Asymmetry in the scattering of protons on polarized deuterons at 1.21 GeV/c

By using a polarized deuteron target we have measured the asymmetry in the differential cross section for elastic scattering of protons on deuterons and for quasi-elastic scattering of protons on protons bound in deuterons between the two states of opposite polarization, normal to the scattering plane of the initial deuteron. The beam momentum was 1.21 GeV/c. It is checked that the neutrons bound in the deuterons are polarized to approximately 20%.     

Probing the spin-orbit coupling of nuclear protons

The strong absorption in quasi-free scattering opens a possibility of measuring the spin-orbit coupling of nuclear protons. Cross sections for polarized incoming protons are expected to exhibit pronounced asymmetries, with size and sign depending on the selected momentum and the spin-orbit coupling in the nuclear state involved.     

Alignment and orientation of charge exchange excitation with polarized projectiles

The alignment and orientation of hydrogenlike excited atoms produced by electron capture in collisions of spin polarized bare atomic nuclei with atomic targets is described in terms of Stokes parameters. TheH(2p)^* excited state formed by spin polarized protons making charge exchange collisions on atomic targets is dealt with extensively for the purpose of illustration. The linear polarization and circular polarization of resulting Lyman-α when polarized protons make electron capture collision on atomic hydrogen target are plotted to compare observable aspects of different theories of electron capture.     

Method for identification of the nuclear collective modes

The analysing power measurements for inelastic scattering of polarized protons with excitation of the first 2⁺ level provide a sensitive method to distinguish two simple collective models-axially symmetric rotational and vibrational. The method is illustrated by the measurements of 24.5 MeV protons scattering on ^148,152Sm and some coupled channel calculations.     

Polarization of protons formed in the electrodisintegration of light nuclei

It is shown that the protons arising from the electrodisintegration of light nuclei may be considerably polarized. Relationships are obtained between the degree of polarization and the escape angle of the protons in the coplanar case. The polarization is extremely sensitive to the choice of the distorted wave function of the proton in its final state.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 7, pp. 31–34, July, 1973.     

On the possibility of measuring the degree of transverse polarization of a proton beam by means of elastic pe scattering

The analyzing power of the elastic scattering of high-energy polarized protons by polarized electrons for the polarimetry of proton beams is calculated. It is shown that this process can be used to measure the degree of transverse polarization of a beam at energies all the way up to those at LHC. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 2, 123–127 (25 January 1997)     

Transfer of CIDNP among coupled spins at low magnetic field

Coherent polarization transfer among groups of dynamically polarized spins is explored and applied to field cycling experiments where spin evolution proceeds at low magnetic field while observation is performed at high field. The case of two nonequivalent spins-1/2 with scalar spin coupling is considered theoretically in detail for the cases of sudden and adiabatic field change. The criterion for efficient polarization transfer is derived theoretically and consistently confirmed experimentally for three photochemical reactions, involving spin systems of increasing complexity that exhibit chemically induced dynamic nuclear polarization: (1) the two polarized protons of the purine base of adenosine monophosphate; (2) four coupled indole protons of tryptophan; and (3) long-range polarization transfer among the aliphatic protons of cycloundecanone. The importance of polarization transfer in other cases with non-equilibrium population of the nuclear spin levels and the possibility of its utilization in field cycling NMR studies are discussed.     

Acceleration of polarized protons to multi-GeV energies and experiments with polarized protons from 2–6 GeV/c

Acceleration of polarized protons. Experiments with polarized protons. Proton-proton total cross-section. Two and three spin proton elastic scattering measurements. Polarization measurements in nucleon-nucleon elastic scattering. Inelastic interactions. Inclusive lambda production. Coherent polarized proton⁴He interactions. Parity tests.Presented at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975. Work supported by the U.S. Energy Research and Development Administration.I would like to thank the authors of all the experiments I have mentioned for their information, both published and unpublished.     

Parity Violation in Proton–Proton Scattering at High Energies

JETP Letters - A new approach has been proposed to describe parity violation in the scattering of polarized protons by protons at high energies. It has been shown that the P-odd proton- proton...     

Direct high-power laser acceleration of ions for medical applications

Theoretical investigations show that linearly and radially polarized multiterawatt and petawatt laser beams, focused to subwavelength waist radii, can directly accelerate protons and carbon nuclei, over micron-size distances, to the energies required for hadron cancer therapy. Ions accelerated by radially polarized lasers have generally a more favorable energy spread than those accelerated by linearly polarized lasers of the same intensity.     

Meson polarized distribution function and mass dependence of the nucleon parton densities

The polarized distribution functions of mesons,including pion,kaon and eta,using the proton structure function,are calculated.We are looking for a relationship between the polarized distribution of mesons and the polarized structure of nucleons.We show that the meson polarized parton distributions leads to zero total spin for the concerned mesons,considering the orbital angular momentum of quarks and gluons inside the meson.Two separate Monte Carlo algorithms are applied to compute the polarized parton distributions of the kaon.Via the mass dependence of quark distributions,the distribution function of the eta meson is obtained.A new method by which the polarized sea quark distributions of protons are evolved separately-which cannot be performed easily using the standard solution of DGLAP equations-is introduced.The mass dependence of these distributions is obtained,using the renormalization group equation which makes their evolutions more precise.Comparison between the evolved distributions and the available experimental data validates the suggested solutions for separated evolutions.     

Quasi-elastic pn scattering in ^6LiD and ^6LiH targets from 1.1 to 2.4 GeV

A polarized proton beam from SATURNE II, the Saclay polarized targets with Li compounds, and an unpolarized target were used to measure spin-dependent observables for protons scattered on bound nucleons. The beam and target polarizations were oriented vertically. The analyzing power and the depolarization were determined at seven energies between 1.1 and 2.4 GeV. The spin correlation parameter was measured at only 1.1 and 1.6 GeV. Measurements with the target at 1.1 GeV provided data for scattering of polarized protons on neutrons in carbon. The quasi-elastic observables are compared with previous elastic scattering measurements and at 1.1 GeV with predictions of phase shift analyses. Received: 19 April 1999 / Published online: 28 September 1999     

A new scaling law for analyzing power in hadron production by transversely polarized baryons

Experimental data on analyzing power for inclusive meson and baryon production in collisions of transversely polarized protons and antiprotons with protons and light nuclei have been analyzed. It is found that the existing data can be described by a simple function of collision energy (), transverse momentum () and a new scaling variable . At beam energies above 40 GeV and above 1.0 GeV/c the analyzing power is described by a function of and only () for both polarized proton fragmentation and central regions of proton-hadron collision. Comparison of data from Fermilab and new IHEP data measured using 40 GeV/c polarized proton beam was most decisive for the revelation of the above regularities. This new scaling law allows one to predict the analyzing powers for kinematic regions, not yet explored in experiments and constrains models of strong interactions. The new scaling law allows one also to use some reactions as polarimeters for experiments with a polarized beam. Received: 19 October 1999 / Revised version: 26 January 2000 / Published online: 6 March 2000     

Polarized prompt photon production in high energy\vec ep collisions

It is shown that high-p _T polarized prompt photons produced by high energy longitudinally polarized electrons scattered off unpolarized protons may be utilized to determine the spin-dependent parton distributions of the photon.     

Parity Violation in the Scattering of a Proton by Carbon and Oxygen

JETP Letters - The effects of parity violation in the interaction of relativistic polarized protons with $$^{{12}}{\text{C}}$$ and $$^{{16}}{\text{O}}$$ nuclei are discussed. Within the Glauber...     

Complete determination of direct reaction amplitude in fluctuation experiment with polarized beam

It is shown that the fluctuation experiment with polarized beam for the nuclear reactions of 1/2+0 → 0+1/2 type in the region of strongly overlapping resonance levels makes possible the complete determination of the direct interaction amplitude, i.e. modules of both components and the phase angle. The method is used to analyze the elastic scattering of polarized protons on²⁸Si.     

Transverse spin effects in diffractive hadron leptoproduction

We consider double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive vector meson and production at high energies within the two-gluon model. The connection of the two-gluon approach with skewed gluon distributions is discussed. The asymmetry predicted for meson production is quite small. The asymmetry for production contains two independent terms which are large and can be used to obtain information on the polarized skewed gluon distributions in the proton. Received: 19 February 2002 / Revised version: 19 March 2002 / Published online: 22 May 2002     

Coherent Polarization Transfer Effects Are Crucial for Interpreting Low-Field CIDNP Data

In this work we demonstrate that low-field chemically induced dynamic nuclear polarization (CIDNP) is strongly affected by re-distribution of polarization, which is formed in the course of spin evolution in transient radical pairs, in diamagnetic reaction products. This phenomenon is of importance when the spins of the reaction product are coupled strongly meaning that spin–spin interactions between them are comparable to the differences in their Zeeman interactions with the external magnetic field. In this case, polarization transfer relies on a coherent mechanism; as a consequence, spins can acquire significant polarization even when they have no hyperfine coupling to the electron spins in the radical pairs, i.e., cannot be polarized directly by CIDNP. This is demonstrated by taking CIDNP of n-butylamine as an example: in this case only the α-CH₂ protons are polarized directly, which is confirmed by high-field CIDNP, whereas the β-CH₂, γ-CH₂ and δ-CH₃ protons get polarized only indirectly due to the transfer of polarization from the α-CH₂ protons. These results show that low-field CIDNP data should be interpreted with care to discriminate between the effects of spin evolution in transient radical pairs and in diamagnetic reaction products.     

Measurement of the spin asymmetry in the photoproduction of pairs of high- p(T) hadrons at HERMES

We present a measurement of the longitudinal spin asymmetry A(||) in photoproduction of pairs of hadrons with high transverse momentum p(T). Data were accumulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a polarized hydrogen target internal to the HERA storage ring. For h(+)h(-) pairs with p(h(1))(T)>1.5 GeV/c and p(h(2))(T)>1.0 GeV/c, the measured asymmetry is A(||) = -0. 28+/-0.12(stat)+/-0.02(syst). This negative value is in contrast to the positive asymmetries typically measured in deep inelastic scattering from protons, and is interpreted to arise from a positive gluon polarization.