Exceeding the MSSM Higgs Mass Bound in a Special Class of U(1) Gauge Models

A special class of supersymmetric U(1) gauge extensions of the standard model was proposed in 2002. It is anomaly-free, has no mu term, and conserves baryon and lepton numbers automatically. It also allows the lightest Higgs boson to have a mass exceeding the MSSM (Minimal Supersymmetric Standard Model) bound, i.e. about 130 GeV, which is of current topical interest from LHC (Large Hadron Collider) data. This and other new aspects of this 2002 proposal are discussed.Comment: 10 pages, 2 tables, version to appear in PL

Quantized Thermal Transport in the Fractional Quantum Hall Effect

We analyze thermal transport in the fractional quantum Hall effect (FQHE), employing a Luttinger liquid model of edge states. Impurity mediated inter-channel scattering events are incorporated in a hydrodynamic description of heat and charge transport. The thermal Hall conductance, $K_H$, is shown to provide a new and universal characterization of the FQHE state, and reveals non-trivial information about the edge structure. The Lorenz ratio between thermal and electrical Hall conductances {\it violates} the free-electron Wiedemann-Franz law, and for some fractional states is predicted to be {\it negative}. We argue that thermal transport may provide a unique way to detect the presence of the elusive upstream propagating modes, predicted for fractions such as $\nu=2/3$ and $\nu=3/5$.Comment: 6 pages REVTeX, 2 postscript figures (uuencoded and compressed

Could Large CP Violation Be Detected at Colliders?

We argue that CP--violation effects below a few tenths of a percent are probably undetectable at hadron and electron colliders. Thus only operators whose contributions interfere with tree--level Standard Model amplitudes are detectable. We list these operators for Standard Model external particles and some two and three body final state reactions that could show detectable effects. These could test electroweak baryogenesis scenarios.Comment: 11pp, LaTeX, UM--TH--92--27(massaged to make TeX output cleaner), no picture

Very-low-mass Stellar and Substellar Companions to Solar-like Stars from Marvels. III. A Short-period Brown Dwarf Candidate around an Active G0IV Subgiant

We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature T_(eff) = 5903 ± 42 K, surface gravity log (g) = 4.07 ± 0.16 (cgs), and metallicity [Fe/H] = -0.23 ± 0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey, which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 3.571 ± 0.041 km s^(–1), period P = 9.0090 ± 0.0004 days, and eccentricity e = 0.226 ± 0.011. Adopting a mass of 1.16 ± 0.11 M_☉ for the subgiant host star, we infer that the companion has a minimum mass of 40.0 ± 2.5 M_(Jup). Assuming an edge-on orbit, the semimajor axis is 0.090 ± 0.003 AU. The host star is photometrically variable at the ~1% level with a period of ~13.16 ± 0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643 ± 10 mas away from TYC 2087-00255-1, which would have a mass of 0.13 M_☉ if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca II H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured v_(rot) sin i, but unusual for a subgiant of this T_(eff). This activity could be explained by ongoing tidal spin-up of the host star by the companion

Single spin asymmetry in πp\pi p Drell-Yan process

We study the single spin asymmetries for the $\pi p^\uparrow\rightarrow\mu^+\mu^-X$ process. We consider the asymmetries contributed by the coupling of the Boer-Mulders function with the transversity distribution and the pretzelosity distribution, characterized by the $\sin(\phi+\phi_S)$ and $\sin(3\phi-\phi_S)$ azimuthal angular dependence, respectively. We estimate the magnitude of these asymmetries at COMPASS by using proper weighting functions. We find that the $\sin(\phi+\phi_S)$ asymmetry is of the size of a few percent and can be measured through the experiment. The $\sin(3\phi-\phi_S)$ asymmetry is smaller than the $\sin(\phi+\phi_S)$ asymmetry. After a cut on $q_T$, we succeed in enhancing the asymmetry.Comment: 11 pages, 2 figures, final version to appear in PL

CP-Violatiing Asymmetries in e^+e^-\ra t\bar{t} with Longitudinally Polarized Elecrtons

New CP-violating asymmetries of decay leptons in e^+\,e^-\;\ra\;t\,\bar{t}, arising from electric and weak dipole couplings of $t\,\bar{t}$ to $\gamma$ and $Z$, are examined in the case of unpolarized and longitudinally polarized electrons. The new asymmetries measured together with the old ones can help to determine independently the real and imaginary parts of the electric as well as weak dipole couplings. Longitudinal beam polarization, if present, obviates the need for the simultaneous measurement of more than one asymmetry, and enhances considerably the sensitivity to the CP-violating parameters. Numerical results are presented for the Next Linear Collider with $\sqrt{s}=500$ GeV and $\int{\cal L}\,dt\;=\;10\,{\rm fb}^{-1}$.Comment: 12 pages LaTex,PRL-TH-94/3

Quasiparticle spectrum in a nearly antiferromagnetic Fermi liquid: shadow and flat bands

We consider a two-dimensional Fermi liquid in the vicinity of a spin-density-wave transition to a phase with commensurate antiferromagnetic long-range order. We assume that near the transition, the Fermi surface is large and crosses the magnetic Brillouin zone boundary. We show that under these conditions, the self-energy corrections to the dynamical spin susceptibility, $\chi (q, \omega)$, and to the quasiparticle spectral function function, $A(k, \omega)$, are divergent near the transition. We identify and sum the series of most singular diagrams, and obtain a solution for $\chi(q, \omega)$ and an approximate solution for $A(k, \omega)$. We show that (i) $A(k)$ at a given, small $\omega$ has an extra peak at $k = k_F + \pi$ (`shadow band'), and (ii) the dispersion near the crossing points is much flatter than for free electrons. The relevance of these results to recent photoemission experiments in $YBCO$ and $Bi2212$ systems is discussed.Comment: a sign and amplitude of the vertex renormalization and few typos are correcte

Three patients with homozygous familial hypercholesterolemia: Genomic sequencing and kindred analysis.

BackgroundHomozygous Familial Hypercholesterolemia (HoFH) is an inherited recessive condition associated with extremely high levels of low-density lipoprotein (LDL) cholesterol in affected individuals. It is usually caused by homozygous or compound heterozygous functional mutations in the LDL receptor (LDLR). A number of mutations causing FH have been reported in literature and such genetic heterogeneity presents great challenges for disease diagnosis.ObjectiveWe aim to determine the likely genetic defects responsible for three cases of pediatric HoFH in two kindreds.MethodsWe applied whole exome sequencing (WES) on the two probands to determine the likely functional variants among candidate FH genes. We additionally applied 10x Genomics (10xG) Linked-Reads whole genome sequencing (WGS) on one of the kindreds to identify potentially deleterious structural variants (SVs) underlying HoFH. A PCR-based screening assay was also established to detect the LDLR structural variant in a cohort of 641 patients with elevated LDL.ResultsIn the Caucasian kindred, the FH homozygosity can be attributed to two compound heterozygous LDLR damaging variants, an exon 12 p.G592E missense mutation and a novel 3kb exon 1 deletion. By analyzing the 10xG phased data, we ascertained that this deletion allele was most likely to have originated from a Russian ancestor. In the Mexican kindred, the strikingly elevated LDL cholesterol level can be attributed to a homozygous frameshift LDLR variant p.E113fs.ConclusionsWhile the application of WES can provide a cost-effective way of identifying the genetic causes of FH, it often lacks sensitivity for detecting structural variants. Our finding of the LDLR exon 1 deletion highlights the broader utility of Linked-Read WGS in detecting SVs in the clinical setting, especially when HoFH patients remain undiagnosed after WES