Negatively Charged Strangelet Search using the E864 Spectrometer at the AGS

We provide a status report on the progress of searching for negatively charged strangelets using the E864 spectrometer at the AGS. About 200 million recorded events representing approximately 14 billion 10% central interactions of Au + Pt at 11.5 GeV/c taken during the 1996-1997 run of the experiment are used in the analysis. No strangelet candidates are seen for charges Z=-1 and Z=-2, corresponding to a 90% confidence level for upper limits of strangelet production of ~1 x 10^{-8} and ~4 x 10^{-9} per central collision respectively. The limits are nearly uniform over a wide range of masses and are valid only for strangelets which are stable or have lifetimes greater than ~50 ns.Comment: 6 pages, 4 figures; Talk at SQM'98, Padova, Italy (July 20-24, 1998

Search for positively charged strangelets and other related results with E864 at the AGS

We report on the latest results in the search for positively charged strangelets from E864's 96/97 run at the AGS with sensitivity of about $8\times 10^{-9}$ per central collision. This contribution also contains new results of a search for highly charged strangelets with $Z=+3$. Production of light nuclei, such as $^6He$ and $^6Li$, is presented as well. Measurements of yields of these rarely produced isotopes near midrapidity will help constrain the production levels of strangelets via coalescence. E864 also measures antiproton production which includes decays from antihyperons. Comparisons with antiproton yields measured by E878 as a function of centrality indicate a large antihyperon-to-antiproton ratio in central collisions.Comment: 8 pages, 4 figures; Talk at SQM'98, Padova, Italy (July 20-24th, 1998

Strange Quark Matter Status and Prospects

The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks

Nucleus-Nucleus Bremsstrahlung from Ultrarelativistic Collisions

The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Soft photons can be used to infer the rapidity distribution of the outgoing charge. An experimental design is outlined.Comment: 12 pages, 7 figures, uses revte

Strangelets: Who is Looking, and How?

It has been over 30 years since the first suggestion that the true ground state of cold hadronic matter might be not nuclear matter but rather strange quark matter (SQM). Ever since, searches for stable SQM have been proceeding in various forms and have observed a handful of interesting events but have neither been able to find compelling evidence for stable strangelets nor to rule out their existence. I will survey the current status and near future of such searches with particular emphasis on the idea of SQM from strange star collisions as part of the cosmic ray flux.Comment: Talk given at International Conference on Strangeness in Quark Matter, 2006. 8 pages. 1 figur

Strangelet dwarfs

If the surface tension of quark matter is low enough, quark matter is not self bound. At sufficiently low pressure and temperature, it will take the form of a crystal of positively charged strangelets in a neutralizing background of electrons. In this case there will exist, in addition to the usual family of strange stars, a family of low-mass large-radius objects analogous to white dwarfs, which we call "strangelet dwarfs". Using a generic parametrization of the equation of state of quark matter, we calculate the mass-radius relationship of these objects.Comment: 10 pages, LaTeX, added discussion of CFL phase and strangelet pollution, version to appear in journal. arXiv admin note: text overlap with arXiv:0808.067

Status of the BNL IFEL accelerator

A 40 MeV electron beam, using the inverse free-electron laser interaction, has been accelerated by {Delta}E/E = 2.5% over a distance of 0.47 m. The electrons interact with a 1--2 GW CO{sub 2} laser beam bounded by a 2.8 mm ID sapphire circular waveguide in the presence of a tapered wiggler with Bmax {approx} 1 T and a period 2.89 cm {le} {lambda}{sub w} {le} 3.14 cm. The experimental results of {Delta}E/E as a function of electron energy E, peak magnetic field Bw and laser power W{sub 1} compare well with analytical and 1-D numerical simulations and permit scaling to higher laser power and electron energy. The present status of the IFEL accelerator and planned near term development are indicated

Calibration of a solid state nuclear track detector (SSNTD) with high detection threshold to search for rare events in cosmic rays

We have investigated a commercially available polymer for its suitability as a solid state nuclear track detector (SSNTD). We identified that polymer to be polyethylene terephthalate (PET) and found that it has a higher detection threshold compared to many other widely used SSNTDs which makes this detector particularly suitable for rare event search in cosmic rays as it eliminates the dominant low Z background. Systematic studies were carried out to determine its charge response which is essential before any new material can be used as an SSNTD. In this paper we describe the charge response of PET to 129Xe, 78Kr and 49Ti ions from the REX-ISOLDE facility at CERN, present the calibration curve for PET and characterize it as a nuclear track detector