Electron production
FORMFACTOR
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Elastic electron scattering on helium 4

Repellin, J.P. ; Lehmann, P. ; Lefrançois, J. ; et al.
Phys.Lett. 16 (1965) 169-170, 1965.
Inspire Record 1385171 DOI 10.17182/hepdata.30380

None

1 data table
Table 1

Axis error includes +- 2/2 contribution.


The Charge Form Factor of the Proton at a Momentum Transfer of 75 F$^-^2$

Bartel, W. ; Dudelzak, B. ; Krehbiel, H. ; et al.
Phys.Lett.B 25 (1967) 236-237, 1967.
Inspire Record 1333753 DOI 10.17182/hepdata.29448

The proton form factors GE(q2) and GM(q2) are determined at q2 = 75fm−2.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurements of the magnetic form-factor of the proton for timelike momentum transfers

Andreotti, M ; Bagnasco, S ; Baldini, W ; et al.
Phys.Lett.B 559 (2003) 20-25, 2003.
Inspire Record 617594 DOI 10.17182/hepdata.27006

Fermilab experiment E835 has measured the cross section for the reaction p ̄ p→e + e − at s =11.63, 12.43, 14.40 and 18.22 GeV 2 . From the analysis of the 66 observed events new high-precision measurements of the proton magnetic form factor are obtained.

3 data tables
Table 1

The measured cross section in the kinematic range defined by COS(THETA).

Table 2

The proton magnetic form factor calculated assuming the equality of the electric and magnetic form factors.

Table 3

The proton magnetic form factor calculated assuming a negligible electric contribution.


Measurement of tensor polarization elastic electron deuteron scattering at large momentum transfer.

The JLAB t(20) collaboration Abbott, D. ; Ahmidouch, A. ; Anklin, H. ; et al.
Phys.Rev.Lett. 84 (2000) 5053-5057, 2000.
Inspire Record 523086 DOI 10.17182/hepdata.40433

Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c)^2. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q^2 the deuteron charge form factors G_C and G_Q. They are in good agreement with relativistic calculations and disagree with pQCD predictions.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurement of the energy dependence of the form-factor f(+) in K0(e3) decay.

The CPLEAR collaboration Apostolakis, A. ; Aslanides, E. ; Backenstoss, G. ; et al.
Phys.Lett.B 473 (2000) 186-192, 2000.
Inspire Record 513277 DOI 10.17182/hepdata.49003

Neutral-kaon decays to π e ν were analysed to determine the q 2 dependence of the K 0 e3 electroweak form factor f + . Based on 365 612 events, this form factor was found to have a linear dependence on q 2 with a slope λ + =0.0245±0.0012 stat ±0.0022 syst .

1 data table
Table 1

The Q2 dependence of FORMFACTOR+ is usually approximated as: FORMFACTOR+(Q2) = CONST * ( 1 + Q2 * CONST(NAME=LAMBDA+)/M(C=PI)**2).


Measurements of the magnetic form factor of the proton in the timelike region at large momentum transfer.

The E835 collaboration Ambrogiani, M. ; Bagnasco, S. ; Baldini, W. ; et al.
Phys.Rev.D 60 (1999) 032002, 1999.
Inspire Record 496464 DOI 10.17182/hepdata.42105

The cross section for the reaction p¯p→e+e− has been measured at s=8.8, 10.8, 12.4, 13.1, and 14.4 GeV2 by Fermilab experiment E835. A non-magnetic spectrometer is used to identify the e+e− final states generated by the antiproton beam intersecting an internal hydrogen gas jet target. From the analysis of the 144 observed events, new high-precision measurements of the proton magnetic form factor for timelike momentum transfers are obtained.

3 data tables
Table 1

No description provided.

Table 2

Assuming ABS(FORMFACTOR(NAME=ELECTRIC)) = ABS(FORMFACTOR(NAME=MAGNETIC)).

Table 3

Neglecting contribution for FORMFACTOR(NAME=ELECTRIC).


Measurement of the form-factor ratios for D/s+ --> Phi l+ nu/l.

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 450 (1999) 294-300, 1999.
Inspire Record 480733 DOI 10.17182/hepdata.42137

We have measured the form factor ratios r_V = V(0)/A_1(0) and r_2 = A_2(0)/A_1(0) for the decay D_s^+ -> phi ell^+ nu_ell, phi -> K^+ K^-, using data from charm hadroproduction experiment E791 at Fermilab. Results are based on 144 signal and 22 background events in the electron channel and 127 signal and 34 background events in the muon channel. We combine the measurements from both lepton channels to obtain r_V = 2.27 +- 0.35 +- 0.22 and r_2 = 1.57 +- 0.25 +- 0.19.

1 data table
Table 1

With a vetor meson in the final state, there are four formfactors, V(Q2), A1(Q2), A2(Q2), A3(Q2). Charge conjugated states are understood.


Measurement of T(20) in elastic electron deuteron scattering.

Bouwhuis, M. ; Alarcon, R. ; Botto, T. ; et al.
Phys.Rev.Lett. 82 (1999) 3755-3758, 1999.
Inspire Record 477409 DOI 10.17182/hepdata.31372

We report on a measurement of the tensor-analyzing power T20 in elastic electron-deuteron scattering in the range of four-momentum transfer from 1.8 to 3.2 fm-1. Electrons of 704 MeV were scattered from a polarized deuterium internal target. The tensor polarization of the deuterium nuclei was determined with an ion-extraction system, allowing an absolute measurement of T20. The data are described well by a non-relativistic calculation that includes the effects of meson-exchange currents.

1 data table
Table 1

No description provided.


Measurement of the probability of the decay K+ ---> pi0 pi0 e+ neutrino

Barmin, V.V. ; Barylov, V.G. ; Davidenko, G.V. ; et al.
Sov.J.Nucl.Phys. 48 (1988) 1032-1034, 1988.
Inspire Record 457321 DOI 10.17182/hepdata.40034

None

1 data table
Table 1

No description provided.


Measurements of |V(cb)|, form factors and branching fractions in the decays anti-B0 --> D*+ l- anti-nu/l and anti-B0 --> D+ l- anti-nu/l.

The ALEPH collaboration Buskulic, D. ; De Bonis, I. ; Decamp, D. ; et al.
Phys.Lett.B 395 (1997) 373-387, 1997.
Inspire Record 425943 DOI 10.17182/hepdata.34082

Two samples of exclusive semileptonic decays, 579 B 0 → D ∗+ ℓ − ν ℓ events and 261 B 0 → D + ℓ − ν ℓ events, are selected from approximately 3.9 million hadronic Z decays collected by the ALEPH detector at LEP. From the reconstructed differential decay rate of each sample, the product of the hadronic form factor F (ω) at zero recoil of the D (∗)+ meson and the CKM matrix element | V cb | are measured to be F D ∗+ (1)|V cb | = (31.9 ± 1.8 stat ± 1.9 syst ) × 10 −3 , F D + (1)| V cb | = (27.8 ± 6.8 stat ± 6.5 syst ) × 10 −3 . The ratio of the form factors F D + (1) and F D ∗+ (1) is measured to be F D + (1) F D ∗+ (1) = 0.87 ± 0.22 stat ± 0.21 syst . A value of | V cb | is extracted from the two samples, using theoretical constraints on the slope and curvature of the hadronic form factors and their normalization at zero recoil, with the result | V cb | = (34.4 ± 1.6 stat ± 2.3 syst ± 1.4 th ) × 10 −3 . The branching fractions are measured from the two integrated spectra to be Br ( B 0 → D ∗+ ℓ − ν ℓ ) = (5.53 ± 0.26 stat ±0.52 syst ) %, Br ( B 0 → D ∗+ ℓ − ν ℓ ) = (2.35 ± 0.20 stat ± 0.44 syst ) %.

3 data tables
Table 1

The formfactors are evaluated at zero recoil of D meson. Two different methods are used (see text for details). VCB is the KCM matrix element. The formfactor fitted to dependence: FF(OM) = FF(1)*(1-CONST*(OM-1)).

Table 2

VCB is the KCM matrix element.

Table 3

VCB is the KCM matrix element.