Color Reflection Invariance and Monopole Condensation in QCD

We review the quantum instability of the Savvidy-Nielsen-Olesen (SNO) vacuum of the one-loop effective action of SU(2) QCD, and point out a critical defect in the calculation of the functional determinant of the gluon loop in the SNO effective action. We prove that the gauge invariance, in particular the color reflection invariance, exclude the unstable tachyonic modes from the gluon loop integral. This guarantees the stability of the magnetic condensation in QCD.Comment: 28 pages, 3 figures, JHEP styl

Mutations and amplification of oncogenes in endometrial cancer

Alterations in oncogenes are critical steps in the development of endometrial cancer. To investigate the potential clinical relevance of the amplification of the oncogenes c-erbB2, c-myc, and int-2 and the mutation of K-ras in endometrial cancer, 112 tumors were examined using PCR-based fluorescent DNA technology. Amplification of the three oncogenes and the mutation of K-ras were correlated with age, tumor size, lymph node status, metastases, stage, histological types, grade, steroid hormone receptor expression (estrogen receptor, ER; progesterone receptor, PgR), family history of cancer, previous history of cancer or precursor lesions, and previous history of hormone replacement therapy. Oncogene amplification of c-erbB2 was detected in 18.9%, of c-myc in 2.7% and of int-2 in 4.2%, and K-ras mutation in 11.6%. No significant correlations could be detected between amplification of c-erbB2 and any of the other parameters. Mutation of K-ras is associated with positive expression of PgR. This might indicate that mutation and activation of K-ras are involved in the development of hormonal independence in endometrial cancer

Compressible Sub-Alfvenic MHD turbulence in Low-beta Plasmas

We present a model for compressible sub-Alfvenic isothermal magnetohydrodynamic (MHD) turbulence in low-beta plasmas and numerically test it. We separate MHD fluctuations into 3 distinct families - Alfven, slow, and fast modes. We find that, production of slow and fast modes by Alfvenic turbulence is suppressed. As a result, Alfven modes in compressible regime exhibit scalings and anisotropy similar to those in incompressible regime. Slow modes passively mimic Alfven modes. However, fast modes show isotropy and a scaling similar to acoustic turbulence.Comment: 4 pages, 8 figures, Phys. Rev. Lett., in pres

Neutron scattering study of novel magnetic order in Na0.5CoO2

We report polarized and unpolarized neutron scattering measurements of the magnetic order in single crystals of Na0.5CoO2. Our data indicate that below T_N=88 K the spins form a novel antiferromagnetic pattern within the CoO2 planes, consisting of alternating rows of ordered and non-ordered Co ions. The domains of magnetic order are closely coupled to the domains of Na ion order, consistent with such a two-fold symmetric spin arrangement. Magnetoresistance and anisotropic susceptibility measurements further support this model for the electronic ground state.Comment: 4 pages, 4 figure

The stransverse mass, MT2, in special cases

This document describes some special cases in which the stransverse mass, MT2, may be calculated by non-iterative algorithms. The most notable special case is that in which the visible particles and the hypothesised invisible particles are massless -- a situation relevant to its current usage in the Large Hadron Collider as a discovery variable, and a situation for which no analytic answer was previously known. We also derive an expression for MT2 in another set of new (though arguably less interesting) special cases in which the missing transverse momentum must point parallel or anti parallel to the visible momentum sum. In addition, we find new derivations for already known MT2 solutions in a manner that maintains manifest contralinear boost invariance throughout, providing new insights into old results. Along the way, we stumble across some unexpected results and make conjectures relating to geometric forms of M_eff and H_T and their relationship to MT2.Comment: 11 pages, no figures. v2 corrects minor typos. v3 corrects an incorrect statement in footnote 8 and inserts a missing term in eq (3.9). v4 and v5 correct minor typos spotted by reader

Photoproduction of h_c

Using the NRQCD factorization formalism, we calculate the total cross section for the photoproduction of h_c mesons. We include color-octet and color-singlet mechanisms as well as next-to-leading order perturbative QCD corrections. The theoretical prediction depends on two nonperturbative matrix elements that are not well determined from existing data on charmonium production. For reasonable values of these matrix elements, the cross section is large enough that the h_c may be observable at the E831 experiment and at the HERA experiments.Comment: Revtex file 8 pages, 1 figure. Macros needed: epsf,floats,rotate Minor typos changed, and reference added. Version to be published in Phys.Rev.

Tunable magnetic interaction at the atomic scale in oxide heterostructures

We report on a systematic study of a number of structurally identical but chemically distinct transition metal oxides in order to determine how the material-specific properties such as the composition and the strain affect the properties at the interface of heterostructures. Our study considers a series of structures containing two layers of ferromagnetic SrRuO3, with antiferromagnetic insulating manganites sandwiched in between. The results demonstrate how to control the strength and relative orientation of interfacial ferromagnetism in correlated electron materials by means of valence state variation and substrate-induced strain, respectively