Adam, H.H.
Max results
Sort by Reverse order

Showing 10 of 2970 results

Date

Lifetimes, Cross-sections and Production Mechanisms of Charmed Particles Produced by 20-{GeV} Photons

The SLAC Hybrid Facility Photon collaboration Abe, K. ; Armenteros, R. ; Bacon, T.C. ; et al.
Phys.Rev.D 33 (1986) 1, 1986.
Inspire Record 214735 DOI 10.17182/hepdata.23544

Seventy-one events containing charmed-particle decays have been observed in an experiment using the SLAC Hybrid Facility exposed to a backward-scattered photon beam. Several improvements were made to the apparatus since the previous experiment on charm photoproduction. Results for the charmed-meson lifetimes are consistent with the published results from the previous experiment and the two data samples have been combined yielding a total sample of 136 charm events. After imposing rigorous cuts, 50 neutral, 48 charged, and 2 charged/neutral ambiguous decays remain. From these, the charmed-meson lifetimes are measured to be &=(8.6±1.3−0.3+0 .7)×10−13 sec, &=(6.1±0.9±0.3)×10 −13 sec, and their ratio &=1.4±0.3− 0.1+0.2. The total charm cross section at a photon energy of 20 GeV has been measured to be (62±8−10+15) nb. There is evidence for both DD¯X and D¯Λc+X production with σD¯Λc+X/σcharm=(71± 11±6)%.

1 data table
Table 1

No description provided.


First Observation and Cross-section Measurement of $\nu_e e^- \to \nu_e e^-$

Allen, R.C. ; Bharadwaj, V. ; Brooks, G.A. ; et al.
Phys.Rev.Lett. 55 (1985) 2401, 1986.
Inspire Record 215874 DOI 10.17182/hepdata.20326

We report the first observation and cross-section measurement of νe+e−→νe+e−. Using neutrinos of energy less than 53 MeV, we observed 63±17 events consistent with ν+e−→ν+e−, of which 51±17 events are assigned to νe+e−→νe+e−. The resulting cross section, {[8.9±3.2(statistical) ±1.5(systematic)]×10−45 cm2/MeV} Eν, agrees with standard electroweak theory, rules out constructive interference between weak charged-current and neutral-current interactions, and begins to indicate the existence of interference between these two interactions.

1 data table
Table 1

No description provided.


Precise Determination of Sin**2-$\theta^-$w From Measurements of the Differential Cross-sections for $\nu_\mu p \to \nu_\mu p$ and $\bar{\nu}_\mu p \to \bar{\nu}_\mu p$

Ahrens, L.A. ; Aronson, S.H. ; Connolly, P.L. ; et al.
Phys.Rev.Lett. 56 (1986) 1107, 1986.
Inspire Record 218044 DOI 10.17182/hepdata.20261

This paper describes measurements of the semileptonic weak-neutral-current reactions νpμ→νpμ and ν¯pμ→ν¯pμ which yield the absolute differential cross sections dσ(νpμ)dQ2 and dσ(ν¯pμ)dQ2. The weak-neutral-current parameter, sin2θW, is determined to be sin2θW=0.220±0.016(stat.)(syst.)−0.031+0.023.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

DIJET PRODUCTION CROSS-SECTION AND FRAGMENTATION OF JETS PRODUCED IN P P COLLISIONS AT S**(1/2) = 63-GEV

The AXIAL FIELD SPECTROMETER collaboration Åkesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 30 (1986) 27-43, 1986.
Inspire Record 221571 DOI 10.17182/hepdata.16017

We present stdies of events triggered on two high-pT jets, produced inpp collisions at the CERN Intersecting Storage Rings (ISR) at\(\sqrt s \)=63 GeV, using a large solid angle calorimeter. The cross-section for producing two jets is measured in the dijet mass range 17–50 GeV/c2. A high-statistics sample of dijet events, where each jet has transverse energy above 10 GeV, is used to study the structure of jets and the associated event. We find the longitudinal fragmentation function to be similar to that of jets emerging frome+e− collisions but considerably harder than that observed at the Super Proton Synchrotron (SPS)\(p\bar p\) Collider. A steepening of the fragmentation function is observed when increasing the jet energy. Studies of the charge distribution in jets show that these predominantly originate from fragmenting valence quarks. The transverse energy and particle flows are presented as functions of the azimuthal distance from the jet axis.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

FRAGMENTATION FUNCTION FOR ET(JET) > 10 GEV.


COHERENT pi MESON PRODUCTION IN NEUTRINO AND ANTI-NEUTRINO INTERACTIONS ON FREON NUCLEI

Grabosch, H.J. ; Kaufmann, H.H. ; Krecker, U. ; et al.
IFVE-86-117, 1986.
Inspire Record 234599 DOI 10.17182/hepdata.40875

None

1 data table
Table 1

No description provided.


INCLUSIVE rho0 MESON PRODUCTIONS IN NEUTRINO INTERACTIONS AT SKAT CHAMBER

Ammosov, V.V. ; Ivanilov, A.A. ; Ivanov, P.V. ; et al.
IFVE-86-133, 1986.
Inspire Record 234594 DOI 10.17182/hepdata.10524

None

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Inclusive $\eta$ Production at Low Transverse Momentum in 63-{GeV} $p p$ Collisions at the {CERN} Intersecting Storage Rings

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 178 (1986) 447, 1986.
Inspire Record 230636 DOI 10.17182/hepdata.30230

The inclusive production of η-mesons in pp collisions at √ s =63GeV and ϑ CM =90° has been measured for p T <1.5GeV/c. The η/π ratio decreases from its previously measured asymptotic value of η/π ∼ 0.5 at high transverse momentum, to η/π ≈0.3 at P T = 750MeV/c and η/π ≈ 0.01 at P T =300MeV/c, in a way that consistent with phase-space considerations, e.g. m T scaling. The η/π ratio, integrated from 0.2–1.5 GeV/ c , is found to be η/π=0.07±0.055.

1 data table
Table 1

No description provided.


Measurement of Neutrino - Proton and anti-neutrino - Proton Elastic Scattering

Ahrens, L.A. ; Aronson, S.H. ; Connolly, P.L. ; et al.
Phys.Rev.D 35 (1987) 785, 1987.
Inspire Record 18763 DOI 10.17182/hepdata.23350

Measurements of the semileptonic weak-neutral-current reactions νμp→νμp and ν¯μp→ν¯μp are presented. The experiment was performed using a 170-metric-ton high-resolution target detector in the BNL wide-band neutrino beam. High-statistics samples yield the absolute differential cross sections dσ(νμp)/dQ2 and dσ(ν¯μp)/dQ2. A measurement of the axial-vector form factor GA(Q2) is also presented. The results are in good agreement with the standard model SU(2)×U(1). The weak-neutral-current parameter sin2thetaW is determined to be sin2θW=0.220±0.016(stat)−0.031+0.023(syst).

1 data table
Table 1

Errors contain both statistics and systematics, except for additional overall normalisation error given above. Neutrino energy is 0 to 5 GeV with peak at 0.8 Gev.


Suppression of Valence Quark Recombination in $\pi^+$ Fragmentation Into $\rho^+$

The EHS/NA22 collaboration Adamus, M. ; Azhinenko, I.V. ; Belokopytov, Yu.A. ; et al.
Phys.Lett.B 183 (1987) 425, 1987.
Inspire Record 238678 DOI 10.17182/hepdata.30207

We present inclusive ϱ ±,0 and ω cross sections in the beam fragmentation region of π + p interactions at 250 GeV/ c . The near equality of the ϱ + and ϱ 0 cross sections implies suppression of valence quark recombination in forward vector meson production.

1 data table
Table 1

No description provided.


Direct Photon Plus Away - Side Jet Production in $p p$ Collisions at $s^1$/2 = 63-{GeV} and a Determination of the Gluon Distribution

The Axial Field Spectrometer collaboration Åkesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 34 (1987) 293, 1987.
Inspire Record 235690 DOI 10.17182/hepdata.15800

We have determined the double inclusive cross-section for opposite-side high-pT photons and away-side jets withθγ≈θjet≈90° produced inpp collisions at the CERN Intersecting Storage Rings at\(\sqrt s= 63\) GeV. Under the assumption that these events arise predominantly from the QCD gluon Compton process we have calculated the gluon structure function in the range 0.15≦x≦0.30 at an average square of the four-momentum transfer of 40 GeV2/c2. The data favour a soft gluon distribution in the proton.

2 data tables
Table 1

No description provided.

Table 2

No description provided.