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Studies of Charged Particle Dynamics for Antihydrogen Synthesis

Description: Synthesis and capture of antihydrogen in controlled laboratory conditions will enable precise studies of neutral antimatter. The work presented deals with some of the physics pertinent to manipulating charged antiparticles in order to create neutral antimatter, and may be applicable to other scenarios of plasma confinement and charged particle interaction. The topics covered include the electrostatic confinement of a reflecting ion beam and the transverse confinement of an ion beam in a purely electrostatic configuration; the charge sign effect on the Coulomb logarithm for a two component (e.g., antihydrogen) plasma in a Penning trap as well as the collisional scattering for binary Coulomb interactions that are cut off at a distance different than the Debye length; and the formation of magnetobound positronium and protonium.
Date: December 2014
Creator: Correa, Jose Ricardo
Partner: UNT Libraries

Final Technical Report: "New Tools for Physics with Low-energy Antimatter"

Description: The objective of this research is to develop new tools to manipulate antimatter plasmas and to tailor them for specific scientific and technical uses. The work has two specific objectives. One is establishing the limits for positron accumulation and confinement in the form of single-component plasmas in Penning-Malmberg traps. This technique underpins a wealth of antimatter applications. A second objective is to develop an understanding of the limits for formation of cold, bright positron beams. The research done in this grant focused on particular facets of these goals. One focus was extracting tailored beams from a high-field Penning-Malmberg trap from the magnetic field to form new kinds of high-quality electrostatic beams. A second goal was to develop the technology for colder trap-based beams using a cryogenically cooled buffer gas. A third objective was to conduct the basic plasma research to develop a new high-capacity multicell trap (MCT) for research with antimatter. Progress is reported here in all three areas. While the goal of this research is to develop new tools for manipulating positrons (i.e., the antiparticles of electrons), much of the work was done with test electron plasmas for increased data rate. Some of the techniques developed in the course of this work are also relevant to the manipulation and use of antiprotons.
Date: October 2, 2013
Creator: Surko, Clifford M.
Partner: UNT Libraries Government Documents Department

Simulation and Optimization of the Spin Coherent Time for the Proton Electric Dipole Moment Measurement

Description: Work during this quarter has concentrated on (1) lattice development of an “all-in-one” storage ring lattice for measuring the EDM's of protons, deuterons, and helium-3 nuclei. (2) COSY EDM precursor experiments; especially using an electric bend element borrowed from the Fermilab Tevatron. (3) establishing benchmark lattices for comparing beam evolution codes. My responsibilities have been to design or alter lattices for these storage ring experiments and to guide the development of the UAL/ETEAPOT, enabling it to simulate beam and polarization evolution and survival in these experiments.
Date: April 1, 2012
Creator: Talman, Richard
Partner: UNT Libraries Government Documents Department

Direct observation limits on antimatter gravitation

Description: The proposed Antihydrogen Gravity experiment at Fermilab (P981) will directly measure the gravitational attraction g between antihydrogen and the Earth, with an accuracy of 1% or better. The following key question has been asked by the PAC: Is a possible 1% difference between g and g already ruled out by other evidence? This memo presents the key points of existing evidence, to answer whether such a difference is ruled out (a) on the basis of direct observational evidence; and/or (b) on the basis of indirect evidence, combined with reasoning based on strongly held theoretical assumptions. The bottom line is that there are no direct observations or measurements of gravitational asymmetry which address the antimatter sector. There is evidence which by indirect reasoning can be taken to rule out such a difference, but the analysis needed to draw that conclusion rests on models and assumptions which are in question for other reasons and are thus worth testing. There is no compelling evidence or theoretical reason to rule out such a difference at the 1% level.
Date: June 1, 2008
Creator: Fischler, Mark; Lykken, Joe; Roberts, Tom & /Fermilab
Partner: UNT Libraries Government Documents Department

Observation of an Antimatter Hypernucleus

Description: Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons - composed of an antiproton, antineutron, and antilambda hyperon - produced by colliding gold nuclei at high energy. Our analysis yields 70 {+-} 17 antihypertritons ({sub {bar {Lambda}}}{sup 3}{bar H}) and 157 {+-} 30 hypertritons ({sub {Lambda}}{sup 3}H). The measured yields of {sub {Lambda}}{sup 3}H ({sub {bar {Lambda}}}{sup 3}{bar H}) and {sup 3}He ({sup 3}{ovr He}) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and nuclei containing strange quarks, have implications spanning nuclear/particle physics, astrophysics, and cosmology.
Date: July 5, 2010
Creator: Collaboration, STAR & Abelev, Betty
Partner: UNT Libraries Government Documents Department

Towards laboratory-produced relativistic electron-positron pair-plasmas

Description: Relativistic pair-plasmas and jets are believed to exist in many astrophysical objects and are often invoked to explain energetic phenomena related to Gamma Ray Bursts and Black Holes. On earth, positrons from radioactive isotopes or accelerators are used extensively at low energies (sub-MeV) in areas related to surface science positron emission tomography and basic antimatter science. Experimental platforms capable of producing the high-temperature pair-plasma and high-flux jets required to simulate astrophysical positron conditions have so far been absent. In the last few years, we performed extensive experiments generating positrons with intense lasers where we found that relativistic electron and positron jets are produced by irradiating a solid gold target with an intense picosecond laser pulse. The positron temperatures in directions parallel and transverse to the beam both exceeded 0.5 MeV, and the density of electrons and positrons in these jets are of order 10{sup 16} cm{sup -3} and 10{sup 13} cm{sup -3}, respectively. With the advent of high-energy ultra-short laser pulses, we expect that a charge-neutral, relativistic pair-plasma is achievable, a novel regime of laboratory-produced hot dense matter. This talk will present some details of the laser-produced pair-plasma experiments.
Date: August 31, 2010
Creator: Chen, H; Wilks, S C; Meyerhofer, D D; Beiersdorfer, P; Cauble, R; Dollar, F et al.
Partner: UNT Libraries Government Documents Department

AntiMatter Physics at Low Energy (AMPLE)

Description: The First Workshop on Antimatter Physics at Low Energy was held at FNAL last spring, April 10-12, 1986, with the stated purpose of gauging the interest in the physics that would be made possible by adding a variable energy pbar storage and cooling ring to the existing Accumulator at FNAL. The Workshop Proceedings are now published and include a concise collection of papers addressing the physics with pbars below 10 GeV/c that could be made available from the present antiproton source at FNAL. It is worth emphasizing that this is a possible without major impact on the primary mission of the laboratory. Such a facility would include provisions for extracted cooled pbar beams as well as future internal targer and colliding beam experiments. Specific experimental proposals would be facilitated by the existence of a reference design for such a facility. A central effort to produce such a reference design would be the logical next step. they are requesting the opportunity to present to this committee an overview of the physics arguments for such a facility; what we would require from the committee is 'strong encouragement' to proceed with such a reference design leading to a formal proposal. The aid of the FNAL staff in drawing up this reference design would be essential. One or more formal proposals for specific physics experiments would be forthcoming.
Date: January 1, 1986
Creator: Bonner, B.E.; U., /Rice; Pinsky, L.S. & U., /Houston
Partner: UNT Libraries Government Documents Department

Progress towards antihydrogen production by the reaction of cold antiprotons with positronium atoms

Description: An experiment aimed at producing antihydrogen atoms by the reaction of cold antiprotons stored in a Penning trap with injected ground state positronium atoms is described. The apparatus developed in an attempt to observe the charge conjugate reaction using proton projectiles is discussed. Technically feasible upgrades to this apparatus are identified which may allow, in conjunction with the PS200 trap, antihydrogen production at LEAR.
Date: March 1, 1995
Creator: Charlton, M.; Laricchia, G. & Deutch, B.I.
Partner: UNT Libraries Government Documents Department

An improved limit on jet handedness in Z{sup 0} decays

Description: We present the results of an improved search for jet handedness in hadronic decays of Z{sup degree} bosons collected by the SLD experiment at SLAC. Quark and antiquark jets, expected to be oppositely polarized in Z{sup degree} decays, were separated using the large forward-backward quark asymmetry induced by the highly polarized SLC electron beam. The larger data sample and beam polarization of the 1994/5 SLC/SLD run yield a factor of two improvement in our sensitivity to jet handedness. Assuming Standard Model values of quark polarizations we set an improved upper limit on the analyzing power of the handedness method.
Date: July 1995
Creator: Collaboration, The SLD
Partner: UNT Libraries Government Documents Department

Formation of low-energy antihydrogen

Description: Antihydrogen atoms, produced near rest, trapped in a magnetic well, and cooled to the lowest possible temperature (kinetic energy) could provide an extremely powerful tool for the search of violations of CPT and Lorentz invariance. The author describes plans to trap antiprotons and positrons in a combined Penning trap and to form a significant number of cold antihydrogen atoms for comparative precision spectroscopy of hydrogen and antihydrogen.
Date: March 1, 1999
Creator: Holzscheiter, M.H. & Collaboration, ATHENA
Partner: UNT Libraries Government Documents Department

Antihydrogen production and precision experiments

Description: The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. In recent years, impressive progress has been achieved in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and in storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. Once antihydrogen atoms have been captured at low energy, spectroscopic methods can be applied to interrogate their atomic structure with extremely high precision and compare it to its normal matter counterpart, the hydrogen atom. Especially the 1S-2S transition, with a lifetime of the excited state of 122 msec and thereby a natural linewidth of 5 parts in 10{sup 16}, offers in principle the possibility to directly compare matter and antimatter properties at a level of 1 part in 10{sup 16}.
Date: December 31, 1996
Creator: Nieto, M.M.; Goldman, T. & Holzscheiter, M.H.
Partner: UNT Libraries Government Documents Department

Tests of CPT, Lorentz invariance and the WEP with antihydrogen

Description: Antihydrogen atoms, produced near rest, trapped in a magnetic well, and cooled to the lowest possible temperature (kinetic energy) could provide an extremely powerful tool for the search of violations of CPT and Lorentz invariance. Equally well, such a system could be used for searches of violations of the Weak Equivalence Principle (WEP) at high precision. The author describes his plans to form a significant number of cold, trapped antihydrogen atoms for comparative precision spectroscopy of hydrogen and antihydrogen and comment on possible first experiments.
Date: March 1999
Creator: Holzscheiter, M. H.
Partner: UNT Libraries Government Documents Department

Artificially Structured Boundary for Control and Confinement of Beams and Plasmas

Description: An artificially structured boundary (ASB) produces a short-range, static electromagnetic field that can reflect charged particles. In the work presented, an ASB is considered to consist of a spatially periodic arrangement of electrostatically plugged magnetic cusps. When used to create an enclosed volume, an ASB may confine a non-neutral plasma that is effectively free of applied electromagnetic fields, provided the spatial period of the ASB-applied field is much smaller than any one dimension of the confinement volume. As envisioned, a non-neutral positron plasma could be confined by an ASB along its edge, and the space-charge of the positron plasma would serve to confine an antiproton plasma. If the conditions of the two-species plasma are suitable, production of antihydrogen via three-body recombination for antimatter gravity studies may be possible. A classical trajectory Monte Carlo (CTMC) simulation suite has been developed in C++ to efficiently simulate charged particle interactions with user defined electromagnetic fields. The code has been used to explore several ASB configurations, and a concept for a cylindrically symmetric ASB trap that employs a picket-fence magnetic field has been developed. Particle-in-cell (PIC) modeling has been utilized to investigate the confinement of non-neutral and partially neutralized positron plasmas in the trap.
Date: May 2018
Creator: Hedlof, Ryan
Partner: UNT Libraries

Examination of Magnetic Plasma Expulsion

Description: Magnetic plasma expulsion uses a magnetic field distortion to redirect incident charged particles around a certain area for the purposes of shielding. Computational studies are carried out and for certain values of magnetic field, magnetic plasma expulsion is found to effectively shield a sizable area. There are however many plasma behaviors and interactions that must be considered. Applications to a new cryogenic antimatter trap design are discussed.
Date: May 2018
Creator: Phillips, Ryan Edward
Partner: UNT Libraries

Beauty for pedestrians toy models for CP violation and baryon asymmetry

Description: Why are particles different from antiparticles? C and P Violation - 1956; CP Violation - 1964. Why so little new experimental information in thirty years? Where has all the antimatter gone? Toy models are presented showing: (1) How CPT and {Delta}I = 1/2 make life difficult in kaon physics by requiring equal K{sup {plus_minus}} total widths and also equal partial widths to many exclusive channels. (2) How to understand and get around CPT restrictions. (3) How CP asymmetries can occur in exclusive partial widths and still add up to equal total widths. (4) Sakharov`s 1966 scenario for how CP Violation + proton decay can explain baryon asymmetry (5) How B physics can help.
Date: December 1, 1995
Creator: Lipkin, H.J.
Partner: UNT Libraries Government Documents Department

Anti-matter propulsion: feasibility, status, and possible enhancement

Description: The possible use of advanced propulsion techniques must be considered if the currently envisioned launch date of the Manned Mars Mission were to be delayed until 2020 or later. Within the next 30 years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of anti-protons to become feasible. Of the possible methods, the anti-proton (anti p), reaction offers the highest potential, the greastest problems, and the most fascination. An Isp of 5000 s would allow the currently envisioned ship to fly to Mars in 3 months and would require about one million pounds to be assembled in Earth orbit. Anti-protons are currently being produced in the world in amounts of about 10/sup 14/ particles per year. With sufficient effort, almost a mg/yr (6 x 10/sup 20/) could be produced by the early 2000s. Current experiments plan to decelerate and capture about 10/sup 10/ or greater anti-protons in an electrostatic Penning trap. Such traps may provide a source of low energy anti p's for development of better storage mechanisms suitable for propulsion. Recently, proposals have been investigated which would amplify the average energy released per anti p used. The proposals entail using the anti p's to produce inertial confinement fusion of a capsule or to produce negative muons which can catalyze fusion. By increasing the energy released per anti p, the effective specific cost, $/joule, can be reduced to attractive levels. These two proposals and other areas of research can be investigated now and will help in assessing the feasibility of an anti p engine.
Date: January 1, 1985
Creator: Howe, S.D.
Partner: UNT Libraries Government Documents Department

A Proposal for Study of Structure and Dynamics of Energy/Matter Based on Production of Gamma-Ray at SLAC Facility

Description: The success of this proposal will open new areas of Chemistry with antimatter: (1) new chemical dynamics; (2) exclusive production of parent ions by energy-tuning the positrons; (3) formation of antimatter compounds; (4) nano- and microscopic imaging of molecules, cells, and tumors (5) multi-positron systems and their thermodynamics and chemical kinetics. Also with o-Ps and p-Ps physics including speculations of dark mater (PAMELA & ATIC reported excesses in the e{sup +}e{sup -} cosmic rays).
Date: December 13, 2011
Creator: Decker, F.-J.; Krasnykh, Anatoly; /SLAC; Perelstein, M.; U., /Cornell; Shramenko, B. et al.
Partner: UNT Libraries Government Documents Department

Direct CP Violation in Charmless Hadronic B-Meson Decays at the PEP-II Asymmetric B-Meson Factory

Description: The study of the quark transition b {yields} s{bar s}s, which is a pure loop-level (''penguin'') process leading to several B-meson-decay final states, most notably {phi}K, is arguably the hottest topic in B-meson physics today. The reason is the sensitivity of the amplitudes and the CP-violating asymmetries in such processes to physics beyond the Standard Model. By performing these measurements, we improve our understanding of the phenomenon of combined-parity (CP) violation, which is believed to be responsible for the dominance of matter over antimatter in our Universe. Here, we present measurements of branching fractions and charge asymmetries in the decays B{sup +} {yields} {phi}K{sup +} and B{sup 0} {yields} {phi}K{sup 0} in a sample of approximately 89 million B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B-meson Factory at SLAC. We determine {Beta}(B{sup +} {yields} {phi}K{sup +}) = (10.0{sub -0.8}{sup +0.9} {+-} 0.5) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}K{sup 0}) = (8.4{sub -1.3}{sup +1.5} {+-} 0.5) x 10{sup -6}, where the first error is statistical and the second is systematic. Additionally, we measure the CP-violating charge asymmetry {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) = 0.04 {+-} 0.09 {+-} 0.01, with a 90% confidence-level interval of [-0.10, 0.18], and set an upper limit on the CKM- and color-suppressed decay B{sup +} {yields} {phi}{pi}{sup +}, {Beta}(B{sup +} {yields} {phi}{pi}{sup +}) < 0.41 x 10{sup -6} (at the 90% confidence level). Our results are consistent with the Standard Model, which predicts {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) {approx}< 1% and {Beta}(B {yields} {phi}{tau}) << 10{sup -7}. Since many models of physics beyond the Standard Model introduce additional loop diagrams with new heavy particles and new CP-violating phases that would contribute to these decays, potentially making {Alpha}{sub CP} (B{sup {+-}} {yields} {phi}K{sup {+-}}) and {Beta}(B {yields} {phi}{pi}) quite ...
Date: May 6, 2005
Creator: Telnov, Alexandre Valerievich & /UC, Berkeley
Partner: UNT Libraries Government Documents Department

A Novel Antimatter Detector with Application to Dark Matter Searches

Description: We report on recent accelerator testing of a prototype general antiparticle spectrometer (GAPS). GAPS uses a novel approach for indirect dark matter searches that exploits the antideuterons produced in neutralino-neutralino annihilations. GAPS captures these antideuterons into a target with the subsequent formation of exotic atoms. These exotic atoms decay with the emission of x-rays of precisely defined energy and a correlated pion signature from nuclear annihilation. This signature uniquely characterizes the antideuterons. Preliminary analysis of data from a prototype GAPS in an antiproton beam at the KEK accelerator in Japan has confirmed the multiple x-ray/pion star topology and indicated x-ray yields consistent with prior expectations. Moreover, our success in utilizing solid rather than gas targets represents a significant simplification over our original approach and offers potential gains in sensitivity through reduced dead mass in the target area.
Date: February 13, 2006
Creator: Craig, W W; Fabris, L; Madden, N; Ziock, K; Hailey, C; Aramaki, T et al.
Partner: UNT Libraries Government Documents Department

Vacuum, matter, antimatter and the problem of cold compression

Description: We discuss the possibility of producing a new kind of nuclear system by putting a few antibaryons inside ordinary nuclei. The structure of such systems is calculated within the relativistic mean-field model assuming that the nucleon and antinucleon potentials are related by the G-parity transformation. The presence of antinucleons leads to decreasing vector potential and increasing scalar potential for the nucleons. As a result, a strongly bound system of high density is formed. Due to the significant reduction of the available phase space the annihilation probability might be strongly suppressed in such systems.
Date: January 1, 2003
Creator: Greiner, Walter, & Buervenich, T. J. (Thomas J.)
Partner: UNT Libraries Government Documents Department

Rare B Meson Decays With Omega Mesons

Description: Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.
Date: April 24, 2006
Creator: Zhang, Lei & U., /Colorado
Partner: UNT Libraries Government Documents Department

Laser Created Relativistic Positron Jets

Description: Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the most energetic phenomena in the universe.
Date: October 8, 2009
Creator: Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N et al.
Partner: UNT Libraries Government Documents Department