13331529
Nonsymmetric gravity has unacceptable global asymptotics
We analyze the radiative aspects of nonsymmetric gravity theory to show that, in contrast to General Relativity, its nonstationary solutions cannot simultaneously exhibit acceptable asymptotic behavior at both future and past null infinity: good behavior at future null infinity is only possible through the use of advanced potentials with concomitant unphysical behavior at past null infinity.
120560048
Free Field Approach to 2-Dimensional Conformal Field Theories
2655982
Theoretical problems in nonsymmetric gravitational theory.
It has recenty been noted that the nonsymmetric metric model of gravity faces severe observational constraints. We show here that it is also subject to physically unacceptable formal difficulties even as an effective field theory: When expanded about a Riemannian background, the model exhibits curvature-coupled negative-energy (ghost) modes and unacceptable asymptotic behavior.
120900374
Vertex operators and fusion rules in the free field realizations of WZNW models
Abstract We study the representation of chiral vertex operators for sl(N) WZNW models in the free field formalism. Exploiting the underlying quantum group structure of the free field resolution, we reduce the problem of constructing the infinite number of components of a chiral vertex to that of finding a single vector in a finite dimensional irreducible representation of U q ( sl (N)) . In particular this provides a new, purely algebraic, characterization of the fusion rules. We briefly summarize the analogous construction for finite dimensional algebras and use it as a guide. Our discussion is illustrated by explicit examples of vertices in sl(2) and sl(3) WZNW models.
122808498
Covariant field theory of the compactified closed bosonic string
We covariantly first-quantize, via the BRST approach, the closed bosonic string compactified on a torus — in particular the 18-dimensional theory with E8 × E8 gauge bosons. Further, we give the corresponding free field theory. Thus the model is ready for the introduction of string interactions, and may be very useful for the study of gauge interactions in string theories.
121585222
N=2 minimal models on Riemann surfaces
Abstract We give a general formalism for the computation of conformal blocks for N =2 minimal models on arbitrary Riemann surfaces. We exploit the factorization of N =2 minimal models as (parafermion) × ( c =1 rational boson), obtaining the parafermion contribution by truncating thez SU(2) k WZNW models discussed in one of our previous papers. We conclude by giving the two-loop characters.
119185671
Observation of associated production of a Z boson with a D meson in the forward region
A bstractA search for associated production of a Z boson with an open charm meson is presented using a data sample, corresponding to an integrated luminosity of 1.0 fb−1 of proton-proton collisions at a centre-of-mass energy of 7TeV, collected by the LHCb experiment. Seven candidate events for associated production of a Z boson with a D0 meson and four candidate events for a Z boson with a D+ meson are observed with a combined significance of 5.1 standard deviations. The production cross-sections in the forward region are measured to be
$ \begin{array}{*{20}{c}} {{\upsigma_{{\mathrm{Z}\to {\upmu^{+}}}}}{{{_{{{\upmu^{-}}}}}}_{{,{{\mathrm{D}}^0}}}}=2.50\pm 1.12\pm 0.22\ \mathrm{pb}} \\ {{\upsigma_{{\mathrm{Z}\to {\upmu^{+}}}}}{{{_{{{\upmu^{-}}}}}}_{{,{{\mathrm{D}}^{+}}}}}=0.44\pm 0.23\pm 0.03\ \mathrm{pb},} \\ \end{array} $
where the first uncertainty is statistical and the second systematic.

121021036
G**p(E) / G**p(M) for bound protons: first results for O-16 with the recoil polarization technique
The first (e,e'p) polarization transfer measurements on a nucleus heavier than deuterium have been carried out at Jefferson Laboratory. Transverse and longitudinal components of the polarization of protons ejected in the reaction 16O(e,e'p) were measured in quasielastic perpendicular kinematics at a Q^2 of 0.8 (GeV/c)^2. The data are in good agreement with state of the art calculations, but do not exclude possible changes in the ratio of the electric to magnetic form factors of the nucleon in the nuclear medium at the level of recent theoretical predictions.
122481610
Depolarization of dynamically polarized solid targets due to beam heating effects
Abstract The behavior of dynamically polarized targets in the presence of a high intensity electron beam was studied. The nuclear polarization seen by the incident electron beam is lower than the overall measured target polarization by NMR due to beam heating and subsequent depolarization. A correction for this beam-induced depolarization is developed here to correct the measured target polarization for these effects. Furthermore, a model has also been developed to calculate the target depolarization in beam, and optimization of running conditions for future experiments of this nature are discussed based on this model.
204937677
Measurement of $C\!P$ asymmetries in the decays $B^0 \rightarrow K^{*0} \mu^+ \mu^-$ and $B^+ \rightarrow K^{+} \mu^+ \mu^-$
The direct $C\!P$ asymmetries of the decays $B^0 \rightarrow K^{*0} \mu^+ \mu^-$ and $B^+ \rightarrow K^{+} \mu^+ \mu^-$ are measured using $pp$ collision data corresponding to an integrated luminosity of 3.0$\mbox{fb}^{-1}$ collected with the LHCb detector. The respective control modes $B^0 \rightarrow J/\psi K^{*0}$ and $B^+ \rightarrow J/\psi K^{+}$ are used to account for detection and production asymmetries. The measurements are made in several intervals of $\mu^+ \mu^-$ invariant mass squared, with the $\phi(1020)$ and charmonium resonance regions excluded. Under the hypothesis of zero $C\!P$ asymmetry in the control modes, the average values of the asymmetries are \begin{align} 
{\cal A}_{C\!P}(B^0 \rightarrow K^{*0} \mu^+ \mu^-) &= -0.035 \pm 0.024 \pm 0.003, \cr 
{\cal A}_{C\!P}(B^+ \rightarrow K^{+} \mu^+ \mu^-) &= \phantom{-}0.012 \pm 0.017 \pm 0.001, \end{align} where the first uncertainties are statistical and the second are due to systematic effects. Both measurements are consistent with the Standard Model prediction of small $C\!P$ asymmetry in these decays.
119297705
Model-independent search for $CP$ violation in $D^{0} \to K^{-}K^{+}\pi^{-}\pi^{+}$ and $D^{0} \to \pi^{-}\pi^{+}\pi^{+}\pi^{-}$ decays
A search for CP violation in the phase-space structures of 130 and 15 decays to the final states K-K+pi(-)pi(+) and pi(-)pi(+)pi(+)pi(-) is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb(-1) collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K-K+pi(-)pi(+) final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the pi(-)pi(+)pi(+)pi(-). final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.