Unusually penetrating particle detected by balloon-borne emulsion chamber

Ichimura, M.; Kamioka, Eiji; Kitazawa, M.; Kobayashi, Tadashi; Shibata, T.; Somemiya, S.; Kogawa, Masakazu; Kuramata, S.; Matsutani, H.; Murabayashi, T.; Nanjyo, H.; Watanabe, Z.; Sugimoto, H.; Nakazawa, Kimitaka

doi:10.1007/bf02771498

Cited by 46 publications

(31 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the strangelets are stable particles, they should be observed as almost neutral heavy particles in experiments. Indeed, several candidates of exotic particles have been observed in the cosmic rays [5,6,7,8,9,10,11]. There are also experiments to search for such exotic particles in heavy ion collision experiments [11,12,13].…”

Section: Introductionmentioning

confidence: 99%

Chiral Symmetry Breaking and Stability of Quark Droplets

Yasui¹

2006

Int. J. Mod. Phys. E

View full text Add to dashboard Cite

We discuss the stability of strangelets -quark droplets with strangeness -in the Nambu-Jona-Lasinio model supplemented by a boundary condition for quark confinement. Effects of dynamical chiral symmetry breaking are considered properly inside quark droplets of arbitrary baryon number. We obtain the energy per baryon number of quark droplets with baryon number from one to thousands. It is shown that strangelets are not the ground states as compared with nuclei, though they can be locally stable.

show abstract

Section: Introductionmentioning

confidence: 99%

Chiral Symmetry Breaking and Stability of Quark Droplets

Yasui¹

2006

Int. J. Mod. Phys. E

View full text Add to dashboard Cite

show abstract

“…Meanwhile, candidate events consistent with strangelet characteristics have been published by several experiments [16,17,18]. The search reported here was specifically motivated by two SQM candidate events found by the Alpha Magnetic Spectrometer (AMS) collaboration during the AMS-01 prototype flight in 1998 [19].…”

mentioning

confidence: 99%

Search for Stable Strange Quark Matter in Lunar Soil

et al. 2009

View full text Add to dashboard Cite

We report results from a search for strangelets (small chunks of Strange Quark Matter) in lunar soil using the Yale WNSL accelerator as a mass spectrometer. We have searched over a range in mass from A=42 to A=70 amu for nuclear charges 5, 6, 8, 9, and 11. No strangelets were found in the experiment. For strangelets with nuclear charge 8, a concentration in lunar soil higher than 10 −16 is excluded at the 95% confidence level. The implied limit on the strangelet flux in cosmic rays is the most sensitive to date for the covered range and is relevant to both recent theoretical flux predictions and a strangelet candidate event found by the AMS-01 experiment.PACS numbers: 21.65. Qr, Strange Quark Matter (SQM) is a proposed state of hadronic matter made up of roughly one-third each of up, down, and strange quarks in a single hadronic bag that can be as small as an atomic nucleus or as large as a star. It has been over 30 years since the first suggestion that the true ground state of cold hadronic matter might be SQM rather than nuclear matter [1,2]. If true, the implications would be tremendous for both basic research and applied science [3]. With this motivation, many searches for stable SQM have been undertaken using a variety of methods. These searches have collectively observed a handful of interesting events but have neither been able to find compelling evidence for stable SQM nor to rule out its existence.The idea that Quark Matter made of only up and down quarks is stable can be dismissed immediately by the observation that normal nuclear matter does not decay into it. However, in the case of SQM such a decay would require many simultaneous weak interactions, making it prohibitively unlikely. The stability of SQM cannot yet be determined from first principles within QCD, but has been addressed in various phenomenological models. The most commonly used of these is the MIT Bag Model [4,5], which also has been extended to include the effects of color flavor locking (CFL) [6,7]. The results of such calculations are inconclusive, but for a significant part of the reasonable parameter space in these models, SQM is in fact absolutely stable for baryon number greater than some minimum value, A min [5,8]. A min is typically found to be larger than 50 and smaller than 1000 although shell effects which are important for A 100 may cause islands of stability at A values smaller than A min . The key point is that SQM stability is a question * Current address: Department of Physics, University of California, Santa Barbara, CA 93106, USA that must be settled experimentally or observationally.If SQM is stable at zero pressure, all compact stars which are commonly thought of as neutron stars may in fact be "strange stars", i.e. composed of SQM [9]. A strange star which is a member of a binary system will eventually suffer a collision with its partner, possibly resulting in the ejection of some fraction of its mass in the form of strangelets. This should ultimately lead to a flux of strangelets in cosmic rays [10,11]. The result...

show abstract

“…The estimated energy and the mass number of the event are h t 5 f 4 ¦ C GeV and ¥ 0 , respectively. [6].…”

mentioning

confidence: 99%

The exotic characteristics of centauro-I: a model to describe Centauro-I

Ohsawa

Shibuya

Tamada

2006

J. Phys. G: Nucl. Part. Phys.

View full text Add to dashboard Cite

In our previous paper on Centauro-I (Ohsawa et al 2004 Phys. Rev. D 70 074028), we showed that the shower cluster, found in the block I12 of the lower chamber, is produced in the target layer by a number of hadrons with appreciable lateral spread. These hadrons are accompanied by no (or one at most) γ-ray(s) with energy above detection threshold, and produce no shower in the upper chamber but 28 visible C-jets (with the visible energy more than 2 TeV) in the target layer. These characteristics are quite exotic and unable to be described by a fluctuation of ordinary atmospheric families. In the present paper, we propose a model of strange quark matter (SQM) among the primary cosmic rays to describe the exotic features of the event. A large SQM droplet enters the atmosphere and fragments into a bundle of small strangelets in the atmosphere without emission of γ-rays, and these small strangelets explode into nucleons in the upper chamber. The number of collisions in the upper chamber is estimated to be as small as 3–4 in contrast to 20–30 collisions in the target layer. We discuss the intensity of Centauro-I together with the exotic events observed by the balloon and satellite experiments, which were also ascribed to strange quark matter.

show abstract

Unusually penetrating particle detected by balloon-borne emulsion chamber

Cited by 46 publications

References 3 publications

Chiral Symmetry Breaking and Stability of Quark Droplets

Chiral Symmetry Breaking and Stability of Quark Droplets

Search for Stable Strange Quark Matter in Lunar Soil

The exotic characteristics of centauro-I: a model to describe Centauro-I

Contact Info

Product

Resources

About