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Multiplicities of charged hadrons in 280 GeV/c muon-proton scattering

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.

Nucl.Phys.B 258 (1985) 90611 249-266, 1985.

Inspire Record 213391 DOI 10.17182/hepdata.33787

Properties of the hadron multiplicity distributions in 280 GeV/c μ⁺p interactions have been investigated. The c.m. energy dependence in the range from 4 to 20 GeV of the total charged multiplicities are presented. No variation faster than logarithmic is seen in the energy range of this experiment. Comparison with νp and $ν p$ data at lower energy has been made and shows good agreement between μ⁺p and $ν p$ total charged multiplicities. It has been found that the average forward multiplicity (charged hadrons with xF > 0) exceeds the average backward multiplicity (charged hadrons with xF < 0) in the whole energy range and presents a different energy variation. The average forward multiplicity has been compared to e⁺e⁻ data and shows a similar dependence on energy. Little correlation was observed between the forward and backward multiplicities indicating that the current and target regions fragment almost independently.

8 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurement of $e^+ e^- \to \mu^+ \mu^-$: A Test of Electroweak Theories

The Mark-J collaboration Adeva, B. ; Becker, U. ; Becker-Szendy, R. ; et al.

Phys.Rev.Lett. 55 (1985) 665, 1985.

Inspire Record 214607 DOI 10.17182/hepdata.3237

We use the reaction e+e−→μ+μ−, in the Mark J detector at the DESY high-energy e+e− collider PETRA, to test the standard electroweak theory and find good agreement. We also set limits on the parameters of several extended gauge theories.

6 data tables

Table 1

CROSS SECTION MEASUREMENT RELATIVE TO PREDICTED QED CROSS SECTION.

Table 2

FORWARD-BACKWARD ASYMMETRY. THE SYSTEMATIC ERROR IN THE ASYMMETRY IS <0.5 PCT.

Table 3

ANGULAR DISTRIBUTIONS NOT GIVEN IN PAPER. SUPPLIED BY E.DEFFUR.

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A detailed study of the proton structure functions in deep inelastic muon - proton scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Nucl.Phys.B 259 (1985) 189, 1985.

Inspire Record 213461 DOI 10.17182/hepdata.13244

The x and Q 2 dependence of the single photon exchange cross section d 2 σ /d Q 2 d x and the proton structure functions F 2 ( x , Q 2 ) and R ( x , Q 2 ) have been measured in deep inelastic muon proton scattering in the region 0.02 < x < 0.8 and 3 < Q 2 < 190 GeV 2 . By comparing data at different incident muon energies R was found to have little kinematic dependence and an average value of −0.010 ± 0.037 (stat.) ± 0.102 (stat.). The observed deviations from scaling gave the value of Λ MS , the QCD mass scale parameter, to be 105 −45 +55 (stat.) −45 +85 (syst.) MeV. The fraction of the momentum of the nucleon carried by gluons was found to be ∼56% at Q 2 ∼22.5 GeV 2 . It is shown that to obtain a description of the data for F 2 ( x , Q 2 ) together with that measured in deep inelastic electron-proton scattering at lower Q 2 it is necessary to include additional higher twist contributions. The value of Λ MS remains unchanged with the inclusion of these contributions which were found to have an x -dependence of the form x 3 /(1 − x ).

285 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

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Q**2 Dependence of the Proton and Neutron Structure Functions from Neutrino and anti-neutrinos Scattering in Deuterium

Allasia, D. ; Angelini, C. ; Baldini, A. ; et al.

Z.Phys.C 28 (1985) 321, 1985.

Inspire Record 213484 DOI 10.17182/hepdata.16015

12,100 νD and 10,500$\bar vD$ charged current interactions in deuterium measured in the BEBC bubble chamber were used to obtain the complete set of structure functions of proton and neutron. Thex andQ2 dependence of the structure functions of up and down valence quarks and antiquarks are presented and discussed. The Adler and Gross-Llewellyn Smith sum rules have been tested at differentQ2 values. A QCD analysis of the four non singlet structure functionsxF3νN,xuv,xdv andF2νn−F2νp has been performed yielding values ofΛLO between 100 and 300 MeV.

18 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

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Continuum Dimuon Production in anti-p W Collisions at 125-GeV/c

Anassontzis, E. ; Katsanevas, S. ; Kostarakis, P. ; et al.

Phys.Rev.Lett. 54 (1985) 2572, 1985.

Inspire Record 213694 DOI 10.17182/hepdata.20379

The cross section for the reaction p¯N→μ+μ−X with muon pairs in the mass range 40 was measured to be σ=0.104±0.005±0.008 nb/nucleon. The distributions dσdxF and M3dσdM were compared to the QCD-improved Drell-Yan model and to calculations including first-order QCD corrections, with use of deep-inelastic structure functions. Excellent agreement with the data was obtained if the calculations were multiplied by factors of 2.45 and 1.41, respectively.

1 data table

Table 1

No description provided.

Intermediate Mass Dimuon Events at the {CERN} $p \bar{p}$ Collider at $\sqrt{s}=540$-{GeV}

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.

Phys.Lett.B 155 (1985) 442-456, 1985.

Inspire Record 213203 DOI 10.17182/hepdata.49630

We report the observation of 21 dimuon events at the CERN p p Collider with the UA1 detector. The events range in invariant dimuon mass from 2 to 22 GeV / c 2 . The properties of these events are given. The bulk of the events are consistent with heavy-flavour production (mainly b b ) with a few candidates for Drell-Yan production. There remain a few events which are difficult to interpret in terms of these processes, in particular two events with isolated, like-sign muons.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

New Results on the Reaction $e^+ e^- \to \mu^+ \mu^-$ at $\sqrt{s}=29$-{GeV}

Derrick, M. ; Fernandez, E. ; Fries, R. ; et al.

Phys.Rev.D 31 (1985) 2352, 1985.

Inspire Record 212767 DOI 10.17182/hepdata.3935

We have measured the process e+e−→μ+μ− at √s =29 GeV using the High Resolution Spectrometer at SLAC PEP. The forward-backward charge asymmetry is Aμμ=-(4.9±1.5±0.5)% based on 5057 events. A subsample of 3488 μ+μ− events in the angular range ‖cosθ‖<0.55 gives a cross-section ratio of Rμμ=0.990±0.017±0.030. The resulting couplings of the weak neutral current are gaegaμ=0.208±0.064± 0.021 and gvegvμ=0.027 ±0.051±0.089. The QED cutoff parameters are Λ+>170 GeV and Λ−>146 GeV at 95% C.L.

4 data tables

Table 1

Corrected for acceptance and O(alpha**3) QED radiation. Numerical values taken from SUGANO-ANL-HEP-CP-84-90.

Table 2

Forward-backward asymmetry based on fit to angular distribution. Result is given combined with earlier data from BENDER et al.

Table 3

No description provided.

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PROMPT MUON PRODUCTION IN e+ e- ANNIHILATIONS AT 29-GeV

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Badtke, D.H. ; et al.

Phys.Rev.D 31 (1985) 2719, 1985.

Inspire Record 213118 DOI 10.17182/hepdata.3937

We have studied the production of prompt muons in hadronic events from e+e− annihilation at a center-of-mass energy of 29 GeV with the PEP4-TPC (Time Projection Chamber) detector. The muon p and pt distributions are well described by a combination of bottom- and charm-quark decays, with fitted semimuonic branching fractions of (15.2±1.9±1.2)% and (6.9±1.1±1.1)%, respectively. The muon spectra imply hard fragmentation functions for both b and c quarks, with 〈z(b quark)〉=0.80±0.05±0.05 and 〈z(c quark)〉=0.60±0.06±0.04. We derive neutral-current axial-vector couplings of a(b quark)=-0.9±1.1±0.3 and a(c quark)=1.5±1.5±0.5 from the forward-backward asymmetries.

5 data tables

Table 1

PT is the transverse momentum of the muon relative to the event thrust axis.

Table 2

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT < 1 GeV/c.

Table 3

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT > 1 GeV/c.

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FRAGMENTATION INTO STRANGE PARTICLES IN HIGH-ENERGY NEUTRINO P, neutrino N, ANTI-NEUTRINO P AND ANTI-NEUTRINO N INTERACTIONS

The AMSTERDAM-BERGEN-BOLOGNA-PADUA-PISA-SACLAY-TURIN collaboration Allasia, D. ; Angelini, C. ; Baldini, A. ; et al.

Phys.Lett.B 154 (1985) 231-235, 1985.

Inspire Record 218756 DOI 10.17182/hepdata.30415

The fragmentation of the hadronic system into Λ, Σ(1385), K ) and K ∗ (892) in deep-inelastic charged-current interactions of high energy neutrinos and antineutrinos with proton and neutron is analyzed. The results obtained for the production of these particles from the various initial states are compared with each other and with the predictions of the Lund fragmentation model. This comparison shows that a spectator diquark does not fragment as a whole in a fraction of the interactions. The role of the sea quarks in the baryon formation process is underlined. Strange vector and pseudoscalar mesons are likely to be produced at similar rates.

3 data tables

Table 1

No description provided.

Table 2

SIG(C=LAMBDA) denotes the inclusive LAMBDA production in the same reaction.

Table 3

SIG(C=KS) denotes the inclusive KS production in the same reaction.