arXiv subjects

Karl M. Ecklund

Publications and source records attributed to Karl M. Ecklund.

6 recordsLinked to original sources

arXiv2011

Top Quark Results Using CMS Data at 7 TeV

I give an overview of recent results on top quark properties and interactions, obtained using data collected with the CMS experiment during the years 2010--2011 at sqrt(s)= 7 TeV. Measurements are presented for the inclusive top pair production cross section, using the dilepton, lepton plus jets, and hadronic channels. The mass of the top quark is measured using the dilepton and lepton plus jets samples. CMS also measures the cross section for electroweak production of single top quarks and constrains the CKM matrix element V_tb. Top quark results are compared with Standard Model predictions and used to search for possible presence of new physics. In particular, measurements of the top-pair invariant mass distribution are used to search for new particles decaying to top pairs. CMS has also investigated the top-pair charge asymmetry to search for possible new physics contributions.

hep-ex↗

arXiv2005

Search for an exotic S=-2, Q=-2 baryon resonance at a mass near 1862 MeV in quasi-real photoproduction

A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed in quasi-real photoproduction on a deuterium target through the decay channel $Ξ^- π^- \to Λπ^- π^- \to p π^- π^- π^-$. No evidence for a previously reported $Ξ^{--}(1860)$ resonance is found in the $Ξ^- π^-$invariant mass spectrum. An upper limit for the photoproduction cross section of 2.1 nb is found at the 90% confidence level. The photoproduction cross section for the $Ξ^{0}(1530)$ is found to be between 9 and 24 nb.

hep-ex↗

arXiv2003

Recent CLEO CKM Results

I report B physics results from the CLEO collaboration, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements |Vcb| and |Vub|. I report a recent measurement of |Vub| through study of the q^2 dependence of B -> pi l nu and B -> rho l nu. I also describe new measurements of the inclusive semileptonic branching fraction BF(B -> X e nu) and of moments of the hadronic invariant mass spectrum in B -> X l nu, with impact on |Vcb|.

hep-ex↗

arXiv2003

|Vcb|, |Vub|, and Hqet at Cleo

I report results from the CLEO collaboration on semileptonic B decays, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements Vcb and Vub. I describe the techniques used to obtain the recent improvements in precision for these measurements, including the use of the b -> s gamma photon spectrum to reduce hadronic uncertainties in semileptonic B decays. I also report new measurements of Vcb using the inclusive semileptonic branching fraction BF(B -> X e nu) and of Vub through study of the q^2 dependence of B -> pi l nu and B -> rho l nu.

hep-ex↗

arXiv2003

CLEO results on |V_cb| and |V_ub|

I report results from the CLEO collaboration on semileptonic B decays, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements |V_cb| and |V_ub|. I describe the techniques used to obtain the recent improvements in precision for these measurements, including the use of the b -> s gamma photon spectrum to reduce hadronic uncertainties in semileptonic B decays.

hep-ex↗

arXiv1999

Semileptonic B Decays from CLEO

I report results in semileptonic decays of B mesons from the CLEO collaboration, with a focus on recent results. Results for exclusive reconstruction of B -> D* l nu, B -> D l nu and B -> rho l nu are given including the q^2 dependence of the form factors. These results are used to measure |V_cb| and |V_ub|. Two preliminary analyses using inclusive techniques measure the lepton momentum spectrum and hadronic recoil mass spectrum in B -> X_c l nu decays, showing promise for future precision measurements of |V_cb|.

hep-ex↗