Dyons as a source of CP and time invariance violation: electric dipole moments and K-meson decays

We consider a mechanism by which dyons (electrically charged magnetic monopoles) can produce both a T- and P-odd (i.e. time reversal invariance and parity violating) mixed polarizability beta [defined by Delta E = -beta E.B, where Delta E is the energy change when electric (E) and magnetic (B) fields are applied to a system] and a T- and P-odd interaction between two particles: psi_1-bar gamma_5 psi_1 psi_2-bar psi_2, where the psi_i are electron and quark spinors. The latter can create atomic and neutron electric dipole moments (EDMs). From experimental bounds on these we find limits on the properties of dyons. Our best limit, using the experimental limit for the EDM of the Tl atom, is M |Q g (Q^2 - g^2)|^(-1/4) > 6 GeV, where M is the dyon mass and Q is the electric and g the magnetic charge of the dyons. The contribution of dyons to CP violation in K-meson decays is also estimated.Comment: 22 pages, 5 figures, RevTe

Effects of Extra Space-time Dimensions on the Fermi Constant

Effects of Kaluza-Klein excitations associated with extra dimensions with large radius compactifications on the Fermi constant are explored. It is shown that the current precision determinations of the Fermi constant, of the fine structure constant, and of the W and Z mass put stringent constraints on the compactification radius. The analysis excludes one extra space time dimension below $\sim 1.6$ TeV, and excludes 2, 3 and 4 extra space dimensions opening simultaneously below $\sim$ 3.5 TeV, 5.7 TeV and 7.8 TeV at the $90$. Implications of these results for future collider experiments are discussed.Comment: 12 pages including one figur

The decay ρ0→π++π−+γ\rho^{0}\to \pi^{+}+\pi^{-}+\gamma and the coupling constant gρσγ_{\rho\sigma\gamma}

The experimental branching ratio for the radiative decay $\rho^{0}\to\pi^{+}+\pi^{-}+\gamma$ is used to estimate the coupling constant $g_{\rho\sigma\gamma}$ for a set of values of $\sigma$-meson parameters M$_{\sigma}$ and $\Gamma_{\sigma}$. Our results are quite different than the values of this constant used in the literature.Comment: 9 pages(RevTex), 5 ps figure

Lepton flavor conserving Z -> l^+ l^-$ decays in the general two Higgs doublet model

We calculate the new physics effects to the branching ratios of the lepton flavor conserving decays Z -> l^+ l^- in the framework of the general two Higgs Doublet model. We predict the upper limits for the couplings |\bar{\xi}^{D}_{N,\mu\tau}| and |\bar{\xi}^{D}_{N,\tau\tau}| as 3\times 10^2 GeV and 1\times 10^2 GeV, respectively.Comment: 9 pages, 3 figure

Parenchymal lung disease in adult onset Still's disease: An emergent marker of disease severity - Characterisation and predictive factors from Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale (GIRRCS) cohort of patients

Background: Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown aetiology usually affecting young adults. Interestingly, recent evidence from the juvenile counterpart of AOSD suggested the emergent high fatality rate of lung disease (LD) in these patients. In this work, we aimed to characterise LD in AOSD, to identify associated clinical features and predictive factors, and to describe long-term outcomes of the disease comparing patients with LD and those without. Methods: A retrospective assessment of prospectively followed patients, from January 2001 to December 2019, was provided to describe the rate of LD in AOSD, associated clinical features and predictive factors, and long-term outcomes. Patients with AOSD, who were included in Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale (GIRRCS) cohort, were assessed. Results: Out of 147 patients included in GIRRCS cohort, 18 (12.25%) patients were reported to be affected by LD, at the time of diagnosis of AOSD, who were characterised by older age, a higher prevalence of myalgia, of lymph node involvement, of pleuritis, and abdominal pain. Furthermore, patients with LD showed higher values of systemic score and ferritin. Among those clinical variables, older age and systemic score were also independently predictors of LD. Chest CT scans were also obtained, and the most common finding was the peripheral consolidations in 8 (44.4%) patients. Finally, a higher mortality rate, of 38.9%, was registered in patients with LD than others, since it was associated with a significant decreased survival rate. Conclusions: The presence of LD could suggest an emergent cause of mortality in AOSD, as observed in juvenile counterpart recognising a further marker of severity and poor prognosis to be careful evaluated. Patients with LD were also characterised by some clinical features, higher values of systemic score and ferritin than the others, identifying a subset of patients mostly burdened by systemic signs and symptoms. Although specific designed future studies are needed to fully elucidate the significance of LD in AOSD, a more accurate evaluation and management of this feature could improve the long-term outcomes of these patients

The Gross--Llewellyn Smith Sum Rule in the Analytic Approach to Perturbative QCD

We apply analytic perturbation theory to the Gross--Llewellyn Smith sum rule. We study the $Q^2$ evolution and the renormalization scheme dependence of the analytic three-loop QCD correction to this sum rule, and demonstrate that the results are practically renormalization scheme independent and lead to rather different $Q^2$ evolution than the standard perturbative correction possesses.Comment: 17 pages, 9 eps figures, REVTe

Predictions on B→πlˉνlB \to \pi \bar{l} \nu_l, D→πlˉνlD \to \pi \bar{l} \nu_l and D→KlˉνlD\to K \bar{l} \nu_l from QCD Light-Cone Sum Rules

The $f^+$ form factors of the $B\to \pi$, $D\to \pi$ and $D\to K$ transitions are calculated from QCD light-cone sum rules (LCSR) and used to predict the widths and differential distributions of the exclusive semileptonic decays $B\to \pi \bar{l}\nu_l$, $D \to\pi \bar{l}\nu_l$ and $D \to K \bar{l}\nu_l$, where $l=e,\mu$. The current theoretical uncertainties are estimated. The LCSR results are found to agree with the results of lattice QCD calculations and with experimental data on exclusive semileptonic D decays. Comparison of the LCSR prediction on $B\to \pi \bar{l} \nu_l$ with the CLEO measurement yields a value of |V_{ub}| in agreement with other determinations.Comment: 24 pages, 12 figures, Latex, epsfig, some additional remarks on the two-pole parameterization, prediction on the $B\to K$ form factor added, version to appear in Phys. Rev.

Near-Threshold Production of omega Mesons in the pp -> pp omega Reaction

The total cross section for omega production in the pp -> pp omega reaction has been measured at five c.m. excess energies from 3.8 to 30 MeV. The energy dependence is easily understood in terms of a strong proton-proton final state interaction combined with a smearing over the width of the state. The ratio of near-threshold phi and omega production is consistent with the predictions of a one-pion-exchange model and the degree of violation of the OZI rule is similar to that found in the pi-p -> n omega/phi reactions.Comment: Report in LaTeX2e. 12 pages with 2 eps figure

The Adler Function for Light Quarks in Analytic Perturbation Theory

The method of analytic perturbation theory, which avoids the problem of ghost-pole type singularities and gives a self-consistent description of both spacelike and timelike regions, is applied to describe the "light" Adler function corresponding to the non-strange vector channel of the inclusive decay of the $\tau$ lepton. The role of threshold effects is investigated. The behavior of the quark-antiquark system near threshold is described by using a new relativistic resummation factor. It is shown that the method proposed leads to good agreement with the ``experimental'' Adler function down to the lowest energy scale.Comment: 13 pages, one ps figure, REVTe

Quark-antiquark potential with retardation and radiative contributions and the heavy quarkonium mass spectra

The charmonium and bottomonium mass spectra are calculated with the systematic account of all relativistic corrections of order v^2/c^2 and the one-loop radiative corrections. Special attention is paid to the contribution of the retardation effects to the spin-independent part of the quark-antiquark potential, and a general approach to accounting for retardation effects in the long-range (confining) part of the potential is presented. A good fit to available experimental data on the mass spectra is obtained.Comment: 20 pages, revtex, 2 Postscript figure