0000000001285854
AUTHOR
Matthias Jamin
What can be learned from the Belle spectrum for the decay τ−→ντKSπ−
Abstract A theoretical description of the differential decay spectrum for the decay τ − → ν τ K S π − , which is based on the contributing Kπ vector and scalar form factors F + K π ( s ) and F 0 K π ( s ) being calculated in the framework of resonance chiral theory (R χ T), additionally imposing constraints from dispersion relations as well as short distance QCD, provides a good representation of a recent measurement of the spectrum by the Belle Collaboration. Our fit allows to deduce the total branching fraction B [ τ − → ν τ K S π − ] = 0.427 ± 0.024 % by integrating the spectrum, as well as the K ∗ resonance parameters M K ∗ = 895.3 ± 0.2 MeV and Γ K ∗ = 47.5 ± 0.4 MeV , where the last t…
Duality violations in τ hadronic spectral moments
Evidence is presented for the necessity of including duality violations in a consistent description of spectral function moments employed in the precision determination of $\alpha_s$ from $\tau$ decay. A physically motivated ansatz for duality violations in the spectral functions enables us to perform fits to spectral moments employing both pinched and unpinched weights. We describe our analysis strategy and provide some preliminary findings. Final numerical results await completion of an ongoing re-determination of the ALEPH covariance matrices incorporating correlations due to the unfolding procedure which are absent from the currently posted versions. To what extent this issue affects ex…
Bottom quark mass and alpha_s from the Upsilon system
The mass of the bottom quark and the strong coupling constant alpha_s are determined from QCD moment sum rules for the Upsilon system. Two analyses are performed using both the pole mass M_b as well as the mass m_b in the $\MSb$ scheme. In the pole-mass scheme large perturbative corrections resulting from coulombic contributions have to be resummed. In the $\MSb$ scheme this can be avoided by an appropriate choice for the renormalization scale. For the bottom quark mass we obtain M_b = 4.60 +- 0.02 GeV and m_b(m_b) = 4.13 +- 0.06 GeV. Our combined result from both determinations for the strong coupling is alpha_s(M_Z) = 0.119 +- 0.008.
Light quark masses from scalar sum rules
7 páginas, 2 figuras, 1 tabla.-- arXiv:hep-ph/0110194v2
QCD corrections to inclusive ΔS = 1, 2 transitions at the next-to-leading order
24 páginas, 3 figuras, 2 tablas.-- arXiv:hep-ph/9402363v1
Strangeness-changing scalar form factors
30 páginas, 2 tablas, 10 figuras.-- arXiv:hep-ph/0110193v1
S-wave Kpi scattering in chiral perturbation theory with resonances
32 páginas, 6 figuras, 2 tablas.-- PACS: 11.80.Et; 12.39.Fe; 13.75.Lb; 13.85.Fb.-- arXiv:hep-ph/0006045v1
Spectral distribution for the decay tau -> v(tau)K pi
With the newly available data sets on hadronic tau decays from the B-factories BaBar and BELLE, and future data from BESIII, precise information on the decay distributions will soon become available. This calls for an improvement of the decay spectra also on the theoretical side. In this work, the distribution function for the decay tau -> v(tau)K pi will be presented with the relevant K pi vector and scalar forth factors being calculated in the framework of the resonance chiral theory, also taking into account additional constraints from dispersion relations and short-distances. As a by-product the slope and curvature of the vector form factor F-+(K pi)(s) are determined to be lambda'(+) =…
Spectral distribution for the decay τ→ντKπ
Abstract With the newly available data sets on hadronic τ decays from the B -factories BaBar and BELLE, and future data from BESIII, precise information on the decay distributions will soon become available. This calls for an improvement of the decay spectra also on the theoretical side. In this work, the distribution function for the decay τ → ν τ K π will be presented with the relevant Kπ vector and scalar form factors being calculated in the framework of the resonance chiral theory, also taking into account additional constraints from dispersion relations and short-distances. As a by-product the slope and curvature of the vector form factor F + K π ( s ) are determined to be λ + ′ = 25.6…
Orderp6chiral couplings from the scalarK form factor
15 páginas, 2 tablas.-- arXiv:hep-ph/0401080v2
Determination of m(s) and vertical bar V-us vertical bar from hadronic tau decays
The mass of the strange quark is determined from SU(3)-breaking effects in the tau hadronic width. Compared to previous analyses, the contributions from scalar and pseudoscalar spectral functions, which suffer from large perturbative corrections, are replaced by phenomenological parametrisations. This leads to a sizeable reduction of the uncertainties in the strange mass from tau decays. Nevertheless, the resulting m(s) value is still rather sensitive to the moment of the invariant mass distribution which is used for the determination, as well as the size of the quark-mixing matrix element \V-us\. Imposing the unitarity fit for the CKM matrix, we obtain m(s)(2 GeV) = 117 +/- 17 MeV, whereas…
Duality violations in hadronic tau decays and the value of alpha_s
We discuss the quantitative impact of duality violations on the determination of the strong coupling constant from hadronic tau decays, based on a preliminary analysis of OPAL data.
Scalar K pi form factor and light quark masses
5 páginas, 2 figuras, 2 tablas.-- PACS numbers: 12.15.Ff, 14.65.Bt, 11.55.Hx.-- arXiv:hep-ph/0605095v2
and from hadronic tau decays
5 paginas.-- Comunicacion presentada al 9o International Workshop on Tau Lepton Physics (TAU06) celebrado del 19 al 22 de Septiembre en Pisa (Italia).-- arXiv:hep-ph/0612154v1
V-us and m(s) from hadronic tau decays
Recent progress in the determination of |V_us| employing strange hadronic tau-decay data are reported. This includes using the recent OPAL update of the strange spectral function, as well as augmenting the dimension-two perturbative contribution with the recently calculated order alpha_s^3 term on the theory side. These updates result in |V_us| = 0.2220 +- 0.0033, with the uncertainty presently being dominated by experiment, and already being competitive with the standard extraction from K_e3 decays and other new proposals to determine |V_us|. In view of the ongoing work to analyse tau-decay data at the B-factories BaBar and Belle, as well as future results from BESIII, the error on |V_us| …
The Belle II Physics Book
cd. autorów: L. Cao48,‡, G. Caria145,‡, G. Casarosa57,‡, C. Cecchi56,‡,D. Cˇ ervenkov10,‡,M.-C. Chang22,‡, P. Chang92,‡, R. Cheaib146,‡, V. Chekelian83,‡, Y. Chen154,‡, B. G. Cheon28,‡, K. Chilikin77,‡, K. Cho70,‡, J. Choi14,‡, S.-K. Choi27,‡, S. Choudhury35,‡, D. Cinabro170,‡, L. M. Cremaldi146,‡, D. Cuesta47,‡, S. Cunliffe16,‡, N. Dash33,‡, E. de la Cruz Burelo9,‡, E. de Lucia52,‡, G. De Nardo54,‡, †Editor. ‡Belle II Collaborator. §Theory or external contributing author. M. De Nuccio16,‡, G. De Pietro59,‡, A. De Yta Hernandez9,‡, B. Deschamps129,‡, M. Destefanis60,‡, S. Dey116,‡, F.Di Capua54,‡, S.Di Carlo75,‡, J. Dingfelder129,‡, Z. Doležal10,‡, I. Domínguez Jiménez125,‡, T.V. Dong30,26,…
What can be learned from the Belle spectrum for the decay tau(-) -> nu(t)K(S)pi(-)
A theoretical description of the differential decay spectrum for the decay tau(-) -> nu(tau)K(S)pi(-), which is based on the contributing K pi vector and scalar form factors F(+)(K pi)(s) and F(0)(K pi)(s) being calculated in the framework of resonance chiral theory (R chi T), additionally imposing constraints from dispersion relations as well as short distance QCD, provides a good representation of a recent measurement of the spectrum by the Belle Collaboration. Our fit allows to deduce the total branching fraction B[tau(-) -> v(tau)K(S)pi(-)] = 0.427 +/- 0.024% by integrating the spectrum, as well as the K* resonance parameters M(K)* = 895.3 +/- 0.2 MeV and Gamma(K)* = 47.5 +/- 0.4 MeV, w…
Vusandmsfrom HadronicτDecays
Recent experimental results on hadronic $\ensuremath{\tau}$ decays into strange particles by the OPAL Collaboration are employed to determine ${V}_{us}$ and ${m}_{s}$ from moments of the invariant mass distribution. Our results are ${V}_{us}=0.2208\ifmmode\pm\else\textpm\fi{}0.0034$ and ${m}_{s}(2\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V})=81\ifmmode\pm\else\textpm\fi{}22\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$. The error on ${V}_{us}$ is dominated by experiment and should be improvable in the future. Nevertheless, already now our result is competitive with the standard extraction of ${V}_{us}$ from ${K}_{e3}$ decays, and it is compatible with unitarity.