Azimuthal correlation between the (p l , p X b) and (p l , P t) planes in the semileptonic rest frame decay of a polarized top quark: An O(α s) effect Abstract The azimuthal correlation between the planes formed by the vectors (p l , p X b) and (p l , P t) in the semileptonic rest frame decay of a polarized top quark t(↑) → X b + l + + ν l belongs to a class of polarization observables involvin...

Recent measurements of the mass of the top quark (t) are presented using 162 pb of data of pp collisions at √ s = 1.96TeV collected by the CDF detector at the Tevatron collider during Run II. The analyses focus on the semi-leptonic decay mode tt̄ → (blν)(bqq̄) with one or two identified bottom quarks (b). The Template Method (TM) reconstructs the invariant mass of the top quark in each event. The...

We present a detailed and complete calculation of the gluino and scalar quarks contribution to the flavour-changing top quark decay into a charm quark and a photon, gluon, or a Z 0 boson within the minimal supersymmetric standard model including flavour changing gluino-quarks-scalar quarks couplings in the right-handed sector. We compare the results with the ones presented in an earlier paper w...

We evaluate masses and semileptonic decay widths for the ground state of doubly heavy Ξ and Ω baryons in the framework of a nonrelativistic quark model. We solve the three-body problem by means of a variational ansatz made possible by heavy-quark spin symmetry constraints. Our masses are comparable to the ones obtained in relativistic calculations and we get one of the best agreements with latt...

A new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at ffiffi s p 1⁄4 8 TeV corresponding to a luminosity of 19.7 fb−1. The top quark mass is measured using the leptonþ jets, all-jets and dilepton decay channels, giving values of 172.35 0.16ðstatÞ 0.48ðsystÞ GeV, 172.32 0.25ðstatÞ 0.59ðsystÞ GeV, and 172.82 0.1...

The computation of exclusive QCD jet observables at higher orders requires a method for the subtraction of infrared singular configurations arising from multiple radiation of real partons. One commonly used method at next-to-leading order (NLO) is based on the antenna factorization of colour-ordered matrix elements, and uses antenna functions to subtract the real radiation singularities. Up to ...

We extend existing calculations of the electromagnetic dipole operator contribution to the total decay rate and the photon energy spectrum of the decay B̄ → Xsγ at O(αs) by working out the exact dependence on the charm quark mass.

QCD sum rules are derived for the heavy hybrid mesons with one heavy quark and JPC = 1−+, 0++, 1+−, 0−− in the leading order of heavy quark effective theory. We obatin the binding energy ΛH = (1.1±0.1), (1.51±0.10), (1.28±0.10), (1.5±0.1) GeV and decay constant fH = (0.205± 0.02), (0.415 ± 0.04), (0.217 ± 0.02), (0.317 ± 0.03)GeV 7 2 for 1−+, 0++, 1+−, 0−− respectively when the light quark is u...

In the quark mass M → ∞ limit, QCD has an exact SU(2Nf) spin-flavour symmetry. This symmetry relates many matrix elements and form factors of hadrons containing heavy quarks [2,3]. In particular, the semileptonic weak decay form factors of s−wave hadrons containing a single infinitely heavy quark can be reduced to two unknown functions, one for mesons (ξ) and another for baryons (ζ). The knowle...