Filtyp
In the hadroproduction of charm in the context of string fragmentation, the pull of a beam remnant at the other end of a string may give a charm hadron more energy than the perturbatively produced charm quark. The collapse of a low-mass string to a single hadron is the extreme case in this direction, and gives rise to asymmetries between charm and anticharm hadron spectra. We study these phenomena
The structure of the general solution of the inhomogeneous evolution equations allows the separation of a photon structure function into perturbative ("anomalous") and non-perturbative contributions. The former part is fully calculable, and can be identified with the high-mass contributions to the dispersion integral in the photon mass. Properly normalized "state" distributions can be defined, whe
We describe a class of three Higgs doublet models (3HDMs) with a softly broken U(1) × U(1) family symmetry that enforces a Cabibbo-like quark mixing while forbidding tree-level flavour changing neutral currents. The hierarchy in the observed quark masses is partly explained by a softer hierarchy in the vacuum expectation values of the three Higgs doublets. As a consequence, the physical scalar spe
We give a short overview of the theory of the muon anomalous magnetic moment with emphasis on the hadronic light-by-light and the pion loop contribution. We explain the difference between the hidden local symmetry and full VMD pion loop and discuss leading logarithms in the anomalous sector of 2-flavour chiral perturbation theory.
The Galactic Archaeology with HERMES (GALAH) survey is a large high-resolution spectroscopic survey using the newly commissioned High Efficiency and Resolution Multi-Element Spectrograph (HERMES) on the Anglo-Australian Telescope. The HERMES spectrograph provides high-resolution (R ~ 28 000) spectra in four passbands for 392 stars simultaneously over a 2 deg field of view. The goal of the survey i
The overlap between the spectroscopic Galactic Archaeology with HERMES (GALAH) survey and Gaia provides a high-dimensional chemodynamical space of unprecedented size. We present a first analysis of a subset of this overlap, of 7066 dwarf, turn-off, and sub-giant stars. These stars have spectra from the GALAH survey and high parallax precision from the Gaia DR1 Tycho-Gaia Astrometric Solution. We
An implicit water all-atom model is used to study folding, aggregation and mechanical unfolding of small proteins. Physically reasonable results obtained for a variety of applications indicate healthy global properties of the interaction potential.
The soft color interaction model (SCI) as an add-on to standard perturbative QCD describes diffractive processes by allowing for additional soft color-octet exchanges below the conventional threshold for parton showering. We discuss how diffractive and inclusive event samples for diffractive hard processes can be obtained from a Monte Carlo in a unified way for pp → p[W± +X]p as an example, and di
We present a study of central exclusive production of W+W - pairs in proton-proton collisions at the LHC. We compare the contribution of the γγ → W+W- mechanism with a new mechanism of exclusive diffractive production through the gg → W+W- subprocess with intermediate virtual Higgs boson and quark box diagrams. The amplitude for the latter process is expressed in terms of the off-diagonal unintegr
We discuss single diffractive gauge bosons (γ*, W±, Z) production in proton-proton collisions at LHC energy (14 TeV) in the framework of the color dipole approach. The calculations are performed for gauge bosons produced at forward rapidities. The diffractive cross section is predicted as a function of fractional momentum and invariant mass of the lepton pair. We found a dramatic breakdown of the
We consider the central exclusive production of qq̄ pairs and Higgs boson in proton-proton collisions at LHC. The amplitude for the process is derived within the k -factorization approach and considered in different kinematical asymptotics, in particular, in the important high quark transverse momenta and massless quark limits. Quark helicity and spin-projection amplitudes in two different frames
Diffractive hard scattering is interpreted as the effect of soft gluon exchanges between the emerging energetic quarks and the nucleon's color field, resulting in an overall color singlet exchange. Summing multiple gluon exchanges to all orders leads to exponentiation and an amplitude in analytic form. Numerical evaluation reproduces the precise HERA data and gives new insights on the density of g
We consider exclusive double diffractive production of polarised axial-vector χc(1+) and tensor χc(2+) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the kt-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental conse
We consider a measurement of exclusive production of scalar Χc(0++) meson in the proton-proton collisions at LHC and RHIC and in the proton-antiproton collisions at the Tevatron via Χc0→π+π- decay. The corresponding amplitude for exclusive double-diffractive Χc0 meson production was obtained within the kt-factorization approach including virtualities of active gluons and the corresponding cross se
We consider exclusive double diffractive production of polarised axial-vector χ c(1 +) and tensor χ c(2 +) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the k t-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental
We discuss exclusive elastic double diffractive axial-vector χc(1+) and tensor χc(2+) mesons production for different meson polarizations in proton-(anti)proton collisions at the Tevatron energy. The amplitude for the process is derived within the kt-factorization approach using unintegrated gluon distributions. Differential cross sections for different χc polarizations are calculated. Angular dis
We present a new model where hard diffraction is an effect of soft gluon rescattering between partons emerging from the hard interaction and the color field of the proton. A resummation to all orders of multiple gluon exchanges leads to an overall color singlet exchange amplitude which reproduces the precise HERA data on diffractive deep inelastic scattering.
We propose central exclusive production of a charged Higgs boson in association with a W boson as a possible signature of certain types of extended Higgs sectors. We calculate the cross section and find that the rate at the LHC could be large enough to allow observation in some models with two-Higgs doublets, where the charged Higgs and at least one of the neutral scalars can be light enough. We u
We construct a QCD-based model where soft gluon rescattering between final state partons in deep inelastic scattering leads to events with large rapidity gaps and a leading proton. The model successfully describes the precise HERA data on the diffractive deep inelastic structure function in the whole available kinematical range.
We report on the results of a theoretical study of the central exclusive production of scalar χ c(0 +) meson via χ c0→π +π - decay in high-energy hadron collisions at the RHIC, Tevatron and LHC. The corresponding amplitude for exclusive double-diffractive χ c0 meson production was obtained within the k t-factorization approach including virtualities of active gluons and the cross section is calcul
