Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology

We present results on the nucleon scalar, axial, and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key observables is carried out using lattice QCD simulations at a physical value of the pion mass. The evaluation is based on gauge configurations generated with two degenerate sea…

We investigate nonlocal field theories, a subject that has attracted some renewed interest in connection with nonlocal gravity models. We study, in particular, scalar theories of interacting delocalized fields, the delocalization being specified by nonlocal integral kernels. We distinguish between strictly nonlocal and quasilocal (compact support) kernels and impose conditions on them to insure U…

The spin decomposition of the proton is a long-standing topic of much interest in hadronic physics. Lattice QCD has had much success in calculating the connected contributions to the quark spin. However complete calculations, which necessarily involve gluonic and strange-quark contributions, still present some challenges. These ``disconnected'' contributions typically involve small signals hidden…

The CMS ${e}^{+}{e}^{\ensuremath{-}}jj$ events of invariant mass near 2 TeV are consistent with a ${W}^{\ensuremath{'}}$ boson decaying into an electron and a right-handed neutrino whose TeV-scale mass is of the Dirac type. We show that the Dirac partner of the right-handed electron neutrino can be the right-handed tau neutrino. A prediction of this model is that the sum of the ${\ensuremath{\tau…

The decay B0→ψ(2S)K+π- is analyzed using 3 fb-1 of pp collision data collected with the LHCb detector. A model-independent description of the ψ(2S)π mass spectrum is obtained, using as input the Kπ mass spectrum and angular distribution derived directly from data, without requiring a theoretical description of resonance shapes or their interference. The hypothesis that the ψ(2S)π mass spectrum ca…

The recent LHCb discovery of states ${P}_{c}^{+}(4380)$, ${P}_{c}^{+}(4450)$, believed to be $c\overline{c}uud$ pentaquark resonances, begs the question of whether equivalent states with $c\overline{c}\ensuremath{\rightarrow}s\overline{s}$ exist, and how they might be produced. The precise analogue to the ${P}_{c}^{+}$ discovery channel ${\mathrm{\ensuremath{\Lambda}}}_{b}\ensuremath{\rightarrow}…

We show that a self-interacting neutrino gas can spontaneously acquire a nonstationary pulsating component in its flavor content, with a frequency that can exactly cancel the ``multiangle'' refractive effects of dense matter. This can then enable homogeneous and inhomogeneous flavor conversion instabilities to exist even at large neutrino and matter densities, where the system would have been sta…

Single- and double-heavy baryons are studied in the constituent quark model. The model Hamiltonian is chosen as a standard one with two exceptions: (1) the color-Coulomb term depends on quark masses and (2) an antisymmetric $LS$ (spin-orbit) force is introduced. Model parameters are fixed by the strange baryon spectra, $\mathrm{\ensuremath{\Lambda}}$ and $\mathrm{\ensuremath{\Sigma}}$ baryons. Th…

For systems with charged chiral fermions, the imbalance of chirality in the presence of magnetic field generates an electric current---this is the chiral magnetic effect (CME). We study the dynamical real-time evolution of electromagnetic fields coupled by the anomaly to the chiral charge density and the CME current by solving the Maxwell-Chern-Simons equations. We find that the CME induces the i…

The electromagnetic form factors of the spin-$3/2$ $\mathrm{\ensuremath{\Omega}}$ baryons, namely $\mathrm{\ensuremath{\Omega}}$, ${\mathrm{\ensuremath{\Omega}}}_{c}^{*}$, ${\mathrm{\ensuremath{\Omega}}}_{cc}^{*}$ and ${\mathrm{\ensuremath{\Omega}}}_{ccc}$, are calculated in full QCD on ${32}^{3}\ifmmode\times\else\texttimes\fi{}64$ PACS-CS lattices with a pion mass of 156(9) MeV. The electric ch…

We study the SU(3) gluon propagator in renormalizable ${R}_{\ensuremath{\xi}}$ gauges implemented on a symmetric lattice with a total volume of $(3.25\text{ }\text{ }\mathrm{fm}{)}^{4}$ for values of the gauge fixing parameter up to $\ensuremath{\xi}=0.5$. As expected, the longitudinal gluon dressing function stays constant at its tree-level value $\ensuremath{\xi}$. Similar to the Landau gauge, …

The problem of obtaining a gauge independent beta function for Newton's constant is addressed. By a specific parametrization of metric fluctuations a gauge independent functional integral is constructed for the semiclassical theory around an arbitrary Einstein space. The effective action then has the property that only physical polarizations of the graviton contribute, while all other modes cance…

Future cosmological measurements should enable the sum of neutrino masses to be determined indirectly through their effects on the expansion rate of the Universe and the clustering of matter. We consider prospects for the gravitationally lensed cosmic microwave background (CMB) anisotropies and baryon acoustic oscillations (BAOs) in the galaxy distribution, examining how the projected uncertainty…

New lattice QCD results for two-nucleon systems are presented, including binding energies for the deuteron and dineutron, and S-wave scattering phase shifts. The results are then explored in the context of nucleon-nucleon effective field theory.

The same leptoquarks that explain the recently observed anomaly in ${R}_{K}$ can generate naturally small Majorana neutrino masses at one-loop level through mixing with the standard model Higgs. This is particularly relevant in models with at least two leptoquarks contributing to $b\ensuremath{\rightarrow}sll$ transitions.

Primordial or big bang nucleosynthesis (BBN) is one of the three historically strong evidences for the big bang model. Standard BBN is now a parameter-free theory, since the baryonic density of the Universe has been deduced with an unprecedented precision from observations of the anisotropies of the cosmic microwave background radiation. There is a good agreement between the primordial abundances…

We provide an exhaustive numerical exploration of the predictions of loop quantum cosmology with a postbounce phase of inflation for the primordial power spectrum of scalar and tensor perturbations. We extend previous analysis by characterizing the phenomenologically relevant parameter space and by constraining it using observations. Furthermore, we characterize the shape of loop quantum cosmolog…

We study the prospects for excluding or discovering vectorlike leptons using multilepton events at the LHC. We consider models in which the vectorlike leptons decay to tau leptons. If the vectorlike leptons are weak isosinglets, then discovery in multilepton states is found to be extremely challenging. For the case that the vectorlike leptons are weak isodoublet, we argue that there may be an opp…

New data from the BABAR Collaboration, on azimuthal asymmetries measured in ${e}^{+}{e}^{\ensuremath{-}}$ annihilations into pion pairs at ${Q}^{2}=112\text{ }\text{ }{\mathrm{GeV}}^{2}$, allow us to take the first, direct glance at the ${p}_{\ensuremath{\perp}}$ dependence of the Collins functions, in addition to their $z$ dependence. These data, together with previous ${e}^{+}{e}^{\ensuremath{-…

We present the graviton propagator for an infinite derivative, $D$-dimensional, nonlocal action, up to quadratic order in curvature around a Minkowski background, and discuss the conditions required for this class of gravity theory to be ghost-free. We then study the gravitational entropy for de-Sitter and anti-de Sitter backgrounds, before comparing with a recently derived result for a Schwarzsc…