679 research outputs found

    Strong and Electromagnetic Mass Splittings in Heavy Mesons

    Get PDF
    The contributions to heavy meson mass differences by the strong hyperfine interaction, the light quark masses and the electromagnetic interaction are obtained from the empirical values of the DD, D∗D^*, BB and B∗B^* masses by means of a mass formula based on the heavy quark mass expansion. The three different types of contributions are determined with significant accuracy to next to leading order in that expansion.Comment: 12 pages, 2 figure

    Genetic characterisation of the cuban creole pig with microsatellites

    Get PDF
    In this work the Criollo Cubano pig has been characterised to know how the breed is and to know the genetic relationships with the main varieties of the Iberian pig calculating genetic distances. It have been studied 93 animals of the Criollo Cubano pig breed belonging to the Entrepelado and LampiĂąo varieties. 20 microsatellites recommended by ISAG for porcine biodiversity studies. These markers were amplified by mean of the polymerase chain reaction (PCR) technique and to get the size separation of the obtained fragments we have developed electrophoresis in polyacrylamide gel in an automatic sequencer ABI377XL. All the microsatellites have been polymorphic and between 4 (S0227) and 12 (S0068) alleles have been found with an average value of 8.2. The expected heterozigosity has been 0.6535 and the observed heterozigosity 0.6335. The Nei"s Ds genetic distance between the Criollo Cubano and the Iberian pig has been calculated and an UPGMA tree has been built. Finally, distances between pairs of individuals (Dsa) have been calculated and an UPGMA individual tree has been built.En este trabajo caracteriza genĂŠticamente el cerdo Criollo Cubano para conocer el estado en que se encuentra esta raza porcina, a la vez que se establecen las relaciones genĂŠticas del mismo con las variedades principales del cerdo IbĂŠrico mediante el cĂĄlculo de distancias genĂŠticas. Se han analizado 93 muestras de cerdo Criollo Cubano pertenecientes a las variedades Entrepelado y LampiĂąo procedentes de la provincia de Granma y de La Habana (Cuba). Se han empleado 20 microsatĂŠlites de los recomendados por la FAO/ISAG (International Society of Animal Genetics) para estudios de biodiversidad porcina. Los microsatĂŠlites se han amplificado mediante la reacciĂłn en cadena de la polimerasa (PCR) y los fragmentos amplificados se han separado mediante electroforesis en un secuenciador automĂĄtico ABI 377XL. Todos los microsatĂŠlites tipificados han resultado polimĂłrficos y se han encontrado entre 4 alelos para el S0227 y 12 para el S0068, con un nĂşmero medio de alelos de 8,2. La heterocigosidad media esperada ha sido 0,6535 y la observada 0,6335. Se ha calculado la distancia genĂŠtica DS de Nei entre el cerdo Criollo Cubano y el cerdo IbĂŠrico y se ha construido un ĂĄrbol de distancias mediante el mĂŠtodo de UPGMA. Por Ăşltimo, se han calculado las distancias entre pares de individuos (DSA) y con ellas se ha construido un ĂĄrbol filogenĂŠtico individual basado en el algoritmo UPGMA

    Increased 1,25(OH)2-Vitamin D Concentrations after Energy Restriction Are Associated with Changes in Skeletal Muscle Phenotype

    Get PDF
    The influence of energy restriction (ER) on muscle is controversial, and the mechanisms are not well understood. To study the effect of ER on skeletal muscle phenotype and the influence of vitamin D, rats (n = 34) were fed a control diet or an ER diet. Muscle mass, muscle somatic index (MSI), fiber-type composition, fiber size, and metabolic activity were studied in tibialis cranialis (TC) and soleus (SOL) muscles. Plasma vitamin D metabolites and renal expression of enzymes involved in vitamin D metabolism were measured. In the ER group, muscle weight was unchanged in TC and decreased by 12% in SOL, but MSI increased in both muscles (p < 0.0001) by 55% and 36%, respectively. Histomorphometric studies showed 14% increase in the percentage of type IIA fibers and 13% reduction in type IIX fibers in TC of ER rats. Decreased size of type I fibers and reduced oxidative activity was identified in SOL of ER rats. An increase in plasma 1,25(OH)2-vitamin D (169.7 Âą 6.8 vs. 85.4 Âą 11.5 pg/mL, p < 0.0001) with kidney up-regulation of CYP27b1 and down-regulation of CYP24a1 was observed in ER rats. Plasma vitamin D correlated with MSI in both muscles (p < 0.001), with the percentages of type IIA and type IIX fibers in TC and with the oxidative profile in SOL. In conclusion, ER preserves skeletal muscle mass, improves contractile phenotype in phasic muscles (TC), and reduces energy expenditure in antigravity muscles (SOL). These beneficial effects are closely related to the increases in vitamin D secondary to ER

    Power counting and effective field theory for charmonium

    Get PDF
    We hypothesize that the correct power counting for charmonia is in the parameter Lambda_QCD/m_c, but is not based purely on dimensional analysis (as is HQET). This power counting leads to predictions which differ from those resulting from the usual velocity power counting rules of NRQCD. In particular, we show that while Lambda_QCD/m_c power counting preserves the empirically verified predictions of spin symmetry in decays, it also leads to new predictions which include: A hierarchy between spin singlet and triplet octet matrix elements in the J/psi system. A quenching of the net polarization in production at large transverse momentum. No end point enhancement in radiative decays. We discuss explicit tests which can differentiate between the traditional and new theories of NRQCD.Comment: 18 pages, 1 figure Replaced plot of the psi polarization parameter alpha as a function of transverse momentum. Alpha is now closer to zero for large transverse moment

    Heavy baryons in the large Nc limit

    Get PDF
    It is shown that in the large N-c limit heavy baryon masses can be estimated quantitatively in a 1/N-c expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass root sigma/m(Q). These estimates implement important 1/N-c corrections and assume a string tension independent of N-c. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. The results provide good estimates for the first sub-leading in 1/N-c corrections.Open Access funded by SCOAPÂł - Sponsoring Consortium for Open Access Publishing in Particle Physics.This work was supported in part by DOE Contract No. DE-AC05-06OR23177 under which JSA operates the Thomas Jefferson National Acceler- ator Facility (J.L.G.), by the National Science Foundation through grant PHY-1307413 (I.P.F. and J.L.G.) and the Spanish Mineco (grant FIS2014-59386-P) and Junta de AndalucĂ­a (grant FQM225) (C.A.T. and E.R.A.). C.A.T. acknowledges a contract from the CPAN

    Heavy quarkonium: progress, puzzles, and opportunities

    Get PDF
    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

    Get PDF
    Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

    Get PDF
    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters
    • …
    corecore