How Could the Proton Transversity be Measured

The perspectives of two new nonstandard methods of transversal quark polarization measurement are considered: the jet handedness and the so-called "Collins effect" due to spin dependent T-odd fragmentation function responsible for the left-right asymmetry in fragmenting of transversally polarized quarks. Recent experimental indications in favor of these effects are observed: 1.The correlation of the T-odd one-particle fragmentation functions found by DELPHI in $Z\to 2$-jet decay. Integrated over the fraction of longitudinal and transversal momenta, this correlation is of 1.6% order, which means order of 13% for the analyzing power. 2.A rather large ($\approx10$) handedness transversal to the production plane observed in the diffractive production of ($\pi^-\pi^+\pi^-$) triples from nuclei by the $40 {\rm GeV/c}$ $\pi^-$--beam. It shows a clear dynamic origin and resembles the single spin asymmetry behavior. All this makes us hope to use these effects in polarized DIS experiments for transversity measurement. The first estimation of transversity was done by using the azimuthal asymmetry in semi-inclusive DIS recently measured by HERMES and SMC.Comment: 8 pages, Latex, czjphys2.sty. Talk at Int. Workshop "PRAHA-SPIN99", Prague 6-11 Sept 1999. To appear in Czech.J.Phys Supp

BCS - BEC crossover and quantum hydrodynamics in p-wave superfluids with a symmetry of the A1 - phase

We solve the Leggett equations for the BCS - BEC crossover in the three dimension resonance p-wave superfluid with the symmetry of the A1 - phase. We calculate the sound velocity, the normal density, and the specific heat for the BCS-domain (\mu > 0), BEC-domain (\mu < 0), and close to important point \mu = 0 in 100% polarized case. We find the indications of quantum phase - transition close to the point \mu(T = 0) = 0. Deep in the BCS and BEC-domains the crossover ideas of Leggett and Nozieres, Schmitt-Rink work pretty well. We discuss the spectrum of orbital waves, the paradox of intrinsic angular momentum and complicated problem of chiral anomaly in the BCS A1 - phase at T = 0. We present two different approaches to a chiral anomaly: one based on supersymmetric hydrodynamics, another one on the formal analogy with the Dirac equation in quantum electrodynamics. We evaluate the damping of nodal fermions due to different decay processes in superclean case at T = 0 and find that we are in a ballistic regime \omega\tau >> 1. We propose to use aerogel or nonmagnetic impurities to reach hydrodynamic regime \omega\tau<< 1 at T = 0. We discuss the concept of the spectral flow and exact cancellations between time-derivatives of anomalous and quasiparticle currents in the equation for the total linear momentum conservation. We propose to derive and solve the kinetic equation for the nodal quasiparticles both in the hydrodynamic and in the ballistic regimes to demonstrate this cancellation explicitly. We briefly discuss the role of the other residual interactions different from damping and invite experimentalists to measure the spectrum and damping of orbital waves in A-phase of 3He at low temperatures.Comment: 14 pages, 10 figure

CP-Violating Effect of QCD Vacuum in Quark Fragmentation

We demonstrate that the non-trivial CP-violating structure of QCD vacuum can lead to an observable effect in $e^+e^-\to q\bar q\to 2$-jet annihilation. We find that the sign of the jet handedness correlation can be opposite to that predicted by factorization of $q~\bar q$ fragmentation and CP-conjugation of the two jets. A simple model estimation of the handedness correlation magnitude is given.Comment: significantly revised and extended version to appear in Phys.Lett.

Collins Asymmetry at Hadron Colliders

We study the Collins effect in the azimuthal asymmetric distribution of hadrons inside a high energy jet in the single transverse polarized proton proton scattering. From the detailed analysis of one-gluon and two-gluon exchange diagrams contributions, the Collins function is found the same as that in the semi-inclusive deep inelastic scattering and e^+e^- annihilations. The eikonal propagators in these diagrams do not contribute to the phase needed for the Collins-type single spin asymmetry, and the universality is derived as a result of the Ward identity. We argue that this conclusion depends on the momentum flow of the exchanged gluon and the kinematic constraints in the fragmentation process, and is generic and model-independent.Comment: 23 pages, 6 figure

On the azimuthal asymmetries in DIS

Using the recent experimental data on the left right asymmetry in fragmentation of transversely polarized quarks and the theoretical calculation of the proton transversity distribution in the effective chiral quark soliton model we explain the azimuthal asymmetries in semi-inclusive hadron production on longitudinal (HERMES) and transversely (SMC) polarized targets with no free parameters. On this basis we state that the proton transversity distribution could be successfully measured in future DIS experiments with longitudinally polarized target.Comment: 8 pages, latex, 5 eps figures, uses epsfig and wrapfi

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