11,563 research outputs found
OPE analysis of the nucleon scattering tensor including weak interaction and finite mass effects
We perform a systematic operator product expansion of the most general form
of the nucleon scattering tensor including electro-magnetic and
weak interaction processes. Finite quark masses are taken into account and a
number of higher-twist corrections are included. In this way we derive
relations between the lowest moments of all 14 structure functions and matrix
elements of local operators. Besides reproducing well-known results, new sum
rules for parity-violating polarized structure functions and new mass
correction terms are obtained.Comment: 50 pages, additional references adde
Higgs boson production in high energy proton-nucleus collisions
We study Higgs boson production from gluon-gluon fusion at mid-rapidity in
high energy proton-nucleus collisions. For this process the presently still
little known gluon distribution function gives a numerically
relevant contribution. We show by explicite calculation that using CGC (color
glass condensate) model input the result obtained in the naive k_t
factorization approach matches the result obtained in the TMD factorization
framework for a dilute medium. We also verify the earlier finding that the k_t
factorization formalism for Higgs production breaks down in a dense medium. In
doing so we formulate a hybrid model which allows one to treat such reactions
theoretically.Comment: a few more references added, vision
QCD at Finite Density and Color Superconductivity
Brief review of current status of the field.Comment: Invited talk at Lattice 99, Pisa, July 1999. 5 pages, 7 fig
Diffractive charged meson pair production
We investigate the possibility to measure the nonforward gluon distribution
function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in
polarized lepton nucleon scattering. The resulting cross sections are small and
are dominated by the gluonic contribution. We find relatively large spin
asymmetries, both for \pi^+\pi^- and for K^+K^- pairs.Comment: 15 pages, version with changed kinematical cuts, to be pubished in
Phys.Lett.
Seasonal changes in microbial dissolved organic sulfur transformations in coastal waters
The marine trace gas dimethylsulfide (DMS) is the single most important biogenic source of atmospheric sulfur, accounting for up to 80% of global biogenic sulfur emissions. Approximately 300 million tons of DMS are produced annually, but the majority is degraded by microbes in seawater. The DMS precursor dimethylsulfoniopropionate (DMSP) and oxidation product dimethylsulphoxide (DMSO) are also important organic sulfur reservoirs. However, the marine sinks of dissolved DMSO remain unknown. We used a novel combination of stable and radiotracers to determine seasonal changes in multiple dissolved organic sulfur transformation rates to ascertain whether microbial uptake of dissolved DMSO was a significant loss pathway. Surface concentrations of DMS ranged from 0.5 to 17.0 nM with biological consumption rates between 2.4 and 40.8 nM·d−1. DMS produced from the reduction of DMSO was not a significant process. Surface concentrations of total DMSO ranged from 2.3 to 102 nM with biological consumption of dissolved DMSO between 2.9 and 111 nM·d−1. Comparisons between 14C2-DMSO assimilation and dissimilation rates suggest that the majority of dissolved DMSO was respired (>94%). Radiotracer microbial consumption rates suggest that dissimilation of dissolved DMSO to CO2 can be a significant loss pathway in coastal waters, illustrating the significance of bacteria in controlling organic sulfur seawater concentrations
On the Stability of Matter
A hypothesis of absolutely stable strange hadronic matter composed of
baryons, here denoted , is tested within many-body
calculations performed using the Relativistic Mean-Field approach. In our
calculations, we employed the interaction compatible with
the binding energy ~MeV given
by the phenomenological energy-independent interaction model by
Yamazaki and Akaishi (YA). We found that the binding energy per , as
well as the central density in many-body systems saturates for mass
number , leaving aggregates highly unstable against
strong interaction decay. Moreover, we confronted the YA interaction model with
kaonic atom data and found that it fails to reproduce the single-nucleon
absorption fractions at rest from bubble chamber experiments.Comment: Proceedings of the HYP2018 conference, Norfolk/Portsmouth, USA, June
24 - 29, 2018, submitted to AIP Conference Proceeding
Diquark Bose Condensates in High Density Matter and Instantons
Instantons lead to strong correlations between up and down quarks with spin
zero and anti-symmetric color wave functions. In cold and dense matter,
and 50 MeV, these pairs Bose-condense,
replacing the usual and
condensates.Comment: 4 pages ReVTeX, 2 eps-figures included using epsf.st
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