Inelastic neutrino-lepton interactions

The interactions of neutrinos (antineutrinos) with electrons and positrons which lead to the formation of muons are studied. The investigation employs the two- and four-component theories of the neutrino. Formulas are obtained which describe the angular distribution of arbitrarily polarized recoil muons emitted during the interaction of neutrinos (antineutrinos) with a polarized target.In conclusion the authors thank B. K. Kerimov for valuable advice and discussions.     

The annihilation of virtual photons into pseudoscalar mesons

We investigate the possibility to constrain the pion distribution amplitude from the transition. For a surprisingly large range in the two photon virtualities we find that the transition form factor is essentially independent of the distribution amplitude. This in turn entails a parameter-free prediction of QCD. The form factors are also briefly discussed. We estimate that experimental studies might be feasible at the existing experiments BaBar, Belle, and CLEO. Received: 30 August 2001 / Published online: 23 November 2001     

Weak decays of pseudoscalar mesons with the formation of leptons in the final state

Leptonic and semileptonic decays of pseudoscalar mesons are considered. The functional dependence of the weak form factors on the wave functions of the (q₁¯q₂) system is found. Numerical values of the coefficients and (for , K, D, and F mesons) determining the interquark potential are obtained. Within the framework of the Coulomb and oscillator models, the probability of semileptonic decays of D and F mesons is found. For D mesons, comparison with experiment is undertaken. Agreement with experiment is observed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 19–23, March, 1982.     

Tau decays into three pseudoscalar mesons

In this paper we compute the branching ratios of the tau decays into three mesons. The hadronic matrix elements are obtained by first using the structure of the chiral currents and that of the Wess-Zumino anomaly and finally implementing all possible low-lying resonances in the different channels.     

Transversity in hard exclusive electroproduction of pseudoscalar mesons

Estimates for electroproduction of pseudoscalar mesons at small values of skewness are presented. Cross-sections and asymmetries for these processes are calculated within the handbag approach which is based on factorization in hard parton subprocesses and soft generalized parton distributions (GPDs). The latter are constructed from double distributions. Transversity GPDs are taken into account; they are accompanied by twist-3 meson wave functions. For most pseudoscalar-meson channels a combination of ˜_T and [`(E)]_T \bar{{E}}_{T}^{} plays a particularly prominent role. This combination of GPDs, which we constrain by moments obtained from lattice QCD, leads, with the exception of the p⁺ \pi^{+}_{} and h^￠ \eta^{\prime}_{} channels, to large transverse cross-sections.     

Production ratio of pseudoscalar to vector mesons

The P/V ratio of directly produced pseudoscalar (P) to vector (V) mesons is analysed using the data on the K⁰_S and K^*(892) total inclusive cross sections in pp, π⁺p and K^±p reactions. The indication for a change of P/V from a value of about 1 at low energies, where the fragmentation processes dominate, to a value of 1/3, suggested by spin-statistics, at high energies is discussed.     

Static and dynamic properties of pseudoscalar mesons

We report the results of form factors, charge radii and decay constants of both light and heavy flavoured pseudoscalar mesons in a QCD inspired quark model. We use the quantum mechanical perturbation theory and discuss its limitations in the present problem. Several predictions are also made for bottom and top flavours.     

D decays into pseudoscalar and scalar mesons

Zeitschrift für Physik C Particles and Fields - In this paper, we study the pseudoscalar-scalar meson (PS) weak decays ofD-mesons in the non-relativistic quark model using factorization...     

Leptonic charge and weak neutrino-lepton interactions

A scheme is discussed according to which the system of leptons is characterized by a single leptonic charge with different values for muonic leptons and electronic leptons. The weak neutrino-lepton interaction is investigated within the framework of this scheme. Charged (V + A)-currents are introduced to describe the and transitions.Translated from Izvestiya VUZ. Fizika, No. 12, pp. 30–34, December, 1971.     

Suppressed decays of D(s)(+) mesons to two pseudoscalar mesons

Using data collected near the D{s}{*+}D{s}{-} peak production energy E_{cm}=4170 MeV by the CLEO-c detector, we study the decays of D{s}{+} mesons to two pseudoscalar mesons. We report on searches for the singly Cabibbo-suppressed D{s}{+} decay modes K{+}eta, K{+}eta', pi{+}K{S}{0}, K{+}pi{0}, and the isospin-forbidden decay mode D{s}{+}-->pi{+}pi{0}. We normalize with respect to the Cabibbo-favored D{s}{+} modes pi{+}eta, pi{+}eta', and K{+}K{S}{0}, and obtain ratios of branching fractions: B(D{s}{+}-->K{+}eta)/B(D{s}{+}-->pi{+}eta)=(8.9+/-1.5+/-0.4)%, B(D{s}{+}-->K{+}eta')/B(D{s}{+}-->pi{+}eta')=(4.2+/-1.3+/-0.3)%, B(D{s}{+}-->pi{+}K{S}{0})/B(D{s}{+}-->K{+}K{S}{0})=(8.2+/-0.9+/-0.2)%, B(D{s}{+}-->K{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})=(5.5+/-1.3+/-0.7)%, and B(D{s}{+}-->pi{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})<4.1% at 90% C.L., where the uncertainties are statistical and systematic, respectively.     

KLOE results on scalar and pseudoscalar mesons

The data collected by the KLOE Collaboration at the Frascati φ-factory DAФNE from 2001 to 2006 have been used for extensive studies in meson spectroscopy. The decays of the scalar mesons a0（980） and f0（980） into two pseudoscalar mesons have been exploited to measure the relevant parameters of those resonances. The radiative decays φ →ηγ and η＇γ have been used for the determination of the pseudoscalar mixing angle and to search for a possible gluonium content in the η＇. The dynamics of the η → 3π decay has been studied and the Dalitz Plot parameters have been measured. The large amount of η mesons produced allowed also to study interesting rare η decays.     

KLOE results on scalar and pseudoscalar mesons

The data collected by the KLOE Collaboration at the Frascati φ-factory DAΦNE from 2001 to 2006 have been used for extensive studies in meson spectroscopy.The decays of the scalar mesons a0(980) and f0(980) into two pseudoscalar mesons have been exploited to measure the relevant parameters of those resonances.The radiative decays φ→ηγ and ηγ have been used for the determination of the pseudoscalar mixing angle and to search for a possible gluonium content in the η.The dynamics of the η→ 3π decay has been studied and the Dalitz Plot parameters have been measured.The large amount of η mesons produced allowed also to study interesting rare η decays.     

Odderon and photon exchange in electroproduction of pseudoscalar mesons

We investigate the reaction where PS denotes a pseudoscalar meson , , , or and X either a proton or resonance or continuum state into which the proton can go by diffractive excitation. At high energies photon and odderon exchange contribute to the reaction. The photon exchange contribution is evaluated exactly using data for the total virtual photon-proton absorption cross section. The odderon exchange contribution is calculated in nonperturbative QCD, using functional integral techniques and the model of the stochastic vacuum. For the proton we assume a quark-diquark structure as suggested by the small odderon amplitude in pp and forward scattering. We show that odderon exchange leads to a much larger inelastic than elastic PS production cross section. Observation of our reaction at HERA would establish the soft odderon as an exchange object on an equal footing with the soft pomeron and would give us valuable insight into both the nucleon structure and the mechanism of high energy diffractive scattering. Received: 2 February 1999 / Revised version: 22 March 1999 / Published online: 28 May 1999     

Annihilation of an electron-positron pair into pseudoscalar mesons

The formation of pseudoscalar mesons in the collision of polarized electron and positron beams is analyzed. The form factors of all particles participating in the reaction are taken into account. Angular and energy distributions are found for the created pairs and for the mesons in the laboratory system.Translated from Izvestiya VUZ. Fizika, No. 5, pp. 48–52, May, 1971.The authors thank B. K. Kerimov for interest in the study and for useful advice.     

Hierarchy of masses for pseudoscalar and vector mesons

Assuming that quark flavors beyond isospin, strangeness, and charm exist, we use the relationship between the structure of chiral symmetry breaking of the strong interaction and the Cabibbo angle in order to estimate the masses of the pseudoscalar and vector mesons carrying the fifth (beauty), sixth (truth), and seventh (illusion) quark flavors.