Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Phys Rev Lett ; 128(13): 132002, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35426724

ABSTRACT

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

2.
Eur Phys J C Part Fields ; 77(11): 791, 2017.
Article in English | MEDLINE | ID: mdl-31997933

ABSTRACT

The strong coupling constant α s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of α s ( m Z ) at the Z-boson mass m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be α s ( m Z ) = 0.1157 ( 20 ) exp ( 29 ) th . Complementary, α s ( m Z ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value α s ( m Z ) = 0.1142 ( 28 ) tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

3.
Article in English | MEDLINE | ID: mdl-27471429

ABSTRACT

This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7[Formula: see text] Framework Programme.

4.
Bioorg Chem ; 29(2): 57-64, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11300695

ABSTRACT

The anti-dithietane-1,3-dioxide --> syn-dithietane-1,3-dioxide isomerization reaction has been theoretically studied on the frame of MO theory both in the gas phase and in solution. In the gas phase the anti (II(a)) <--> syn (II(s)) equilibrium is slightly displaced to the anti isomer formation. The syn concentration ([Syn]) is ca. 36% in the gas phase, whereas in low polarity solvent, such as carbon tetrachloride, [Syn] is ca. 63%. In medium-high polarity solvents like acetonitrile and dimethyl-sulfoxide the [ anti]/[ syn ] ratio is ca. 0.37.


Subject(s)
Heterocyclic Compounds/chemical synthesis , Sulfides/chemical synthesis , Acetonitriles , Dimethyl Sulfoxide/chemistry , Heterocyclic Compounds/chemistry , Isomerism , Models, Molecular , Molecular Conformation , Solvents , Sulfides/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...