J. J. Jarmer's research while affiliated with Los Alamos National Laboratory and other places

Publications (73)

Article
Measurements are presented for several mixtures of the spin observables CSS, CLS= CLS, CLL, and CNN for neutron-proton elastic scattering. These data were obtained with a free polarized neutron beam, a polarized proton target, and a large magnetic spectrometer for the outgoing proton. The neutron beam kinetic energies were 484, 567, 634, 720, and 7...
Article
Measurements are presented for several mixtures of the spin observables CSS,CSL=CLS, CLL, and CNN for neutron-proton elastic scattering. These data were obtained with a free polarized neutron beam, a polarized proton target, and a large magnetic spectrometer for the outgoing proton. The neutron beam kinetic energies were 484, 567, 634, 720, and 788...
Article
Full-text available
Analyzing powers Ay were measured for pi+ and pi- elastic scattering from polarized 13C at incident pion energies Tpi near the P33 pi-nucleon resonance. At Tpi=130 MeV, the values of Ay are significantly different from zero for pi- scattering. For pi+ at Tpi=130 MeV and for both pi- and pi+ at all other energies, the Ay are mostly consistent with z...
Article
A measurement of [Delta][sigma][sub [ital L]]([ital np]), the difference between neutron-proton total cross sections for pure longitudinal spin states, is described. Data were taken at LAMPF for five neutron beam kinetic energies: 484, 568, 634, 720, and 788 MeV. The statistical errors are in the range of 0.64--1.35 mb. Various sources of systemati...
Article
The spin correlation parameter A00NN for 497.5 MeV proton + proton elastic scattering was determined over the center-of-momentum scattering angle region 23.1°–64.9 °. The new A00NN extend to more forward angles than existing A00NN and have significantly smaller statistical errors (±0.01–0.04). The A00NN are qualitatively described by recent phase s...
Article
Results are presented for the spin-spin correlation parameters CSS and CLS for free np elastic scattering at neutron beam kinetic energies of 484, 634, 720, and 788 MeV and c.m. angles between 25° and 80°. The measurements were performed with a polarized neutron beam and a polarized proton target. These are the first measurements of this type to be...
Article
Full-text available
Recent theoretical work has shown that mechanical detection of magnetic resonance from a single nuclear spin is in principle possible. This theory has recently been experimentally validated by the mechanical detection of electron spin resonance signals using microscale cantilevers. Currently we are extending this technology in an attempt to detect...
Article
Full-text available
Final results are presented for the spin-spin correlation parameters CsL and C« for np elastic scattering with a polarized neutron beam incident on a polarized proton target. The beam kinetic energies are 484, 634, and 788 MeV, and the c.m. angular range is 80'—180'. These data will contribute significantly to the determination of the isospin-0 amp...
Article
The spin-correlation observable ALL for p-p elastic scattering has been measured at energies 589, 640, 692, 743, and 793 MeV, over a c.m. angular range between 20° and 100°. The spin observable ASL was also measured in this angular range at energies 640 and 793 MeV. At 488 MeV both the spin observables were measured, but only near the c.m. angle of...
Article
Results of the first pion single-charge-exchange experiment on a polarized nuclear target are reported. Analyzing powers {ital A}{sub {ital y}} for the ({pi}{sup +},{pi}{sup 0}) reaction at {ital T}{sub {pi}}{sup +}=163 MeV on a polarized {sup 13}C target were measured over an angular range between 20{degree} and 60{degree} in the laboratory system...
Article
Full-text available
Analyzing powers {ital A}{sub {ital y}} were measured for {pi}{sup +} and {pi}{sup {minus}} elastic scattering from polarized {sup 13}C at energies near the {ital P}{sub 33} resonance. At {ital T}{sub {pi}}=132 MeV the values of {ital A}{sub {ital y}} are significantly different from zero for {pi}{sup {minus}}. For {pi}{sup +} at 132 MeV and for bo...
Article
A measurement of DELTA-sigma-L (np), the difference between neutron-proton total cross sections in pure longitudinal spin states, is described. Data were taken for five energies between 500 and 800 MeV, with statistical errors of almost-equal-to 1.5 mb and an estimated normalization error of 6%. The data, combined with other results, show some evid...
Chapter
Ethylene glycol, 1-butanol, and toluene highly enriched in 13C have been used at LAMPF to produce dynamically polarized 13C targets for scattering experiments with protons and pions. Preparation of the materials and characteristic properties of these, targets are described.
Article
The p$\rightarrow${}${+}^{13}$C$\rightarrow${} (polarized target) elastic-scattering spin observables ${\mathit{A}}_{000\mathit{n}}$ (target analyzing power) and ${\mathit{A}}_{00\mathit{n}\mathit{n}}$ (spin-correlation parameter) were determined at 497.5 MeV over the laboratory angular range 12\ifmmode^\circ\else\textdegree\fi{}\char21{}30\ifmmode...
Article
Full-text available
Analyzing powers, Ay, were measured at the Clinton P. Anderson Meson Physics Facility for π+ and π- elastic scattering from polarized 13C in the energy region of the [3,3] resonance. The Ay were found to be small in general and, at small momentum transfers, q < 1 fm-1, were reproduced best by a first order optical potential description and standard...
Article
Analyzing powers for the reaction π-p-->-->π0n were measured at an incident pion energy of T-π=161 MeV with a transversely polarized proton target over the angular range of about 20°-60°. The results are well described by calculations based on current sets of πN phase shifts.
Article
New differential cross section (dsigma/dOmega), analyzing power (Ay), and spin-rotation-depolarization (Dij) data for 500 MeV p-->+12C,13C elastic scattering are reported. The dsigma/dOmega and Ay data span scattering angles from approximately 5°-37° c.m., while the Dij data cover 5°-26° c.m. Except at the largest angles, statistical errors are typ...
Article
New differential cross section ({ital d}Ï/{ital d}Ω), analyzing power ({ital A}{sub {ital y}}), and spin-rotation-depolarization ({ital D}{sub {ital i}{ital j}}) data for 500 MeV {ital {rvec p}}+¹²C,¹³C elastic scattering are reported. The {ital d}Ï/{ital d}Ω and {ital A}{sub {ital y}} data span scattering angles from approximately 5°--37°...
Article
The mixed spin-spin correlation parameter Cσσ ~=0.5CSS-0.8CSL for np elastic scattering was measured for incident-neutron-beam kinetic energies of 484, 634, and 788 MeV over the center-of-mass angular range 75°-180°. These Cσσ data are important for determining the I=0 nucleon-nucleon amplitudes and provide strong constraints on the phase-shift sol...
Article
The spin-correlation parameter Ann for free n-p elastic scattering has been measured for the first time for incident-neutron-beam energy En=790 MeV and c.m. angles 48°
Article
We studied microwave dynamic cooling of 19F and 1H nuclei in mixtures of 1,1,1,3,3,3-hexafluoro-2-propanol and water, doped with Cr(V) complex. Equal spin temperatures of the two nuclei are produced, and the highest spin polarizations (≈ 80%) are found in mixtures near the eutectic ratio. The high fluorine content and polarization make this a suita...
Article
Full-text available
As part of an experimental study of the nucleon-nucleon interaction at medium energy, the free neutron-proton analyzing power ${A}_{n}$(${$\theta${}}_{n}^{\mathrm{*}}$,${T}_{n}$) has been measured at nine incident neutron energies in the range 375$\le${}${T}_{n}$$\le${}775 MeV and for neutron c.m. angles in the range 57\ifmmode^\circ\else\textdegre...
Article
A polarized ¹³C target has been developed and used to measure spin observables for 500-MeV p - ¹³C elastic scattering. The material was ethylene glycol, ¹³CâHâOâ, enriched to 99% in ¹³C. Both the ¹³C and ¹H spins were dynamically polarized in a ³He refrigerator at 2.5-T magnetic field. The polarization of both species was measured by us...
Article
A solid polarized deuterated-ammonia target has been used to measure spin observables for p&drarr;-d&drarr; elastic scattering at LAMPF. The target polarization was dynamically enhanced to over 30% and monitored with a bridge-type NMR circuit. A method for determining the vector and tensor polarization is presented which is independent of any assum...
Conference Paper
We have studied microwave dynamic cooling ¹⁹F and ¹H nuclei in mixtures of 1,1,1,3,3,3‐hexafluoro‐2‐propanol and water, doped with Cr(V) complex. Equal spin temperatures of the two nuclei are produced, and the highest spin polarizations (∼80%) are found in mixtures near the eutectic ratio. The high fluorine content and polarization make this a suit...
Article
Angular distributions of the spin-correlation parameters Asl and All for the reaction pp→π+d have been measured at pion center-of-mass angles 40°≤θπ+*≤130° at incident energies of 500, 650, and 800 MeV. Additional measurements of All were made at 600, 700, and 750 MeV. The results of the experiment are compared with the predictions of several unifi...
Conference Paper
A polarized /sup 13/C target has been developed and used to measure spin observables for 500-MeV p - /sup 13/C elastic scattering. The material was ethylene glycol, /sup 13/C/sub 2/H/sub 6/O/sub 2/, enriched to 99% in /sup 13/C. Both the /sup 13/C and /sup 1/H spins were dynamically polarized in a /sup 3/He refrigerator at 2.5-T magnetic field. The...
Article
The spin-spin correlation parameters ${C}_{\mathrm{LL}}$=(L,L;0,0)=${A}_{\mathrm{LL}}$ and ${C}_{\mathrm{SL}}$=(S,L;0,0)=${A}_{\mathrm{SL}}$ for np elastic scattering were measured for incident polarized-neutron\char21{}beam kinetic energies of 484 and 634 MeV over the center-of-mass angles from $\simeq${}80\ifmmode^\circ\else\textdegree\fi{} to 18...
Article
Angular distributions of the spin observables Ann, Ano, and Aon for the reaction pp-->dπ+ have been measured for pion c.m. angles 30°<θ*π<110° at beam kinetic energies of 500, 600, 650, 700, 733, and 800 MeV. These are precision data spanning the energy region of two conjectured dibaryon resonances in the NN system, one near 650 MeV (1D2) and one n...
Article
The 13C nuclei in ethylene-1,2-13C2 glycol have been dynamically polarized to 28%. The material appears suited for use as a polarized nuclear target for intermediate energy hadron+13C scattering experiments.
Article
We present results of calculations which suggest that several of the spin observables for elastic scattering of 500-MeV polarized protons from a polarized 13C target are sensitive to relativistic aspects of nuclear structure.
Article
Measurements of ALL between 500 and 800 MeV and spin dependent cross sections derived from these measurements are presented for the reaction pp-->πd at c.m. angles θ*π of 50°, 70°, and 90°. Angular distributions for ASL are also presented for energies 500, 650, and 800 MeV. These are the first measurements of spin-correlation parameters in this cha...
Article
Measurements of the spin observables ANN(90∘) and AN0(90∘) for the reaction pp→dπ+ between 500 and 800 MeV are presented and compared with previous measurements and with predictions from theories and a partial-wave analysis. These are the first available measurements of ANN above 590 MeV.
Article
Measurements are reported of the difference ΔσL between proton-proton total cross sections for parallel and antiparallel spin states and of the parameter CLL for proton-proton elastic scattering near 90°, for thirteen energies between 300 and 800 MeV. The ΔσL results agree well with previous ANL ZGS and SIN data, but disagree with recent results fr...
Article
The spin-spin correlation parameter C/sub S/S = (S,S;0,0) has been measured for p-p elastic scattering over a large angular range. The data are particularly useful in checking currently available phase-shift solutions.
Article
The spin-spin correlation parameter CSS=(S,S;0,0) has been measured for p-p elastic scattering over a large angular range. The data are particularly useful in checking currently available phase-shift solutions.
Article
Full-text available
We report first measurements of the spin correlation parameters, ANN and ALL, for pp-->npπ+ above the Δ-production threshold. Our results for this dominant inelastic channel are in good agreement with a theoretical model that does not include any dibaryon resonances.
Article
A description is given of a beam polarimeter constructed for use at the Argonne ZGS and later at LAMPF. Details of the absolute calibration of these polarimeters are described. Conclusions for the absolute beam polarization at the ZGS impact a number of past polarized beam experiments, causing normalization changes in some cases of 8–25%. The norma...
Article
A polarized target incorporating two target cells has been built and used in an experiment at LAMPF. Under cryogenic conditions either cell could be positioned on beam line in a few minutes permitting fairly rapid change over from one to the other.
Article
A frozen spin polarized proton target has been developed and used at LAMPF to measure the spin correlation parameter ASS for proton‐proton elastic scattering. The target consisted of a horizontal dilution refrigerator, superconducting magnet, plus other equipment. The target refrigerator was fixed and the magnet moved on a rail system. The design p...
Article
Measurements of CLL of pp elastic scattering near θc.m. = 90° at thirteen energies between 300 and 800 MeV are reported. These, together with previous values of CNN, are used to extract values of two quantities, and , which contain only spin-singlet and only coupled spin-triplet partial waves, respectively. The curve, which is not dependent on CLL,...
Article
The difference between total cross sections in pure transverse-initial-spin states for the p-p interaction has been measured at Tp=487, 639, and 791 MeV, using a frozen-spin target. A comparison with previous data and available phase-shift analyses is made.
Article
Precise measurements are reported of the spin-correlation parameter ANN for 500-800 MeV pp elastic scattering at thetac.m.=pi2. While not reproducing the large value of ANN reported earlier at 697 MeV, the data show a pronounced maximum in the 90° triplet-to-singlet ratio near the location of the reported 3F3 dibaryon resonance. In contradiction wi...
Article
The spin correlation parameter A/sub n/n and the analyzing power A have been measured at 643 MeV from 35 to 90° c.m. with statistical uncertainties of +- 0.01 to +- 0.02 and normalization uncertainty of +- 2%. The data are in fair agreement with phase shift predictions and with the trend of most previous data near this energy.
Article
The spin correlation parameter Ann and the analyzing power A have been measured at 643 MeV from 35 to 90° c.m., with statistical uncertainties of +/-0.01 to +/-0.02 and normalization uncertainty of +/-2%. The data are in fair agreement with phase shift predictions and with the trend of most previous data near this energy. NUCLEAR REACTIONS 1H(p,p)1...
Article
We have measured the difference between proton-proton total cross sections for parallel and antiparallel longitudinal spin states [$$\Delta${}{$\sigma${}}_{L}={$\sigma${}}^{\mathrm{tot}}($\rightleftarrows${})$-${}{$\sigma${}}^{\mathrm{tot}}($\rightleftarrows${})$] at 13 incident energies between 300 and 800 MeV, which cover the region of possible $...
Article
As a major step in determining the neutron-proton scattering matrix, the free neutron-proton analyzing power has been measured at the Los Alamos Meson Physics Facility in two separate experiments as a function of energy and angle. Additional polarization measurements in this energy range will be presented separately at this conference. The experime...
Article
The spin correlation parameter A/sub n/n(theta) for pp elastic scattering has been measured at 796 MeV from 30/sup 0/ to 90/sup 0/ c.m. The typical relative uncertainties of +- 0.01 are almost an order of magnitude better than those of previous data near this energy. The absolute normalization uncertainty is +- 2%. Data are consistent with previous...
Article
The spin correlation parameter Ann(θ) for pp elastic scattering has been measured at 796 MeV from 30° to 90° c.m. The typical relative uncertainties of +/-0.01 are almost an order of magnitude better than those of previous data near this energy. The absolute normalization uncertainty is +/-2%. Data are consistent with previous measurements near thi...
Article
The polarized beam at LAMPF was used for the measurements along with a polarized target of propanedial doped with chromium. (AIP)
Article
A survey of the advantage and disadvantages of various possible target materials is persented. Among the topics covered are radiation damage, EPR measurements, and dynamic polarization.(AIP)
Article
Angular distributions of the polarization transfer coefficients Kx'x(θ), Kx'z(θ), Kyy(θ), and the polarization P(θ) in the reaction 3H(p,n)3He have been measured for proton energies of 5.97 and 9.9 MeV. The measurements of polarization transfer were done with an incident polarized proton beam. The polarizations of the neutrons were measured with a...
Article
Angular distributions of the analyzing power of the reaction 3H(p⃗,n)3He have been measured at proton energies of 6.00, 9.96, and 13.55 MeV. These data are compared with available neutron-polarization data for the same reaction on a point-by-point basis and by means of associated Legendre-polynomial coefficients. In contrast to the comparison below...
Article
Angular distributions of six polarization transfer coefficients Kxx'(theta), kxz'(theta), Kzx(theta), Kzz(theta), and Kyyý(theta) of the four analyzing powers Ay(theta), Axx(theta), Ayy(theta), and Azz(theta) and of the polarization function Pý(theta), have been measured atEd = 10.00 MeV for the reaction 2H(d, n)3He. Measurements were made for neut...
Article
The longitudinal polarization of neutrons has been measured for the reaction T-->p, -->n)3He with the incident proton beam longitudinally polarized. Measurements were performed at 0° for proton energies from 4 to 15 MeV and an angular distribution was measured at 10 MeV. The data determine the polarization transfer coefficient Kzz', which is equiva...
Article
We have measured the longitudinal neutron polarization in the D(d,n)3He reaction, at theta=0°, for an incident longitudinally polarized deuteron beam. A deuteron energy range of 3.3-14.9 MeV was covered. The polarization transfer from the deuteron to the neutron is found to be large, and the reaction is potentially useful as a source of polarized n...
Article
The analyzing power A of the reaction T(p, n)3He has been measured at 45° c.m. from 1.5 to 12 MeV with a polarized proton beam. A comparison with existing data for the neutron polarization P shows that P and A have similar excitation functions at this angle, but that the magnitude of P is generally less than that of A. While the R-matrix formalism...
Article
Angular distributions of the spin observables A/sub n//sub n/, A/sub n//sub o/, and A/sub o//sub n/ for the reaction pp..-->..d..pi../sup +/ have been measured for pion c.m. angles 30°
Article
Topics of discussion included static and dynamic methods for polarizing nuclei, proton and pion nucleus scattering experiments, and possible future experiments at LAMPF. Separate abstracts were prepared for 11 papers in this report. (DWL)
Article
Ethylene glycol, 1-butanol, and toluene highly enriched in ¹³C have been used at LAMPF to produce dynamically polarized ¹³C targets for scattering experiments with protons and pions. Preparation of the materials and characteristic properties of these targets are described. 17 refs., 1 fig.
Article
We report first measurements of the spin correlation parameters, A/sub N/N and A/sub L/L, for pp..-->..np..pi../sup +/ above the ..delta..-production threshold. Our results for this dominant inelastic channel are in good agreement with a theoretical model that does not include any dibaryon resonances.
Article
Samples of [sup 7]LiH material were irradiated with an electron beam of 30 MeV; doses ranged from 0.5 to 3.6[star]10[sup 17]e[sup [minus]]/cm[sup 2]. During irradiation the material was cooled by cold helium gas with a gas temperature range of 180--200 K. The samples were dynamically polarized in either a dilution or a [sup 3]He evaporation refrige...

Citations

... The data are from Ref. [68] for A y and from Refs. [69] (open square) and [70] (filled circle) for P y a small under prediction of the data at forward angles the calculated elastic differential cross sections follow the data over the whole energy range, including the region of the minima. As for proton A y there is a very consistent over prediction of the data at the minima but a smaller under prediction at the maxima compared to p-3 He, The most interesting, and in some way impressive results, emerge in Fig. 9 for the charge exchange reaction p-3 H to n-3 He differential cross sections in the energy range E p = 2.5-30 MeV. ...
... The structures below 800 MeV, first observed by Argonne, are now well confirmed. The Saclay data is in good agreement with the SIN results [26] at 0.52 GeV and with Argonne ZGS [27] and LAMPF [28] near that energy. The lRIUMF data [29]-are systematically larger ,but the energy behaviour is well reproduced.This illustrates the difficulty in controlling the systematic errors which come essentially from the beam and target polarizations and from the hydrogen content in the target. ...
... However, there are also a few disagreements with the data whose magnitude is sensitive to the force model used and may serve as a fertile ground for the investigation of nuclear interactions. Still missing in this study is the extension of the nucleon transfer reactions 2 H(d, p) 3 H and 2 H(d, n) 3 He initiated by deuteron-deuteron collisions at energies well above the breakup threshold where the existing differential cross section and analyzing power data [20][21][22][23][24][25][26][27][28][29][30][31][32] show a complicated structure involving several maxima and minima that change with the energy. Therefore in * arnoldas.deltuva@tfai.vu.lt the present manuscript we aim to investigate 2 H(d, p) 3 H and 2 H(d, n) 3 He reactions up to about 25 MeV deuteron beam energy. ...
... However, the statement that hadron helicity flip is in contradiction with pQCD is currently under debate [167,168]. In pp scattering, the striking energy and angular dependence of the spinspin correlation factor A N N attracts attention [169][170][171][172][173]. Furthermore, pQCD calculations of the magnitudes of form factors [174][175][176][177] fail to describe the data, as non-perturbative longdistance effects are shown to play a crucial role. ...
... 7 and 8 results for elastic p-3 H dσ/dΩ and proton A y for energies ranging from Fig. 7. The data are from Ref. [68] for A y and from Refs. [69] (open square) and [70] (filled circle) for P y a small under prediction of the data at forward angles the calculated elastic differential cross sections follow the data over the whole energy range, including the region of the minima. ...
... For p lab ≤ 1 GeV/c, σ tot can be as small as 25 mb or so and ∆σ L can reach the value −30 mb, so by using Eq. (4.7) one gets |∆σ T | ≤ 10 mb, with some errors, an interesting limit which is, indeed, satisfied by the data [141,142]. ...
... This form also reproduces very well the LAMPF data [15] provided that it is multiplied by a factor of 1.021. This 2% difference is to be compared with the 3% precision in the beam polarization measurements with EDDA [13], which is our dominant systematic uncertainty, and the 2% systematic uncertainty in the LAMPF beam polarization [16]. The only obvious theoretical description of proton-deuteron elastic scattering data is the refined Glauber model of Platonova and Kukulin [17]. ...
... Polarizations of the π − p → π 0 n reaction compared with the experimental data (open circles) from[74,94,[96][97][98] and the solutions (dotted curves) from the GWU group [38]. The first and second numbers in each figure correspond to the incoming π momentum P π (MeV) and the πN c.m. energy W (MeV), respectively. ...
... The time needed to measure A N with the accuracy of 5%: T=N A /N If we put numbers into the table, we will see the following: Data for cross-sections and analizing powers are taken from [1]. ...
... Precise measurements at SACLAY ended just below the d * region [41,42]. Hence corresponding analyzing power measurements extending over practically the full angular range were undertaken with [41,42,43,44,45,46,47,48]. The solid line gives the previous SAID partial-wave solution, the dashed line the new SAID solution after including the WASA data. ...