Study of factorization in QCD with polarized beams and Λ production at large pT

Abstract We discuss what aspects of the leading orders in QCD could be tested in the large pT reactions p ¯ → p → Λ → + X , p ¯ p → → Λ → + X and p ¯ → p → → Λ + X

The 16th moment of the three loop anomalous dimension of the non-singlet transversity operator in QCD

We present the result of the three loop anomalous dimension of non-singlet transversity operator in QCD for the Mellin moment N=16. The obtained result coincides with the prediction from arXiv:1203.1022 and can serve as a confirmation of the correctness of the general expression for three loop anomalous dimension of non-singlet transversity operator in QCD for the arbitrary Mellin moment.Comment: 7 pages, 1 figure, minor changes in the tex

Transversity K Factors for Drell-Yan

The question of the K factor in transversely polarised Drell-Yan (DY) processes is examined. The transverse-spin case is peculiar for the absence of a reference point in deeply inelastic scattering (DIS). Therefore, in order to study more fully the possible effects of higher-order corrections on DY asymmetries, a DIS definition for transversity is devised using a hypothetical scalar (Higgs-like) vertex. The results show that some care may be required in interpreting experimentally extracted partonic transversity, in particular when comparing with model calculations or predictions.Comment: 8 pages, 4 figures (eps and feynmp); uses standard LaTeX/MiKTeX packages [svjour.cls, amsmath, bbm, feynmp, graphicx, maybemath, natbib, psfrag, slashed] some homespun packages (included in the zip file); discussion augmented, 1 figure removed; resubmitted to Eur. Phys. J. section

Alteration of glyoxalase genes expression in response to testosterone in LNCaP and PC3 human prostate cancer cells.

Glyoxalase system, a ubiquitous detoxification pathway protecting against cellular damage caused by potent cytotoxic metabolites, is involved in the regulation of cellular growth. Aberrations in the expression of glyoxalase genes in several human cancers have been reported. Recently, we described a possible regulatory effect by estrogens on glyoxalase genes in human breast cancer cell lines. This result, along with those ones regarding changes in glyoxalases activity and expression in other human hormone-regulated cancers, such as prostate cancer, has prompted us to investigate whether also androgens, whose functional role in prostate cancer pathogenesis is well known, could modulate glyoxalases gene expression. Therefore, we treated LNCaP androgen-responsive and PC3 androgen-independent human prostate cancer cell lines with testosterone at the concentrations of 1 nM and 100 nM. After a two days treatment, glyoxalases mRNA levels as well as cell proliferation were evaluated by real-time RT-PCR analysis and [3H]thymidine incorporation, respectively. Results pointed out that testosterone affects the expression of glyoxalase system genes and cell proliferation in a different manner in the two cell lines. The possibility that modulation of glyoxalase genes expression by testosterone is due to glyoxalases-mediated intracellular response mechanisms to the androgen-induced oxidative stress or to the presence of androgen response elements (ARE) in glyoxalase promoters are discussed. Knowledge regarding the regulation of glyoxalases by testosterone may provide insights into the importance of these enzymes in human prostate carcinomas in vivo

Double Transverse-Spin Asymmetries in Drell-Yan Processes with Antiprotons

We present next-to-leading order predictions for double transverse-spin asymmetries in Drell--Yan dilepton production initiated by proton--antiproton scattering. The kinematic region of the proposed PAX experiment at GSI: 30\lesssim{s}\lesssim200\GeV^2 and 2\lesssim{M}\lesssim7\GeV is examined. The Drell--Yan asymmetries turn out to be large, in the range 20--40%. Measuring these asymmetries would provide the cleanest determination of the quark transversity distributions.Comment: 11 pages, 7 figures, uses elsart and feynmp (included); one new reference adde

Three loop anomalous dimension of the second moment of the transversity operator in the MSbar and RI' schemes

We compute the anomalous dimension of the second moment of the transversity operator, \bar{\psi} \sigma^{\mu\nu} D^\rho \psi, at three loops in both the MSbar and RI' schemes. As a check on the result we also determine the O(1/N_f) critical exponent of the n-th moment of the transversity operator in d-dimensions in the large N_f expansion and determine leading order information on the n dependence of the anomalous dimension at three and four loops in MSbar. In addition the RI' anomalous dimension of the non-singlet twist-2 operator, \bar{\psi} \gamma^\mu D^\nu \psi, is also determined.Comment: 18 latex pages; additional reference include

Evolution of transverse momentum dependent distribution and fragmentation functions

We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading order in a 1/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins fragmentation function. The moments of these functions are matrix elements of known twist two and twist three operators. We present the evolution in the large N_c limit, restricting to non-singlet for the chiral-even functions.Comment: 15 pages revte

Double transverse spin asymmetries in vector boson production

We investigate a helicity non-flip double transverse spin asymmetry in vector boson production in hadron-hadron scattering, which was first considered by Ralston and Soper at the tree level. It does not involve transversity functions and in principle also arises in W-boson production for which we present the expressions. The asymmetry requires observing the transverse momentum of the vector boson, but it is not suppressed by explicit inverse powers of a large energy scale. However, as we will show, inclusion of Sudakov factors causes suppression of the asymmetry, which increases with energy. Moreover, the asymmetry is shown to be approximately proportional to x_1 g_1(x_1) x_2 \bar g_1(x_2), which gives rise to additional suppression at small values of the light cone momentum fractions. This implies that it is negligible for Z or W production and is mainly of interest for \gamma^* at low energies. We also compare the asymmetry with other types of double transverse spin asymmetries and discuss how to disentangle them.Comment: 12 pages, Revtex, 2 Postscript figures, uses aps.sty, epsf.sty; figures replaced, a few minor other correction

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