Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisions

We discuss Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron scattering at high energies. We show that the physical picture proposed in a recent Letter is consistent with the experimental observation that $\Lambda$ polarization in the diffractive process, $pp\to \Lambda K^+p$, is much higher than that in the inclusive reaction, $pp\to \Lambda X$. We make predictions for the left-right asymmetry, A_N, and for the spin transfer, $D_{NN}^\Lambda$, in the single-spin process $p(\uparrow)p\to \Lambda K^+p$ and suggest further experimental tests of the proposed picture.Comment: 14 pages, 3 ps-figures. Phys. Rev. D (in press

Finite calculation of divergent selfenergy diagrams

Using dispersive techniques, it is possible to avoid ultraviolet divergences in the calculation of Feynman diagrams, making subsequent regularization of divergent diagrams unnecessary. We give a simple introduction to the most important features of such dispersive techniques in the framework of the so-called finite causal perturbation theory. The method is also applied to the 'divergent' general massive two-loop sunrise selfenergy diagram, where it leads directly to an analytic expression for the imaginary part of the diagram in accordance with the literature, whereas the real part can be obtained by a single integral dispersion relation. It is pointed out that dispersive methods have been known for decades and have been applied to several nontrivial Feynman diagram calculations.Comment: 15 pages, Latex, one figure, added reference

Non-Abelian dynamics and heavy multiquarks, Steiner-tree confinement in hadron spectroscopy

A brief review is first presented of attempts to predict stable multiquark states within current models of hadron spectroscopy. Then a model combining flip-flop and connected Steiner trees is introduced and shown to lead to stable multiquarks, in particular for some configurations involving several heavy quarks and bearing exotic quantum numbers.Comment: 8 pages, 5 figures, Invited talk at the 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, August 29th--September 3rd, 2010, to appear in the Proceedings, ed.~A.~Valcarce et al., to appear in Few-Body Syste

Azimuthal asymmetries at CLAS: Extraction of e^a(x) and prediction of A_{UL}

First information on the chirally odd twist-3 proton distribution function e(x) is extracted from the azimuthal asymmetry, A_{LU}, in the electro-production of pions from deeply inelastic scattering of longitudinally polarized electrons off unpolarized protons, which has been recently measured by CLAS collaboration. Furthermore parameter-free predictions are made for azimuthal asymmetries, A_{UL}, from scattering of an unpolarized beam on a polarized proton target for CLAS kinematics.Comment: 9 pages, 5 figures, late

Accessing Transversity in Double-Spin Asymmetries at the BNL-RHIC

We give upper bounds for transverse double-spin asymmetries in polarized proton-proton collisions by saturating the positivity constraint for the transversity densities at a low hadronic resolution scale. We consider prompt photon, jet, pion, and heavy flavor production at the BNL Relativistic Heavy Ion Collider (RHIC). Estimates of the expected statistical accuracy for such measurements are presented, taking into account the acceptance of the RHIC detectors.Comment: 15 pages, LaTeX, 2 figures as eps file

Next-to-leading order QCD corrections to A_TT for prompt photon production

We present a next-to-leading order QCD calculation of the cross section for isolated large-p_T prompt photon production in collisions of transversely polarized protons. We devise a simple method of dealing with the phase space integrals in dimensional regularization in the presence of the cos(2 phi) azimuthal-angular dependence occurring for transverse polarization. Our results allow to calculate the double-spin asymmetry A_TT for this process at next-to-leading order accuracy, which may be used at BNL-RHIC to measure the transversity parton distributions of the proton.Comment: 19 pages, LaTeX, 2 figures as eps file

Q^2-Evolution of Nucleon's Chiral-Odd Twist-3 Structure Function: h_L(x,Q^2)

We investigate the $Q^{2}$-evolution of the chiral-odd spin-dependent parton distribution $h_{L}(x, Q^{2})$ relevant for the polarized Drell-Yan processes. The results are obtained in the leading logarithmic order in the framework of the renormalization group and the standard QCD perturbation theory. We calculate the anomalous dimension matrix for the twist-3 operators for $h_{L}$ in the one-loop order. The operator mixing among the relevant twist-3 operators including the operators proportional to the QCD equations of motion is treated properly in a consistent scheme. Implications for future experiments are also discussed.Comment: HUPD-9419, Latex file, 21 pages, 7 figures available on reques

Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas -- particle, nuclear and atomic is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for EPJ

Intraocular pressure and its correlation with blood gas parameters in crested caracaras (Caracara plancus) anesthetized with isoflurane and sevoflurane Pressão intra-ocular e sua correlação com parâmetros hemogasométricos em caracarás (Caracara plancus) anestesiados com isofluorano e sevofluorano

The intraocular pressure (IOP) and its correlations with arterial carbon dioxide partial pressure (PaCO2) and arterial pH were studied in five crested caracaras (Caracara plancus) anesthetized with isoflurane (ISO) and sevoflurane (SEV). Baseline IOP values were measured in both eyes (M0). Brachial artery was previously catheterized to obtain blood gas and cardiorespiratory analysis. Anesthesia was induced with 5% ISO and maintained with 2.5% for 40 minutes. IOP measurements and blood samples were evaluated in different moments until the end of the procedure. After recovering, a second anesthesia was induced with 6% SEV and maintained with 3.5%. Parameters were evaluated at the same time points of the previous procedure. IOP reduced significantly (P= 0.012) from M0 at all time points and no significative changes were observed between ISO and SEV anesthesias. Correlation between IOP and PaCO2 and between PIO and blood pH were found only for SEV. IOP and blood pH decreased in parallel with IOP, whereas values of PaCO2 increased in caracaras anesthetized with isoflurane and sevoflurane.<br>Avaliou-se a pressão intra-ocular (PIO) e estimaram-se as correlações entre PIO e pressão de dióxido de carbono (PaCO2) e pH arterial de cinco caracarás (Caracara plancus), anestesiados com isofluorano (ISO) ou sevofluorano (SEV). Valores basais da PIO foram aferidos em ambos os olhos (M0). Cateterizou-se previamente a artéria braquial para obtenção de parâmetros hemogasométricos e cardiorrespiratórios. Anestesia foi induzida com ISO a 5V% e mantida por 40 minutos com 2,5V%. PIO e amostras de sangue foram avaliadas em diferentes momentos até o final do procedimento. Após recuperação, uma segunda anestesia foi realizada com SEV a 6% e mantida com 3,5%. Os parâmetros foram aferidos nos mesmos momentos estabelecidos previamente. A PIO decresceu significativamente (P=0,012) de M0 em todos os momentos e não houve diferença estatística entre ISO e SEV. Correlações significativas entre PIO e PaCO2 e entre PIO e pH sangüíneo foram observadas apenas para a anestesia com SEV. O pH sangüíneo decresceu paralelamente a PIO, enquanto a PaCO2 aumentou, em carcarás anestesiados com isofluorano e sevofluorano