arXiv subjects

Michael Trott

Publications and source records attributed to Michael Trott.

77 records · Page 5Linked to original sources

arXiv2004

Global analysis of inclusive B decays

In light of the large amount of new experimental data, we revisit the determination of V_{cb} and m_b from inclusive semileptonic and radiative B decays. We study shape variables to order lqcd^3/m_b^3 and alpha_s^2β_0, and include the order alpha_s, lqcd/m_b correction to the hadron mass spectrum in semileptonic decay, which improves the agreement with the data. We focus on the 1S and kinetic mass schemes for the b quark, with and without expanding m_b-m_c in HQET. We perform fits to all available data from BABAR, BELLE, CDF, CLEO, and DELPHI, discuss the theoretical uncertainties, and compare with earlier results. We find V_{cb} = (41.4 +- 0.6 +- 0.1) x 10^{-3} and m_b^{1S} = 4.68 +- 0.03 GeV, including our estimate of the theoretical uncertainty in the fit.

hep-ph↗

arXiv2004

Improving Extractions of |Vcb| and the b Quark Mass from Semileptonic Inclusive B Decay

Recent advances in improving extractions of |Vcb| and m_b from spectra of semileptonic inclusive B decay are reported. Results of a general moment analysis of the lepton energy spectrum and the hadronic invariant mass spectrum are summarized. The calculation of the general O(α_s) structure functions for semileptonic B decay is reported, which has allowed the calculation of the O(α_s Lambda_{QCD} /m_b) terms for the hadronic invariant mass moments to be carried out. Recent theoretical advances and improvements in experimental data has allowed extractions of the CKM element |Vcb| to improve to the 2% level.

hep-ph↗

arXiv2004

Improving Extractions of |Vcb| and mb from the Hadronic Invariant Mass Moments of Semileptonic Inclusive B decay

We calculate the hadronic tensor for inclusive semileptonic B decay to O(alpha_s). This allows O(alpha_s Lambda_{QCD}/mb) corrections to hadronic invariant mass observables to be directly evaluated with experimentally required cuts on phase space. Several moments of phenomenological interest are presented to O(alpha_s Lambda_{QCD}/mb) and O(Lambda_{QCD}^3/mb^3), allowing a consistent extraction of the HQET parameters up to O(Lambda_{QCD}^3/mb^3) and the b quark mass with theoretical error ~ 50 MeV. The hadronic invariant mass spectrum is examined with a general moment to obtain observables that test the theoretical error estimate assigned to these parameters; in particular, fractional moments that directly test the OPE for inconsistencies in the hadronic invariant mass spectrum are reported. The mb Lambda_{QCD}/mc^2 expansion present for fractional moments of the hadronic invariant mass spectum is discussed and shown to introduce a numerically suppressed uncertainty of O(mb^4 Lambda_{QCD}^4/mc^8).

hep-ph↗

arXiv2002

Reducing theoretical uncertainties in mb and lambda1

We calculate general moments of the lepton energy spectrum in inclusive semileptonic B -> X_c l νdecay. Moments which allow the determination of mb^{1S} and lambda1 with theoretical uncertainties Delta(mb^{1S}) ~ 0.04 GeV and Delta(lambda1) ~ 0.05 GeV^2 are presented. The short distance 1S mass is used to extract a mass parameter free of renormalon ambiguities. Moments which are insensitive to mb and lambda1 and therefore test the size of the 1/mb^3 matrix elements and the validity of the OPE are also presented. Finally, we give an expression for the total branching ratio with a lower cut on the lepton energy, which allows one to eliminate a source of model dependence in current determinations of |Vcb| from B -> X_c l νdecay.

hep-ph↗

arXiv2000

High-Precision Value for the Quartic Anharmonic Oscillator Ground State

We will describe how a new, quite simple, but highly effective algorithm, together with the asymptotically fast FFT-based high-precision number multiplication of Mathematica 4 can calculate the ground state of the x^4 anharmonic oscillator to the new record of more than 1000 digits.

quant-ph↗