ground. Together, Hubble, Compton, Chandra, and Spitzer have provided the scientific community with an agile and powerful suite of telescopes with which to attack broad scientific questions, and react to a rapidly changing scientific landscape. As the existing Great Observatories age, or are decommissioned, community access to these wavelengths will diminish, with an accompanying loss of scientific capability. This report, commissioned by the NASA Cosmic Origins, Physics of the Cosmos and Exoplanet Exploration Program Analysis Groups (PAGs), analyzes the importance of multi-wavelength observations from space during the epoch of the Great Observatories, providing examples that span a broad range of astrophysical investigations.
159 - Gerhard Baur , 2003
Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the (target) nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic matrixelem ents and astrophysical S-factors for radiative capture processes can be extracted from experiments. We describe the basic elements of the theory of nonrelativistic and relativistic electromagnetic excitation with heavy ions. This is contrasted to electromagnetic excitation with leptons (electrons), with their small electric charge and the absence of strong interactions. We discuss various approaches to the study of higher order electromagnetic effects and how these effects depend on the basic parameters of the experiment. The dissociation of neutron halo nuclei is studied in a zero range model using analytical methods. We also review ways how to treat nuclear interactions, show their characteristics and how to avoid them (as far as possible). We review the experimental results from a theoretical point of view. Of special interest for nuclear structure physics is the appearence of low lying electric dipole strength in neutron rich nuclei. Applications of Coulomb dissociation to some selected radiative capture reactions relevant for nuclear astrophysics are discussed. The Coulomb dissociation of 8B is relevant for the solar neutrino problem. The potential of the method especially for future investigations of (medium) heavy exotic nuclei for nuclear structure and astrophysics is explored. We conclude that the Coulomb dissociation mechanism is theoretically well understood, the potential difficulties are identified and can be taken care of. Many interesting experiments have been done in this field and many more are expected in the future.
382 - Aurel Bulgac , Shi Jin , 2019
Recent developments in theoretical modeling and in computational power have allowed us to make significant progress on a goal not achieved yet in nuclear theory: a fully microscopic theory of nuclear fission. The complete microscopic description rema ins a computationally demanding task, but the information that can be provided by current calculations can be extremely useful to guide and constrain phenomenological approaches. First, a truly microscopic framework that can describe the real-time dynamics of the fissioning system can justify or rule out assumptions and approximations incompatible with an accurate quantum treatment or with our understanding of the inter nucleon interactions. Second, the microscopic approach can be used to obtain trends such as: the excitation energy sharing mechanism between fission fragments (FFs) with increasing excitation energy of the fissioning system, the angular momentum content of the FFs, or even to compute observables that cannot be otherwise calculated in phenomenological approaches or even measured, as in the case of astronomical environments. Merely the characterization of the trends would be of great importance for various application. We present here arguments that a truly microscopic approach to fission does not support the assumption of adiabaticity of the large amplitude collective motion in fission, particularly starting from the outer saddle down to the scission configuration.
119 - Kwang-il Seon 2020
We review the history of space mission in Korea focusing on the field of astronomy and astrophysics. For each mission, scientific motivation and achievement are reviewed together with some technical details of the program including mission schedule. This review includes the ongoing and currently approved missions as well as some planned ones. Within the admitted limitations of authors perspectives, some comments on the future direction of space program for astronomy and astrophysics in Korea are made at the end of this review.
292 - D. Blaschke 2002
We investigate the in-medium modification of pseudoscalar and vector mesons in a QCD motivated chiral quark model by solving the Dyson-Schwinger equations for quarks and mesons at finite temperature for a wide mass range of meson masses, from light ( pi, rho) to open-charm (D, D*) states. At the chiral / deconfinement phase transition, the quark-antiquark bound states enter the continuum of unbound states and become broad resonances (the hadronic Mott effect). We calculate the in-medium cross sections for charmonium dissociation due to collisions with light hadrons in a chiral Lagrangian approach, and show that the D and D* meson spectral broadening lowers the threshold for charmonium dissociation by pi and rho meson impact. This leads to a step-like enhancement in the reaction rate. We suggest that this mechanism for enhanced charmonium dissociation may be the physical mechanism underlying the anomalous J/Psi suppression observed by NA50.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا