Supersymmetric Electroweak Cosmic Strings

We study the connection between $N=2$ supersymmetry and a topological bound in a two-Higgs-doublet system with an $SU(2)\times U(1)_Y\times U(1)_{Y^{\prime}}$ gauge group. We derive the Bogomol'nyi equations from supersymmetry considerations showing that they hold provided certain conditions on the coupling constants, which are a consequence of the huge symmetry of the theory, are satisfied. Their solutions, which can be interpreted as electroweak cosmic strings breaking one half of the supersymmetries of the theory, are studied. Certain interesting limiting cases of our model which have recently been considered in the literature are finally analyzed.Comment: 20 pages, RevTe

Phases of dual superconductivity and confinement in softly broken N=2 supersymmetric Yang-Mills theories

We study the electric flux tubes that undertake color confinement in N=2 supersymmetric Yang-Mills theories softly broken down to N=1 by perturbing with the first two Casimir operators. The relevant Abelian Higgs model is not the standard one due to the presence of an off-diagonal coupling among different magnetic U(1) factors. We perform a preliminary study of this model at a qualitative level. BPS vortices are explicitely obtained for particular values of the soft breaking parameters. Generically however, even in the ultrastrong scaling limit, vortices are not critical but live in a "hybrid" type II phase. Also, ratios among string tensions are seen to follow no simple pattern. We examine the situation at the half Higgsed vacua and find evidence for solutions with the behaviour of superconducting strings. In some cases they are solutions to BPS equations.Comment: 15 pages, 1 figure, revtex; v2: typos corrected, final versio

Magnetoelectric effects in heavy-fermion superconductors without inversion symmetry

We investigate effects of strong electron correlation on magnetoelectric transport phenomena in noncentrosymmetric superconductors with particular emphasis on its application to the recently discovered heavy-fermion superconductor CePt$_3$Si. Taking into account electron correlation effects in a formally exact way, we obtain the expression of the magnetoelectric coefficient for the Zeeman-field-induced paramagnetic supercurrent, of which the existence was predicted more than a decade ago. It is found that in contrast to the usual Meissner current, which is much reduced by the mass renormalization factor in the heavy-fermion state, the paramagnetic supercurrent is not affected by the Fermi liquid effect. This result implies that the experimental observation of the magnetoelectric effect is more feasible in heavy-fermion systems than that in conventional metals with moderate effective mass.Comment: 8 pages, 2 figures, minor correction

Helical vortex phase in the non-centrosymmetric CePt_3Si

We consider the role of magnetic fields on the broken inversion superconductor CePt_3Si. We show that upper critical field for a field along the c-axis exhibits a much weaker paramagnetic effect than for a field applied perpendicular to the c-axis. The in-plane paramagnetic effect is strongly reduced by the appearance of helical structure in the order parameter. We find that to get good agreement between theory and recent experimental measurements of H_{c2}, this helical structure is required. We propose a Josephson junction experiment that can be used to detect this helical order. In particular, we predict that Josephson current will exhibit a magnetic interference pattern for a magnetic field applied perpendicular to the junction normal. We also discuss unusual magnetic effects associated with the helical order.Comment: 5 pages, 2 figures, Accepted as Phys Rev. Lette

Risk factors for Barrett’s esophagus among patients with gastroesophageal reflux disease: A community clinic-based case-control study

Objective: To measure the relative risks of Barrett’s esophagus (BE) associated with demographic factors, measures of adiposity and smoking among patients with gastroesophageal reflux disease (GERD). Methods: Patients newly diagnosed with specialized intestinal metaplasia (SIM) (n=197) were compared to patients with GERD (n= 418) in a community clinic-based case-control study. Case sub-groups included those with any visible columnar epithelium (VBE) (n=97), and those with a long segment (=2cm) of columnar epithelium (LSBE) (n=54). Results: Risks increased with older age (adjusted odds ratio (aOR) per decade for SIM=1.3, 95% confidence interval (CI)= 1.1-1.5; VBE aOR=1.4 ,CI=1.1-1.6; LSBE aOR=1.5, CI=1.2-1.9), male gender (SIM aOR=1.5, CI=1.1-2.2; VBE aOR=2.7, CI=1.6-4.5; LSBE aOR=3.9, CI=1.9- 8.1) and possibly Asian race. Increased risk of BE in particular was observed with high waist-tohip ratio (WHR, male high: =0.9, female high: =0.8) (SIM aOR=1.3, CI=0.9-2.1; VBE aOR=1.9, CI=1.0-3.5; LSBE aOR=4.1, CI=1.5-11.4). These associations were independent of body mass index (BMI) for the VBE and LSBE case groups but not for SIM which was the only case group in which BMI was a significant risk factor. Ever smoking cigarettes increased risk similarly for all case groups (SIM aOR=1.8, CI=1.2-2.6; VBE aOR=1.6, CI=1.0-2.6; LSBE aOR=2.6, CI=1.3- 4.9), although dose response relationship was not detected for duration or intensity of smoking. Conclusions: Older age, male gender and history of smoking increased risk of SIM and BE among GERD patients independent of other risk factors for BE. Central adiposity was most strongly related to risk of VBE and LSBE. These results may be useful in development of risk profiles for screening GERD patients

Sirolimus attenuates disease progression in an orthologous mouse model of human autosomal dominant polycystic kidney disease

In autosomal dominant polycystic kidney disease (ADPKD), abnormal proliferation of tubular cells drives cyst development and growth. Sirolimus, an inhibitor of the protein kinase mammalian target of rapamycin (mTOR) and a potent anti-proliferative agent, decreases cyst growth in several genetically distinct rodent models of polycystic kidney disease (PKD). We determined here the effect of sirolimus on renal cyst growth in Pkd2WS25/− mice; an ortholog of human ADPKD involving mutation of the Pkd2 gene. In Pkd2WS25/− mice treated with sirolimus, both the two kidney/total body weight (2K/TBW) ratio and the cyst volume density (CVD) were significantly decreased by over half compared with untreated mice suffering with PKD. However, there was no effect on the increased blood urea nitrogen (BUN) levels as an index of kidney function. There are two distinct complexes containing mTOR depending on its binding partners: mTORC1 and mTORC2. Western blot analysis of whole kidney lysates and immunohistochemistry of the cysts found that phospho-S6 ribosomal protein, a marker of mTORC1 activity, was increased in Pkd2WS25/− mice and its phosphorylation was decreased by sirolimus treatment. Phospho-Akt at serine 473, a marker associated with mTORC2 activity, was not different between Pkd2WS25/− mice and normal littermate controls. Hence, our study found that inhibition of mTORC1 by sirolimus correlated with decreased renal cyst growth in this model of human ADPKD but had no effect on the decline in renal function

Pion and Kaon Polarizabilities and Radiative Transitions

CERN COMPASS plans measurements of gamma-pi and gamma-K interactions using 50-280 GeV pion (kaon) beams and a virtual photon target. Pion (kaon) polarizabilities and radiative transitions will be measured via Primakoff effect reactions such as pi+gamma->pi'+gamma and pi+gamma->meson. The former can test a precise prediction of chiral symmetry; the latter for pi+gamma->a1(1260) is important for understanding the polarizability. The radiative transition of a pion to a low mass two-pion system, pi+gamma->pi+pi0, can also be studied to measure the chiral anomaly amplitude F(3pi) (characterizing gamma->3pi), arising from the effective Chiral Lagrangian. We review here the motivation for the above physics program. We describe the beam, target, detector, and trigger requirements for these experiments. We also describe FNAL SELEX attempts to study related physics via the interaction of 600 GeV pions with target electrons. Data analysis in progress aims to identify the reactions pi+e->pi'+e'+pi0 related to the chiral anomaly, and pi+e->pi'+e'+gamma related to pion polarizabilities.Comment: 16 pages, 6 figures, Latex Springer-Verlag style Tel Aviv U. Preprint TAUP-2469-97, Contribution to the Workshop on Chiral Dynamics Theory and Experiment, U. of Mainz, Sept. 1-5, 1997, to be published in Springer-Verlag, Eds. A. Bernstein, Th. Walcher, 199

Construction of exact solutions to eigenvalue problems by the asymptotic iteration method

We apply the asymptotic iteration method (AIM) [J. Phys. A: Math. Gen. 36, 11807 (2003)] to solve new classes of second-order homogeneous linear differential equation. In particular, solutions are found for a general class of eigenvalue problems which includes Schroedinger problems with Coulomb, harmonic oscillator, or Poeschl-Teller potentials, as well as the special eigenproblems studied recently by Bender et al [J. Phys. A: Math. Gen. 34 9835 (2001)] and generalized in the present paper to higher dimensions.Comment: 10 page

High-Field de Haas-van Alphen Effect in non-centrosymmetric CeCoGe3 and LaCoGe3

We report on de Haas-van Alphen effect measurements in the non-centrosymmetric systems CeCoGe3 and LaCoGe3 in magnetic field up to 28 Tesla. In both compounds, two new high frequencies were observed in high fields. The frequencies were not detected in previous lower field measurements. The frequencies do not originate from magnetic breakdown, and, therefore, are likely to be intrinsic features of the compounds. In CeCoGe3, the corresponding effective masses are strongly enhanced, being of the order of 30 bare electron masses.Comment: 3 pages, 4 figures, to be published in Proc. Int. Conf. Heavy Electrons (ICHE2010) J. Phys. Soc. Jpn. 80 (2011