Download or read book Search for Long Lived Heavy Particles and the Production of Anti nuclei by 400 GeV Protons Cross Sections Relative Rates written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A high sensitivity search was performed for massive long-lived particles produced at 2.5mr by 400 GeV/c protons on a beryllium target using time-of-flight, Cherenkov, and calorimetric techniques. A total of 10/sup 11/ light particles (.pi./sup -/, K/sup -/, anti p) was sampled at 70 GeV/c. This experiment places a limit of 1.1 x 10/sup -37/ cm/sup 2//(GeV/c)/sup 2//nucleon on the invariant cross section for the production of stable particles in the mass range of 4 to 10 GeV/c/sup 2/. As a by-product of this search the relative production rates are also measured for anti p, anti d, anti t, He-3, and He-4. 23 references.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1979 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1979 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book INIS Atomindex written by and published by . This book was released on 1980 with total page 1166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Massive Long Lived Particles in Aluminum Targets Irradiated by 300 GeV and 400 GeV Protons written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A directional gas Cherenkov counter, which employed six phototubes to sample Cherenkov light from single particles having a gamma greater than ~10 was used to achieve accidental rates of less than one per day if operated near targets with surface radiation levels of as high as 10/sup +3/ r/hr. The cosmic ray background measured by the apparatus was reduced to less than one per day by mounting our directional Cherenkov counter above the irradiated targets and facing toward the earth. Two searches of a few days duration, after bombardments at energies of 300 and 400 GeV with>10/sup 16/ protons at NAL, were made in four inch thick targets of aluminum, mounted just down stream from another aluminum target. No long-lived particles were observed with cross sections for production and capture of approximately less than a micro-micro barn in a lifetime range of a few to a few thousand hours. (auth) from the decay of a long-lived intermediate state. (auth).

Download or read book Coherent Production of Charged Particles on Nuclei by 400 GeV c Protons written by and published by . This book was released on 1977 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological cross sections [delta]{sub coh}{sup (n)} (n = 1,3,5 and 7) of coherent diffractive dissociation of 400 Gev/c protons on nuclei of photoemulsion elements have been measured. Topological cross sections increase in the energy range from 20 to 400 Gev/c. This growth is the most noticeable for multiprong topologies. The total cross section of diffractive coherent production also increases from 8 to 25 mb/nucleus in this energy range. The increasing of the average multiplicity of charged particles in reaction of coherent proton dissociates is consistent with the logarithmic law n{sub coh} = (90.25 ± 0.05) inp. + (1.3 ± 0.25).

Download or read book A Search for Long lived Strongly produced Heavy Particles in Proton antiproton Collisions at Center of mass Energy 630 GeV written by Ira Joseph Kroll and published by . This book was released on 1989 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Long lived Charged Particles in Proton proton Collisions at math Display written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented of a search for heavy stable charged particles produced in proton-proton collisions at √s = 13 TeV using a data sample corresponding to an integrated luminosity of 2.5 fb-1 collected in 2015 with the CMS detector at the CERN LHC. The search is conducted using signatures of anomalously high energy deposits in the silicon tracker and long time-of-flight measurements by the muon system. The data are consistent with the expected background, and upper limits are set on the cross sections for production of long-lived gluinos, top squarks, tau sleptons, and lepton-like long-lived fermions. These upper limits are equivalently expressed as lower limits on the masses of new states; the limits for gluinos, ranging up to 1610 GeV, are the most stringent to date. Furthermore, limits on the cross sections for direct pair production of long-lived tau sleptons are also determined.

Download or read book High Energy Physics Index written by and published by . This book was released on 1989 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1980 with total page 1130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charged and Neutral Particle Production from 400 GeV c Proton Proton Collisions written by Richard Kass and published by . This book was released on 1978 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1971 with total page 1372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Long lived Neutral Particles Decaying to Quark antiquark Pairs in Proton proton Collisions at u221A s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is performed for long-lived massive neutral particles decaying to quark-antiquark pairs. The experimental signature is a distinctive topology of a pair of jets, originating at a secondary vertex. Events were collected with the CMS detector at the CERN LHC in proton-proton collisions at a center-of-mass energy of 8 TeV. The data analyzed correspond to an integrated luminosity of 18.5 fb–1. No significant excess is observed above standard model expectations. Upper limits at 95% confidence level are set on the production cross section of a heavy neutral scalar particle, H, in the mass range of 200 to 1000 GeV, decaying promptly into a pair of long-lived neutral X particles in the mass range of 50 to 350 GeV, each in turn decaying into a quark-antiquark pair. For X with mean proper decay lengths of 0.4 to 200 cm, the upper limits are typically 0.5–200 fb. The results are also interpreted in the context of an R-parity-violating supersymmetric model with long-lived neutralinos decaying into a quark-antiquark pair and a muon. For pair production of squarks that promptly decay to neutralinos with mean proper decay lengths of 2–40 cm, the upper limits on the cross section are typically 0.5–3 fb. As a result, the above limits are the most stringent on these channels to date.

Download or read book Search for Long lived Particles that Decay Into Final States Containing Two Electrons Or Two Muons in Proton proton Collisions at sqrt s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a displaced secondary vertex. Events corresponding to an integrated luminosity of 19.6 (20.5) fb-1 in the electron (muon) channel were collected with the CMS detector at the CERN LHC in proton-proton collisions at √s=8 TeV. No significant excess is observed above standard model expectations. Upper limits on the product of the cross section and branching fraction of such a signal are presented as a function of the long-lived particle's mean proper decay length. The limits are presented in an approximately model-independent way, allowing them to be applied to a wide class of models yielding the above topology. Over much of the investigated parameter space, the limits obtained are the most stringent to date. In the specific case of a model in which a Higgs boson in the mass range 125-1000 GeV/c2 decays into a pair of long-lived neutral bosons in the mass range 20-350 GeV/c2, each of which can then decay to dileptons, the upper limits obtained are typically in the range 0.2-10 fb for mean proper decay lengths of the long-lived particles in the range 0.01-100 cm. In the case of the lowest Higgs mass considered (125 GeV/c2), the limits are in the range 2-50 fb. As a result, these limits are sensitive to Higgs boson branching fractions as low as 10-4.

Download or read book Precise measurements of particle production by 400 GeV c protons on beryllium targets written by and published by . This book was released on 1980 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Search for Displaced Leptons in the ATLAS Detector written by Lesya Horyn and published by Springer Nature. This book was released on 2022-02-07 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for long-lived particles decaying into displaced electrons and/or muons with large impact parameters. This signature provides unique sensitivity to the production of theoretical lepton-partners, sleptons. These particles are a feature of supersymmetric theories, which seek to address unanswered questions in nature. The signature searched for in this thesis is difficult to identify, and in fact, this is the first time it has been probed at the Large Hadron Collider (LHC). It covers a long-standing gap in coverage of possible new physics signatures. This thesis describes the special reconstruction and identification algorithms used to select leptons with large impact parameters and the details of the background estimation. The results are consistent with background, so limits on slepton masses and lifetimes in this model are calculated at 95% CL, drastically improving on the previous best limits from the Large Electron Positron Collider (LEP).

Download or read book Particle Physics Reference Library written by Christian W. Fabjan and published by Springer Nature. This book was released on 2020 with total page 1083 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access