673 research outputs found
Constraints for the nuclear parton distributions from Z and W production at the LHC
The LHC is foreseen to finally bring also the nuclear collisions to the TeV
scale thereby providing new possibilities for physics studies, in particular
related to the electro-weak sector of the Standard Model. We study here the Z
and W production in proton-lead and lead-lead collisions at the LHC,
concentrating on the prospects of testing the factorization and constraining
the nuclear modifications of the parton distribution functions (PDFs).
Especially, we find that the rapidity asymmetries in proton-nucleus collisions,
arising from the differences in the PDFs between the colliding objects, provide
a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus
case. We comment on how such studies will help to improve our knowledge of the
nuclear PDFs.Comment: The version accepted for publication in JHEP. New figures has been
added, and we also discuss the single charged lepton productio
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Studies of Bs2∗(5840)0 and Bs1(5830)0 mesons including the observation of the Bs2∗(5840)0→B0KS0 decay in proton-proton collisions at s=8TeV.
Measurements of Bs2∗(5840)0 and Bs1(5830)0 mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of , collected with the CMS detector at the LHC at a centre-of-mass energy of 8TeV . The analysis studies P-wave Bs0 meson decays into B(∗)+K- and B(∗)0KS0 , where the B+ and B0 mesons are identified using the decays B+→J/ψK+ and B0→J/ψK∗(892)0 . The masses of the P-wave Bs0 meson states are measured and the natural width of the Bs2∗(5840)0 state is determined. The first measurement of the mass difference between the charged and neutral B∗ mesons is also presented. The Bs2∗(5840)0 decay to B0KS0 is observed, together with a measurement of its branching fraction relative to the Bs2∗(5840)0→B+K- decay
Evidence for Escherichia coli DcuD carrier dependent FOF1-ATPase activity during fermentation of glycerol
During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work
reveals the total and N,N’-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5
in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest
at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in
dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40%
and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by
DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD
mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min
when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD
is absent. No significant differences were determined in wild type and mutants specific growth rate
except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact
on H+ fluxes, FOF1-ATPase activity and depends on potassium ions
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