Transcription and the Pitch Angle of DNA

The question of the value of the pitch angle of DNA is visited from the perspective of a geometrical analysis of transcription. It is suggested that for transcription to be possible, the pitch angle of B-DNA must be smaller than the angle of zero-twist. At the zero-twist angle the double helix is maximally rotated and its strain-twist coupling vanishes. A numerical estimate of the pitch angle for B-DNA based on differential geometry is compared with numbers obtained from existing empirical data. The crystallographic studies shows that the pitch angle is approximately 38 deg., less than the corresponding zero-twist angle of 41.8 deg., which is consistent with the suggested principle for transcription.Comment: 7 pages, 3 figures; v2: minor modifications; v3: major modifications compared to v2. Added discussion about transcription, and reference

The electromagnetic self-force on a charged spherical body slowly undergoing a small, temporary displacement from a position of rest

The self-force of classical electrodynamics on a charged "rigid" body of radius R is evaluated analytically for the body undergoing a slow (i.e., with a speed v<<c), slight (i.e., small compared to R), and temporary displacement from an initial position of rest. The results are relevant to the Bohr-Rosenfeld analysis of the measurability of the electromagnetic field, which has been the subject of a recent controversy.Comment: REVTeX, 15 pages, 3 figures, accepted by J. Phys.

Color symmetrical superconductivity in a schematic nuclear quark model

In this note, a novel BCS-type formalism is constructed in the framework of a schematic QCD inspired quark model, having in mind the description of color symmetrical superconducting states. The physical properties of the BCS vacuum (average numbers of quarks of different colors) remain unchanged under an arbitrary color rotation. In the usual approach to color superconductivity, the pairing correlations affect only the quasi-particle states of two colors, the single particle states of the third color remaining unaffected by the pairing correlations. In the theory of color symmetrical superconductivity here proposed, the pairing correlations affect symmetrically the quasi-particle states of the three colors and vanishing net color-charge is automatically insured. It is found that the groundstate energy of the color symmetrical sector of the Bonn model is well approximated by the average energy of the color symmetrical superconducting state proposed here

Self-consistent Skyrme QRPA for use in axially-symmetric nuclei of arbitrary mass

We describe a new implementation of the quasiparticle random phase approximation (QRPA) in axially-symmetric deformed nuclei with Skyrme and volume-pairing energy-density functionals. After using a variety of tests to demonstrate the accuracy of the code in ^{24,26}Mg and ^{16}O, we report the first fully self-consistent application of the Skyrme QRPA to a heavy deformed nucleus, calculating strength distributions for several K^pi in ^{172}Yb. We present energy-weighted sums, properties of gamma-vibrational and low-energy K^pi=0^+ states, and the complete isovector E1 strength function. The QRPA calculation reproduces the properties of the low-lying 2^+ states as well or better than it typically does in spherical nuclei.Comment: 5 pages, 6 figure

Finite-Temperature Gluon Condensate with Renormalization Group Flow Equations

Within a self-consistent proper-time Renormalization Group (RG) approach we investigate an effective QCD trace anomaly realization with dilatons and determine the finite-temperature behavior of the gluon condensate. Fixing the effective model at vanishing temperature to the glueball mass and the bag constant a possible gluonic phase transition is explored in detail. Within the RG framework the full non-truncated dilaton potential analysis is compared with a truncated potential version.Comment: 22 pages, 11 figures, LaTeX2e; revised version accepted for publication in Phys. Rev.

Complementarity and Scientific Rationality

Bohr's interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohr's influence, in the pre-war period of 1927-1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglie's had no reasonable foundation. But Bohr's interpretation changed little from the time of its first appearance, and stood independent of any philosophical presuppositions. The principle of complementarity is itself best read as a conjecture of unusually wide scope, on the nature and future course of explanations in the sciences (and not only the physical sciences). If it must be judged a failure today, it is not because of any internal inconsistency.Comment: 29 page

Quadrupole collective variables in the natural Cartan-Weyl basis

The matrix elements of the quadrupole collective variables, emerging from collective nuclear models, are calculated in the natural Cartan-Weyl basis of O(5) which is a subgroup of a covering $SU(1,1)\times O(5)$ structure. Making use of an intermediate set method, explicit expressions of the matrix elements are obtained in a pure algebraic way, fixing the $\gamma$-rotational structure of collective quadrupole models.Comment: submitted to Journal of Physics

Monodromy and Kawai-Lewellen-Tye Relations for Gravity Amplitudes

We are still learning intriguing new facets of the string theory motivated Kawai-Lewellen-Tye (KLT) relations linking products of amplitudes in Yang-Mills theories and amplitudes in gravity. This is very clearly displayed in computations of N=8 supergravity where the perturbative expansion show a vast number of similarities to that of N=4 super-Yang-Mills. We will here investigate how identities based on monodromy relations for Yang-Mills amplitudes can be very useful for organizing and further streamlining the KLT relations yielding even more compact results for gravity amplitudes.Comment: 6 pages, 12th Marcel Grossman meeting 200

String theory and the KLT-relations between gravity and gauge theory including external matter

We consider the Kawai-Lewellen-Tye (KLT) factorizations of gravity scalar-leg amplitudes into products of scalar-leg Yang-Mills amplitudes. We check and examine the factorizations at O(1) in $\alpha'$ and extend the analysis by considering KLT-mapping in the case of generic effective Lagrangians for Yang-Mills theory and gravity.Comment: 7 pages, ReVTeX4, references updated, changes to text and typos correcte

Fission Decay Widths for Heavy-Ion Fusion-Fission Reactions

Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state; the temperature dependence of the location of fission transition points; and the orientation degree of freedom. We see no evidence to suggest that the nuclear viscosity departs from the surface-plus-window dissipation model. The strong increase in the nuclear viscosity above a temperature of ~1 MeV deduced by others is an artifact generated by an inadequate fission model.Comment: 14 pg, 6 fig, submitted to Physical Revie