Becker, H.
ACCMOR
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Upper Limits for Charm Production in 150-{GeV} $p$ Be Interactions

The ACCMOR collaboration Bailey, R. ; Becker, H. ; Belau, E. ; et al.
Nucl.Phys.B 239 (1984) 15-26, 1984.
Inspire Record 193967 DOI 10.17182/hepdata.33882

A search has been made for the hadronic production of charmed baryons and mesons with a large aperture forward magnetic spectrometer using 150 GeV protons originating from the CERN-SPS. A prompt electron trigger was used as a signature for charm. Upper limits at 90% confidence level have been obtained for the production of Λ c + D 0 , D 0 D + and D − : σ(Λ c ) ⩽ 8 μ b , σ( D 0 ) ⩽ 64 μ b , σ( D 0 ) < 37 μ b , σ( D + ) ⩽ 51 μ b and σ( D − ) ⩽ 49 μ b per nucleon, assuming linear A dependence. Systematic errors due to uncertainties in branching ratios and to model dependence of the acceptance calculation are discussed.

1 data table match query
Table 1

No description provided.


EVIDENCE FOR A NONTENSOR (Q ANTI-Q) MESON AT 1410-MEV PRODUCED IN THE REACTION PI- P ---> K0(S) K0(S) N AT 63-GEV

The ACCMOR collaboration Daum, C. ; Hertzberger, L.O. ; Hoogland, W. ; et al.
Z.Phys.C 23 (1984) 339-347, 1984.
Inspire Record 204305 DOI 10.17182/hepdata.16225

We present an analysis of theKs0Ks0 system produced in the reaction π−p→Ks0Ks0n at 63 GeV based on ∼700 events in the kinematical region of |t|<0.5 GeV2. We concentrate on masses between 1,200 and 1,600 MeV where a double maximum structure is observed. Performing an amplitude analysis in this mass interval we find thatS,D0 andD+ waves contribute to the mass spectrum at approximately equal strength. The peaks are attributed to spin 2 waves. However, we failed to explained them by interferingf(1270),A2(1310) andf′(1520) resonances alone. While the first peak can be associated withf(1270)−A2(1310) production, an additional tensor meson is needed with mass of ∼1410 MeV and a narrow width for a description of the second one. The analysis as well as the energy dependence deduced from some publishedKs0Ks0 mass spectra suggests this object to be dominantly produced by a natural parity exchange. Because the 2++\(q\bar q\) nonet is already complete the nature of the new tensor meson is an open question.

1 data table match query
Table 1

No description provided.


Experimental Proof of the Existence of the A1 Meson

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 281-284, 1980.
Inspire Record 143044 DOI 10.17182/hepdata.27272

In partial wave analyses of the ( π − π − π + ) system, substantial shape changes of the 1 + S ( ϱπ ) intensity as a function of t , and relative phase changes of ≈ 90°, provide compelling evidence for a resonant A 1 of mass ≈ 1280 MeV and width ≈ 300 MeV.

1 data table match query
Table 1

No description provided.


3 $\pi$ Resonances in 2- Partial Waves

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 285-289, 1980.
Inspire Record 143045 DOI 10.17182/hepdata.27275

The J PC = 2 −+ partial wave intensities and their large phase changes prove the resonant nature of the A 3 meson (mass ≈ 1670 MeV, width ≈ 210 MeV). The decay modes are f 0 π , ϱ 0 π , and ϵ 0 π . Evidence is found for a further 2 − enhancement.

1 data table match query
Table 1

No description provided.


A2 Meson Production at 63-{GeV} and 94-{GeV} in the Reaction $\pi^- p \to \pi^- \pi^- \pi^+ p$

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 276-280, 1980.
Inspire Record 143255 DOI 10.17182/hepdata.27274

The A 2 meson is studied in the decay mode ϱ 0 π − using partial wave analyses of 600 000 events from the reaction π − p→ π − π − π + p at 63 and 94 GeV incident momentum. Common production mechanisms are indicated for this resonance and diffractive 1 + and 2 − components.

1 data table match query
Table 1

No description provided.


Observation of $D^*$+- and ($\bar{D}$)0 / $D^\pm$ Production in High-energy $\pi^-$ Be Interactions at the {SPS}

The ACCMOR & Amsterdam-Bristol-CERN-Cracow-Munich-Rutherford collaborations Bailey, R. ; Bardsley, D.G. ; Becker, H. ; et al.
Phys.Lett.B 132 (1983) 230-236, 1983.
Inspire Record 190658 DOI 10.17182/hepdata.30633

An experiment has been performed to search for associated hadronic production of charmed mesons, using a large-aperture forward magnetic spectrometer setup in a π − beam at the CERN SPS. A prompt electron trigger was used to select events containing a pair by charmed particles. D mesons have been identified by reconstruction of hadronic decay modes such as Kπ, Kππ. Data have been taken at 120, 175, and 200 GeV, The D D cross section measured at 175 200 GeV is σ( D D ) = (48 ± 15) μ b with a systematic uncertainty of ±50%. The energy dependence of the cross section is measured to be σ( D D ) [120 GeV )/σ( D D [175/200 GeV ] = 0.62 ± 0.34 .

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Diffractive Production of Strange Mesons at 63-{GeV}

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Nucl.Phys.B 187 (1981) 1-41, 1981.
Inspire Record 164180 DOI 10.17182/hepdata.34277

Nearly 200 000 examples of the diffractive process K − p → K − π − π + p at 63 GeV have been obtained using a two magnet spectrometer equipped with Čerenkov counters for secondary particle identification. In addition some 2000 examples of the process K − p → ω K − p have been obtained. The K ππ data have been subjected to partial-wave analysis. The dominant J P = 1 + system couples to K ∗ π , in both S and D waves, ϱ K, κπ and ε K. The data confirm the existence of two J P = 1 + Q mesons and their masses, widths and branching ratios are given. The ifωK data show that the couplings of the Q mesons to ω K are approximately equal to the couplings to ϱ 0 K. The two 1 + nonets expected in the quark model are discussed in the light of this and other recent experiments. There is strong evidence for a broad J P = 0 − resonance at about 1.46 GeV. At higher masses, structure in the J P = 2 − partial waves establishes the existence of at least one J P = 2 − L meson.

1 data table match query
Table 1

JP=1+ S-WAVE PARTIAL WAVE INTENSITIES AND TOTAL INTENSITY FOR Q-REGION. THE <K* PI> INTENSITY IS DOMINATED BY QHIGH. THE <K RHO> AND <KAPPA PI> INTENSITIES ARE DOMINATED BY QLOW.


Diffractive Production of 3 $\pi$ States at 63-{GeV} and 94-{GeV}

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Nucl.Phys.B 182 (1981) 269-336, 1981.
Inspire Record 156369 DOI 10.17182/hepdata.34314

Diffractive production of the 3 π system has been studied at 63 and 94 GeV using a two magnet spectrometer with high, uniform acceptance. The total number of events used in the analysis is ∼600 000. The A 2 meson is shown to be diffractively produced. The existence of a resonant component in both the 1 + and 2 − enhancements is established and resonance parameters for the corresponding A 1 and A 3 mesons are given. There are several indications in the data of states which would correspond to radial excitations in the quark model.

4 data tables match query
Table 1

SEE C. DAUM ET AL., PL 89B, 276 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+486> RED = 486 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+420> RED = 420 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

Table 2

SEE C. DAUM ET AL., PL 89B, 281 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+487> RED = 487 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+419> RED = 419 </a>) OF THE GENEVA CONFERENCE PREPRINT, G. THOMPSON ET AL. (1979).

Table 3

SEE C. DAUM ET AL., PL 89B, 285 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+488> RED = 488 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+421> RED = 421 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

More…

Production of the charmed baryon Lambda(c)+ in pi- Cu and K- Cu interactions at 230-GeV

The ACCMOR collaboration Barlag, S. ; Becker, H. ; Bohringer, T. ; et al.
Phys.Lett.B 247 (1990) 113-120, 1990.
Inspire Record 296999 DOI 10.17182/hepdata.29658

We present results from the NA32 experiment at CERN on the production characteristics of the charmed baryon Λ + c in 230 GeV π − Cu and K − Cu interactions. A high resolution vertex detector consisting of change-coupled devices and silicon microstrip detectors allowed the selection of a very clean sample of 154 Λ + c → pK − π + (and charge conjugate) decays. Results on differential and integrated cross sections are given.

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Charmed pair correlations in pi- Cu interactions at 230-GeV/c.

The ACCMOR collaboration Barlag, S. ; Becker, H. ; Bożek, A. ; et al.
Phys.Lett.B 302 (1993) 112-118, 1993.
Inspire Record 362064 DOI 10.17182/hepdata.28956

In the CERN NA32 experiment a high-resolution silicon vertex detector and a purely topological approach were used to collect 557 events consistent with associated charm production, both decay vertices being observed. The pseudorapidity gap distribution appears to be nearly independent of the nature of the charmed hadrons. This distribution is reasonably consistent with the next-to-leading order QCD calculations. However the azimuthal-angle distribution is significantly broader than the above predictions.

2 data tables match query
Table 1

FOR ONLY 20 EVENTS IN WICH BOTH DECAYS ARE FULLY RECONSTRUCTED ( 26 D0 , 8 D+ , 5 D/S+ , 1 LAMBDA/C+ CHARMED PARTICLES ).

Table 2

No description provided.