Supersymmetric Electroweak Corrections to Charged Higgs Boson Production in Association with a Top Quark at Hadron Colliders

We calculate the $O(\alpha_{ew}m_{t(b)}^{2}/m_{W}^{2})$ and $O(\alpha_{ew} m_{t(b)}^4/m_W^4)$ supersymmetric electroweak corrections to the cross section for the charged Higgs boson production in association with a top quark at the Tevatron and the LHC. These corrections arise from the quantum effects which are induced by potentially large Yukawa couplings from the Higgs sector and the chargino-top(bottom)-sbottom(stop) couplings, neutralino-top(bottom)-stop(sbottom) couplings and charged Higgs-stop-sbottom couplings. They can decrease or increase the cross section depending on $\tan\beta$ but are not very sensitive to the mass of the charged Higgs boson for high $\tan\beta$. At low $\tan\beta(=2)$ the corrections decrease the total cross sections significantly, which exceed -12% for $m_{H^{\pm}}$ below $300GeV$ at both the Tevatron and the LHC, but for $m_{H^{\pm}}>300GeV$ the corrections can become very small at the LHC. For high $\tan\beta(=10,30)$ these corrections can decrease or increase the total cross sections, and the magnitude of the corrections are at most a few percent at both the Tevatron and the LHC.Comment: 28 pages including 4 eps figure

Gut microbiota, innate immune pathways, and inflammatory control mechanisms in patients with major depressive disorder

Although alterations in the gut microbiota have been linked to the pathophysiology of major depressive disorder (MDD), including through effects on the immune response, our understanding is deficient about the straight connection patterns among microbiota and MDD in patients. Male and female MDD patients were recruited: 46 patients with a current active MDD (a-MDD) and 22 in remission or with only mild symptoms (r-MDD). Forty-five healthy controls (HC) were also recruited. Psychopathological states were assessed, and fecal and blood samples were collected. Results indicated that the inducible nitric oxide synthase expression was higher in MDD patients compared with HC and the oxidative stress levels were greater in the a-MDD group. Furthermore, the lipopolysaccharide (an indirect marker of bacterial translocation) was higher in a-MDD patients compared with the other groups. Fecal samples did not cluster according to the presence or the absence of MDD. There were bacterial genera whose relative abundance was altered in MDD: Bilophila (2-fold) and Alistipes (1.5-fold) were higher, while Anaerostipes (1.5-fold) and Dialister (15-fold) were lower in MDD patients compared with HC. Patients with a-MDD presented higher relative abundance of Alistipes and Anaerostipes (1.5-fold) and a complete depletion of Dialister compared with HC. Patients with r-MDD presented higher abundance of Bilophila (2.5-fold) compared with HC. Thus, the abundance of bacterial genera and some immune pathways, both with potential implications in the pathophysiology of depression, appear to be altered in MDD, with the most noticeable changes occurring in patients with the worse clinical condition, the a-MDD group. © 2021, The Author(s)

A Phenomenological Analysis of Gluon Mass Effects in Inclusive Radiative Decays of the J/ψ\rm{J/\psi} and $\Upsilon

The shapes of the inclusive photon spectra in the processes \Jp \to \gamma X and \Up \to \gamma X have been analysed using all available experimental data. Relativistic, higher order QCD and gluon mass corrections were taken into account in the fitted functions. Only on including the gluon mass corrections, were consistent and acceptable fits obtained. Values of $0.721^{+0.016}_{-0.068}$ GeV and $1.18^{+0.09}_{-0.29}$ GeV were found for the effective gluon masses (corresponding to Born level diagrams) for the \Jp and \Up respectively. The width ratios \Gamma(V \to {\rm hadrons})/\Gamma(V \to \gamma+ {\rm hadrons}) V=\Jp, \Up were used to determine $\alpha_s(1.5 {\rm GeV})$ and $\alpha_s(4.9 {\rm GeV})$. Values consistent with the current world average $\alpha_s$ were obtained only when gluon mass correction factors, calculated using the fitted values of the effective gluon mass, were applied. A gluon mass $\simeq 1$ GeV, as suggested with these results, is consistent with previous analytical theoretical calculations and independent phenomenological estimates, as well as with a recent, more accurate, lattice calculation of the gluon propagator in the infra-red region.Comment: 50 pages, 11 figures, 15 table

LHC sensitivity to the resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector

We present a unified analysis of the two main production processes of vector boson pairs at the LHC, VV-fusion and qqbar annihilation, in a minimal strongly interacting electroweak symmetry breaking sector. Using a unitarized electroweak chiral Lagrangian formalism and modeling the final V_L V_L strong rescattering effects by a form factor, we describe qqbar annihilation processes in terms of the two chiral parameters that govern elastic V_L V_L scattering. Depending on the values of these two chiral parameters, the unitarized amplitudes may present resonant enhancements in different angular momentum-isospin channels. Scanning this two parameter space, we generate the general resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector and determine the regions that can be probed at the LHC.Comment: Final version to appear in Phys. Rev. D, including a more detailed exposition and a few more references. Conclusions and results unchanged. 14 pages, 5 figure

A measurement of lifetime differences in the neutral D-meson system

Using a high statistics sample of photoproduced charm particles from the FOCUS experiment at Fermilab, we compare the lifetimes of neutral D mesons decaying via D0 to K- pi+ and K- K+ to measure the lifetime differences between CP even and CP odd final states. These measurements bear on the phenomenology of D0 - D0bar mixing. If the D0 to K-pi+ is an equal mixture of CP even and CP odd eigenstates, we measure yCP = 0.0342 \pm 0.0139 \pm 0.0074.Comment: 15 pages, 5 figure

Search for CP violation in D0 and D+ decays

A high statistics sample of photoproduced charm particles from the FOCUS (E831) experiment at Fermilab has been used to search for CP violation in the Cabibbo suppressed decay modes D+ to K-K+pi+, D0 to K-K+ and D0 to pi-pi+. We have measured the following CP asymmetry parameters: A_CP(K-K+pi+) = +0.006 +/- 0.011 +/- 0.005, A_CP(K-K+) = -0.001 +/- 0.022 +/- 0.015 and A_CP(pi-pi+) = +0.048 +/- 0.039 +/- 0.025 where the first error is statistical and the second error is systematic. These asymmetries are consistent with zero with smaller errors than previous measurements.Comment: 12 pages, 4 figure

Measurements of the Sigma_c^0 and Sigma_c^{++} Mass Splittings

Using a high statistics sample of photoproduced charmed particles from the FOCUS experiment at Fermilab (FNAL-E831), we measure the mass splittings of the charmed baryons Sigma_c^0 and Sigma_c^{++}. We find M(Sigma_c^0 - Lambda_c^+) = 167.38 +/- 0.21 +/- 0.13 MeV/c^2 and M(Sigma_c^++ - Lambda_c^+) = 167.35 +/- 0.19 +/- 0.12 MeV/c^2 with samples of 362 +/- 36 and 461 +/- 39 events, respectively. We measure the isospin mass splitting M(Sigma_c^++ - Sigma_c^0) to be -0.03 +/- 0.28 +/- 0.11 Mev/c^2. The first errors are statistical and the second are systematic.Comment: 10 pages, 2 figure

A measurement of the tau mass and the first CPT test with tau leptons

We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

Measurement of the B0 Lifetime and Oscillation Frequency using B0->D*+l-v decays

The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.Comment: 17 pages, 4 figures, submitted to Phys. Lett.

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio