摘要:

Electron‐positron pairs with an effective mass up to 10 GeV have been observed in proton‐beryllium collisions at 400 GeV at Fermilab. In addition to high mass continuum events, evidence is presented for a new resonance at 6 GeV. The J/&psgr; is observed and its production dynamics measured near x of 0 and out to PTof 1.6 GeV. The decay angular distribution is found to be best fit with (1+cos2&Vthgr;*). A 90% C.L. upper limit of 2% is placed on the branching ratio times cross section for &psgr;′ relative to &psgr;.

ISSN:0094-243X    

DOI:10.1063/1.30735

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A systematic search for charm particles was made using the MIT‐BNL double arm spectrometer, in the h+h−, h+h−&mgr; and h±e±final states with 28.5 GeV incident proton beam interacting on Be target. No evidence was found in any of the reactions.

ISSN:0094-243X    

DOI:10.1063/1.30729

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We report preliminary results from a search for new particles produced in proton‐nucleus collisions at 400 GeV/c. A double‐arm spectrometer is used to detect two‐body final states where each spectrometer arm has the capability of uniquely identifying &Pgr;±,K±,p, ?, &mgr;±, and &fgr;. TheJ&psgr; is measured in the &mgr;+&mgr;−mode.

ISSN:0094-243X    

DOI:10.1063/1.30713

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

This paper reports the results of an experiment performed at the CERN ISR to search for new particles, produced in pp collisions at &sqrt;s=53 GeV, which decay into two long‐lived hadrons (i.e. &pgr;+, &pgr;−,K+,K−,por ?).

ISSN:0094-243X    

DOI:10.1063/1.30715

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Searches for charmed particle production using bubble chambers with hadronic beams are summarized. These searches depend on the detection of neutral strange particles. Upper limits are given for long‐lived particles (tc≳10−11 sec), for short‐lived particles showing up in mass distributions and for semi‐leptonic decays involving &mgr;’s plus V’s.

ISSN:0094-243X    

DOI:10.1063/1.30716

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We summarize calculations of backgrounds for cosmic ray candidates for new particles in emulsions. Even if only the strongest cosmic ray candidates are accepted as genuine, the implication is that their production cross sections would be relatively large at accelerator energies (≳1&mgr;b) and that decay modes with &pgr;0appear to be prominent. We refer to current accelerator upper bounds on &sgr;×BK&pgr;for production of hadrons withM≳2 GeV and discuss the relation between these bounds and the cosmic ray events.

ISSN:0094-243X    

DOI:10.1063/1.30717

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

The spectroscopy and decays of the new particles are reviewed from the point of view of the charmonium model. The review proceeds from general features expected to be true in a wide class of spin 1/2 constituent models to predictions that depend in more detail on the dynamics of the color SU(3) quark gluon theory. A list of important and unresolved problems is presented at the end.

ISSN:0094-243X    

DOI:10.1063/1.30718

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

The A‐dependence of &psgr; photoproduction was measured on Beryllium and Tantalum. From this we found &sgr;&psgr;N=2.75±0.90 mb. A study was made of excess leptons relative to pion production in photoproduction. A &mgr;/&pgr; ratio of 1.40±‐0.25×10−4was found at 20 GeV incident photon energy. The energy dependence of &psgr; photoproduction was determined and appeared to have a ’’pseudo‐threshold’’ at 12 GeV.

ISSN:0094-243X    

DOI:10.1063/1.30719

出版商:AIP    

年代:1976

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.30720

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We are currently studying the associated production of prompt muons and other particles produced in n‐Be collisions in the M‐3 neutral beam at Fermilab. The muon arm of our two‐arm spectrometer provides excellent hadron rejection and accepts particles of transverse momentum greater than 0.35 GeV/c. The muon momentum is measured with an accuracy of about ±25%. The precision forward arm of the spectrometer has large acceptance (x≳0.2) and is instrumented with equipment for lepton identification. The system is triggered whenever one or more charged particles traverse the muon arm in conjunction with at least one charged particle in the forward arm. Preliminary distributions for particles in the muon arm will be presented.

ISSN:0094-243X    

DOI:10.1063/1.30721

出版商:AIP    

年代:1976

数据来源: AIP