Date

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Exclusive rho0 production in deep inelastic scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
PMC Phys. A1 (2007) 6, 2007.
Inspire Record 757991 DOI 10.17182/hepdata.54963

Exclusive rho^0 electroproduction at HERA has been studied with the ZEUS detector using 120 pb^{-1} of integrated luminosity collected during 1996-2000. The analysis was carried out in the kinematic range of photon virtuality 2 < Q^2 < 160 GeV$^2, and gamma^* p centre-of-mass energy 32 < W < 180 GeV. The results include the Q^2 and W dependence of the gamma^* p --> rho^0 p cross section and the distribution of the squared-four-momentum transfer to the proton. The helicity analysis of the decay-matrix elements of the rho^0 was used to study the ratio of the gamma^* p cross section for longitudinal and transverse photon as a function of Q^2 and W. Finally, an effective Pomeron trajectory was extracted. The results are compared to various theoretical predictions.

30 data tables

Measurement of the spin density matrix element r_04_00 as a function of Q**2.

Measurement of the spin density matrix element RE(r_04_10) as a function of Q**2.

Measurement of the spin density matrix element r_04_1-1 as a function of Q**2.

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Measurement of exclusive omega electroproduction at HERA

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Phys.Lett. B487 (2000) 273-288, 2000.
Inspire Record 528588 DOI 10.17182/hepdata.46936

The exclusive electroproduction of omega mesons, ep -> e omega p, has been studied in the kinematic range 3<Q^2<20 GeV^2, 40<W<120 GeV and |t|<0.6 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb^{-1}. The omega mesons were identified via the decay omega -> pi^+pi^-pi^0. The exclusive (ep -> e omega p) cross section in the above kinematic region is 0.108 +- 0.014(stat.) +- 0.026(syst.) nb. The reaction ep -> e phi p, phi -> pi^+pi^-pi^0, has also been measured. The cross sections, as well as the cross-section ratios omega/rho and omega/phi, are presented as a function of W and Q^2. Thus, for the first time, the properties of omega electroproduction can be compared to those of rho^0, phi and J/psi electroproduction at high W.

6 data tables

The cross sections for OMEGA and PHI electroproduction.

The corresponding photoproduction cross sections of OMEGA and PHI mesons. The RHO0 data is taken from a previous ZEUS publication (EPJ C6,603).

Ratio of the photoproduction cross sections.

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Elastic electroproduction of rho mesons at HERA

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J. C13 (2000) 371-396, 2000.
Inspire Record 495311 DOI 10.17182/hepdata.44043

The elastic electroproduction of rho mesons is studied at HERA with the H1 detector for a photon virtuality in the range 1 < Q^2 < 60 GeV^2 and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the pipi mass distribution in the rho resonance region is measured as a function of Q^2. The full set of rho spin density matrix elements is determined, and evidence is found for a helicity flip amplitude at the level of 8 +- 3 % of the non-flip amplitudes. Measurements are presented of the dependence of the cross section on Q^2, W and t (the four-momentum transfer squared to the proton). They suggest that, especially at large Q^2, the gamma^*p cross section develops a stronger W dependence than that expected from the behaviour of elastic and total hadron-hadron cross sections.

15 data tables

Average values of the spin density matrix elements measured for the 1996 data sample.

Spin density matrix elements measured for 3 Q**2 values for the 1996 data sample.

Spin density matrix elements measured for 3 W values for the 1996 data sample.

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Exclusive electroproduction of $\rho^0$ and $J/\psi$ mesons at HERA

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J. C6 (1999) 603-627, 1999.
Inspire Record 475083 DOI 10.17182/hepdata.44217

Exclusive production of $\rho^0$ and $J/\psi$ mesons in e^+ p collisions has been studied with the ZEUS detector in the kinematic range $0.25 < Q^2 < 50 GeV^2, 20 < W < 167 GeV$ for the $\rho^0$ data and $2 < Q^2 < 40 GeV^2, 50 < W < 150 GeV$ for the $J/\psi$ data. Cross sections for exclusive $\rho^0$ and $J/\psi$ production have been measured as a function of $Q^2, W$ and $t$. The spin-density matrix elements $r^{04}_{00}, r^1_{1-1}$ and $Re r^{5}_{10}$ have been determined for exclusive $\rho^0$ production as well as $r^{04}_{00}$ and $r^{04}_{1-1}$ for exclusive $J/\psi$ production. The results are discussed in the context of theoretical models invoking soft and hard phenomena.

32 data tables

Exclusive RHO0 electro- and photo- production and cross sections as a function of Q**2 from the BPC data set.

Exclusive RHO0 electro- and photo- production cross section as a function of W from the BPC data set.

Exclusive RHO0 electro- and photo- production cross sections as a function of W from the DIS data set.

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Proton dissociative $\rho$ and elastic $\phi$ electroproduction at HERA

The H1 collaboration Adloff, C. ; Aid, S. ; Anderson, M. ; et al.
Z.Phys. C75 (1997) 607-618, 1997.
Inspire Record 443293 DOI 10.17182/hepdata.44590

The electroproduction of rho mesons with proton diffractive dissociation for Q^2 > 7 GeV^2 and the elastic electroproduction of Phi mesons for Q^2 > 6 Gev^2 are studied in e^+ p collisions at HERA with the H1 detector, for an integrated luminosity of 2.8 pb-1. The dependence of the cross sections on P_t^2 and Q^2 is measured, and the vector meson polarisation obtained. The cross section ratio between proton dissociative and elastic production of rho mesons is measured and discussed in the framework of the factorisation hypothesis of diffractive vertices. The ratio of the elastic cross section for Phi and rho meson production is investigated as a function of Q^2.

11 data tables

Corrected PT**2 distribution for RHO production from the proton dissociative sample. Statistical errors only.

Cross sections and ratio of proton dissociative to elastic cross sections.

Cross sections and ratio of proton dissociative to elastic cross sections.

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Diffractive production of $\rho^0(770)$ mesons in muon proton interactions at 470-GeV

The E665 collaboration Adams, M.R. ; Aderholz, M. ; Aid, S. ; et al.
Z.Phys. C74 (1997) 237-261, 1997.
Inspire Record 441201 DOI 10.17182/hepdata.14214
14 data tables

Statistical errors only.

Statistical errors only.

Cross section extrapolated to Q**2 = 0.

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Elastic electroproduction of $\rho^0$ and $J/\psi$ mesons at large Q$^2$ at HERA

The H1 collaboration Aid, S. ; Andreev, V. ; Andrieu, B. ; et al.
Nucl.Phys. B468 (1996) 3-36, 1996.
Inspire Record 416228 DOI 10.17182/hepdata.51967

The total cross sections for the elastic electroproduction of $\rh0$ and $J/\Psi$ mesons for $Q~2$ $>$ 8 GeV$~2$ and $\langle W \rangle \simeq 90$ GeV/c$~2$ are measured at HERA with the H1 detector. The measurements are for an integrated electron$-$proton luminosity of $\simeq$3pb$~{-1}$. The dependences of the total virtual photon$-$proton ($\gamma~* p$) cross sections on $Q~2$, $W$ and the momentum transfer squared to the proton ($t$), and, for the $\rho$, the dependence on the polar decay angle ($\cos \theta~*$), are presented. The $J/\Psi$ : $\rh0$ cross section ratio is determined. The results are discussed in the light of theoretical models and of the interplay of hard and soft physics processes.

20 data tables

Overall EP cross section for M(PI+PI-) < 1.5 GEV.

Overall EP cross section, taking into account the J/PSI --> LEPTON+ LEPTON - branching fraction 0.12.

Integrated EP cross section.

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Exclusive $\rho^0$ and $\phi$ Production in Deep Inelastic Muon Scattering

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, Guenter ; et al.
Z.Phys. C39 (1988) 169, 1988.
Inspire Record 252743 DOI 10.17182/hepdata.15619
6 data tables

No description provided.

No description provided.

No description provided.

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Exclusive $\rho^0$ production in deep inelastic muon proton scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett. B161 (1985) 203, 1985.
Inspire Record 214930 DOI 10.17182/hepdata.30353
8 data tables

No description provided.

No description provided.

SYSTEMATIC ERROR ON SLOPE IN 0.8.

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EXCLUSIVE RHO PRODUCTION BY VIRTUAL PHOTONS

Ahrens, L.A. ; Berkelman, Karl ; Cassel, D.G. ; et al.
Phys.Rev.Lett. 42 (1979) 208, 1979.
Inspire Record 129526 DOI 10.17182/hepdata.20809
1 data table

No description provided.


Exclusive $\rho^0$, $\omega$ and $\phi$ Electroproduction

Cassel, D.G. ; Ahrens, L.A. ; Berkelman, Karl ; et al.
Phys.Rev. D24 (1981) 2787, 1981.
Inspire Record 166020 DOI 10.17182/hepdata.24050
8 data tables

FOUR CHANNEL FIT TO TWO PION PRODUCTION ASSUMING NO INTERFERENCE.

DEPENDENCE OF TOTAL, LONGITUDINAL (L) AND TRANSVERSE (U) DIFFERENTIAL CROSS SECTIONS ON C*DELTA(TAU), THE FORMATION TIME FOR VIRTUAL INTERMEDIATE HADRON STATES. DELTA(TAU) IS 1/DELTA(E) WHERE DELTA(E) IS E(RF=LAB,P=3) - NU = SQRT(NU**2 + Q2 + M(RHO)**2) - NU.

No description provided.

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Electroproduction of $\rho^0$ Mesons

Cohen, I. ; Erickson, R. ; Messing, F. ; et al.
Phys.Rev. D25 (1982) 634, 1982.
Inspire Record 152921 DOI 10.17182/hepdata.47139
8 data tables

No description provided.

No description provided.

No description provided.

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Exclusive Vector Meson Production in Muon - Proton Scattering

del Papa, C. ; Dorfan, David E. ; Flatte, Stanley M. ; et al.
Phys.Rev. D19 (1979) 1303, 1979.
Inspire Record 130570 DOI 10.17182/hepdata.24312
4 data tables

THE ABSOLUTE TOTAL CROSS SECTION IS FROM A FIT TO THE MIT-SLAC ELECTRON SCATTERING DATA BY W. ATWOOD AND S. STEIN.

No description provided.

FOR 0.6 < M(PI+ PI-) < 0.9 GEV, USING THE METHOD OF MOMENTS.

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Rho Production by Virtual Photons

Joos, P. ; Ladage, A. ; Meyer, H. ; et al.
Nucl.Phys. B113 (1976) 53-92, 1976.
Inspire Record 108749 DOI 10.17182/hepdata.35708
10 data tables

DIPION CHANNEL CROSS SECTION.

THE TOTAL CROSS SECTION WAS OBTAINED BY THE AUTHORS FROM A FIT TO THE SINGLE ARM DATA OF S. STEIN ET AL., PR D12, 1884 (1975).

No description provided.

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