Polarization in proton-beryllium and proton-proton scattering at 1.7 GeV

Bareyre, P. ; Detoeuf, J.F. ; Van Rossum, L. ; et al.
Nuovo Cim. 20 (1961) 1049-1066, 1961.
Inspire Record 1185005 DOI 10.17182/hepdata.37750

The polarization in p-Be and p-p scattering has been measured by counter techniques at a proton kinetic energy of 1.74 GeV. The maximum polarization in p-Be scattering was found to beP max==0.19±0.04 and occurs at an angleθ max⩾3.5°. Inelastic scatters were rejected when the inelastic momentum loss was more than about 1% in the first scatter (magnetic analysis) or more than about 5% in the second scatter (Čerenkov threshold counter). The maximum polarization in p-p scattering isP max=0.30±0.09 and occurs at an angle 35°<θ max<<55° (c.m.). The angular dependence of the polarization is consistent with a distribution proportional to sin 2θ within large statistical errors. Optical model calculations applied to the data on p-Be scattering yield an almost all imaginary central potential of about 43 MeV and a spin-orbit potential of between 0.9 MeV and 2.0 MeV which is also almost all imaginary, in contrast with the predominantly real spin-orbit potential needed to explain the large polarization in the region of several hundred MeV.

2 data tables

'1'. '2'. '3'. '4'.

'1'. '2'. '3'. '5'.


Photon electroproduction from hydrogen at backward angles and momentum transfer squared of Q**2 = 1.0-GeV**2.

The JLab Hall A collaboration Laveissiere, G. ; Degrande, N. ; Jaminion, S. ; et al.
JLAB-PHY-04-34, 2004.
Inspire Record 652965 DOI 10.17182/hepdata.38623

We have made the first measurements of the virtual Compton scattering process via the e p -> e p gamma exclusive reaction at Q**2 = 1 GeV**2 in the nucleon resonance region. The cross section is obtained at center of mass (CM) backward angle, theta_gamma_gamma*, in a range of total (gamma* p) CM energy W from the proton mass up to W = 1.91 GeV. The data show resonant structures in the first and second resonance regions, and are well reproduced at higher W by the Bethe-Heitler+Born cross section, including t-channel pi0-exchange. At high W, our data, together with existing real photon data, show a striking Q**2 independence. Our measurement of the ratio of H(e,e'p)gamma to H(e,e'p)pi0 cross sections is presented and compared to model predictions.

18 data tables

Cross section for the reaction E P --> E P GAMMA at a polar angle given by COS(THETA) = -0.975 and azimuthal angle PHI = 15 degrees both in the centre-of-mass frame of the GAMMA* P --> GAMMA* P reaction.

Cross section for the reaction E P --> E P GAMMA at a polar angle given by COS(THETA) = -0.975 and azimuthal angle PHI = 45 degrees both in the centre-of-mass frame of the GAMMA* P --> GAMMA* P reaction.

Cross section for the reaction E P --> E P GAMMA at a polar angle given by COS(THETA) = -0.975 and azimuthal angle PHI = 75 degrees both in the centre-of-mass frame of the GAMMA* P --> GAMMA* P reaction.

More…

Measurements of electron proton elastic cross sections for 0.4-(GeV/c)**2 < Q**2 < 5.5-(GeV/c)**2.

The E94110 collaboration Christy, M.E. ; Ahmidouch, A. ; Armstrong, C.S. ; et al.
Phys.Rev.C 70 (2004) 015206, 2004.
Inspire Record 643262 DOI 10.17182/hepdata.31763

We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 unique kinematic settings covering a range in momentum transfer of 0.4 $<$ $Q^2$ $<$ 5.5 $(\rm GeV/c)^2$. These measurements represent a significant contribution to the world's cross section data set in the $Q^2$ range where a large discrepancy currently exists between the ratio of electric to magnetic proton form factors extracted from previous cross section measurements and that recently measured via polarization transfer in Hall A at Jefferson Lab.

7 data tables

Measured values of the electron-proton elastic cross section for beam energy 1.148 GeV.

Measured values of the electron-proton elastic cross section for beam energy 1.882 GeV.

Measured values of the electron-proton elastic cross section for beam energy 2.235 GeV.

More…

Measurement of the cross-section for the process gamma gamma --> p anti-p at s(ee)**(1/2) = 183-GeV - 189-GeV at LEP.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 28 (2003) 45-54, 2003.
Inspire Record 595836 DOI 10.17182/hepdata.48881

The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons had been studied using data taken at sqrt(s)_ee=183 GeV and 189 GeV with the OPAL detector at LEP. Results are presented for Ppbar invariant masses, W, in the range 2.15 W< <3.95 GeV. The cross-section measurements are compared with previous data and with recent analytic calculations based on the quark-diquark model.

3 data tables

Cross section as a function of the invariant mass of the pbar-p pair.

Cross section for two photon production of the pbar-p pair.

Angular distributions in 3 W ranges.


Search for new heavy particles in the W Z0 final state in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 88 (2002) 071806, 2002.
Inspire Record 560924 DOI 10.17182/hepdata.42895

We present a search for new heavy particles, $X$, which decay via $X \to WZ \to e\nu +jj$ in $p{\bar p}$ collisions at $\sqrt{s}$ = 1.8 TeV. No evidence is found for production of $X$ in 110 pb$^{-1}$ of data collected by the Collider Detector at Fermilab. Limits are set at the 95% C.L. on the mass and the production of new heavy charged vector bosons which decay via $W'\to WZ$ in extended gauge models as a function of the width, $\Gamma (W')$, and mixing factor between the $W'$ and the Standard Model $W$ bosons.

1 data table

CONST(NAME=XI) is the mixing factor between WPRIME and W-boson.


Search for narrow diphoton resonances and for gamma gamma + w /z signatures in p anti p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.D 64 (2001) 092002, 2001.
Inspire Record 557012 DOI 10.17182/hepdata.42918

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 $pb^{-1}$ of $p\bar{p}$ collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both $p\bar{p} \to \gamma \gamma + X$ and $p \bar{p} \to \gamma \gamma + W/Z$. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale $\sqrt{F}$ in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for $H \to \gamma \gamma$. Finally, we set a lower limit on the mass of a 'bosophilic' Higgs boson (e.g. one which couples only to $\gamma, W,$ and $Z$ bosons with standard model couplings) of 82 GeV/$c^2$ at 95% confidence level.

2 data tables

No description provided.

No description provided.


Search for first-generation scalar and vector leptoquarks

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abdesselam, A. ; et al.
Phys.Rev.D 64 (2001) 092004, 2001.
Inspire Record 557085 DOI 10.17182/hepdata.42922

We describe a search for the pair production of first-generation scalar and vector leptoquarks in the eejj and enujj channels by the D0 Collaboration. The data are from the 1992--1996 ppbar run at sqrt{s} = 1.8 TeV at the Fermilab Tevatron collider. We find no evidence for leptoquark production; in addition, no kinematically interesting events are observed using relaxed selection criteria. The results from the eejj and enujj channels are combined with those from a previous D0 analysis of the nunujj channel to obtain 95% confidence level (C.L.) upper limits on the leptoquark pair-production cross section as a function of mass and of beta, the branching fraction to a charged lepton. These limits are compared to next-to-leading-order theory to set 95% C.L. lower limits on the mass of a first-generation scalar leptoquark of 225, 204, and 79 GeV/c^2 for beta=1, 1/2, and 0, respectively. For vector leptoquarks with gauge (Yang-Mills) couplings, 95% C.L. lower limits of 345, 337, and 206 GeV/c^2 are set on the mass for beta=1, 1/2, and 0, respectively. Mass limits for vector leptoquarks are also set for anomalous vector couplings.

3 data tables

No description provided.

No description provided.

No description provided.


Double spin asymmetry in the cross section for exclusive rho0 production in lepton proton scattering.

The HERMES collaboration Airapetian, A. ; Akopov, N. ; Akopov, Z. ; et al.
Phys.Lett.B 513 (2001) 301-310, 2001.
Inspire Record 553236 DOI 10.17182/hepdata.46781

None

7 data tables

The photoabsorption asymmetry A1 for exclusive RHO0 production.

The photoabsorption asymmetry A1 for exclusive RHO0 production as a function of Q**2.

The photoabsorption asymmetry A1 for exclusive RHO0 production as a function of W.

More…

Search for neutral supersymmetric Higgs bosons in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 86 (2001) 4472-4478, 2001.
Inspire Record 535426 DOI 10.17182/hepdata.42952

We present the results of a search for neutral Higgs bosons produced in association with $b$ quarks in $p\bar{p}\to b\bar{b} \phi\to b\bar{b}b\bar{b}$ final states with $91 \pm 7$ pb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt{s}=1.8$ TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data is interpreted in the context of the neutral Higgs sector of the Minimal Supersymmetric extension of the Standard Model. With basic parameter choices for the supersymmetric scale and the stop quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for $\tb$ values in excess of 35.

1 data table

Here HIGGS stands for H(1)0 or H(2)0 or A0 supersymmetric Higgs boson.


Cross-section for b jet production in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 85 (2000) 5068-5073, 2000.
Inspire Record 531669 DOI 10.17182/hepdata.42975

Bottom quark production in pbar-p collisions at sqrt(s)=1.8 TeV is studied with 5 inverse picobarns of data collected in 1995 by the DO detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region (|y(b)| < 1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, DO results are found to be higher than, but compatible with, next-to-leading-order QCD predictions.

1 data table

No description provided.