Finite Higgs mass without Supersymmetry

We identify a class of chiral models where the one-loop effective potential for Higgs scalar fields is finite without any requirement of supersymmetry. It corresponds to the case where the Higgs fields are identified with the components of a gauge field along compactified extra dimensions. We present a six dimensional model with gauge group U(3)xU(3) and quarks and leptons accomodated in fundamental and bi-fundamental representations. The model can be embedded in a D-brane configuration of type I string theory and, upon compactification on a T^2/Z_2 orbifold, it gives rise to the standard model with two Higgs doublets.Comment: 28 pages, 4 figures, uses axodraw. Some typos corrected and references rearrange

MUTANTS OF NONPRODUCER CELL LINES TRANSFORMED BY MURINE SARCOMA VIRUSES : I. INDUCTION, ISOLATION, PARTICLE PRODUCTION, AND TUMORIGENICITY

A variety of cell mutants were obtained by a single 5'-bromodeoxyuridine (BrdU) treatment of an nonproducer (NP) cell line transformed by the Kirsten strain of murine sarcoma virus (Ki-MSV). Isolation procedures of these cell See PDF for Structure mutants are described. The cell mutants obtained were classified by tumorigenic potential and shedding of Type C virus particles. The cell mutants were classified into four groups: (A) tumorigenic, without particles; (B) tumorigenic, with Type C particles; (C) nontumorigenic, without particles; and (D) nontumorigenic, with Type C particles. The tumorigenic cell lines showed variability in morphology with both flat and typical transformed appearing cell lines showing equal transplantability

MUTANTS OF NONPRODUCER CELL LINES TRANSFORMED BY MURINE SARCOMA VIRUS : III. DETECTION AND CHARACTERIZATION OF RNA SPECIFIC FOR HELPER AND SARCOMA VIRUSES

BALB/3T3 cells transformed by the Kirsten sarcoma virus (nonvirus producer BALB/3T3 cells) and mutant cell lines derived therefrom by treatment with bromodeoxyuridine (BrdU) were analyzed for expression of virus-specific RNA using single-stranded DNA transcripts of Rauscher leukemia virus (RLV), a virus activated in one of the cell lines (58-2T), and Ki-SV-specific DNA transcript; the latter transcript after removal of all sequences cross-reactive with RLV RNA. The Rauscher virus DNA detected multiple copies of viral RNA in virus-producing cells (∼2.5 x 103/cell) whether infected with RLV or activated to produce virus with BrdU. Nonproducer (NP) cells and normal BALB cells showed small numbers of RNA genomes (70–250/cell) and only partial saturation of the transcript. The intracellular RNA sedimented at 35S (main peak) with a variable minor peak at 20S with the exception of one mutant cell, M-43-2 (main peak at 26–27S). The 58-2T transcript reacted preferentially in NP cells and their derivatives with biphasic kinetics suggesting the possibility of sequences specific for the original transforming virus. The size of Ki-SV specific sequences were 30S in mutant cells whether or not complete virus was being produced and independent of in vivo transplantability

The Origin of Spontaneous Symmetry Breaking in Theories with Large Extra Dimensions

We suggest that the electroweak Higgs particles can be identified with extra-dimensional components of the gauge fields, which after compactification on a certain topologically non-trivial background become tachyonic and condense. If the tachyonic mass is a tree level effect, the natural scale of the gauge symmetry breaking is set by the inverse radius of the internal space, which, in case of the electroweak symmetry, must be around $\sim 1/$TeV. We discuss the possibility of a vanishing tree level mass for the Higgs. In such a scenario the tachyonic mass can be induced by quantum loops and can be naturally smaller than the compactification scale. We give an example in which this possibility can be realized. Starting from an Einstein--Yang--Mills theory coupled to fermions in 10-dimensions, we are able to reproduce the spectrum of the Standard Model like chiral fermions and Higgs type scalars in 4-dimensions upon compactifying on ${\mathbb{C}}P^1\times {\mathbb{C}}P^2$. The existence of a monopole solution on ${\mathbb{C}}P^1$ and a self dual U(1) instanton on ${\mathbb{C}}P^2$ are essential in obtaining chiral fermions as well as tachyonic or massless scalars in 4-dimensions. We give a simple rule which helps us to identify the presence of tachyons on the monopole background on $S^2$.Comment: 33 pages. Version accepted for publication in Phys.Rev.

MUTANTS OF NONPRODUCER CELL LINES TRANSFORMED BY MURINE SARCOMA VIRUS : II. RELATIONSHIP OF TUMORIGENICITY TO PRESENCE OF VIRAL MARKERS AND RESCUABLE SARCOMA GENOME

Tumorigenic and nontumorigenic mutants induced by a single 5'-bromodeoxyuridine (BrdU) treatment of a nonproducer (NP) tumorigenic cell line were isolated and characterized. Among the cloned derivatives were examples of virus-free and sarcoma virus-producing cell lines. Oncogenicity did not correlate with production of virus or ease of rescue of the sarcoma genome. All lines, including nononcogenic derivatives, retained the sarcoma genome. Phenotypic reversion of some cell mutants was observed after in vivo inoculation or long term in vitro cultivation. The M-50T cell line, obtained from a tumor induced by M-50 cells, had a sarcoma genome rescuable by direct superinfection; this was only achieved with parental M-50 cells by a cell fusion rescue technique. The M-43-2T cell, obtained from a single small static tumor induced by otherwise nononcogenic M-43-2 cells, shed sarcoma virus and became tumorigenic. M-58-4-48 became tumorigenic after passage 48 of the M-58-4 line, which was originally nontumorigenic. These observations of phenotypic reversion demonstrate that the presence of the sarcoma gene in cells is an essential but not sufficient condition of tumorigenesis

Extranatural Inflation

We present a new model of inflation in which the inflaton is the extra component of a gauge field in a 5d theory compactified on a circle. The chief merit of this model is that the potential comes only from non-local effects so that its flatness is not spoiled by higher dimensional operators or quantum gravity corrections. The model predicts a red spectrum (n ~ 0.96) and a significant production of gravitational waves (r ~ 0.11). We also comment on the relevance of this idea to quintessence.Comment: 4 pages. Minor corrections and references added. Accepted for PR

Selectivity of the Nucleon Induced Deuteron Breakup and Relativistic Effects

Theoretical predictions for the nucleon induced deuteron breakup process based on solutions of the three-nucleon Faddeev equation including such relativistic features as the relativistic kinematics and boost effects are presented. Large changes of the breakup cross section in some complete configurations are found at higher energies. The predicted relativistic effects, which are mostly of dynamical origin, seem to be supported by existing data.Comment: 4 pages, 4 figure