摘要:

A light neutralino, with mass belowmW, is considered as a candidate for dark matter. It is found that, in minimal supersymmetry, for predominantly gaugino‐like and higgsino‐like neutralinos the relic mass density is naturally close to the critical density, while for a general superposition of both gauginos and higgsinos it is typically very small. If at least one light sfermion exists, then a light gaugino‐like neutralino also becomes cosmologically less attractive.

ISSN:0094-243X    

DOI:10.1063/1.42639

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The one‐loop decayst→cV, whereV=&ggr;,g, orZ, andt→cHare examined in the Standard and two‐ Higgs‐doublet models.

ISSN:0094-243X    

DOI:10.1063/1.42640

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

This is an extract from the Expression of interest EOI14 for a Super Fixed Target Beauty Facility (SFT) at the Superconducting Super Collider to be built in Texas, USA. It has been presented at the K Decays & Novel Flavor Factories’’, held in S. Monica, USA on 12‐15 Feb. 1991.

ISSN:0094-243X    

DOI:10.1063/1.42641

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The bounds on the top quark mass from both theory and experiment are critically examined and the future prospects for the discovery of the top quark are discussed.

ISSN:0094-243X    

DOI:10.1063/1.42642

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We study the single particle and collective dynamics of a storage ring where the momentum compaction is made small to make the ring nearly isochronous and reduce the bunch length and increase the peak current. We find that a quasi‐isochronous ring makes it possible to obtain a bunch length in the millimeter range, about one order of magnitude shorter than the present values, and to increase the beam longitudinal brilliance by more than one order of magnitude. The shorter bunch length allows one to reduce the betatron function and the beam area at the interaction point of an electron‐positron collider, leading to larger luminosity. We also design a ring whose momentum compaction can be varied over several orders of magnitude.

ISSN:0094-243X    

DOI:10.1063/1.42643

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The high luminosity projects imply collisions of intense short bunches with micro‐beta at the IP, which entails high variations of the particle energy on the IP passage, due to the opposing bunch electric fields. This effect is shown to put the limit on the attainable luminosities. The estimates are made for the stability of the incoherent and coherent longitudinal motion which enhance the required RF voltage depending on the design beta minimum at the IP. The results of the analytical treatment and the computer simulation of the off‐axis particle synchrobetatron motion relate the limitations, imposed on the space charge parameter by the longitudinal beam‐beam effects, and the main parameters of the machine.

ISSN:0094-243X    

DOI:10.1063/1.42644

出版商:AIP    

年代:1992

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.42645

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Thee+e−linac‐on‐ring collider concept requires special attention due to the highly asymmetric nature of the beam‐beam interaction. A brief review of recent studies is presented followed by some specific offset collision studies. Luminosity as a function of offset is also presented.

ISSN:0094-243X    

DOI:10.1063/1.42646

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We compute the angular distribution of radiation in the near field of a long damping wiggler that is required to determine the equilibrium emittance and the damping decrement in the low energy ring of a high luminsoity B factory. From the power distribution we can estimate the size of the vacuum chamber, the photon channel, and the photon dump that can tolerate the enormous average power of x‐rays generated in the wiggler.

ISSN:0094-243X    

DOI:10.1063/1.42626

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Utilizing a next generation electron‐positron collider of energy ≥250 GeV, we describe how to produce copious hot photons of energy ≥500 GeV. These hot photons can in turn scatter off nuclei and photoproduce bb and &tgr;+&tgr;−pairs in a scheme called BACKGAMMON. Using a vertex detector, such a scheme would allow one to measure ∼109bb and ≳108&tgr;+&tgr;−pairs per year. Moreover, by employing polarized electron and laser beams, one could obtain polarized &tgr;’s, thus allowing one to directly study in a unique way the vector and axial‐vector structure of &tgr; decay.

ISSN:0094-243X    

DOI:10.1063/1.42627

出版商:AIP    

年代:1992

数据来源: AIP