322 research outputs found
Mass of the B_c Meson in Three-Flavor Lattice QCD
We use lattice QCD to predict the mass of the meson. We use the MILC
Collaboration's ensembles of lattice gauge fields, which have a quark sea with
two flavors much lighter than a third. Our final result is
. The first error bar is a sum in quadrature
of statistical and systematic uncertainties, and the second is an estimate of
heavy-quark discretization effects.Comment: 4 pages, 3 figures; shorten to fit in PRL; published versio
Predictions from Lattice QCD
In the past year, we calculated with lattice QCD three quantities that were
unknown or poorly known. They are the dependence of the form factor in
semileptonic decay, the decay constant of the meson, and the
mass of the meson. In this talk, we summarize these calculations, with
emphasis on their (subsequent) confirmation by experiments.Comment: v1: talk given at the International Conference on QCD and Hadronic
Physics, Beijing, June 16-20, 2005; v2: poster presented at the XXIIIrd
International Symposium on Lattice Field Theory, Dublin, July 25-3
Vortices on Orbifolds
The Abelian and non-Abelian vortices on orbifolds are investigated based on
the moduli matrix approach, which is a powerful method to deal with the BPS
equation. The moduli space and the vortex collision are discussed through the
moduli matrix as well as the regular space. It is also shown that a quiver
structure is found in the Kahler quotient, and a half of ADHM is obtained for
the vortex theory on the orbifolds as the case before orbifolding.Comment: 25 pages, 4 figures; references adde
Sub-Sets of Cancer Stem Cells Differ Intrinsically in Their Patterns of Oxygen Metabolism
PMCID: PMC3640080This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Strong-isospin-breaking correction to the muon anomalous magnetic moment from lattice QCD at the physical point
All lattice-QCD calculations of the hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment to-date have been performed with degenerate up- and down-quark masses. Here we calculate directly the strong-isospin-breaking correction to for the first time with physical values of and and dynamical , , , and quarks, thereby removing this important source of systematic uncertainty. We obtain a relative shift to be applied to lattice-QCD results obtained with degenerate light-quark masses of = +1.5(4)\%, in agreement with estimates from phenomenology and a recent lattice-QCD calculation with unphysically heavy pions
Expression of UDP-glucuronosyltransferase 1A4 in human placenta at term
The placenta contains a large variety of metabolizing enzymes, among them UDP-glucuronosyltransferase (UGT). Several UGT2B isozymes have so far been detected in human placenta, but little is known on placental expression of UGT1A isozymes. The antiepileptic drug lamotrigine (LTG) is a UGT1A4-substrate, and its serum concentration falls by over 50% during pregnancy, leading to impaired seizure control. The placenta may be involved in this. Microsomes from term placentas of 4 LTG-users and 10 healthy control subjects were prepared. Western blot analysis detected UGT1A proteins in all placentas. The presence of UGT1A4 in placenta from LTG users was confirmed with UGT1A4 commercial standard and a specific UGT1A4 primary antibody. Since LTG is primarily metabolized by UGT1A4 and this isozyme is shown to be present in placenta at term, it may be hypothesized that the placenta is involved in the fall of LTG serum concentrations during pregnancy
QCD corrections to plus -boson production at the LHC
The associated production at the LHC is an important process in
investigating the color-octet mechanism of non-relativistic QCD in describing
the processes involving heavy quarkonium. We calculate the next-to-leading
order (NLO) QCD corrections to the associated production at the
LHC within the factorization formalism of nonrelativistic QCD, and provide the
theoretical predictions for the distribution of the transverse
momentum. Our results show that the differential cross section at the
leading-order is significantly enhanced by the NLO QCD corrections. We conclude
that the LHC has the potential to verify the color-octet mechanism by measuring
the production events.Comment: 14 page revtex, 5 eps figures, to appear in JHEP. fig5 and the
corresponding analysis are correcte
Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study
This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions
Linking the subcultures of physics: Virtual empiricism and the bonding role of trust
This article draws on empirical material concerning the communication and use of knowledge in experimental physics and their relations to the culture of theoretical physics. The role that trust plays in these interactions is used to create a model of social distance between interacting theoretical and experimental cultures. This article thus seeks to reintroduce trust as a fundamental element in answering the problem of disunity in the sociology of knowledge
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