Date

Deep inelastic scattering with leading protons or large rapidity gaps at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 816 (2009) 1-61, 2009.
Inspire Record 804915 DOI 10.17182/hepdata.52860

The dissociation of virtual photons, $\gamma^{\star} p \to X p$, in events with a large rapidity gap between $X$ and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities $Q^2>2$ GeV$^2$ and $\gamma^{\star} p$ centre-of-mass energies $40<W<240$ GeV, with $M_X>2$ GeV, where $M_X$ is the mass of the hadronic final state, $X$. Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of $t$, the squared four-momentum transfer at the proton vertex and $\Phi$, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of $Q^2$ and $\xpom$, the fraction of the proton's momentum carried by the diffractive exchange, as well as $\beta$, the Bjorken variable defined with respect to the diffractive exchange.

48 data tables

The differential cross section DSIG/DT for the LRG and the LPS data samples.

The fitted exponential slope of the T distribution as a function of X(NAME=POMERON).

The fitted exponential slope of the T distribution as a function of X(NAME=POMERON).

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Measurement of the Nucleon Strange-Antistrange Asymmetry at Next-to-Leading Order in QCD from NuTeV Dimuon Data

The NuTeV collaboration Mason, D. ; Brau, J. ; Drucker, R.B. ; et al.
Phys.Rev.Lett. 99 (2007) 192001, 2007.
Inspire Record 774494 DOI 10.17182/hepdata.42701

We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the first to use a complete next to leading order QCD d escription of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma . We also report a new measurement of the charm mass.

6 data tables

Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 88.

Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 174.

Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 247.

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A Precise Measurement of the Muon Neutrino-NucleonInclusive Charged Current Cross-Section off an IsoscalarTarget in the Energy Range\boldmath{$2.5 < E_\nu < 40$}~GeV by NOMAD

The NOMAD collaboration Wu, Q. ; Mishra, Sanjib Ratan ; Godley, A. ; et al.
Phys.Lett.B 660 (2008) 19-25, 2008.
Inspire Record 767013 DOI 10.17182/hepdata.50629

We present a measurement of the muon neutrino-nucleon inclusive charged current cross-section, off an isoscalar target, in the neutrino energy range $2.5 \leq E_\nu \leq 40$ GeV. The significance of this measurement is its precision, $\pm 4$% in $2.5 \leq E_\nu \leq 10$ GeV, and $\pm 2.6$% in $10 \leq E_\nu \leq 40$ GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.

1 data table

Inclusive muon-neutrino charged current cross section.


Leading neutron energy and p(T) distributions in deep inelastic scattering and photoproduction at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 776 (2007) 1-37, 2007.
Inspire Record 744787 DOI 10.17182/hepdata.45630

The production of energetic neutrons in $ep$ collisions has been studied with the ZEUS detector at HERA. The neutron energy and $p_T^2$ distributions were measured with a forward neutron calorimeter and tracker in a $40 \pb^{-1}$ sample of inclusive deep inelastic scattering (DIS) data and a $6 \pb^{-1}$ sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper $p_T^2$ distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data.

35 data tables

Ratio of leading neutron to inclusive cross sections integrated to the full PT range.

Normalized double differential cross sections for leading neutron production for the full DIS sample. Statistical errors only are given.

Normalized double differential cross sections for leading neutron production for the full DIS sample. Statistical errors only are given.

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Measurement of K0(S), Lambda, anti-Lambda production at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 51 (2007) 1-23, 2007.
Inspire Record 734144 DOI 10.17182/hepdata.45796

The production of the neutral strange hadrons $K^{0}_{S}$, $\Lambda$ and $\bar{\Lambda}$ has been measured in $ep$ collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, $\Lambda$ ($\bar{\Lambda}$) asymmetry and polarization have been measured in three kinematic regions: $Q^2 > 25 \gev^2$: $5 < Q^2 < 25 \gev^2$: and in photoproduction ($Q^2 \simeq 0$). In photoproduction the presence of two hadronic jets, each with at least $5 \gev$ transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at $e^+ e^-$ colliders, except for an enhancement of baryon relative to meson production in photoproduction.

59 data tables

Differential K0S cross section in DIS events as a function of transverse momentum (lab). for Q**2 from 5 to 25 GeV**2.

Differential K0S cross section in DIS events as a function of transverse momentum (lab). for Q**2 > 25 GeV**2.

Differential K0S cross section in DIS events as a function of pseudorapidity (lab). for Q**2 from 5 to 25 GeV**2.

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Measurement of nucleon structure functions in neutrino scattering.

The CHORUS collaboration Onengut, G. ; van Dantzig, R. ; de Jong, M. ; et al.
Phys.Lett.B 632 (2006) 65-75, 2006.
Inspire Record 699123 DOI 10.17182/hepdata.6187

After completion of the data taking for the νμ→ντ oscillation search, the CHORUS lead–scintillator calorimeter was used in the 1998 run as an active target. High-statistics samples of charged-current interactions were collected in the CERN SPS west area neutrino beam. This beam contained predominantly muon (anti-)neutrinos from sign-selected pions and kaons. We measure the flux and energy spectrum of the incident neutrinos and compare them with beam simulations. The neutrino–nucleon and anti-neutrino–nucleon differential cross-sections are measured in the range 0.01<x<0.7 , 0.05<y<0.95 , 10<Eν<200 GeV . We extract the neutrino–nucleon structure functions F2(x,Q2) , xF3(x,Q2) , and R(x,Q2) and compare these with results from other experiments.

121 data tables

The measured F2 and xF3 at X = 0.020.

The measured F2 and xF3 at X = 0.045.

The measured F2 and xF3 at X = 0.080.

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Multijet production in neutral current deep inelastic scattering at HERA and determination of alpha(s).

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 44 (2005) 183-193, 2005.
Inspire Record 676091 DOI 10.17182/hepdata.46201

Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 < Q2 < 5000 GeV2. The data were taken at the ep collider HERA with centre-of-mass energy sqrt(s) = 318 GeV using the ZEUS detector and correspond to an integrated luminosity of 82.2 pb-1. Jets were identified in the Breit frame using the k_T cluster algorithm in the longitudinally invariant inclusive mode. Measurements of differential dijet and trijet cross sections are presented as functions of jet transverse energy E_{T,B}{jet}, pseudorapidity eta_{LAB}{jet} and Q2 with E_{T,B}{jet} > 5 GeV and -1 < eta_{LAB}{jet} < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant alpha_s(M_Z), determined from the ratio of the trijet to dijet cross sections, is alpha_s(M_Z) = 0.1179 pm 0.0013(stat.) {+0.0028}_{-0.0046}(exp.) {+0.0064}_{-0.0046}(th.)

10 data tables

Inclusive trijet cross section as a function of the jet transverse energy in the Breit frame for the jet with the highest transverse energy.

Inclusive trijet cross section as a function of the jet transverse energy in the Breit frame for the jet with the second highest transverse energy.

Inclusive trijet cross section as a function of the jet transverse energy in the Breit frame for the jet with the third highest transverse energy.

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Study of deep inelastic inclusive and diffractive scattering with the ZEUS forward plug calorimeter.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 713 (2005) 3-80, 2005.
Inspire Record 675372 DOI 10.17182/hepdata.11816

Deep inelastic scattering and its diffractive component, ep -> e'gamma*p ->e'XN, have been studied at HERA with the ZEUS detector using an integrated luminosity of 4.2 pb-1. The measurement covers a wide range in the gamma*p c.m. energy W (37 - 245 GeV), photon virtuality Q2 (2.2 - 80 GeV2) and mass Mx. The diffractive cross section for Mx > 2 GeV rises strongly with W: the rise is steeper with increasing Q2. The latter observation excludes the description of diffractive deep inelastic scattering in terms of the exchange of a single Pomeron. The ratio of diffractive to total cross section is constant as a function of W, in contradiction to the expectation of Regge phenomenology combined with a naive extension of the optical theorem to gamma*p scattering. Above Mx of 8 GeV, the ratio is flat with Q2, indicating a leading-twist behaviour of the diffractive cross section. The data are also presented in terms of the diffractive structure function, F2D(3)(beta,xpom,Q2), of the proton. For fixed beta, the Q2 dependence of xpom F2D(3) changes with xpom in violation of Regge factorisation. For fixed xpom, xpom F2D(3) rises as beta -> 0, the rise accelerating with increasing Q2. These positive scaling violations suggest substantial contributions of perturbative effects in the diffractive DIS cross section.

135 data tables

Measurement of the proton structure function F2 at Q**2 = 2.7 GeV**2.

Measurement of the proton structure function F2 at Q**2 = 4.0 GeV**2.

Measurement of the proton structure function F2 at Q**2 = 6.0 GeV**2.

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Jet production in charged current deep inelastic e+ p scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Eur.Phys.J.C 31 (2003) 149-164, 2003.
Inspire Record 620434 DOI 10.17182/hepdata.46434

The production rates and substructure of jets have been studied in charged current deep inelastic e+p scattering for Q**2>200 GeV**2 with the ZEUS detector at HERA using an integrated luminosity of 110.5 pb**-1. Inclusive jet cross sections are presented for jets with transverse energies E_T(jet) > 14 GeV and pseudorapidities in the range -1 < eta(jet) < 2. Dijet cross sections are presented for events with a jet having E_T(jet) > 14 GeV and a second jet having E_T(jet) > 5 GeV. Measurements of the mean subjet multiplicity, <n_sbj>, of the inclusive jet sample are presented. Predictions based on parton-shower Monte Carlo models and next-to-leading-order QCD calculations a re compared to the measurements. The value of alphas(M_Z), determined from <n_sbj> at y_cut=0.01 for jets with 25<E_T(jet)<119 GeV, is alphas(M_Z) = 0.1202 +-0.0052 (stat.) +0.0060-0.0019 (syst.) +0.0065-0.0053 (th.). The mean subjet multiplicity as a function of Q**2 is found to be consistent with that measured in NC DIS.

20 data tables

Inclusive jet cross section DSIG/DQ**2 for jets in the lab. frame. Data from the 1995-1997 sample.

Inclusive jet cross section DSIG/DQ**2 for jets in the lab. frame. Data from the 1999-2000 sample.

Inclusive jet cross section DSIG/DQ**2 for jets in the lab. frame. Data from the combined sample.

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Measurement of inclusive jet cross-sections in photoproduction at HERA

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J.C 29 (2003) 497-513, 2003.
Inspire Record 613857 DOI 10.17182/hepdata.46480

Inclusive jet cross sections are measured in photoproduction at HERA using the H1 detector. The data sample of e+ p -> e+ + jet + X events in the kinematic range of photon virtualities Q^2 &lt; 1 GeV^2 and photon-proton centre-of-mass energies 95 &lt; W_gammap &lt; 285 GeV represents an integrated luminosity of 24.1 pb^-1. Jets are defined using the inclusive k_T algorithm. Single- and multi-differential cross sections are measured as functions of jet transverse energy E_T^jet and pseudorapidity \eta^jet in the domain 5 &lt; E_T^jet &lt; 75 GeV and -1 &lt; \eta^jet &lt; 2.5. The cross sections are found to be in good agreement with next-to-leading order perturbative QCD calculations corrected for fragmentation and underlying event effects. The cross section differential in E_T^jet, which varies by six orders of magnitude over the measured range, is compared with similar distributions from p pbar colliders at equal and higher energies.

15 data tables

Measured differential E+ P cross section DSIG/DET for inclusive jet photoproduction (Q**2 < 1 GeV**2) integrated over the jet pseudorapidity range -1 to 2.5 in the W(C=GAMMA P) range 95 to 285 GeV.

Measured differential E+ P cross section DSIG/DET for inclusive jet photoproduction (Q**2 < 1 GeV**2) integrated over the jet pseudorapidity range -1 to 2.5 in the W(C=GAMMA P) ranges 95 to 212, and 212 to 285 GeV.

Measured differential E+ P cross section DSIG/DET for inclusive jet photoproduction for the two Q**2 ranges integrated over the jet pseudorapidity range -1to 2.5 in the W(C=GAMMA P) range 164 to 242 GeV.

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