Leitch, M.J.
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Experimental Limits on Heavy Lepton Production by Neutrinos

Cnops, A.M. ; Connolly, P.L. ; Kahn, S.A. ; et al.
Phys.Rev.Lett. 40 (1978) 144-146, 1978.
Inspire Record 121918 DOI 10.17182/hepdata.37905

We present upper limits on the production of heavy leptons (L±) by neutrinos via the process νμ+Ne→L±+⋯, L±→e±+ν+ν¯. These limits imply that the L− and L+, if they couple in full strength to νμ, are heavier than 7.5 and 9 GeV, respectively. They also imply that the coupling strength νμ to the recently discovered 1.9-GeV heavy lepton τ is less than 0.025 of the normal νμ−μ coupling.

1 data table
Table 1

No description provided.


Confirmation of the Existence of the Sigma(c)++ and Lambda(c)+ Charmed Baryons

Baltay, C. ; Caroumbalis, D. ; French, H. ; et al.
Phys.Rev.Lett. 42 (1979) 1721, 1979.
Inspire Record 140761 DOI 10.17182/hepdata.50280

In a broadband neutrino exposure of the Fermilab 15-ft bubble chamber, we observe the production of the Σc++(2426) charmed baryon followed by its decay to Λc+(2260) and π+. We find the mass of the Λc+ to be 2257±10 MeV and the m(Σc++)−m(Λc+) mass difference to be 168±3 MeV. Previously unseen two-body decay modes of the Λc+(2260) are observed.

1 data table
Table 1

No description provided.


Search for the decay D0 ---> mu+ mu-

The E789 collaboration Mishra, C.S. ; Brown, C.N. ; Cooper, W.E. ; et al.
Phys.Rev.D 50 (1994) R9-R12, 1994.
Inspire Record 374150 DOI 10.17182/hepdata.42371

Using a silicon-microstrip detector array to identify secondary vertices occurring downstream of a short platinum target, we have searched for the decay D0→μ+μ−. Normalized relative to the J/ψ→μ+μ− signal observed in the same data sample, for a 3.25-mm minimum decay distance our branching-ratio sensitivity is (4.8±1.4)×10−6 per event, and after background subtraction we observe -4.1±4.8 events. Using the statistical approach advocated by the Particle Data Group, we obtain a limit B(D0→μ+μ−)<3.1×10−5 at 90% confidence, confirming with a different technique the limit previously obtained by Louis et al. The interpretation of the upper limit involves complex statistical issues; we present another approach which is more suitable for combining the results of different experiments.

2 data tables
Table 1

Measured branching ratio.

Table 2

Classical 90 PCT upper limit of branching ratio.


Observation of orbitally excited B mesons

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 345 (1995) 598-608, 1995.
Inspire Record 382208 DOI 10.17182/hepdata.48321

Experimental evidence for the existence of orbitally excited B meson states is presented in an analysis of the Bπ and B ∗ π distribution of Q = m(B ∗∗ ) − m(B (∗) ) − m(π) using Z 0 decay data taken with the DELPHI detector at LEP. The mean Q-value of the decays B ∗∗ → B (∗) π is measured to be 284 ± 5 (stat.) ± 15 (syst.) MeV/c 2 , and the Gaussian width of the signal is 79 ± 5 (stat.) ± 8 (syst.) MeV/c 2 . This signal can be described as a single resonance of mass m = 5732 ± 5 (stat.) ± 20 (syst.) MeV/c 2 and full width Γ = 145 ± 28 MeV/c 2 . The observed shape is also consistent with the production of several broad and narrow states as predicted by the quark model and partly observed in the D-meson sector. The production rate of B ∗∗ per b-jet is found to be 0.27 ± 0.02 (stat.) ± 0.06 (syst.).

1 data table
Table 1

No description provided.


Nuclear dependence of J / psi production by 800-GeV/c protons near x(F) = 0

Leitch, M.J. ; Boissevain, J. ; Brown, C.N. ; et al.
Phys.Rev.D 52 (1995) 4251-4253, 1995.
Inspire Record 394199 DOI 10.17182/hepdata.55727

The nuclear dependence for 800 GeV/c proton production of J/ψ’s has been measured near xF=0. $J/ psi—’s produced from beryllium, carbon, and tungsten targets were detected with the Fermilab E789 pair spectrometer. These data extend the results from E772 down to the range xF=-0.1 to 0.1 and indicate a gradually increasing suppression as xF falls below zero.

3 data tables

rivet Analysis
B* production in Z decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 68 (1995) 353-362, 1995.
Inspire Record 395026 DOI 10.17182/hepdata.52359

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Search for exclusive charmless B meson decays with the DELPHI detector at LEP

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 357 (1995) 255-266, 1995.
Inspire Record 397145 DOI 10.17182/hepdata.52353

Charmless hadronic decays of beauty mesons have been searched for using the data collected with the DELPHI detector at the LEP collider. Several two, three and four-body decay modes have been investigated. Particle identification was used to distinguish the final states with protons, kaons and pions. Three candidate events selected in two-body decay modes are interpreted as evidence for charmless B decays. No excess has been found in higher multiplicity modes and improved upper limits for some of the branching ratios are given.

3 data tables
Table 1

Two body decay modes. Upper limits at 90% CL. In computing of limits the fractions of B/(d,u)(0,-) and B/S0 mesons were assumed to be 0.39 and 0.12 respectively. Limits are given for the weighted average of the decay rates of the two neutral B mesons.

Table 2

Three body decay modes. Upper limits at 90% CL.

Table 3

Four body decay modes. Upper limits at 90% CL.


Measurement of the average b baryon lifetime and the product branching ratio f (b --> Lambda(b)) x BR (Lambda(b) --> Lambda lepton- anti-neutrino X)

The OPAL collaboration Akers, R. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 69 (1996) 195-214, 1996.
Inspire Record 397395 DOI 10.17182/hepdata.51966

None

1 data table
Table 1

Charged conjugate state is assumed.


A Measurement of the tau leptonic branching fractions

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 357 (1995) 715-724, 1995.
Inspire Record 398321 DOI 10.17182/hepdata.48138

A sample of 25000 Z 0 → τ + τ − events collected by the DELPHI experiment at LEP in 1991 and 1992 is used to measure the leptonic branching fractions of the τ lepton. The results are B(τ → eν ν ) = (17.51 ± 0.39) % and B(τ → μν ν ) = (17.02 ± 0.31) %. The ratio of the muon and electron couplings to the weak charged current is measured to be g μ g e = 1.000 ± 0.013 , satisfying e-μ universality. The leptonic branching fraction corrected to the value for a massless lepton, assuming e-μ universality, is found to be B(τ → lν ν ) = (17.50 ± 0.25) %.

3 data tables
Table 1

Axis error includes +- 0.23/0.23 contribution (Data statistics).

Table 2

Axis error includes +- 0.19/0.19 contribution (Data statistics).

Table 3

Combined from the two branching fractions above. E-MU universality assumed.


Upsilon production in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amendolia, S.R. ; et al.
Phys.Rev.Lett. 75 (1995) 4358, 1995.
Inspire Record 398187 DOI 10.17182/hepdata.42349

We report on measurements of the ϒ(1S), ϒ(2S), and ϒ(3S) differential, (d2σdPtdy)y=0, and integrated cross sections in pp¯ collisions at s=1.8 TeV using a sample of 16.6 ± 0.6 pb−1 collected by the Collider Detector at Fermilab. The three resonances were reconstructed through the decay ϒ→μ+μ−. Comparison is made to a leading order QCD prediction.

7 data tables
Table 1

SIG*Br(UPSI --> MU+ MU-).

Table 2

SIG*Br(UPSI --> MU+ MU-).

Table 3

SIG*Br(UPSI --> MU+ MU-).

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