نتایج جستجو برای: روش charm

تعداد نتایج: 374417  

1998
Urs Langenegger

Heavy avor production at HERA is dominated by photoproduction where a quasi real photon scatters o a gluon in the proton While open D and hidden J charm have been measured since the rst real evidence of hidden beauty was seen only in The present analysis measures open beauty and charm photoproduction in the kinematic range Q GeV and yJB and uses data taken with the H detector in the years corre...

2001
Urs Langenegger

We present measurements of the inclusive semileptonic branching fractions of charged and neutral B mesons using 20.6 fb−1 of data measured at the Υ (4S) with the BABAR detector. Events are tagged with a fully reconstructed hadronic decay of a B meson. The correlation between the flavor of the tag B meson and the electron charge allows the separation of prompt semileptonic B decays and cascade s...

2001
I. I. Bigi

After sketching heavy quark expansions as applied to heavy flavour decays I emphasize the relevance of nonperturbative dynamics at the charm scale for exclusive b → c modes. I address the issue of quark-hadron duality for charm and discuss both the experimental and theoretical status of D − D̄ oscillations. Finally I argue that comprehensive CP studies of charm decays provide novel portals to Ne...

1995
R. M. Godbole

We compute the contributions to large-pT J/ψ production at HERA coming from fragmentation of gluons and charm quarks. We find that the charm quark fragmentation contribution dominates over the direct production of J/ψ via photon-gluon fusion at large-pT , while the gluon fragmentation is negligibly small over the whole range of pT . An experimental study of pT distributions of J/ψ at HERA will ...

2001
R. W. GARDNER

We discuss a search for CPT violation in neutral charm meson oscillations. The data come from the Fermilab fixed-target experiment FOCUS. While flavor mixing in the charm sector is predicted to be small by the standard model, it is still possible to investigate CPT violation through study of the proper time dependence of the asymmetry in right-sign decay rates for D0 and D̄0. Using present limit...

2003
H. Wittig A. A. Petrov D. G. Cassel

We introduce the contributions to the proceedings of Working Group V. The main topics were: present and future experiments dedicated to charm physics, the interplay between high-precision measurements and better control over theoretical uncertainties, and searches for signals of new physics in the charm sector. The comparison of Lattice QCD calculations with precise measurements of charm semi-l...

Journal: :journal of sciences islamic republic of iran 0

in this research we described the effective hamiltonian theory and applied this theory to the calculation of current-current (q1,2) and qcd penguin (q3,…,6) c quark decay rates. we calculated the decay rates of semileptonic and hadronic of charm quark in the effective hamiltonian theory. we investigated the decay rates of d meson decays according to spectator quark model (sqm) for the calculati...

Journal: :International Journal of Modern Physics A 2017

1995
I. I. Bigi

The recent progress in our understanding of heavy-flavour decays allows us to define more reliably which future measurements on charm decays are needed to further advance our understanding of QCD and to get our theoretical tools ready for treating beauty decays. After sketching the theoretical landscape I list those required measurements. I argue that some – in particular those concerning inclu...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید