On the measurement of $\pi^{+}$ meson photoproduction from hydrogen near threshold

Lewis, G.M. ; Azuma, R.E. ;
Proc.Phys.Soc. 73 (1959) 873-880, 1959.
Inspire Record 1393355 DOI 10.17182/hepdata.26968

None

1 data table

No description provided.


Cross sections and Rosenbluth separations in 1H(e, e'K+)Lambda up to Q2=2.35 GeV2

The Jefferson Lab Hall A collaboration Coman, M. ; Markowitz, P. ; Aniol, K.A. ; et al.
Phys.Rev.C 81 (2010) 052201, 2010.
Inspire Record 837422 DOI 10.17182/hepdata.54197

The kaon electroproduction reaction 1H(e,e'K+)Lambda was studied as a function of the virtual-photon four-momentum, Q2, total energy, W, and momentum transfer, t, for different values of the virtual- photon polarization parameter. Data were taken at electron beam energies ranging from 3.40 to 5.75 GeV. The center of mass cross section was determined for 21 kinematics corresponding to Q2 of 1.90 and 2.35 GeV2 and the longitudinal, sigmaL, and transverse, sigmaT, cross sections were separated using the Rosenbluth technique at fixed W and t. The separated cross sections reveal a flat energy dependence at forward kaon angles not satisfactorily described by existing electroproduction models. Influence of the kaon pole on the cross sections was investigated by adopting an off-shell form factor in the Regge model which better describes the observed energy dependence of sigmaT and sigmaL.

11 data tables

Measured values of the separated cross section at Q**2 = 2.35 GeV**2 and W = 1.85 GeV.. Errors contain both statistics and systematics.

Measured values of the separated cross section at Q**2 = 1.90 GeV**2.. Errors contain both statistics and systematics.

Measured values of the separated cross section at Q**2 = 2.35 GeV**2.. Errors contain both statistics and systematics.

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Near threshold electroproduction of the omega meson at Q**2 approx. 0.5-GeV**2.

The Jefferson Laboratory E91-016 collaboration Ambrozewicz, P. ; Mitchell, J. ; Dunne, J. ; et al.
Phys.Rev.C 70 (2004) 035203, 2004.
Inspire Record 645605 DOI 10.17182/hepdata.31643

Electroproduction of the omega meson was investigated in the p(e,e'p)omega reaction. The measurement was performed at a 4-momentum transfer Q2 ~ 0.5 GeV2. Angular distributions of the virtual photon-proton center-of-momentum cross sections have been extracted over the full angular range. These distributions exhibit a strong enhancement over t-channel parity exchange processes in the backward direction. According to a newly developed electroproduction model, this enhancement provides significant evidence of resonance formation in the gamma* p -> omega p reaction channel.

2 data tables

Differential cross section for an average W of 1.75 GeV.

Differential cross section for an average W of 1.79 GeV.


Elastic Compton scattering from the deuteron and nucleon polarizabilities

Hornidge, D.L. ; Warkentin, B.J. ; Igarashi, R. ; et al.
Phys.Rev.Lett. 84 (2000) 2334-2337, 2000.
Inspire Record 507811 DOI 10.17182/hepdata.6711

Cross sections for elastic Compton scattering from the deuteron were measured over the laboratory angles 35-150 deg. Tagged photons in the laboratory energy range 84-105 MeV were scattered from liquid deuterium and detected in the large-volume Boston University NaI (BUNI) spectrometer. Using the calculations of Levchuk and L'vov, along with the measured differential cross sections, the isospin-averaged nucleon polarizabilities in the deuteron were estimated. A best-fit value of (alpha-beta) = 2.6+/-1.8 was determined, constrained by dispersion sum rules. This is markedly different from the accepted value for the proton of (alpha-beta) = 10.0+/-1.5+/-0.9.

3 data tables

No description provided.

Neutron polarizability is evaluated from the deuteron data.

No description provided.


Observation of a (Sigma)He-4 bound state in the He-4(K-,pi-) reaction at 600-MeV/c.

Nagae, T. ; Miyachi, T. ; Fukuda, T. ; et al.
Phys.Rev.Lett. 80 (1998) 1605-1609, 1998.
Inspire Record 468090 DOI 10.17182/hepdata.19553

We have observed a clear peak below the Σ+-production threshold in the 4He(K−,π−) reaction at 600MeV/c and θKπ=4∘. This is confirmation of the existence of the bound state of Σ4He, which was reported in the 4He(stoppedK−,π−) reaction. As in the case of stopped kaons, no such peak was found in the 4He(K−,π+) spectrum. Quantitatively reliable parameters for this level have been established. The binding energy and the width of the bound state are 4.4±0.3(stat)±1(syst) MeV and 7.0±0.7(stat)−0.0+1.2(syst) MeV, respectively.

1 data table

$HE4/S represents the HE4/SIGMA+ bound state.


Elastic and inelastic scattering of K+ from Li-6 and C-12

Chrien, R.E. ; Sawafta, R. ; Peterson, R.J. ; et al.
Nucl.Phys.A 625 (1997) 251-260, 1997.
Inspire Record 453025 DOI 10.17182/hepdata.36467

Cross sections for inelastic scattering of 635 and 715 MeV/ c K + from 12 C are compared with DWIA calculations in order to check for possible density-dependent effects on K + -nucleon cross sections within nuclei. New fits to 715 MeV/ c K + scattering spectra from 6 Li give elastic and inelastic cross sections and permit an evaluation of the density dependence of these effects. The same DWIA methods are also used to estimate quadrupole non-central contributions to elastic K + scattering from the 1 + ground state of 6 Li, and these are found to be very small.

8 data tables

Axis error includes +- 0.0/0.0 contribution (?////NORMALIZATION UNCERTAINTIES ARE INCLUDED).

Axis error includes +- 0.0/0.0 contribution (?////NORMALIZATION UNCERTAINTIES ARE INCLUDED).

Axis error includes +- 0.0/0.0 contribution (?////NORMALIZATION UNCERTAINTIES ARE INCLUDED).

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Addendum to *Search for the weak decay of an H dibaryon*.

The BNL-E888 collaboration Belz, J. ; Cousins, R.D. ; Diwan, M.V. ; et al.
Phys.Rev.Lett. 76 (1996) 3277-3280, 1996.
Inspire Record 404164 DOI 10.17182/hepdata.21937

We have searched for a neutral $H$ dibaryon decaying via $H\rightarrow\Lambda n$ and $H\rightarrow\Sigma~0 n$. Our search has yielded two candidate events from which we set an upper limit on the $H$ production cross section. Normalizing to the inclusive $\Lambda$ production cross section, we find $(d\sigma_H/d\Omega)\,/\,(d\sigma_\Lambda/d\Omega) < 6.3\times 10~{-6}$ at 90\% C.L., for an $H$ of mass $\approx$\,2.15GeV/$c~2$.

1 data table

No description provided.


Two body photodisintegration of the deuteron up to 2.8-GeV

Belz, J.E. ; Potterveld, D.H. ; Anthony, P. ; et al.
Phys.Rev.Lett. 74 (1995) 646-649, 1995.
Inspire Record 399936 DOI 10.17182/hepdata.19630

Measurements were performed for the photodisintegration cross section of the deuteron for photon energies from 1.6 to 2.8 GeV and center-of-mass angles from 37° to 90°. The measured energy dependence of the cross section at θc.m.=90° is in agreement with the constituent counting rules.

1 data table

Statistical and systematic errors have been added in quadrature. Photon energy and angle (in deg) are in center-of-mass system.


Measurements of cross-section and charge asymmetry for e+ e- ---> mu+ mu- and e+ e- ---> tau+ tau- at s**(1/2) = 57.8-GeV

The AMY collaboration Velissaris, C. ; Lusin, S. ; Chung, Y.S. ; et al.
Phys.Lett.B 331 (1994) 227-235, 1994.
Inspire Record 373861 DOI 10.17182/hepdata.38344

With data corresponding to 142 pb −1 accumulated at s = 57.8 GeV by the AMY detector at TRISTAN we measure the cross section of the reactions e + e − → μ + μ − and e + e − → τ + τ − and the symmetry in the angular distributions. For the lowest order cross section we obtain σ μμ = 27.54 ± 0.65 ± 0.95 pb and σ ττ = 28.27 ± 0.87 ± 0.69 pb, and for the forward-backward asymmetry, A μμ = 0.303 ± 0.027 ± 0.008 and A ττ = −0.291 ± 0.040 ± 0.019. These measurements agree with the standard model. Assuming e − μ − τ univrsality we extract the vector and axial coupling constants | gν | = 0.00 ± 0.09 and | g A | = 0.476 ± 0.024. A fit of data to composite models places lower bounds (95% confidence level) on the compositeness scale of 2–4 TeV.

5 data tables

Lowest order cross section and forward-backward asymmetry.

Errors are statistical only.

Lowest order cross section and forward-backward asymmetry.

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K+ nucleus quasielastic scattering

Kormanyos, C.M. ; Peterson, R.J. ; Shepard, J.R. ; et al.
Phys.Rev.Lett. 71 (1993) 2571-2574, 1993.
Inspire Record 356948 DOI 10.17182/hepdata.47080

K$~+$--nucleus quasielastic cross sections measured for a laboratory kaon beam momentum of 705 MeV/$c$ are presented for 3--momentum transfers of 300 and 500 MeV/$c$. The measured differential cross sections for C, Ca and Pb at 500 MeV/$c$ are used to deduce the effective number of nucleons participating in the scattering, which are compared with estimates based on the eikonal approximation. The long mean free path expected for K$~+$ mesons in nuclei is found. Double differential cross sections for C and Ca are compared to relativistic nuclear structure calculations.

1 data table

No description provided.