9,986 research outputs found
LHCb Results on Semileptonic B/B/ Decays
Studies of semileptonic decays of b hadrons with the LHCb experiment are
reported. In particular, measurements of the b hadron production fractions at
the LHC and Bs semileptonic decays in P-wave charmed mesons are presented. An
outlook of the LHCb potential in measuring the CKM matrix elements Vub and Vcb,
as well as decays involving taus, is given.Comment: Proceedings of CKM 2012, the 7th International Workshop on the CKM
Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October
201
B Mixing and Lifetime Measurements with the BaBar Detector
Recent BaBar measurements on lifetime and mixing of B mesons are reported.
Various techniques are used, ranging from the full reconstruction of hadronic B
decays, to partial reconstruction techniques, and to a totally inclusive
approach with dilepton events. The results presented are based on a data sample
collected by BaBar during the 1999-2000 data taking, and should be considered
as preliminary.Comment: 6 pages, 5 postscript figues, submitted to BCP4 proceeding
Q_T resummation in Higgs boson production at the LHC
When considering the transverse momentum distribution (q_T) of the Higgs
boson production it is necessary to separate the small q_T region (q_T << M_H)
from the medium and large (q_T > M_H) one, the former being treated by means of
resummation techniques of logaritmhically-enhanced contributions and the latter
by fixed-order perturbation theory. Then these two approaches have to be
consistently matched to avoid double-counting in the intermediate q_T region.
Here soft gluon resummation is implemented up to NNLL order and the matching to
the corresponding NLO perturbative result is performed. Numerical results are
shown for the LHC. The main features of the differential distribution turn out
to be quite stable with respect to perturbative uncertainties.Comment: 5 pages, 2 figures,. Talk given in italian at "Incontri sulla Fisica
delle Alte Energie", Lecce, Italy, 23-26 April 200
Soft-gluon resummation for Higgs differential distributions at the Large Hadron Collider
We study the transverse-momentum (q_T) and rapidity (y) distributions of the
Higgs boson in perturbative QCD, including the most advanced theoretical
information presently available: fixed-order perturbation theory at
Next-to-Leading Order (NLO) in the large-q_T region (q_T ~ M_H, being M_H the
Higgs mass), and soft-gluon resummation at the Next-to-Next-to-Leading
Logarithmic accuracy (NNLL) in the small-q_T region (q_T << M_H). We present
numerical results for the doubly-differential (q_T and y) cross section for the
production of a Standard Model Higgs boson at the Large Hadron Collider (LHC).Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 4 PostScript
figure
Selected Items in Jet Algorithms
I provide a very brief overview of recent developments in jet algorithms,
mostly focusing on the issue of infrared-safety.Comment: 3 pages. Talk given at IFAE 2008, Bologna, Italy, 26-28 March 200
Joint resummation for slepton pair production at hadron colliders
We present a precision calculation of the transverse-momentum and
invariant-mass distributions for supersymmetric particle pair production at
hadron colliders, focusing on Drell-Yan like slepton pair and slepton-sneutrino
associated production at the CERN Large Hadron Collider. We implement the joint
resummation formalism at the next-to-leading logarithmic accuracy with a
process-independent Sudakov form factor, thus ensuring a universal description
of soft-gluon emission, and consistently match the obtained result with the
pure perturbative result at the first order in the strong coupling constant,
i.e. at O(alpha_s). We also implement three different recent parameterizations
of non-perturbative effects. Numerically, we give predictions for ~e_R ~e_R^*
production and compare the resummed cross section with the perturbative result.
The dependence on unphysical scales is found to be reduced, and
non-perturbative contributions remain small.Comment: 12 pages, 4 figure
Applications of Graphene at Microwave Frequencies
In view to the epochal scenarios that nanotechnology discloses, nano-electronics has the potential to introduce a paradigm shift in electronic systems design similar to that of the transition from vacuum tubes to semiconductor devices. Since low dimensional (1D and 2D) nano-structured materials exhibit unprecedented electro-mechanical properties in a wide frequency range, including radio-frequencies (RF), microwave nano-electronics provides an enormous and yet widely undiscovered opportunity for the engineering community. Carbon nano-electronics is one of the main research routes of RF/microwave nano-electronics. In particular, graphene has shown proven results as an emblematic protagonist, and a real solution for a wide variety of microwave electronic devices and circuits. This paper introduces graphene properties in the microwave range, and presents a paradigm of novel graphene-based devices and applications in the microwave/RF frequency range
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