118464550
Self-protection of massive cosmological gravitons
Relevant deformations of gravity present an exciting window of opportunity to probe the rigidity of gravity on cosmological scales. For a single-graviton theory, the leading relevant deformation constitutes a graviton mass term. In this paper, we investigate the classical and quantum stability of massive cosmological gravitons on generic Friedman backgrounds. For a Universe expanding towards a de Sitter epoch, we find that massive cosmological gravitons are self-protected against unitarity violations by a strong coupling phenomenon.
209999169
Black Hole Production in Large Extra Dimensions at the Tevatron: New Limit on the Fundamental Scale of Gravity
37247936
Degravitation of the cosmological constant and graviton width
We study the possibility of decoupling gravity from the vacuum energy. This is effectively equivalent to promoting Newton's constant to a high-pass filter that degravitates sources of characteristic wavelength larger than a certain macroscopic (super) horizon scale L. We study the underlying physics and the consistency of this phenomenon. In particular, the absence of ghosts, already at the linear level, implies that in any such theory the graviton should either have a mass 1/L, or be a resonance of similar width. This has profound physical implications for the degravitation idea.
119280123
Brane Induced Gravity: From a No-Go to a No-Ghost Theorem
Numerous claims in the literature suggest that gravity induced on a higher co-dimensional surface violates unitarity in the weak coupling regime. However, it remained unclear, why a conserved source localized on this surface and giving rise to an induced gravity term at low energies would absorb and emit the associated ghost, given a consistent source-free theory. In this article it is shown that the appearance of the induced Einstein Hilbert term does not threaten the unitarity of the theory. The physics arguments behind this statement are presented in a semi-covariant language, but the detailed proof is given using Dirac's constraint analysis. It is shown that the would-be ghost highlighted in previous works is non-dynamical and therefore not associated with a state in the Hilbert space. As a result of these investigations, brane induced gravity goes without a ghost, opening an exciting window of opportunity for consistent deformations of gravity at the largest observable distances.
119430795
The Casimir effect in the presence of compactified universal extra dimensions
Abstract The Casimir force in a system consisting of two parallel conducting plates in the presence of compactified universal extra dimensions (UXD) is analyzed. The Casimir force with UXDs differs from the force obtained without extra dimensions. A new power law for the Casimir force is derived. By comparison to experimental data the size R of the universal extra dimensions can be restricted to R ⩽10 nm for one extra dimension.
37255447
A Quantum Bound-State Description of Black Holes
A relativistic framework for the description of bound states consisting of a large number of quantum constituents is presented, and applied to black-hole interiors. At the parton level, the constituent distribution, number and energy density inside black holes are calculated, and gauge corrections are discussed. A simple scaling relation between the black hole mass and constituent number is established.
120335892
Study of SHE at the GSI-SHIP
Abstract An overview of present experimental investigation of superheavy elements is given. Using cold fusion reactions which are based on lead and bismuth targets, relatively neutron deficient isotopes of the elements from 107 to 113 were synthesized at GSI in Darmstadt, Germany, and/or at RIKEN in Wako, Japan. In hot fusion reactions of 48 Ca projectiles with actinide targets more neutron rich isotopes of the elements from 112 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these data, which represent the first identification of nuclei located on the predicted island of SHEs, were confirmed in two independent experiments. The data are compared with theoretical descriptions.
123051492
The velocity filter ship, a separator of unslowed heavy ion fusion products
The velocity filter SHIP installed at the UNILAC (GSI Darmstadt) is described. It is used for the investigation of neutron deficient nuclei generated by heavy ion induced fusion. The two stage filter separates unretarded reaction products emerging from a thin target with high efficiency and low background of primary beam particles. For reaction products covering an angular range of 3° in horizontal and vertical directions and a velocity range of 10% the transmission is between 30% and 60%. The separation time is of the order of 10−6s. High suppression of primary particles by factors of 107-1011 permits the investigation of reaction products in the direction of the primary beam. α-active reaction products have been implanted into a surface barrier detector and identified by their decay. 
 
A description of the ion optical principles, technical details and the performance of SHIP is given.
16408480
Effective Kaon energy from a novel chiral SU(3) model
Abstract A new chiral SU(3) Lagrangian is proposed to describe the properties of kaons and anti-kaons in the nuclear medium, The saturation properties of nuclear matter are reproduced as well as the results of the Dirac-Briickner theory, After introducing the coupling between the omega meson and the kaon, our results for effective kaon and anti-kaon energy are quite similar as calculated in the one-boson-exchange model.
124901090
Evidence for hindrance in fusion between sulfur and lead nuclei
The influence of the structure of projectile and target nuclei on the capture cross sections was investigated for the reactions ${}^{34}\mathrm{S}\phantom{\rule{0.16em}{0ex}}+{\phantom{\rule{0.16em}{0ex}}}^{204,206,208}$Pb and ${}^{36}\mathrm{S}\phantom{\rule{0.16em}{0ex}}+{\phantom{\rule{0.16em}{0ex}}}^{204,206,208}$Pb. Capture cross sections were deduced by measuring the fission fragments using multiwire proportional counters. An enhancement of the capture cross sections relative to a one-dimensional barrier penetration model was observed for all reactions at energies below the interaction barriers. The enhancement is larger in the case of reactions with ${}^{34}$S than with ${}^{36}$S. This observation is explained by a stronger coupling to the vibrational states in the reactions with ${}^{34}$S. Comparing the capture cross sections and the evaporation-residue cross sections for the reactions ${}^{36}\mathrm{S}\phantom{\rule{0.16em}{0ex}}+{\phantom{\rule{0.16em}{0ex}}}^{206}$Pb and ${}^{34}\mathrm{S}\phantom{\rule{0.16em}{0ex}}+{\phantom{\rule{0.16em}{0ex}}}^{208}$Pb, both yielding the same compound nucleus ${}^{242}$Cf, it is shown that the latter reaction has a lower fusion probability.
120695709
Strong influence of the entrance channel on the formation of compound nuclei Th216,222* and their evaporation residues
The dynamical effects of the entrance channel on the formation of the evaporation residues are studied by analyzing the $^{40}\mathrm{Ar}+^{176}\mathrm{Hf}$, $^{86}\mathrm{Kr}+^{130,136}\mathrm{Xe}$, $^{124}\mathrm{Sn}+^{92}\mathrm{Zr}$, and $^{48}\mathrm{Ca}+^{174}\mathrm{Yb}$ reactions leading to the $^{216}\mathrm{Th}{}^{*}$ and $^{222}\mathrm{Th}{}^{*}$ compound nuclei. We find that the difference between the evaporation residue cross sections for the reactions leading to the same compound nucleus is caused by the different angular momentum distributions of the partial fusion cross sections ${\ensuremath{\sigma}}_{\mathrm{fus}}^{\ensuremath{\ell}}({E}_{c.m.})$. The strong dependence of the fusion angular momentum distribution on the mass (charge) asymmetry and shell structure of reactants is demonstrated. The effect of the $A/Z$ ratio for the $^{86}\mathrm{Kr}+^{130,136}\mathrm{Xe}$ reactions is discussed. The dynamical conditions of capture affect the competition between complete fusion and quasifission and, consequently, the shape of the angular momentum distribution of the compound nucleus. By this way the peculiarities of the entrance channel also affect the fission-evaporation competition of the excited intermediate nuclei along the deexcitation cascade of the compound nucleus and, consequently, the evaporation residue formation.