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.

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Study of the gamma gamma decays of the chi(c2) (1**3 P(2)) and chi(c0) (1**3 P(0)) charmonium resonances

Ambrogiani, M. ; Argiro, S. ; Bagnasco, S. ; et al.
Phys.Rev.D 62 (2000) 052002, 2000.
Inspire Record 531059 DOI 10.17182/hepdata.3517

We report the branching ratios of the χc2(13P2) and χc0(13P0) charmonium resonances to two photons using event samples collected by Fermilab experiment E835 in the reactions p¯p→χc2(13P2)[χc0(13P0)]. Our result for the χc2 is B(χc2→γγ)=(1.35±0.25±0.12)×10−4. We set a 95% upper limit for the χc0 branching ratio B(χc0→γγ) at 2.09×10−4.

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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.

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Study of the eta(c) (s wave singlet) state of charmonium formed in anti-p p annihilations and a search for the eta(c)-prime (s wave doublet)

The E760 collaboration Armstrong, T.A. ; Bettoni, D. ; Bharadwaj, V. ; et al.
Phys.Rev.D 52 (1995) 4839-4854, 1995.
Inspire Record 395314 DOI 10.17182/hepdata.42381

The E760 Collaboration performed an experiment in the Antiproton Accumulator at Fermilab to study the two photon decay of the ηc(1 1S0) charmonium state formed in p¯p annihilations. This resulted in a new measurement of the mass Mηc=2988.3−3.1+3.3 MeV/c2 and of the product B(ηc→p¯p)×Γ(ηc→γγ) =(8.1−2.0+2.9) eV. We performed a search for the process p¯p→ηc′(2 1S0)→γγ over a limited range of center-of-mass energies. Since no signal was observed, we derived upper limits on the product of branching ratios B(ηc′→p¯p)×B(ηc′→γγ) in the center-of-mass energy range 3584≤ √s ≤3624 MeV. We observed no signal for the nonresonant process p¯+p→γ+γ and obtain upper limits.

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Two-body neutral final states produced in $\bar{p}p$ annihilations at 2.911-GeV <= $\sqrt{s}$ <= 3.686-GeV

The Fermilab E760 collaboration Armstrong, T.A. ; Bettoni, D. ; Bharadwaj, V. ; et al.
Phys.Rev.D 56 (1997) 2509-2531, 1997.
Inspire Record 444897 DOI 10.17182/hepdata.22300

We have performed an experiment in the Antiproton Accumulator at Fermilab to study two-body neutral final states formed in p¯p annihilations. Differential cross sections are determined in the center-of-mass energy range 2.911<s<3.686 GeV for the final states π0π0, ηπ0, ηη, π0γ, and γγ. The energy dependence of differential cross sections at 90° in the center of mass is studied to test the predictions of phenomenological QCD scaling hypotheses which predict power-law dependence.

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Precision measurements of anti-proton proton forward elastic scattering parameters in the 3.7-GeV/c to 6.2-GeV/c region

The E760 collaboration Armstrong, T.A. ; Bettoni, D. ; Bharadwaj, V. ; et al.
Phys.Lett.B 385 (1996) 479-486, 1996.
Inspire Record 431921 DOI 10.17182/hepdata.28348

Differential cross sections for p p elastic scattering have been measured for very small momentum transfers at six different incident antiproton momenta in the range 3.7 to 6.2 GeV/c by the detection of recoil protons at scattering angles close to 90°. Forward scattering parameters σ T , b , and ϱ have been determined. For the ϱ-parameter, up to an order of magnitude higher level of precision has been achieved compared to that in earlier experiments. It is found that existing dispersion theory predictions are in disagreement with our results for the ϱ-parameter.

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Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion. FNAL-564 experiment

Dayon, M. ; Rappoport, V. ; Smirnitsky, V. ; et al.
Z.Phys.C 56 (1992) 391-393, 1992.
Inspire Record 345621 DOI 10.17182/hepdata.14532

Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT0=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ∼15 (GeV/c)2 (the neutrino energy over ∼50 GeV) was observed.

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$\pi^{\pm} p$, $K^{\pm} p$, $pp$ and $p\bar{p}$ Elastic Scattering from 50-GeV/c to 175-GeV/c

The Fermilab Single Arm Spectrometer Group collaboration Ayres, D.S. ; Diebold, R. ; Maclay, G.J. ; et al.
Phys.Rev.D 15 (1977) 3105, 1977.
Inspire Record 110409 DOI 10.17182/hepdata.24653

The differential cross sections for the elastic scattering of π+, π−, K+, K−, p, and p¯ on protons have been measured in the t interval -0.04 to -0.75 GeV2 at five momenta: 50, 70, 100, 140, and 175 GeV/c. The t distributions have been parametrized by the quadratic exponential form dσdt=Aexp(B|t|+C|t|2) and the energy dependence has been described in terms of a single-pole Regge model. The pp and K+p diffraction peaks are found to shrink with α′∼0.20 and ∼0.15 GeV−2, respectively. The p¯p diffraction peak is antishrinking while π±p and K−p are relatively energy-independent. Total elastic cross sections are calculated by integrating the differential cross sections. The rapid decline in σel observed at low energies has stopped and all six reactions approach relatively constant values of σel. The ratio of σelσtot approaches a constant value for all six reactions by 100 GeV, consistent with the predictions of the geometric-scaling hypothesis. This ratio is ∼0.18 for pp and p¯p, and ∼0.12-0.14 for π±p and K±p. A crossover is observed between K+p and K−p scattering at |t|∼0.19 GeV2, and between pp and p¯p at |t|∼0.11 GeV2. Inversion of the cross sections into impact-parameter space shows that protons are quite transparent to mesons even in head-on collisions. The probability for a meson to pass through a proton head-on without interaction inelastically is ∼20% while it is only ∼6% for an incident proton or antiproton. Finally, the results are compared with various quark-model predictions.

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Proton - Deuteron Elastic Scattering at Small Momentum Transfer from 50-GeV/c to 400-GeV/c

Akimov, Y. ; Golovanov, L. ; Mukhin, S. ; et al.
Phys.Rev.D 12 (1975) 3399, 1975.
Inspire Record 99829 DOI 10.17182/hepdata.24883

Proton-deuteron elastic scattering has been measured in the four-momentum transfer squared region 0.013<|t|<0.14 (GeV/c)2 and for incident proton beam momenta from 50 to 400 GeV/c. The data can be fitted with the Bethe interference formula. We observe shrinkage of the diffraction cone with increasing energy equal to (0.94±0.04)ln(s1 GeV2) (GeV/c)−2. This shrinkage is greater than that observed in pp elastic scattering. The ratio of the elastic to the total cross section is approximately 0.1 and independent of energy above ∼ 150 GeV. In order to extract information on pn scattering we fit our data using the Glauber approach and a form factor which is the sum of exponentials. The values we obtain for the slope parameter in pn scattering are sensitive to the details of the inelastic double-scattering term.

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Total cross-section measurements with pi-, Sigma- and protons on nuclei and nucleons around 600-GeV/c

The SELEX collaboration Dersch, U. ; Akchurin, N. ; Andreev, V.A. ; et al.
Nucl.Phys.B 579 (2000) 277-312, 2000.
Inspire Record 509036 DOI 10.17182/hepdata.24823

Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.

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Hadronic Production of $\Lambda_c$ from 600-GeV/c $\pi^-, \Sigma^-$ and $p$ Beams

The SELEX collaboration Garcia, F.G. ; Alkhazov, G. ; Atamantchouk, A.G. ; et al.
Phys.Lett.B 528 (2002) 49-57, 2002.
Inspire Record 562836 DOI 10.17182/hepdata.26997

We present data from Fermilab experiment E781 (SELEX) on the hadroproduction asymmetry for anti-Lambda_c compared to Lambda_c+ as a function of xF and pt2 distributions for Lambda_c+. These data were measured in the same apparatus using incident pi-, sigma- beams at 600 GeV/c and proton beam at 540 GeV/c. The asymmetry is studied as a function of xF. In the forward hemisphere with xF >= 0.2 both baryon beams exhibit very strong preference for producing charm baryons rather than charm antibaryons, while the pion beam asymmetry is much smaller. In this energy regime the results show that beam fragments play a major role in the kinematics of Lambda_c formation, as suggested by the leading quark picture.

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Inclusive and Semiinclusive rho0 Production in pi- p Interactions at 147-GeV/c.

Fong, D. ; Heller, M. ; Shapiro, A.M. ; et al.
Phys.Lett.B 60 (1975) 124-128, 1975.
Inspire Record 102526 DOI 10.17182/hepdata.27734

We present data on inclusive and semi-inclusive ϱ 0 production in 147 GeV/ c π − p interactions. We find a total cross section of 7.3 ± 1.3 mb. Most of this cross section is found in the lower topology events (⩽ 10 prongs), and in the central and forward rapidity regions. The P T 2 dependence of ϱ 0 production, 〈: n > ϱ 0 per event, and the ϱ 0 / π + ratios are also discussed.

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Diffraction dissociation in $\bar{p} p$ collisions at $\sqrt{s}$ = 1.8-TeV

The E710 collaboration Amos, Norman A. ; Avila, C. ; Baker, W.F. ; et al.
Phys.Lett.B 301 (1993) 313-316, 1993.
Inspire Record 342944 DOI 10.17182/hepdata.28955

We have studied single diffraction dissociation ( p p→ p X ) in proton-antiproton collisions at √ s =1.8TeV, covering the ranges 3⪅ M X ⪅200 GeV and 0.05⪅| t |⪅0.11 (GeV/ c ) 2 . Parameterizing the production to be of the form dσ ( d t d M 2 X ) = (M 2 X ) −α exp (bt) , we obtain α = 1.13±0.07 and b = 10.5±1.8(GeV/ c ) −2 . The total single diffraction dissociation cross section is 2 σ SD =8.1±1.7 mb. Comparisons are made to previous lower energy data, and to an earlier measurement by us at the same energy.

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Distributions of charged hadrons observed in deep inelastic muon - deuterium scattering at 490-GeV

The E-665 collaboration Adams, M.R. ; Aid, S. ; Anthony, P.L. ; et al.
Phys.Lett.B 272 (1991) 163-168, 1991.
Inspire Record 318993 DOI 10.17182/hepdata.29288

Longitudinal and transverse momentum spectra of final state hadrons produced in deep-inelastic muon-deuterium scattering at incident muon energy of 490 GeV have been measured up to a hadronic center of mass energy of 30 GeV. The longitudinal distributions agree well with data from earlier muon-nucleon scattering experiments; these distributions tend to increase in steepness as the center of mass energy increases. Comparisons with e + e − data at comparable center of mass energies indicate slight differences. The transverse momentum distributions show an increase in mean p T 2 with an increase in the center of mass energy.

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Analyzing Power Measurements of Coulomb Nuclear Interference With the Polarized Proton and Anti-proton Beams at 185-{GeV}/$c$

The E581/704 collaboration Akchurin, N. ; Carey, David C. ; Coleman, R. ; et al.
Phys.Lett.B 229 (1989) 299-303, 1989.
Inspire Record 280476 DOI 10.17182/hepdata.29782

The analyzing power A N of proton-proton, proton-hydrocarbon, and antiproton-hydrocarbon, scattering in the Coulomb-nuclear interference region has been measured using thhe 185 GeV/ c Fermilab polarized-proton and -antiproton beams. The results are found to be consistent with theoretical predictions within statistical uncertainties.

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Measurement of the Proton Elastic Form-factors for $Q^2=1$-{GeV}/$c^2$ - 3-{GeV}/$c^2$

Walker, R.C. ; Filippone, B.W. ; Jourdan, J. ; et al.
Phys.Lett.B 224 (1989) 353-353, 1989.
Inspire Record 284687 DOI 10.17182/hepdata.29803

We report measurements of the proton elastic form factors, G E p and G M p , extracted from electron scattering in the range 1⩽ Q 2 ⩽3(GeV/ c ) 2 . The uncertainties are <15% in G E p and <3% in G M p . The values of G E p are larger than indicated by most theoretical parameterizations, The ratio of Pauli and Dirac form factors, Q 2 F 2 p / F 1 p , is lower and demonstrates less Q 2 dependence than most of these parameterizations. Comparisons are made to theoretical models, including those based on perturbative QCD and vector-meson dominance.

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Asratian, A.E. ; Efremenko, V.I. ; Fedotov, A.V. ; et al.
Phys.Lett.B 137 (1984) 122-124, 1984.
Inspire Record 203433 DOI 10.17182/hepdata.30593

The total v μ N charged current cross section in the energy interval 10–50 GeV is unfolded from 15' bubble chamber antineutrino data. The method is to isolate the quasielastic events and determine their relative contribution to the overall charged current sample. The scale parameter is found to be (0.29 ± 0.03) × 10 −38 cm 2 GeV −1 . Relevance of the method for neutrino oscillation studies is discussed.

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The FERMILAB-MINNESOTA-ROCHESTER collaboration Cihangir, S. ; Berg, D. ; Biel, J. ; et al.
Phys.Lett.B 117 (1982) 119-122, 1982.
Inspire Record 182836 DOI 10.17182/hepdata.30869

Using the Primakoff formalism, we have extracted the radiative decay width of the A + 2 (1310) produced in coherent interactions of 200 GeV/ c π + mesons in nuclear targets. The width obtained is 295 ± 60 keV, a value consistent with quark-model predictions.

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The FERMILAB-MINNESOTA-ROCHESTER collaboration Cihangir, S. ; Berg, D. ; Biel, J. ; et al.
Phys.Lett.B 117 (1982) 123-125, 1982.
Inspire Record 184277 DOI 10.17182/hepdata.30878

Using the Primakoff formalism, we have extracted the radiative decay width of the K ∗+ (1430) produced in coherent interactions of 200 GeV/ c K + mesons in nuclear targets. The width obtained is 240 ± 45 keV, a value reasonably consistent with quark-model predictions.

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High x(t) single spin asymmetry in pi0 and eta production at x(F) = 0 by 200-GeV polarized anti-protons and protons

The E581 & E704 collaborations Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 276 (1992) 531-535, 1992.
Inspire Record 314231 DOI 10.17182/hepdata.29252

A measurement of the single-spin asymmetry A N in p↑ + p→ π 0 + X at 200 GeV with x F = 0 shows a transition in the production process from a “ low -x T ” regime with A N = 0, through an intermediate region of negative asymmetry, to a “ high -x T ” regime with A N > 0.3. This transition occurs at x T ≈ 0.4 and is consistent with x T -scaling of A N in pion production using polarized beams or targets from √− s =5.2 to 19.4 GeV. Results for A N in η production by polarized protons and in π 0 production by polarized antiprotons are also presented.

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Analyzing power in inclusive pi+ and pi- production at high x(F) with a 200-GeV polarized proton beam

The FNAL-E704 collaboration Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 264 (1991) 462-466, 1991.
Inspire Record 315569 DOI 10.17182/hepdata.29360

The analyzing power in inclusive charged pion production has been measured using the 200 GeV Fermilab polarized proton beam. A striking dependence in x F is observed in which A N increases from 0 to 0.42 with increasing x F for the π + data and decreases from 0 to −0.38 with increasing x F for π − data. The kinematic range covered is 0.2⩽ x F ⩽0.9 and 0.2⩽ p T ⩽2.0 GeV / c . In a simple model our data indicate that at large x F the transverse spin of the proton is correlated with that of its quark constituents.

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Measurement of the Inclusive Charged Current Cross-section for Neutrino and Anti-neutrino Scattering on Isoscalar Nucleons

Auchincloss, Priscilla S. ; Blair, R. ; Haber, C. ; et al.
Z.Phys.C 48 (1990) 411-432, 1990.
Inspire Record 27761 DOI 10.17182/hepdata.15124

This paper reports on measurements of the total cross section for the inclusive reaction vμ+N, as a function of incident energy. Neutrinos and antineutrinos with energy in the range 3

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Nucleon Structure Functions from High-Energy Neutrino Interactions with Iron and QCD Results

MacFarlane, D. ; Purohit, M.V. ; Messner, R.L. ; et al.
Z.Phys.C 26 (1984) 1-12, 1984.
Inspire Record 195928 DOI 10.17182/hepdata.16212

Nucleon structure functions obtained from neutrino and anti-neutrino scattering on iron nuclei at high energies (Ev=30 to 250 GeV) are presented. These results are compared with the results of other lepton-nucleon scattering experiments. The structure functions are used to test the validity of the Gross-Llewellyn-smith sum rule, which measures the number of valence quarks in the nucleons, and to obtain leading and second order QCD fits.

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Mass splitting and production of sigma(c)0 and sigma(c)++ measured in 500-GeV pi- n interactions

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 379 (1996) 292-298, 1996.
Inspire Record 417432 DOI 10.17182/hepdata.16213

>From a sample of $2722 \pm 78$ $\Lambda_c~+$ decaying to the $pK~-\pi~+$ final state, we have observed, in the hadroproduction experiment E791 at Fermilab, $143 \pm 20$ $\Sigma_c~0$ and $122 \pm 18$ $\Sigma_c~{++}$ through their decays to $\Lambda_c~+ \pi~{\pm}$. The mass difference $M(\Sigma_c~0) - M(\Lambda_c~+$) is measured to be $(167.38\pm 0.29\pm 0.15)\,\mbox{MeV}$; for $M(\Sigma_c~{++}) - M(\Lambda_c~+)$, we find $(167.76\pm 0.29\pm0.15)\,\mbox{MeV}$. The rate of $\Lambda_c~+$ production from decays of the $\Sigma_c$ triplet is $(22\pm 2\pm 3)\,\mbox{\%}$ of the total $\Lambda_c~+$ production assuming equal rate of production from all three, as measured for $\Sigma_c~0$ and $\Sigma_c~{++}$. We do not observe a statistically significant $\Sigma_c$ baryon-antibaryon production asymmetry. The $x_F$ and $p_t~2$ spectra of $\Lambda_c~+$ from $\Sigma_c$ decays are observed to be similar to those for all $\Lambda_c~+$'s produced.

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Negative Hyperon Production in High-Energy Proton Interactions

Hungerbuhler, V. ; Majka, R. ; Marx, J.N. ; et al.
Phys.Rev.D 12 (1975) 1203-1210, 1975.
Inspire Record 104138 DOI 10.17182/hepdata.4668

Momentum spectra for forward Σ− and Ξ− production by protons on beryllium are presented. Σ− production data for two primary proton momenta are compared to test scaling of the invariant cross section. In addition, the observed single-particle momentum distributions are compared with single-particle spectra from other inclusive reactions initiated by protons.

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