On Antimatter and Cosmology.

Science.gov (United States)

Kevane, C J

1961-02-24

A cosmological model based on a gravitational plasma of matter and antimatter is discussed. The antigravitational interaction of matter and antimatter leads to segregation and an expansion of the plasma universe. The expansion time scale is controlled by the aggregation time scale.

Matter-antimatter asymmetry

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

The Conference is devoted to a multidisciplinary study of matter-antimatter asymmetry and, in particular, from the point of view of particle physics, astrophysics and cosmology. A number of topics, such as the practical applications of antimatter in medical imaging, of particular interest to non-specialists, will also be briefly covered. More than thirty years after the discovery of CP violation in the kaon system, precision experiments with kaons at CERN and Fermilab have demonstrated the existence of direct CP violation, opening a window on a hitherto poorly explored part of particle physics. On the one hand, two experiments devoted mainly to CP violation in B mesons, BABAR and Belle, are beginning to test CP violation in the Standard Model in a decisive way. On the other hand, balloon experiments and the space-based AMS project are circumscribing precise limits on the cosmological abundance of antimatter. Finally, the fundamental problem of cosmological matter-antimatter asymmetry at a Grand Unification scale or at the Electroweak phase transition has been the object of intense theoretical activity in recent years. This document gathers most of the slides that have been presented in the plenary and parallel sessions.

Search for cosmic-ray antimatter

Science.gov (United States)

Smoot, G. F.; Buffington, A.; Orth, C. D.

1975-01-01

It appears probable that some fraction of the cosmic rays has extragalactic origin. A search for antimatter nuclei was conducted with the aid of a balloon-borne superconducting magnetic spectrometer. The investigation made use of the fact that matter and antimatter nuclei, because of their opposite signs of charge, would be deflected in opposite directions when passing through a magnetic field. The antimatter flux limits set by the experiments are discussed.

Matter and antimatter in the universe

International Nuclear Information System (INIS)

Dolgov, A.D.

2002-01-01

Different scenarios of baryogenesis are briefly reviewed from the point of view of possibility of generation of cosmologically interesting amount of antimatter. It is argued that creation of antimatter is possible and natural in many models. In some models not only anti-helium may be produced but also a heavier anti-elements and future observations of the latter would be critical for discovery or establishing stronger upper limits on existence of antimatter. Incidentally a recent observation of iron-rich quasar may present a support to one special model of antimatter creation

Alternative pathways to antimatter containment

International Nuclear Information System (INIS)

Rejcek, J.M.; Browder, M.K.; Fry, J.L.; Koymen, A.; Weiss, A.H.

2003-01-01

Antimatter containment is a gateway technology for future advancements in many areas. Immediate applications in propulsion, medicine, and instrumentation have already been envisioned and many others are yet to be considered. Key to this technological advance is identifying one or more pathways to achieve safe reliable containment of antimatter in sufficient quantities to be useful on an engineering and industrial scale. The goal of this paper is to review current approaches and discuss possible alternative pathways to antimatter containment. Specifically, this paper will address the possibility of designing a solid-state containment system that will safely hold antimatter in quantities dense enough to be of any engineering utility. A discussion of the current research, the needed engineering requirements, and a survey of current research is presented

Large-scale regions of antimatter

International Nuclear Information System (INIS)

Grobov, A. V.; Rubin, S. G.

2015-01-01

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era

Large-scale regions of antimatter

Energy Technology Data Exchange (ETDEWEB)

Grobov, A. V., E-mail: alexey.grobov@gmail.com; Rubin, S. G., E-mail: sgrubin@mephi.ru [National Research Nuclear University MEPhI (Russian Federation)

2015-07-15

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era.

Matter-antimatter Cosmology

Science.gov (United States)

Omnes, R.

1973-01-01

The possible existence of antimatter on a large scale in the universe is evaluated. As a starting point, an attempt was made to understand the origin of matter as being essentially analogous to the origin of backgound thermal radiation. Several theories and models are examined, with particular emphasis on nucleon-antinucleon interactions at intermediate energies. Data also cover annihilation interaction with the matter-antimatter boundary to produce the essential fluid motion known as coalesence.

Observation of the antimatter helium-4 nucleus.

Science.gov (United States)

2011-05-19

High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus (4He), also known as the anti-α (α), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the α-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B antimatter nuclei and a benchmark for possible future observations of 4He in cosmic radiation.

Cosmic antimatter

International Nuclear Information System (INIS)

Tarle, G.; Swordy, S.

1998-01-01

In 1928 Paul Dirac forecasted the existence of antimatter and 4 years later Carl Anderson detected the first antiparticle: the positron in a cloud chamber while studying cosmic radiation. Antiprotons were more difficult to find but in 1955 physicists from Lawrence Berkeley Laboratory got some in a particle accelerator. In 1995 a team from the CERN synthesized atoms of anti-hydrogen by binding positrons to antiprotons in a particle accelerator. Astrophysicists have built more and more complex detectors to study cosmic rays. The detector HEAT (high energy antimatter telescope) has been designed to study positrons above the atmosphere. This detector has been launched for the first time in 1994 and has measured cosmic radiation for 32 hours at an altitude of 37000 meters. The results were challenging: whereas the number of low energy positrons detected agrees with the theory, the number of high energy positrons is too important. It suggests the existence of unknown sources of positrons somewhere in the universe. The massive particles that interact weakly (WIMP) could be such sources. This article draws the history of the quest for antimatter and its implications in cosmology, the detector HEAT is described. (A.C.)

Baryogenesis model predicting antimatter in the Universe

International Nuclear Information System (INIS)

Kirilova, D.

2003-01-01

Cosmic ray and gamma-ray data do not rule out antimatter domains in the Universe, separated at distances bigger than 10 Mpc from us. Hence, it is interesting to analyze the possible generation of vast antimatter structures during the early Universe evolution. We discuss a SUSY-condensate baryogenesis model, predicting large separated regions of matter and antimatter. The model provides generation of the small locally observed baryon asymmetry for a natural initial conditions, it predicts vast antimatter domains, separated from the matter ones by baryonically empty voids. The characteristic scale of antimatter regions and their distance from the matter ones is in accordance with observational constraints from cosmic ray, gamma-ray and cosmic microwave background anisotropy data

Negative numbers and antimatter particles

International Nuclear Information System (INIS)

Tsan, Ung Chan

2012-01-01

Dirac's equation states that an electron implies the existence of an antielectron with the same mass (more generally same arithmetic properties) and opposite charge (more generally opposite algebraic properties). Subsequent observation of antielectron validated this concept. This statement can be extended to all matter particles; observation of antiproton, antineutron, antideuton … is in complete agreement with this view. Recently antihypertriton was observed and 38 atoms of antihydrogen were trapped. This opens the path for use in precise testing of nature's fundamental symmetries. The symmetric properties of a matter particle and its mirror antimatter particle seem to be well established. Interactions operate on matter particles and antimatter particles as well. Conservation of matter parallels addition operating on positive and negative numbers. Without antimatter particles, interactions of the Standard Model (electromagnetism, strong interaction and weak interaction) cannot have the structure of group. Antimatter particles are characterized by negative baryonic number A or/and negative leptonic number L. Materialization and annihilation obey conservation of A and L (associated to all known interactions), explaining why from pure energy (A = 0, L = 0) one can only obtain a pair of matter particle antimatter particle — electron antielectron, proton and antiproton — via materialization where the mass of a pair of particle antiparticle gives back to pure energy with annihilation. These two mechanisms cannot change the difference in the number of matter particles and antimatter particles. Thus from pure energy only a perfectly symmetric (in number) universe could be generated as proposed by Dirac but observation showed that our universe is not symmetric, it is a matter universe which is nevertheless neutral. Fall of reflection symmetries shattered the prejudice that there is no way to define in an absolute way right and left or matter and antimatter

Gravity and antimatter

International Nuclear Information System (INIS)

Goldman, T.; Hughes, R.J.; Nieto, M.M.

1988-01-01

No one has ever dropped a single particle of antimatter. Yet physicists assume that it would fall to the ground just like ordinary matter. Their arguments are based on two well established ideas: the equivalence principle of gravitation and the quantum-mechanical symmetry between matter and antimatter. Today this line of reasoning is being undermined by the possibility that the first of these ideas, the principle of equivalence, may not be true. Indeed all modern attempts to include gravity with the other forces of nature in a consistent, unified quantum theory predict the existence of new gravitational-strength forces, that among other things, will violate the principle. Such effects have been seen already in recent experiments. Hence, an experiment to measure the gravitational acceleration of antimatter could be of great importance to the understanding of quantum gravity. An international team has been formed to measure the graviational acceleration of antiprotons. Such an experiment would provide an unambiquous test, if new gravitational interactions do exist. 10 figs

Antimatter annihilation detection with AEgIS

CERN Document Server

Gligorova, Angela

2015-01-01

AE ̄ gIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an antimatter exper- iment based at CERN, whose primary goal is to carry out the first direct measurement of the Earth’s gravitational acceleration on antimatter. A precise measurement of antimatter gravity would be the first precision test of the Weak Equivalence Principle for antimatter. The principle of the experiment is based on the formation of antihydrogen through a charge exchange reaction between laser excited (Rydberg) positronium and ultra-cold antiprotons. The antihydrogen atoms will be accelerated by an inhomogeneous electric field (Stark acceleration) to form a pulsed cold beam. The free fall of the antihydrogen due to Earth’s gravity will be measured using a moiré de- flectometer and a hybrid position detector. This detector is foreseen to consist of an active silicon part, where the annihilation of antihydrogen takes place, followed by an emulsion part coupled to a fiber time-of-flight detector. This overview prese...

Antimatter: Its history and its properties

International Nuclear Information System (INIS)

Nieto, M.M.; Hughes, R.J.

1987-01-01

We review the conceptual developments of quantum theory and special relativity which culminated in the discovery of and understanding of antimatter. In particular, we emphasize how quantum theory and special relativity together imply that antimatter must exist. Our modern understanding of antimatter is summarized in the CPT theorem of relativistic quantum field theory. The implications of this theorem have never been contradicted by any experiment ever done. 38 refs

Vast antimatter regions and SUSY-condensate baryogenesis

International Nuclear Information System (INIS)

Kirilova, D.; Panayotova, M.; Valchanov, T.

2002-10-01

Natural and abundant creation of antimatter in the Universe in a SUSY baryogenesis model is described. The scenario predicts vast quantities of antimatter, corresponding to galaxy and galaxy cluster scales, separated from the matter ones by baryonically empty voids. Observational constraints on such antimatter regions are discussed. (author)

Antimatter: What is and where did it go?

International Nuclear Information System (INIS)

Roodman, Aaron

2008-01-01

In this public lecture we will explore the mystery of antimatter: Where did it go? Why is the universe made up of only matter, with no observable antimatter? And why does the universe have any matter left in it anyway? The SLAC 'B'-Factory was built to answer these questions. Over the last decade, almost a billion 'B'-mesons were created and studied at the B-Factory to search for subtle differences between matter and antimatter, differences that lie at the heart of the antimatter mystery. We will explain the matter-antimatter discoveries made at the B-Factory, and their connection to this year's Nobel prize in physics. It does not matter if you have no prior knowledge of Antimatter; just bring your curiosity.

CPT symmetry and antimatter gravity in general relativity

Science.gov (United States)

Villata, M.

2011-04-01

The gravitational behavior of antimatter is still unknown. While we may be confident that antimatter is self-attractive, the interaction between matter and antimatter might be either attractive or repulsive. We investigate this issue on theoretical grounds. Starting from the CPT invariance of physical laws, we transform matter into antimatter in the equations of both electrodynamics and gravitation. In the former case, the result is the well-known change of sign of the electric charge. In the latter, we find that the gravitational interaction between matter and antimatter is a mutual repulsion, i.e. antigravity appears as a prediction of general relativity when CPT is applied. This result supports cosmological models attempting to explain the Universe accelerated expansion in terms of a matter-antimatter repulsive interaction.

The lost worlds of antimatter

International Nuclear Information System (INIS)

Davies, P.

1980-01-01

Given that matter can exist in two forms, each the mirror image of the other which annihilate each other on contact, producing energy, Dirac's cosmological model explains why there is no conspicuous antimatter in the world since it cannot co-exist with ordinary matter. However, if the creation of matter is always accompanied by an equal and opposite quantity of antimatter, how has all the material of the Universe come into existence without being infested by its mirror substance. The question of whether Grand Unified Theories can bring about an imbalance between matter and antimatter in the primeval Universe is considered. (UK)

Antimatter: What is and where did it go?

Energy Technology Data Exchange (ETDEWEB)

Roodman, Aaron (Stanford University)

2008-10-28

In this public lecture we will explore the mystery of antimatter: Where did it go? Why is the universe made up of only matter, with no observable antimatter? And why does the universe have any matter left in it anyway? The SLAC 'B'-Factory was built to answer these questions. Over the last decade, almost a billion 'B'-mesons were created and studied at the B-Factory to search for subtle differences between matter and antimatter, differences that lie at the heart of the antimatter mystery. We will explain the matter-antimatter discoveries made at the B-Factory, and their connection to this year's Nobel prize in physics. It does not matter if you have no prior knowledge of Antimatter; just bring your curiosity.

The Mystery of the Missing Antimatter

CERN Document Server

Quinn, Helen R

2008-01-01

In the first fractions of a second after the Big Bang lingers a question at the heart of our very existence: why does the universe contain matter but almost no antimatter? The laws of physics tell us that equal amounts of matter and antimatter were produced in the early universe--but then, something odd happened. Matter won out over antimatter; had it not, the universe today would be dark and barren. But how and when did this occur? Helen Quinn and Yossi Nir guide readers into the very heart of this mystery--and along the way offer an exhilarating grand tour of cutting-edge physics. They explain both the history of antimatter and recent advances in particle physics and cosmology. And they discuss the enormous, high-precision experiments that particle physicists are undertaking to test the laws of physics at their most fundamental levels--and how their results reveal tantalizing new possibilities for solving this puzzle at the heart of the cosmos. The Mystery of the Missing Antimatter is at once a history of i...

Vast Antimatter Regions and Scalar Condensate Baryogenesis

OpenAIRE

Kirilova, D.; Panayotova, M.; Valchanov, T.

2002-01-01

The possibility of natural and abundant creation of antimatter in the Universe in a SUSY-baryogenesis model with a scalar field condensate is described. This scenario predicts vast quantities of antimatter, corresponding to galaxy and galaxy cluster scales today, separated from the matter ones by baryonically empty voids. Theoretical and observational constraints on such antimatter regions are discussed.

Antimatter in the universe and laboratory

OpenAIRE

Dolgov, A. D.

2014-01-01

Possible signatures which may indicate an existence of antimatter in the Galaxy and in the early universe are reviewed. A model which could give rise to abundant antimatter in the Galaxy is considered.

Matter-antimatter domains in the universe

International Nuclear Information System (INIS)

Dolgov, A.

2001-01-01

A possible existence of cosmologically large domains of antimatter or astronomical 'anti-objects' is discussed. A brief review of different scenarios of baryogenesis predicting a noticeable amount of antimatter is given. Though both theory and observations indicate that the universe is most possibly uniformly charge asymmetric without any noticeable amount of antimatter, several natural scenarios are possible that allow for cosmologically (astronomically) interesting objects in close vicinity to us. The latter may be discovered by observation of cosmic ray antinuclei

Antimatter Experiments

CERN Multimedia

2004-01-01

Antimatter should behave in identical fashion to matter if a form of spacetime symmetry called CPT invariance holds. Two experiments at CERN near Geneva are testing this hypothesis using antihydrogen atoms

Antimatter in the universe and laboratory

Directory of Open Access Journals (Sweden)

Dolgov A.D.

2015-01-01

Full Text Available Possible signatures which may indicate an existence of antimatter in the Galaxy and in the early universe are reviewed. A model which could give rise to abundant antimatter in the Galaxy is considered.

Matter and antimatter in the universe

International Nuclear Information System (INIS)

Canetti, Laurent; Shaposhnikov, Mikhail; Drewes, Marco

2012-01-01

We review observational evidence for a matter–antimatter asymmetry in the early universe, which leads to the remnant matter density we observe today. We also discuss bounds on the presence of antimatter in the present-day universe, including the possibility of a large lepton asymmetry in the cosmic neutrino background. We briefly review the theoretical framework within which baryogenesis, the dynamical generation of a matter–antimatter asymmetry, can occur. As an example, we discuss a testable minimal particle physics model that simultaneously explains the baryon asymmetry of the universe, neutrino oscillations and dark matter. (paper)

The Search for Cosmological Antimatter

Science.gov (United States)

Streitmatter, Robert E.

2004-01-01

For more than 40 years, experimentalists have searched in the cosmic radiation for evidence of antimatter which may have been created in the early Universe. The experimental evidence for cosmologically significant amounts of antimatter in the Universe is reviewed. There is no compelling evidence, either theoretical of experimental. However, the possibility is not completely ruled out.

High density storage of antimatter for space propulsion applications

International Nuclear Information System (INIS)

Smith, Gerald A.; Coughlin, Dan P.

2001-01-01

The specific energy of antimatter is 180 MJ/μg, making it the largest specific energy density material known to humankind. Three challenges remain to be solved for space propulsion applications: first, sufficient amounts must be made to permit missions into deep space; second, efficient methods must be found to turn the antimatter into thrust and Isp; and third, the antimatter must be stored for long periods of time. This paper addresses the third issue. We discuss conventional (electromagnetic) methods of confining antimatter, as well as unconventional concepts, including the use of quantum effects in materials and antimatter chemistry

Antimatter in the classroom

CERN Multimedia

CERN Bulletin

2010-01-01

A brand new teaching resource has just been made available on the CERN Education website. The Antimatter Teaching Module contains eight lesson plans, together with background materials and extension topics, which are part of a wide educational project whose aim is to stimulate interest in science by introducing themes in modern physics to students aged 14-15 years, that is, earlier than is the practice in most national curricula. Terrence Baine (left) and Rolf Landua (right) with an antimatter trap from the film 'Angels & Demons'. In his capacity as CERN’s first Teacher in Residence, Terrence Baine’s primary project was to develop teaching modules to help high school teachers around the world incorporate modern particle physics into their curricula. “Back in October, it was decided that the first module should be on antimatter”, explains Terrence, who worked on it in collaboration with Rolf Landua, head of the Education Group and antimatter expert. “...

Gravity measurement on antimatter and supergravity

International Nuclear Information System (INIS)

Beverini, N.; Poggiani, R.; Torelli, G.; Lagomarsino, V.; Manuzio, G.; Scuri, F.

1988-01-01

The relevance of gravity measurements with antimatter is discussed assuming both scalar and vector terms in the generalized gravitational potential. On the basis of previous experimental results a suitable parametrization allows to point out the different sensitivity between matter-matter and matter-antimatter experiments. (orig.)

Turning the Star Trek Dream into Reality by Understanding Matter & Antimatter

Science.gov (United States)

Hansen, Norm

2002-04-01

People are going to learn all about matter and antimatter. Where matter and antimatter comes from. Where antimatter exists within our solar system. What the Periodic Table of Matter-AntiMatter Elements looks like. What each of the 109 antimatter element's nuclear, physical, and chemical characteristics are. How much energy is produced from matter and antimatter. And what needs to be done to turn the Star Trek Dream into Reality. The Milky Way Galaxy is composed of matter and antimatter. At the center of the galaxy, there are two black holes. One black hole is composed of matter; and the other is antimatter. The black holes are ejecting matter and antimatter into space forming a halo and spiral arms of matter & antimatter stars. The sun is one of the billions of stars that are composed of matter. There are a similar number of antimatter stars. Our Solar System contains the sun, earth, planets, and asteroids that are composed of matter, and comets that are composed of antimatter. When galactic antimatter enters our solar system, the antimatter is called comets. Astronomers have observed hundred of comets orbiting the sun and are finding new comets every year. During the last century, mass destruction has resulted when antimatter collided with Jupiter and Earth. How Humanity deals with the opportunities and dangers of antimatter will determine our destiny. Mankind has known about comets destructive power for thousands of years going back to the days of antiquity. Did comets have anything to do with the disappearance of Atlantis over twelve thousand years ago? We may never know; but is there a similar situation about to take place? Scientists have been studying antimatter by producing, storing, and colliding small quantities at national laboratories for several decades. Symmetry exists between matter and antimatter. Science and Technology provides unlimited opportunities to benefit humanity. Antimatter can be used, as a natural source of energy, to bring every country

Charged anti-cluster decay modes of antimatter nuclei

International Nuclear Information System (INIS)

Poenaru, D.N.; Gherghescu, R.A.; Greiner, W.

2015-01-01

Antimatter may exist in large amounts in far-away galaxies due to cosmic inflation in the primordial time of the universe. The antimatter character of Dirac’s negative energy states of electrons became clear after discovery in 1932 of the positron by C.D. Anderson. A positron soon finds an electron, undergo annihilation, and produces a pair of 511 keV rays. Antimatter is a material composed of antiparticles which bind with each other, e.g. e"+ and p can form an H atom. Charged antimatter can be confined by a combination of electric and magnetic fields, in a Penning trap. Anti-atoms are difficult to produce; the antihydrogen ( H ) was produced and confined for about 1000 s. The antimatter helium-4 nucleus, "4He, or , is the heaviest observed antinucleus. It was established that every antiparticle has the same mass with its particle counterpart; they differ essentially by the sign of electric charge: m_e_+ = m_e_-, m_p = m_p, m_n = m_n, etc. Also every antinucleus has the same mass or binding energy as its mirror nucleus. We expect that anti-alpha spontaneous emission from an antimatter nucleus will have the same Q-value and half-life as alpha emission from the corresponding mirror nucleus. The same will be true for anti-cluster decay and spontaneous fission of antimatter nuclei. This is the consequence of the invariance of binding energy as well as of the surface and Coulomb energy when passing from matter to antimatter nuclei. (author)

Matter-antimatter puzzle: LHCb improves resolution

CERN Multimedia

Antonella Del Rosso

2012-01-01

In 2010, Fermilab’s DØ experiment reported a one percent difference in the properties of matter and antimatter in decays of B mesons (that is, particles containing beauty quarks) to muons. Saturday, at the ICHEP Conference in Melbourne, the LHCb experiment at CERN presents new results, which do not confirm this anomaly and are consistent with the Standard Model predictions. The same experiment has also presented the first evidence of asymmetry arising in other decays of the same family of mesons. The image becomes clearer but the puzzle has not yet been solved.   Inside the LHCb detector. The matter-antimatter imbalance in the Universe is a very hot topic in physics. The conundrum arises from the fact that, although objects made of antimatter are not observed in the Universe, theory predicts that matter and antimatter be created equally in particle interactions and in the Big Bang. Only small deviations from this very symmetric behaviour are incorporated in the theory. E...

Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen

Science.gov (United States)

2002-06-24

UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012494 TITLE: Cold Antimatter Plasmas, and Aspirations for Cold...part numbers comprise the compilation report: ADP012489 thru ADP012577 UNCLASSIFIED Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen G...and positrons. The antiprotons come initially from the new Antiproton Decel- erator facility at CERN. Good control of such cold antimatter plasmas is

Theoretical aspects of antimatter and gravity.

Science.gov (United States)

Blas, Diego

2018-03-28

In this short contribution, I review the physical case of studying the gravitational properties of antimatter from a theoretical perspective. I first discuss which elements are desirable for any theory where the long-range interactions between matter and antimatter differ from those of matter with itself. Afterwards I describe the standard way to hide the effects of new forces in matter-matter interactions which still allows one to generate ponderable matter-antimatter interactions. Finally, I comment on some recent ideas and propose some possible future directions.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Author(s).

Scientists hope to crack missing antimatter

CERN Multimedia

2000-01-01

CERN announced that it would be able to study antimatter in depth using the world's first 'antimatter factory'. The AD has a circumference of 188 meters and will slow down particles and antiparticles to one tenth of the speed of light and then deliver them to experiments for study (1 page).

Antimatter, a new frontier of science

International Nuclear Information System (INIS)

Clayton, E.D.

1988-09-01

The interest in antimatter arises because antimatter offers such high potential, and it also happens to be the most fascinating of materials. In the discussions that follow, considerations will be made on the potential utilization of antimatter in various applications including: Alternate energy source for rocket propulsion and space missions; Pion-induced fission; Muon-catalyzed cold fusion; and Medicine: in treatment of cancer, and for superior radiographs. Comments also are provided that presently discount antiproton-proton annihilation as a possible source of negative muons in hypothetical hybrid fusion-fission reactors, but this could change in the future. Reasons are given as to why further exploratory work should be undertaken at this time. 42 refs., 7 figs., 3 tabs

Antimatter questions the big-bang theory

International Nuclear Information System (INIS)

Daninos, F.

2005-01-01

A few moments after the big-bang matter an antimatter existed in the same quantities. Today the universe seems to be exclusively composed of matter. Nature prefers matter to antimatter but scientists do not know why. Experimental results from Babar and Belle experiments have confirmed the existence of CP violation in quark systems. This article draws the story of the quest for symmetry violation since the discovery of P violation in cobalt decay in the end of the fifties. Our understanding of CP violation is by far insufficient for explaining the matter-antimatter imbalance and may be we will have to admit that CP violation might concern other systems like neutrinos or super-symmetric particles. (A.C.)

Antimatter Requirements and Energy Costs for Near-Term Propulsion Applications

Science.gov (United States)

Schmidt, G. R.; Gerrish, H. P.; Martin, J. J.; Smith, G. A.; Meyer, K. J.

1999-01-01

The superior energy density of antimatter annihilation has often been pointed to as the ultimate source of energy for propulsion. However, the limited capacity and very low efficiency of present-day antiproton production methods suggest that antimatter may be too costly to consider for near-term propulsion applications. We address this issue by assessing the antimatter requirements for six different types of propulsion concepts, including two in which antiprotons are used to drive energy release from combined fission/fusion. These requirements are compared against the capacity of both the current antimatter production infrastructure and the improved capabilities that could exist within the early part of next century. Results show that although it may be impractical to consider systems that rely on antimatter as the sole source of propulsive energy, the requirements for propulsion based on antimatter-assisted fission/fusion do fall within projected near-term production capabilities. In fact, a new facility designed solely for antiproton production but based on existing technology could feasibly support interstellar precursor missions and omniplanetary spaceflight with antimatter costs ranging up to $6.4 million per mission.

Observation of the antimatter helium-4 nucleus

NARCIS (Netherlands)

Agakishiev, H.; Aggarwal, M.M.; Braidot, E; Peitzmann, T.; Zoulkarneeva, Y.

2011-01-01

High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang1; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple

Search for antimatter in primary cosmic rays.

Science.gov (United States)

Buffington, A.; Smith, L. H.; Smoot, G. F.; Alvarez, L. W.; Wahlig, M. A.

1972-01-01

Data from two flights of a new superconducting magnetic spectrometer are reported. This instrument was capable of a direct matter-antimatter separation in the cosmic rays. Antimatter events would appear in the spectrometer as trajectories which curve in the opposite direction to common matter, because of their negative charge. A brief description of the equipment and of the characteristics of the instrument is presented, along with the data processing techniques used. A new upper limit on the amount of antimatter in primary cosmic rays has been established. The limits are considerably lower than those for any previous experiment.

Matter-antimatter asymmetry - aspects at low energy

NARCIS (Netherlands)

Willmann, Lorenz; Jungmann, Klaus

2015-01-01

The apparent dominance of matter over antimatter in our universe is an obvious and puzzling fact which cannot be adequately explained in present physical frameworks that assume matter-antimatter symmetry at the big bang. However, our present knowledge of starting conditions and of known sources of

Does antimatter fall with the same acceleration as ordinary matter?

International Nuclear Information System (INIS)

Adelberger, E.G.; Heckel, B.R.; Stubbs, C.W.; Su, Y.

1991-01-01

Equivalence-principle experiments with ordinary matter probe the gravivector acceleration of antimatter in the same way as do direct measurements of antimatter in free fall and set stringent upper limits on the gravivector acceleration of antimatter predicted by certain quantum-gravity models

How did matter gain the upper hand over antimatter?

International Nuclear Information System (INIS)

Quinn, Helen

2009-01-01

Antimatter exists. We routinely make it in laboratories. For every familiar particle type we find a matching antiparticle with opposite charge, but exactly the same mass. For example, a positron with positive charge has the same mass as an electron; an antiproton with negative charge has the same mass as a proton. Antimatter occurs naturally all over the universe wherever high-energy particles collide. The laws of physics for antimatter are very, very similar to those for antimatter--so far we know only one tiny difference in them, a detail of the weak interactions of quarks that earned Makoto Kobayashi and Toshihide Maskawa a share of the 2008 Nobel Prize for Physics. Our understanding of the early Universe also tells us that after inflation ended equal amounts of matter and antimatter were produced. Today there's a lot of matter in the universe, but very little antimatter. This leaves a big question for cosmology. How did matter gain the upper hand over antimatter? It's a question at the root of our existence. Without this excess, there would be no stars, no Earth, and no us. When a particle meets its antiparticle, they annihilate each other in a flash of radiation. This process removed all the antimatter and most of the matter as the universe expanded and cooled. All that's left today is the excess amount of matter when destruction began to dominate over production. To get from equality to inequality for matter and antimatter requires a difference in the laws of physics between them and some special situation where it affects the balance between them. But, when we try to use the tiny difference we know about between quark and antiquark weak interactions to generate the imbalance, it doesn't work. We find a way that it can indeed give a small excess of matter over antimatter, but not nearly enough to give us all the matter we see in our universe. We can patch up the theory by adding unknown particles to it to make a scenario that works. Indeed we can do that in

Antimatter applied for Earth protection from asteroid collision

Science.gov (United States)

Satori, Shin; Kuninaka, Hitoshi; Kuriki, Kyoichi

1990-01-01

An Earth protection system against asteroids and meteorites in colliding orbit is proposed. The system consists of detection and deorbiting systems. Analyses are given for the resolution of microwave optics, the detectability of radar, the orbital plan of intercepting operation, and the antimatter mass require for totally or partially blasting the asteroid. Antimatter of 1 kg is required for deorbiting an asteroid 200 m in diameter. An experimental simulation of antimatter cooling and storage is planned. The facility under construction is discussed.

Fusion Reactions and Matter-Antimatter Annihilation for Space Propulsion

Science.gov (United States)

2005-07-13

FUSION REACTIONS AND MATTER- ANTIMATTER ANNIHILATION FOR SPACE PROPULSION Claude DEUTSCH LPGP (UMR-CNRS 8578), Bât. 210, UPS, 91405 Orsay...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE šFusion Reactions And Matter- Antimatter Annihilation For Space Propulsion 5a...which is possible with successful MCF or ICF. Appropriate vessel designs will be presented for fusion as well as for antimatter propulsion. In

Avatars of a Matter-Antimatter Universe

CERN Document Server

De Rújula, Alvaro

1997-01-01

An elegantly symmetric Universe, consisting of large islands of matter and antimatter, is by no means obviously out of the question. I review the observations that lead to the usual prejudice that the Universe contains only matter. I discuss recent work inferring that this prejudice can be converted into an inescapable conclusion. I argue that our theoretical conviction should not discourage direct searches for antimatter in cosmic rays.

In defense of anti-matter

International Nuclear Information System (INIS)

Rogers, S.; Thompson, W.B.

1980-01-01

There appears to be a prejudice in the astronomical world against an obvious high-energy source - the mutual annihilation of matter and anti-matter. In favor of this prejudice is the lack of any convincing evidence of the presence of naturally occurring anti-matter. Only recently have cosmic-ray antiprotons been detected (cf. Golden et al., 1979), and then in numbers consistent with secondary production in flight, while annihilation X-rays have also been detected, but again in circumstances where they might well be attributed to secondary effects of some other high-energy process. (orig.)

The antimatter factory is ready for another successful year

CERN Multimedia

CERN Bulletin

2011-01-01

CERN’s contribution to antimatter research is interspersed with important breakthroughs: from the creation of the very first anti-atoms in 1995 to the production of large quantities in 2002 and the invention in 2010 of the technique that freezes them down to allow precise studies of their properties. This week, antimatter experiments are on the starting blocks for a new run that promises to be just as exciting.   The Antiproton Decelerator (AD). CERN’s Antimatter Decelerator (AD) is a unique antimatter factory that produces low-energy anti-protons for creating anti-atoms. The AD delivers its precious ingredients to several experiments that use them to study antimatter properties from many different angles. The 2011 run is about to start, and the experiments are ready to enter a new data-taking period. Their scientific goals for this year include applying spectroscopy techniques for the first time to probe the inner workings of antihydrogen atoms; evaluating the biological effe...

Observation of the Antimatter Nuclei in Relativistic Heavy Ion Collisions

International Nuclear Information System (INIS)

Yoo, I.-K.

2013-01-01

Recently antimatter hyper-triton nuclei ( 3 Λ¯ H ¯) and antimatter helium nuclei ( 4 2 He ¯ ) are discovered with the Solenoidal Tracker At RHIC detector in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) (STAR Collaboration in Science 328(5974):58-62, 2010; STAR Collaboration in Nature 473:353-356, 2011). In this presentation, discoveries of antimatter particle are historically scanned and the recent observations at RHIC are reported in details as well as potential possibilities of discovery of antimatter nuclei at ALICE. (author)

Does antimatter emit a new light?

International Nuclear Information System (INIS)

Santilli, Ruggero Maria

1997-01-01

Contemporary theories of antimatter have a number of insufficiencies which stimulated the recent construction of the new isodual theory based on a certain anti-isomorphic map of all (classical and quantum) formulations of matter called isoduality. In this note we show that the isodual theory predicts that antimatter emits a new light, called isodual light, which can be distinguished from the ordinary light emitted by matter via gravitational interactions (only). In particular, the isodual theory predicts that all stable antiparticles such as the isodual photon, the positron and the antiproton experience antigravity in the field of matter (defined as the reversal of the sign of the curvature tensor). The antihydrogen atom is therefore predicted to: experience antigravity in the field of Earth; emit the isodual photon; and have the same spectroscopy of the hydrogen atom, although subjected to an anti-isomorphic isodual map. In this note we also show that the isodual theory predicts that bound states of elementary particles and antiparticles (such as the positronium) experience ordinary gravitation in both fields of matter and antimatter, thus bypassing known objections against antigravity. A number of intriguing and fundamental, open theoretical and experimental problems of 'the new physics of antimatter' are pointed out

Does antimatter emit a new light?

Energy Technology Data Exchange (ETDEWEB)

Santilli, Ruggero Maria [Instituto per la Ricerca di Base (Italy)

1997-08-15

Contemporary theories of antimatter have a number of insufficiencies which stimulated the recent construction of the new isodual theory based on a certain anti-isomorphic map of all (classical and quantum) formulations of matter called isoduality. In this note we show that the isodual theory predicts that antimatter emits a new light, called isodual light, which can be distinguished from the ordinary light emitted by matter via gravitational interactions (only). In particular, the isodual theory predicts that all stable antiparticles such as the isodual photon, the positron and the antiproton experience antigravity in the field of matter (defined as the reversal of the sign of the curvature tensor). The antihydrogen atom is therefore predicted to: experience antigravity in the field of Earth; emit the isodual photon; and have the same spectroscopy of the hydrogen atom, although subjected to an anti-isomorphic isodual map. In this note we also show that the isodual theory predicts that bound states of elementary particles and antiparticles (such as the positronium) experience ordinary gravitation in both fields of matter and antimatter, thus bypassing known objections against antigravity. A number of intriguing and fundamental, open theoretical and experimental problems of 'the new physics of antimatter' are pointed out.

Does antimatter emit a new light?

International Nuclear Information System (INIS)

Santilli, R.M.

1996-01-01

Contemporary theories of antimatter have a number of insufficiencies which stimulated the recent construction of the new isodual theory based on a certain anti-isomorphic map of all (classical and quantum) formulations of matter called isoduality. In this note we show that the isodual theory predicts that antimatter emits a new light, called isodual light, which can be distinguished from the ordinary light emitted by matter via gravitational interactions (only). In particular, the isodual theory predicts that all stable antiparticles such as the isodual photon, the positron and the antiproton experience antigravity in the field of matter (defined as the reversal of the sign of the curvature tensor). The antihydrogen atom is therefore predicted to: experience antigravity in the field of Earth; emit the isodual photon; and have the same spectroscopy of the hydrogen atom, although subjected to an anti-isomorphic isodual map. In this note we also show that the isodual theory predicts that bound states of elementary particle sand antiparticles (such as the positronium) experience ordinary gravitation in both fields of matter and antimatter, thus by passing known objections against antigravity. A number of intriguing and fundamental, open theoretical and experimental problems of 'the new physics of antimatter' are pointed out. 16 refs

The antimatter goes back in the time

International Nuclear Information System (INIS)

Larousserie, D.; Loubiere, P.; Mathieu, L.

1999-01-01

This paper presents general aspects of the antimatter that offers new possibilities in cosmology and astrophysics but also promotes in medicine the medical imagery for the cancer diagnostic (the antiproton therapy). Different aspects of the antimatter are considered. It deals first with the instrumentation: the AD (Antiproton Decelerator) of the CERN, braking ring that produces 10 millions of antiproton per hours. Ten question-answer about the subject are abstracted to better understand this theory. It presents the AMS (Alpha Magnetic Spectrometer), that analysed ten millions particles (anti-electrons and antiprotons) during its fly with Discovery. Antimatter, as the matter mirror, don't respect the symmetry laws. The authors explain these symmetry violations. (A.L.B.)

The Matter-Antimatter Asymmetry of the Universe

Science.gov (United States)

Stecker, F. W.; White, Nicholas E. (Technical Monitor)

2002-01-01

I will give here an overview of the present observational and theoretical situation regarding the question of the matter-antimatter asymmetry of the universe and the related question of the existence of antimatter on a cosmological scale. I will also give a simple discussion of the role of CP (charge conjugation parity) violation in this subject.

Antimatter cancer treatment

CERN Multimedia

Van Noorden, Richard

2006-01-01

"The idea that antimatter beams could treat cancer might seem ridiculous. But researchers working at Cerns particle accelerator laboratory in Geneva don't think so. They have just reported a successful first experiment into the biological effects of antiprotons radiation on living cells."

Balloon test project: Cosmic Ray Antimatter Calorimeter (CRAC)

Science.gov (United States)

Christy, J. C.; Dhenain, G.; Goret, P.; Jorand, J.; Masse, P.; Mestreau, P.; Petrou, N.; Robin, A.

1984-01-01

Cosmic ray observations from balloon flights are discussed. The cosmic ray antimatter calorimeter (CRAC) experiment attempts to measure the flux of antimatter in the 200-600 Mev/m energy range and the isotopes of light elements between 600 and 1,000 Mev/m.

What's the matter with Antimatter? Exhibition Science Bringing Nations Together

CERN Multimedia

2000-01-01

Antimatter may be the stuff of science fiction, but to physicists it poses a serious question. Why is there not more of it around? At the Big Bang, matter and antimatter should have been created in equal amounts, yet today we seem to live in a Universe entirely made of matter. So where has all the antimatter gone?

Antimatter Production at a Potential Boundary

Science.gov (United States)

LaPointe, Michael R.; Reddy, Dhanireddy (Technical Monitor)

2001-01-01

Current antiproton production techniques rely on high-energy collisions between beam particles and target nuclei to produce particle and antiparticle pairs, but inherently low production and capture efficiencies render these techniques impractical for the cost-effective production of antimatter for space propulsion and other commercial applications. Based on Dirac's theory of the vacuum field, a new antimatter production concept is proposed in which particle-antiparticle pairs are created at the boundary of a steep potential step formed by the suppression of the local vacuum fields. Current antimatter production techniques are reviewed, followed by a description of Dirac's relativistic quantum theory of the vacuum state and corresponding solutions for particle tunneling and reflection from a potential barrier. The use of the Casimir effect to suppress local vacuum fields is presented as a possible technique for generating the sharp potential gradients required for particle-antiparticle pair creation.

A moiré deflectometer for antimatter.

Science.gov (United States)

Aghion, S; Ahlén, O; Amsler, C; Ariga, A; Ariga, T; Belov, A S; Berggren, K; Bonomi, G; Bräunig, P; Bremer, J; Brusa, R S; Cabaret, L; Canali, C; Caravita, R; Castelli, F; Cerchiari, G; Cialdi, S; Comparat, D; Consolati, G; Derking, H; Di Domizio, S; Di Noto, L; Doser, M; Dudarev, A; Ereditato, A; Ferragut, R; Fontana, A; Genova, P; Giammarchi, M; Gligorova, A; Gninenko, S N; Haider, S; Huse, T; Jordan, E; Jørgensen, L V; Kaltenbacher, T; Kawada, J; Kellerbauer, A; Kimura, M; Knecht, A; Krasnický, D; Lagomarsino, V; Lehner, S; Magnani, A; Malbrunot, C; Mariazzi, S; Matveev, V A; Moia, F; Nebbia, G; Nédélec, P; Oberthaler, M K; Pacifico, N; Petràček, V; Pistillo, C; Prelz, F; Prevedelli, M; Regenfus, C; Riccardi, C; Røhne, O; Rotondi, A; Sandaker, H; Scampoli, P; Storey, J; Vasquez, M A Subieta; Špaček, M; Testera, G; Vaccarone, R; Widmann, E; Zavatarelli, S; Zmeskal, J

2014-07-28

The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational interaction is of high interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics--the moiré deflectometer--for a measurement of the acceleration of slow antiprotons. The setup consists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleration of neutral antimatter.

Feasibility for EGRET detection of antimatter concentrations in the universe

Science.gov (United States)

Hartman, R. C.

1990-01-01

Although the Grand Unified Theories of elementary particle dynamics have to some extent reduced the aesthetic attraction of matter-antimatter symmetry in the Universe, the idea is still not ruled out. Although first introduced by Alfven (1965), most of the theoretical development related to gamma-ray astronomy was carried out by Stecker, who has proposed (Stecker, Morgan, and Bredekamp, 1971) matter-antimatter annihilation extending back to large redshifts as a possible explanation of the apparently extragalactic diffuse gamma radiation. Other candidate explanations were also proposed, such as superposition of extragalactic discrete sources. Clearly, the existence of significant amounts of antimatter in the universe would be of great cosmological importance; its detection, however, is not simple. Since the photon is its own antiparticle, it carries no signature identifying whether it originated in a matter or an antimatter process; even aggregates of photons (spectra) are expected to be identical from matter and antimatter processes. The only likely indicator of the presence of concentrations of antimatter is evidence of its annihilation with normal matter, assuming there is some region of contact or overlap. The EGRET (Energetic Gamma-Ray Experimental Telescope) on the Gamma Ray Observatory, with a substantial increase in sensitivity compared with earlier high energy gamma ray telescopes, may be able to address this issue. The feasibility of using EGRET in such a search for antimatter annihilation in the Universe is considered.

Feasibility for EGRET detection of antimatter concentrations in the universe

International Nuclear Information System (INIS)

Hartman, R.C.

1990-01-01

Although the Grand Unified Theories of elementary particle dynamics have to some extent reduced the aesthetic attraction of matter-antimatter symmetry in the Universe, the idea is still not ruled out. Although first introduced by Alfven (1965), most of the theoretical development related to gamma-ray astronomy was carried out by Stecker, who has proposed (Stecker, Morgan, and Bredekamp, 1971) matter-antimatter annihilation extending back to large redshifts as a possible explanation of the apparently extragalactic diffuse gamma radiation. Other candidate explanations were also proposed, such as superposition of extragalactic discrete sources. Clearly, the existence of significant amounts of antimatter in the universe would be of great cosmological importance; its detection, however, is not simple. Since the photon is its own antiparticle, it carries no signature identifying whether it originated in a matter or an antimatter process; even aggregates of photons (spectra) are expected to be identical from matter and antimatter processes. The only likely indicator of the presence of concentrations of antimatter is evidence of its annihilation with normal matter, assuming there is some region of contact or overlap. The EGRET (Energetic Gamma-Ray Experimental Telescope) on the Gamma Ray Observatory, with a substantial increase in sensitivity compared with earlier high energy gamma ray telescopes, may be able to address this issue. The feasibility of using EGRET in such a search for antimatter annihilation in the Universe is considered

Gravitational properties of antimatter

International Nuclear Information System (INIS)

Goldman, T.; Nieto, M.M.

1985-01-01

Quantum gravity is at the forefront of modern particle physics, yet there are no direct tests, for antimatter, of even the principle of equivalence. We note that modern descriptions of gravity, such as fibre bundles and higher dimensional spacetimes, allow violations of the commonly stated form of the principle of equivalence, and of CPT. We review both indirect arguments and experimental tests of the expected gravitational properties of CPT-conjugate states. We conclude that a direct experimental test of the gravitational properties of antimatter, at the 1% (or better) level, would be of great value. We identify some experimental reasons which make the antiproton a prime candidate for this test, and we strongly urge that such an experiment be done at LEAR. 21 references

Possible measurements of the gravitational acceleration with neutral antimatter

International Nuclear Information System (INIS)

Beverini, N.; Torelli, G.; Lagomarsino, V.; Manuzio, G.; Scuri, F.

1989-01-01

The interest in measuring the gravitational acceleration using neutral antimatter is discussed as well as the advantages compared with using charged antimatter, and a few possible experimental schemes are briefly discussed. (orig.)

Development of high-capacity antimatter storage

International Nuclear Information System (INIS)

Howe, Steven D.; Smith, Gerald A.

2000-01-01

Space is vast. Over the next few decades, humanity will strive to send probes farther and farther into space to establish long baselines for interferometry, to visit the Kuiper Belt, to identify the heliopause, or to map the Oort cloud. In order to solve many of the mysteries of the universe or to explore the solar system and beyond, one single technology must be developed--high performance propulsion. In essence, future missions to deep space will require specific impulses between 50,000 and 200,000 seconds and energy densities greater than 10 14 j/kg in order to accomplish the mission within the career lifetime of an individual, 40 years. Only two technologies available to mankind offer such performance--fusion and antimatter. Currently envisioned fusion systems are too massive. Alternatively, because of the high energy density, antimatter powered systems may be relatively compact. The single key technology that is required to enable the revolutionary concept of antimatter propulsion is safe, reliable, high-density storage. Under a grant from the NASA Institute of Advanced Concepts, we have identified two potential mechanisms that may enable high capacity antimatter storage systems to be built. We will describe planned experiments to verify the concepts. Development of a system capable of storing megajoules per gram will allow highly instrumented platforms to make fast missions to great distances. Such a development will open the universe to humanity

A simulation study of antimatter-helium ion planar channeling in silicon

International Nuclear Information System (INIS)

Wijesundera, Dharshana; Jayarathna, Sandun; Bellwied, Rene; Chu, Wei-Kan

2012-01-01

With the physical significance arising with the reports on experimental observation of antimatter-He nuclei, we have investigated a case of 2 MeV antimatter-He ion planar channeling in Si (1 0 0) in comparison with He channeling, by simulation. For a negatively charged antimatter-He nucleus, the planar potential well is centered at the atomic plane itself as opposed to the center-channel minimum for He ions; the antimatter-He ion distribution therefore tends to concentrate toward the atomic lattice planes. The antimatter-He ion flux distribution and the resulting close encounter probability are crucial in determining the probability of close encounter events including annihilation at channeling incidence. We have therefore analyzed the variation of antimatter-He ion flux distribution within the channels with respect to the angle of incidence and have thereby derived the orientation dependence of probability of close encounter events, or an antimatter-He channeling angular scan. The angular scan is inverted with a maximum yield at the perfect beam-planar alignment. The half-angle is narrower compared to He channeling, as a consequence of the narrower planar channeling potential centered at the lattice planes. The high de-channeling rate associated with the higher antimatter-He ion concentration in the proximity of lattice planes causes the maximum yield to be less prominent and to decrease rapidly with depth. The shoulder region shows strong depth dependent reduction that can be associated to near surface depth dependent ion flux variation.

Studying Antimatter Gravity with Muonium

Directory of Open Access Journals (Sweden)

Aldo Antognini

2018-04-01

Full Text Available The gravitational acceleration of antimatter, g ¯ , has yet to be directly measured; an unexpected outcome of its measurement could change our understanding of gravity, the universe, and the possibility of a fifth force. Three avenues are apparent for such a measurement: antihydrogen, positronium, and muonium, the last requiring a precision atom interferometer and novel muonium beam under development. The interferometer and its few-picometer alignment and calibration systems appear feasible. With 100 nm grating pitch, measurements of g ¯ to 10%, 1%, or better can be envisioned. These could constitute the first gravitational measurements of leptonic matter, of 2nd-generation matter, and possibly, of antimatter.

Do we live in the universe successively dominated by matter and antimatter?

CERN Document Server

Hajdukovic, Dragan Slavkov

2011-01-01

We wonder if a cyclic universe may be dominated alternatively by matter and antimatter. Such a scenario demands a mechanism for transformation of matter to antimatter (or antimatter to matter) during the final stage of a big crunch. By giving an example, we have shown that in principle such a mechanism is possible. Our mechanism is based on a hypothetical repulsion between matter and antimatter, existing at least deep inside the horizon of a black hole. When universe is reduced to a supermassive black hole of a small size, a very strong field of the conjectured force might create (through a Schwinger type mechanism) particle-antiparticle pairs from the quantum vacuum. The amount of antimatter created from the vacuum is equal to the decrease of mass of the black hole and violently repelled from it. When the size of the black hole is sufficiently small, the creation of antimatter may become so fast, that matter of our Universe might be transformed to antimatter in a fraction of second. Such a fast conversion of...

Gravity and Antimatter.

Science.gov (United States)

Goldman, Terry; And Others

1988-01-01

Discusses the theory and history behind an experiment that will be performed to measure the gravitational forces that effect antimatter. Describes conditions under which the principle of equivalence would be violated or supported. Reviews historical tests of equivalence, current theory and experiments. Presents the design of the new experiment.…

CP violation and the matter-antimatter asymmetry of the Universe

International Nuclear Information System (INIS)

Hambye, T.

2012-01-01

In our everyday environment one observes only matter. That is quite a fortunate situation... Any sizeable presence of antimatter on Earth, from the enormous energy it would release through annihilation with matter, would prevent us talking about it. For the physicist this fact, at first sight obvious, is nevertheless a kind of surprise: antimatter, which is observed in cosmic rays, in radioactive decays of nuclei, which has been copiously produced and extensively studied in accelerators and which is nowadays currently used in hospitals, turns out to have pretty much the same properties as matter. Moreover, the fact that matter dominates appears to be a general property of our Universe: no evidence of large quantities of antimatter has been observed at any distance from us. Why would matter have taken the advantage on antimatter? In this short review we explain how, through a limited number of basic elements, one can find answers to this question. Matter and antimatter have, in fact, not exactly the same properties: from laboratory experiments CP conservation is known not to be a fundamental law of nature. (author)

When clusters collide: constraints on antimatter on the largest scales

International Nuclear Information System (INIS)

Steigman, Gary

2008-01-01

Observations have ruled out the presence of significant amounts of antimatter in the Universe on scales ranging from the solar system, to the Galaxy, to groups and clusters of galaxies, and even to distances comparable to the scale of the present horizon. Except for the model-dependent constraints on the largest scales, the most significant upper limits to diffuse antimatter in the Universe are those on the ∼Mpc scale of clusters of galaxies provided by the EGRET upper bounds to annihilation gamma rays from galaxy clusters whose intracluster gas is revealed through its x-ray emission. On the scale of individual clusters of galaxies the upper bounds to the fraction of mixed matter and antimatter for the 55 clusters from a flux-limited x-ray survey range from 5 × 10 −9 to −6 , strongly suggesting that individual clusters of galaxies are made entirely of matter or of antimatter. X-ray and gamma-ray observations of colliding clusters of galaxies, such as the Bullet Cluster, permit these constraints to be extended to even larger scales. If the observations of the Bullet Cluster, where the upper bound to the antimatter fraction is found to be −6 , can be generalized to other colliding clusters of galaxies, cosmologically significant amounts of antimatter will be excluded on scales of order ∼20 Mpc (M∼5×10 15 M sun )

Gamma ray astronomy and search for antimatter in the universe

International Nuclear Information System (INIS)

Schoenfelder, V.

1989-01-01

Gamma ray astronomy provides a powerful tool for searching antimatter in the universe; it probably provides the only means to determine, if the universe has baryon symmetry. Presently existing gamma-ray observations can be interpreted without postulating the existence of antimatter. However, the measurements are not precise enough to definitely exclude the possibility of its existence. The search for antimatter belongs to one of the main scientific objectives of the Gamma Ray Observatory GRO of NASA, which will be launched in 1990 by the Space Shuttle. (orig.)

Antimatter atoms

International Nuclear Information System (INIS)

Anon.

1996-01-01

In january 1996, CERN broadcasted the information of the creation of nine anti-hydrogen atoms, observed through disintegration products. The experimental facility was CERN LEAR ring. An antiproton beam scattered a xenon jet, and the resulting antimatter was first selected by its insensitivity to beam bending magnets. Their disintegration was detected in thin NaI detectors, in which the anti-atoms are at once deprived from their positron. Then, magnetic and time-of-flight spectrometers are used. (D.L.)

The antimatter. Press breakfast 23 may 2000

International Nuclear Information System (INIS)

Spiro, M.; Dejardin, M.; Debu, P.; Aleksan, R.

2000-05-01

This document brings together the subjects discussed during the Press breakfast of 23 may 2000 on the antimatter, with scientists of the CEA and the CNRS. It presents the research programs and the experiments on the antimatter and the symmetry violation: the CP LEAR and the NA48 experiments at CERN, the BaBar detector at SLAC, the fundamental research at the CEA and the impacts on the energy policy. It provides also links for more detailed inquiries. (A.L.B.)

Investigation of matter-antimatter interaction for possible propulsion applications

Science.gov (United States)

Morgan, D. L., Jr.

1974-01-01

Matter-antimatter annihilation is discussed as a means of rocket propulsion. The feasibility of different means of antimatter storage is shown to depend on how annihilation rates are affected by various circumstances. The annihilation processes are described, with emphasis on important features of atom-antiatom interatomic potential energies. A model is developed that allows approximate calculation of upper and lower bounds to the interatomic potential energy for any atom-antiatom pair. Formulae for the upper and lower bounds for atom-antiatom annihilation cross-sections are obtained and applied to the annihilation rates for each means of antimatter storage under consideration. Recommendations for further studies are presented.

Santilli’s detection of antimatter galaxies: An introduction and experimental confirmation

International Nuclear Information System (INIS)

Bhujbal, P. M.

2015-01-01

Studies accompanied over the past few decades on the generalization of quantum mechanics known as hadronic mechanics, initiated in 1978 by the Italian-American physicist Ruggero Maria Santilli and its application for detection of light from antimatter galaxy is reported in this paper. The isodual (antimatter) light has negative energy E d =-E with negative unit, experiences a negative curvature tensor R d =-R (gravitational repulsion) when in a matter gravitational field, and possesses a negative index of refraction n d =-n when propagating within a transparent matter medium. Detection of antimatter galaxies is possible by the refractive telescope with concave lenses constructed by Santilli which follow the concept of negative energy and negative index of refraction for antimatter

Gravitational mass of relativistic matter and antimatter

Science.gov (United States)

Kalaydzhyan, Tigran

2015-12-01

The universality of free fall, the weak equivalence principle (WEP), is a cornerstone of the general theory of relativity, the most precise theory of gravity confirmed in all experiments up to date. The WEP states the equivalence of the inertial, m, and gravitational, mg, masses and was tested in numerous occasions with normal matter at relatively low energies. However, there is no confirmation for the matter and antimatter at high energies. For the antimatter the situation is even less clear - current direct observations of trapped antihydrogen suggest the limits - 65 antigravity phenomenon, i.e. repulsion of the antimatter by Earth. Here we demonstrate an indirect bound 0.96 antigravity. By considering the absolute potential of the Local Supercluster (LS), we also predict the bounds 1 - 4 ×10-7

Some examples of propulsion applications using antimatter

International Nuclear Information System (INIS)

Augenstein, B.W.

1985-07-01

Macroapplications of antimatter and annihilation energies to various uses beyond very high energy physics, which presupposes the solution of basic production and storage problems is discussed. Propulsion applications in identifiable missions which cannot be achieved conventionally are discussed. The use of annihilation energies provides ways to access effective exhaust velocities from 10 Km/sec to a major fraction of light velocity. The promise of antimatter is illustrated by considering a mix ratio r = amount of normal matter/amount of antimatter and calculating the effective attained temperature of the mixture as approx. 2 GeV/r. Ensuring that this mixing produces high temperatures and that the energy does not largely escape from the mix is the art of utilizing annihilation energies. The immediate product of nucleon-antinucleon annihilations is almost wholly pions. The subsequent reaction trains and the ultimate forms of the end products, their spectral attributes, the decay or capture mechanisms, are documented

Antimatter in the Milky Way

International Nuclear Information System (INIS)

Bambi, C.; Dolgov, A.D.

2007-01-01

Observational signatures of existence of antimatter objects in the Galaxy are discussed. We focus on point-like sources of gamma radiation, diffuse galactic gamma ray background and anti-nuclei in cosmic rays

Santilli’s detection of antimatter galaxies: An introduction and experimental confirmation

Energy Technology Data Exchange (ETDEWEB)

Bhujbal, P. M. [Department of Physics, Nutan Adarsh Arts, Commerce and Smt. Maniben Harilal Wegad Science College, Umrer-441203, India. Email: prashantmbhujbal@yahoo.com (India)

2015-03-10

Studies accompanied over the past few decades on the generalization of quantum mechanics known as hadronic mechanics, initiated in 1978 by the Italian-American physicist Ruggero Maria Santilli and its application for detection of light from antimatter galaxy is reported in this paper. The isodual (antimatter) light has negative energy E{sup d} =-E with negative unit, experiences a negative curvature tensor R{sup d}=-R (gravitational repulsion) when in a matter gravitational field, and possesses a negative index of refraction n{sup d}=-n when propagating within a transparent matter medium. Detection of antimatter galaxies is possible by the refractive telescope with concave lenses constructed by Santilli which follow the concept of negative energy and negative index of refraction for antimatter.

a Classical Isodual Theory of Antimatter and its Prediction of Antigravity

Science.gov (United States)

Santilli, Ruggero Maria

An inspection of the contemporary physics literature reveals that, while matter is treated at all levels of study, from Newtonian mechanics to quantum field theory, antimatter is solely treated at the level of second quantization. For the purpose of initiating the restoration of full equivalence in the treatment of matter and antimatter in due time, and as the classical foundations of an axiomatically consistent inclusion of gravitation in unified gauge theories recently appeared elsewhere, in this paper we present a classical representation of antimatter which begins at the primitive Newtonian level with corresponding formulations at all subsequent levels. By recalling that charge conjugation of particles into antiparticles is antiautomorphic, the proposed theory of antimatter is based on a new map, called isoduality, which is also antiautomorphic (and more generally, antiisomorphic), yet it is applicable beginning at the classical level and then persists at the quantum level where it becomes equivalent to charge conjugation. We therefore present, apparently for the first time, the classical isodual theory of antimatter, we identify the physical foundations of the theory as being the novel isodual Galilean, special and general relativities, and we show the compatibility of the theory with all available classical experimental data on antimatter. We identify the classical foundations of the prediction of antigravity for antimatter in the field of matter (or vice-versa) without any claim on its validity, and defer its resolution to specifically identified experiments. We identify the novel, classical, isodual electromagnetic waves which are predicted to be emitted by antimatter, the so-called space-time machine based on a novel non-Newtonian geometric propulsion, and other implications of the theory. We also introduce, apparently for the first time, the isodual space and time inversions and show that they are nontrivially different than the conventional ones, thus

The need for expanded exploration of matter-antimatter annihilation for propulsion application

Science.gov (United States)

Massier, P. F.

1982-01-01

The use of matter-antimatter annihilation as a propulsion application for interstellar travel is discussed. The physical basis for the superior energy release in such a system is summarized, and the problems associated with antimatter production, collection and storage are assessed. Advances in devising a workable propulsion system are reported, and the parameters of an antimatter propulsion system are described.

Can we detect antimatter from other galaxies

Science.gov (United States)

Ahlen, S. P.; Price, P. B.; Salamon, M. H.; Tarle, G.

1982-01-01

A novel particle detection technique employing well established principles of high order quantum electrodynamics for searching for antimatter in cosmic rays is described, and shown to have both collecting power and resolution superior to conventional alternatives. By taking into account various estimates of the metagalactic cosmic-ray energy density, and the possible modulation of metagalactic cosmic rays by a galactic wind within the framework of the dynamical halo model, it is shown that the experiment proposed would be the first to be sensitive to the presence of extragalactic antimatter.

Observation of the antimatter partner of Rutherford's α-particle - 4He-bar

International Nuclear Information System (INIS)

Tang, Aihong

2012-01-01

The antimatter helium-4 nucleus ( 4 He-bar, or anti-α) has not been observed previously although the α-particle was identified a century ago by Rutherford. High-energy nuclear collisions recreate energy densities similar to that of the universe microseconds after the Big Bang, and in both cases, matter and antimatter are created with comparable abundances. However, the relatively short-lived expansion in nuclear collisions makes it possible for antimatter to decouple quickly from matter. This makes a high-energy accelerator facility the ideal environment for producing and studying antimatter. In this paper, we report 18 antihelium-4 nuclei discovered by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The measured invariant differential cross section is consistent with expectation from thermodynamics and coalescent nucleosynthesis models, which has implications for future production of even heavier antimatter nuclei, as well as for experimental searches for new phenomena in the cosmos. Future directions of rare and exotic matter searches from STAR will also be discussed.

2nd International Workshop on Antimatter and Gravity

CERN Document Server

Scampoli, P

2013-01-01

The purpose of this meeting is to review the experimental and theoretical aspects of the interaction of antimatter with gravity. Tests of the weak equivalence principle with e.g. positronium, muonium and antihydrogen with be discussed. Progress reports on the experiments at the CERN Antiproton Decelerator and on the available future facilities will be presented. A session on the relevance of antimatter with respect to Dark Energy and Dark Matter in the Universe (theory and experiments) is also foreseen.

Antimatter Production for Near-Term Propulsion Applications

Science.gov (United States)

Gerrish, Harold P.; Schmidt, George R.

1999-01-01

This presentation discusses the use and potential of power generated from Proton-Antiproton Annihilation. The problem is that there is not enough production of anti-protons, and that the production methods are inefficient. The cost for 1 gram of antiprotons is estimated at 62.5 trillion dollars. Applications which require large quantities (i.e., about 1 kg) will require dramatic improvements in the efficiency of the production of the antiprotons. However, applications which involve small quantities (i.e., 1 to 10 micrograms may be practical with a relative expansion of capacities. There are four "conventional" antimatter propulsion concepts which are: (1) the solid core, (2) the gas core, (3) the plasma core, and the (4) beam core. These are compared in terms of specific impulse, propulsive energy utilization and vehicle structure/propellant mass ratio. Antimatter-catalyzed fusion propulsion is also evaluated. The improvements outlined in the presentation to the Fermilab production, and other sites. capability would result in worldwide capacity of several micrograms per year, by the middle of the next decade. The conclusions drawn are: (1) the Conventional antimatter propulsion IS not practical due to large p-bar requirement; (2) Antimatter-catalyzed systems can be reasonably considered this "solves" energy cost problem by employing substantially smaller quantities; (3) With current infrastructure, cost for 1 microgram of p-bars is $62.5 million, but with near-term improvements cost should drop; (4) Milligram-scale facility would require a $15 billion investment, but could produce 1 mg, at $0.1/kW-hr, for $6.25 million.

Polarization of photons in matter–antimatter annihilation

Energy Technology Data Exchange (ETDEWEB)

Moskaliuk, S.S. [Bogolyubov Institute for Theoretical Physics, Metrolohichna Street, 14-b, Kyiv-143, Ukraine, UA-03143 e-mail: mss@bitp.kiev.ua (Ukraine)

2015-03-10

In this work we demonstrate the possibility of generation of linear polarization of the electromagnetic field (EMF) due to the quantum effects in matter-antimatter annihilation process for anisotropic space of the I type according to Bianchi. We study the dynamics of this process to estimate the degree of polarisation of the EMF in the external gravitational field of the anisotropic Bianchi I model. It has been established that the quantum effects in matter-antimatter annihilation process in the external gravitational field of the anisotropic Bianchi I model provide contribution to the degree of polarisation of the EMF in quadrupole harmonics.

Antimatter search with AMS (Alpha Magnetic Spectrometer) during STS-91 precursor flight

International Nuclear Information System (INIS)

Alpat, Behcet

2000-01-01

The Alpha Magnetic Spectrometer (AMS) is designed to study the antimatter, matter and dark matter in space. AMS successfully flown on space shuttle Discovery during precursor flight STS-91 in a 51.7 degree sign orbit at altitudes between 320 and 390 km. No antimatter nuclei with Z ≥ 2 were detected. In this report we present the AMS performances during shuttle flight and we give new limits on antimatter/matter flux ratio

Antimatter in the Direct-Action Theory of Fields

Directory of Open Access Journals (Sweden)

Ruth E. Kastner

2016-01-01

Full Text Available One of Feynman's greatest contributions to physics was the interpretation of negative energies as antimatter in quantum field theory. A key component of this interpretation is the Feynman propagator, which seeks to describe the behavior of antimatter at the virtual particle level. Ironically, it turns out that one can dispense with the Feynman propagator in a direct-action theory of fields, while still retaining the interpretation of negative energy solutions as antiparticles. Quanta 2016; 5: 12–18.

Taiwan university joins search for antimatter

CERN Multimedia

Chiu, Y

2002-01-01

National Cheng Kung University announced yesterday that it will be joining the Alpha Magnetic Spectrometer, an international scientific research project aimed at looking for antimatter in space (1 page).

Antimatter in the universe

International Nuclear Information System (INIS)

Papini, P.; Spillantini, P.

1996-01-01

In this paper, the present knowledge on the study of antimatter in the universe is summarized. From the theoretical point of view, both baryon symmetric and asymmetric cosmologies are possible in the framework of big-bang theories. With the three 'Sakharov's conditions', it is possible to imagine an evolution from the big bang toward a universe with 'all matter' inside or toward a symmetric universe with matter and antimatter separated in domains. Measurement of the γ ray cosmic background implies only a local asymmetry and does not rule out the possibility of a symmetry on a large scale. Observations of the antiproton spectrum and antinuclei in cosmic rays are useful tools for studying the possible existence of an antigalaxy. The number and quality of the present data are poor, and no data are available at high energy, where the presence of an antigalaxy must be revealable owing to a large amount of antiprotons and antinuclei. In this paper, the future experimental projects to measure the antiproton flux at high energies and to search for antinuclei in cosmic rays are briefly presented

Antimatter, the SME, and gravity

Energy Technology Data Exchange (ETDEWEB)

Tasson, Jay D., E-mail: jtasson@carleton.edu [Whitman College, Department of Physics (United States)

2012-12-15

A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.

Antimatter, the SME, and gravity

International Nuclear Information System (INIS)

Tasson, Jay D.

2012-01-01

A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.

Beta limitation of matter-antimatter boundary layers

International Nuclear Information System (INIS)

Lehnert, B.

1987-08-01

A model has earlier been proposed for a boundary layer which separates a cloud of matter from one of antimatter in a magnetized ambiplasma. In this model steady pressure equilibrium ceases to exist when a certain beta limit is exceeded. The latter is defined as the ratio between the ambiplasma and magnetic field pressures which balance each other in the boundary layer. Thus, at an increasing density, the high-energy particles created by annihilation within the layer are 'pumped up' to a pressure which cannot be balanced by a given magnetic field. The boundary layer then 'disrupts'. The critical beta limit thus obtained falls within the observed parameter ranges of galaxies and other large cosmical objects. Provided that the considered matter-antimatter balance holds true, this limit is thus expected to impose certain existence conditions on matter-antimatter boundary layers. Such a limitation may apply to certain cosmical objects and cosmological models. The maximum time scale for the corresponding disruption development has been estimated to be in the range from about 10 -4 to 10 2 seconds for boundary layers at ambiplasma particle densities in the range from 10 4 to 10 -2 m -3 , respectively. (author)

Antimatter/HiPAT Support Services

Science.gov (United States)

Lewis, Raymond A.

2001-01-01

Techniques were developed for trapping normal matter in the High Performance Antiproton Trap (HiPAT). Situations encountered included discharge phenomena, charge exchange and radial diffusion processes. It is important to identify these problems, since they will also limit the performance in trapping antimatter next year.

Antimatter production in proton-proton and heavy-ion collisions at ultrarelativistic energies

International Nuclear Information System (INIS)

Cleymans, J.; Kabana, S.; Kraus, I.; Oeschler, H.; Redlich, K.; Sharma, N.

2011-01-01

One of the striking features of particle production at high beam energies is the near-equal abundance of matter and antimatter in the central rapidity region. In this paper we study how this symmetry is reached as the beam energy is increased. In particular, we quantify explicitly the energy dependence of the approach to matter-antimatter symmetry in proton-proton and in heavy-ion collisions. Expectations are presented also for the production of more complex forms of antimatter such as antihypernuclei.

Cosmic matter-antimatter asymmetry and gravitational force

Science.gov (United States)

Hsu, J. P.

1980-01-01

Cosmic matter-antimatter asymmetry due to the gravitational interaction alone is discussed, considering the gravitational coupling of fermion matter related to the Yang-Mills (1954) gauge symmetry with the unique generalization of the four-dimensional Poincare group. Attention is given to the case of weak static fields which determines the space-time metric where only large source terms are retained. In addition, considering lowest-order Feynman diagrams, there are presented gravitational potential energies between fermions, between antifermions, and between a fermion and an antifermion. It is concluded that the gravitational force between matter is different from that between antimatter; implications from this concerning the evolution of the universe are discussed.

Can we detect antimatter from other galaxies

International Nuclear Information System (INIS)

Ahlen, S.P.; Price, P.B.; Salamon, M.H.; Tarle, G.

1982-01-01

Recent developments in particle detection technology now make it possible to use well-established principles of high-order quantum electrodynamics to search for antimatter in the cosmic rays with unprecedented sensitivity. The technique is described and is shown to be superior in both collecting power and resolution to other, more conventional, techniques used in the past. By considering various estimates of the metagalactic cosmic-ray energy density and by taking into account the possible modulation of metagalactic cosmic rays by a galactic wind within the framework of the dynamical halo model, we show that our proposed experiment would be the first to be sensitive to the presence of extragalactic antimatter

Heavy weak bosons, cosmic antimatter and DUMAND. 2: Looking for cosmic antimatter with DUMAND

Science.gov (United States)

Stecker, F. W.; Brown, R. W.

1980-01-01

Discussion of various means for using high energy neutrino astronomy to directly test for the existence of cosmic antimatter on a significant cosmological scale is presented. Studies of the ultrahigh energy diffuse neutrino background using acoustic detector and high mass Glashow resonances are reported. Point source studies are also discussed.

Isodual theory of antimatter applications to antigravity, grand unification and cosmology

CERN Document Server

Santilli, Ruggero Maria

2006-01-01

Antimatter, already conjectured by A. Schuster in 1898, was actually predicted by P.A.M. Dirac in the late 19-twenties in the negative-energy solutions of the Dirac equation. Its existence was subsequently confirmed via the Wilson chamber and became an established part of theoretical physics. Dirac soon discovered that particles with negative energy do not behave in a physically conventional manner, and he therefore developed his "hole theory". This restricted the study of antimatter to the sole level of second quantization. As a result antimatter created a scientific imbalance, because matter was treated at all levels of study, while antimatter was treated only at the level of second quantization. In search of a new mathematics for the resolution of this imbalance the author conceived what we know today as Santilli’s isodual mathematics, which permitted the construction of isodual classical mechanics, isodual quantization and isodual quantum mechanics. The scope of this monograph is to show that our classi...

Measuring antimatter gravity with muonium

Directory of Open Access Journals (Sweden)

Kaplan Daniel M.

2015-01-01

Full Text Available The gravitational acceleration of antimatter, ḡ, has never been directly measured and could bear importantly on our understanding of gravity, the possible existence of a fifth force, and the nature and early history of the universe. Only two avenues for such a measurement appear to be feasible: antihydrogen and muonium. The muonium measurement requires a novel, monoenergetic, low-velocity, horizontal muonium beam directed at an atom interferometer. The precision three-grating interferometer can be produced in silicon nitride or ultrananocrystalline diamond using state-of-the-art nanofabrication. The required precision alignment and calibration at the picometer level also appear to be feasible. With 100 nm grating pitch, a 10% measurement of ḡ can be made using some months of surface-muon beam time, and a 1% or better measurement with a correspondingly larger exposure. This could constitute the first gravitational measurement of leptonic matter, of 2nd-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.

Enabling Exploration of Deep Space: High Density Storage of Antimatter

Science.gov (United States)

Smith, Gerald A.; Kramer, Kevin J.

1999-01-01

Portable electromagnetic antiproton traps are now in a state of realization. This allows facilities like NASA Marshall Space Flight Center to conduct antimatter research remote to production sites. MSFC is currently developing a trap to store 10(exp 12) antiprotons for a twenty-day half-life period to be used in future experiments including antimatter plasma guns, antimatter-initiated microfusion, and the synthesis of antihydrogen for space propulsion applications. In 1998, issues including design, safety and transportation were considered for the MSFC High Performance Antimatter Trap (HiPAT). Radial diffusion and annihilation losses of antiprotons prompted the use of a 4 Tesla superconducting magnet and a 20 KV electrostatic potential at 10(exp -12) Torr pressure. Cryogenic fluids used to maintain a trap temperature of 4K were sized accordingly to provide twenty days of stand-alone storage time (half-life). Procurement of the superconducting magnet with associated cryostat has been completed. The inner, ultra-high vacuum system with electrode structures has been fabricated, tested and delivered to MSFC along with the magnet and cryostat. Assembly of these systems is currently in progress. Testing under high vacuum conditions, using electrons and hydrogen ions will follow in the months ahead.

The gravitational properties of antimatter

International Nuclear Information System (INIS)

Goldman, T.; Hughes, R.J.; Nieto, M.M.

1986-09-01

It is argued that a determination of the gravitational acceleration of antimatter towards the earth is capable of imposing powerful constraints on modern quantum gravity theories. Theoretical reasons to expect non-Newtonian non-Einsteinian effects of gravitational strength and experimental suggestions of such effects are reviewed. 41 refs

Anti-helium flux as a signature for antimatter globular clusters in our galaxy

International Nuclear Information System (INIS)

Belotskij, K.M.; Golubkov, Yu.A.; Khlopov, M.Yu.; Konoplich, R.V.; Sakharov, A.S.

2000-01-01

The alpha magnetic spectrometer experiment is shown to be sensitive to test the hypothesis on the existence of antimatter globular cluster in our Galaxy. The hypothesis follows from the analysis of possible tests for the mechanisms of baryosynthesis and uses antimatter domain in the matter domain Universe as the probe for the physics underlaying the origin of the matter. The interval of masses for the antimatter in our Galaxy is fixed from below by the condition of antimatter domain survival in the matter dominated Universe and from above by the observed gamma-ray flux. For this interval the expected fluxes of anti-helium-3 and anti-helium-4 are calculated with the account of their interaction with the matter in the Galaxy [ru

Anti-helium flux as a signature for antimatter globular clusters in our galaxy

International Nuclear Information System (INIS)

Belotsky, K.M.; Golubkov, Yu.A.; Khlopov, M.Yu.; Konoplich, R.V.; Sakharov, A.S.

2000-01-01

The Alpha Magnetic Spectrometer experiment is shown to be sensitive to test the hypothesis on the existence of antimatter globular cluster in our Galaxy. The hypothesis follows from the analysis of possible tests for the mechanisms of baryosynthesis and uses antimatter domains in the matter-dominated Universe as the probe for the physics underlying the origin of matter. The interval of masses for the antimatter in our Galaxy is fixed from below by the condition of antimatter domain survival in the matter-dominated Universe and from above by the observed gamma-ray flux. For this interval, the expected fluxes of anti-helium-3 and anti-helium-4 are calculated with account for their interaction with the matter in the Galaxy

Complementary aspects on matter-antimatter boundary layers

International Nuclear Information System (INIS)

Lehnert, B.

1990-05-01

This paper gives some complementary aspects on the problems of the matter-antimatter metagalaxy model and its cellular structure, as being proposed by Klein and Alfven. A previously outlined one-dimensional model of a magnetized matter-antimatter boundary layer is updated and extended, by introducing amended nuclear annihilation data, and by making improved approximations of the layer structure and its dependence on relevant parameters. The critical beta value obtained from this model leads to critical plasma densities which are not high enough to become reconcilable with a cellular matter-antimatter structure within the volume of a galaxy. Additional investigations are required on the questions whether the obtained beta limit would still apply to cells of the size of a galaxy, and whether large modification of this limit could result from further refinement of the theory and from the transition to a three-dimensional model. Attention is called to the wide area of further research on ambiplasma physics, and on a three-dimensional cell structure with associated problems of equilibrium and stability. In particular, the high-energy ambiplasma component has to be further analysed in terms of kinetic theory, on account of the large Larmor radii of the corresponding electrons and positrons

Interchange Instability and Transport in Matter-Antimatter Plasmas

Science.gov (United States)

Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

2017-06-01

Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

Interchange Instability and Transport in Matter-Antimatter Plasmas.

Science.gov (United States)

Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

2017-06-09

Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

ALICE’s wonderland reveals the heaviest antimatter ever observed

CERN Multimedia

CERN Bulletin

2011-01-01

Producing and observing antiparticles is part of everyday life for many physics laboratories around the world, including CERN. However, recreating and observing the anti-nuclei of complex atoms is a much more difficult task. Analysing data collected in a run of just one month, ALICE has recently found evidence of the formation of four anti-nuclei of Helium 4, the heaviest antimatter ever created in a laboratory.   The STAR experiment at RHIC came first and published the result in March: they presented evidence of 18 anti-nuclei of Helium 4 collected over several years of data taking. “ALICE came second but it's amazing to see how fast the results came,” exclaims Paolo Giubellino, the experiment’s spokesperson. “We were able to confirm the observation of 4He anti-nuclei with data collected in November 2010.” Scientists agree on the fact that antimatter was created in the Big Bang together with matter. However, today we do not observe antimatter outsid...

EXAM: An experiment to search for antimatter in distant clusters of galaxies

International Nuclear Information System (INIS)

Ahlen, S.P.

1986-01-01

It is often claimed that the absence of antimatter in the universe is evidence in favor of Grand Unified Theories (GUT's) of particle physics. This is due to the three requirements initially enumerated by Sakharov, for the evolution of a matter-antimatter symmetric universe to an asymmetric universe: 1) Existence of baryon number non-conserving processes such as predicted by GUT's, 2) Existence of CP violating processes in the hot early universe, 3) Deviations from thermal equilibrium in the early universe. However, before this argument can be accepted, one must examine the evidence against antimatter in the universe

Antimatter persuaded to react with matter

CERN Multimedia

Van Noorden, Richard

2006-01-01

"Matter and antimatter usually destroy each other in a flash of energy and a spray of exotic particles when they meet. Yet the two have been coaxed into a chemical reaction by the international research group Athena." (2/3 page)

Golden Jubilee photos: Gathering Antimatter

CERN Multimedia

2004-01-01

One day, antimatter might take people where no one has gone before, but it isn't science fiction. Protons are easily obtainable by stripping electrons from hydrogen atoms, but their antimatter counterparts, the antiprotons, have to be created artificially at accelerators. Roughly one antiproton can be produced from around a million protons bombarding a target at 26 GeV. In 1978, when CERN decided to take the unprecedented step of turning the SPS accelerator into a proton-antiproton collider, it had to deal with the scarcity, and had to concentrate the beam until it was intense enough for the experiment. Antiprotons are produced with a wide range of angles and energy, so before they can be used in an accelerator they have to be captured and 'cooled', reducing the beam dimensions by many orders of magnitude. This was the job of the Antiproton Accumulator (AA), completed in 1980 and shown here before it disappeared from view under concrete shielding. It followed the pioneering Initial Cooling Experiment (ICE) i...

A moiré deflectometer for antimatter

CERN Document Server

Aghion, S; Amsler, C; Ariga, A; Ariga, T; Belov, A S; Berggren, K; Bonomi, G; Braunig, P; Bremer, J; Brusa, R S; Cabaret, L; Canali, C; Caravita, R; Castelli, F; Cerchiari, G; Cialdi, S; Comparat, D; Consolati, G; Derking, H; Di Domizio, S; Di Noto, L; Doser, M; Dudarev, A; Ereditato, A; Ferragut, R; Fontana, A; Genova, P; Giammarchi, M; Gligorova, A; Gninenko, S N; Haider, S; Huse, T; Jordan, E; Jørgensen, L V; Kaltenbacher, T; Kawada, J; Kellerbauer, A; Kimura, M; Knecht, A; Krasnicky, D; Lagomarsino, V; Lehner, S; Magnani, A; Malbrunot, C; Mariazzi, S; Matveev, V A; Moia, F; Nebbia, G; Nedelec, P; Oberthaler, M K; Pacifico, N; Petracek, V; Pistillo, C; Prelz, F; Prevedelli, M; Regenfus, C; Riccardi, C; Røhne, O; Rotondi, A; Sandaker, H; Scampoli, P; Storey, J; Subieta Vasquez, M A; Spacek, M; Testera, G; Vaccarone, R; Widmann, E; Zavatarelli, S; Zmeskal, J

2014-01-01

The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational inter- action is of high interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics—the moire ́ deflectometer—for a measurement of the acceleration of slow antiprotons. The setup con- sists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleratio...

Problems of matter-antimatter boundary layers

International Nuclear Information System (INIS)

Lehnert, B.

1975-01-01

This paper outlines the problems of the quasi-steady matter-antimatter boundary layers discussed in Klein-Alfven's cosmological theory, and a crude model of the corresponding ambiplasma balance is presented: (i) at interstellar particle densities, no well-defined boundary layer can exist in presence of neutral gas, nor can such a layer be sustained in an unmagnetized fully ionized ambiplasma. (ii) Within the limits of applicability of the present model, sharply defined boundary layers are under certain conditions found to exist in a magnetized ambiplasma. Thus, at beta values less than unity, a steep pressure drop of the low-energy components of matter and antimatter can be balanced by a magnetic field and the electric currents in the ambiplasma. (iii) The boundary layer thickness is of the order of 2x 0 approximately 10/BT 0 sup(1/4) meters, where B is the magnetic field strength in MKS units and T 0 the characteristic temperature of the low-energy components in the layer. (Auth.)

Kinetics of Interactions of Matter, Antimatter and Radiation Consistent with Antisymmetric (CPT-Invariant Thermodynamics

Directory of Open Access Journals (Sweden)

A.Y. Klimenko

2017-05-01

Full Text Available This work investigates the influence of directional properties of decoherence on kinetics rate equations. The physical reality is understood as a chain of unitary and decoherence events. The former are quantum-deterministic, while the latter introduce uncertainty and increase entropy. For interactions of matter and antimatter, two approaches are considered: symmetric decoherence, which corresponds to conventional symmetric (CP-invariant thermodynamics, and antisymmetric decoherence, which corresponds to antisymmetric (CPT-invariant thermodynamics. Radiation, in its interactions with matter and antimatter, is shown to be decoherence-neutral. The symmetric and antisymmetric assumptions result in different interactions of radiation with matter and antimatter. The theoretical predictions for these differences are testable by comparing absorption (emission of light by thermodynamic systems made of matter and antimatter. Canonical typicality for quantum mixtures is briefly discussed in Appendix A.

Asymmetric creation of matter and antimatter in the expanding universe

International Nuclear Information System (INIS)

Papastamatiou, N.J.; Parker, L.

1979-01-01

We consider a simple model in which the matter-antimatter asymmetry of the universe is brought about by an effective two-particle interaction that violates baryon-number conservation as well as CP invariance. The particle fields participating in the interaction are quantized, and their time development in an isotropically expanding universe is found to all orders in the coupling constant. Pair production by the asymmetric interaction, as well as symmetric production by the gravitational field of the expanding universe, appear simultaneously in the solution. Taking an initial state in which no particles participating in the asymmetric interaction are present, we find the created baryon-number density. We consider in more detail the case when the matter-antimatter asymmetry is produced during a stage when the radius of the universe is small with respect to its present value. We make numerical estimates of the created matter-antimatter asymmetry, and put limits on possible values of the parameters of this model

Antimatter. Past, present and future

International Nuclear Information System (INIS)

Zichichi, A.

2001-01-01

In order to have matter it needs to have fundamental fermions (quarks and leptons), particles (mesons and baryons) and nuclei. For antimatter to exist, the anti fundamental fermions as well as the antiparticles and the antinuclei are needed. The masses associated with these components of matter are the intrinsic (quarks and leptons), the confinement (mesons and baryons) and the binding [either nuclear (nuclei), or electromagnetic (atoms)]. The first two are positive, the two binding ones are negative. These masses have different origins. No one has been able to establish the origin of the intrinsic masses (it could be the Higgs mechanism, but this lacks experimental confirmation so far). The confinement masses are QCD non-perturbative effects. The nuclear binding masses are QCD-induced colour neutral effects; the electromagnetic binding is due to QED and, since QED is the best experimentally checked RQFT, its validity in terms of the CPT symmetry cannot easily be questioned and this is why the electromagnetic binding is not included in this review.If CPT were theoretically well established as it was when discovered, all mass differences, between any matter and its antimatter partner, should be zero

Gravitational mass of relativistic matter and antimatter

Directory of Open Access Journals (Sweden)

Tigran Kalaydzhyan

2015-12-01

Full Text Available The universality of free fall, the weak equivalence principle (WEP, is a cornerstone of the general theory of relativity, the most precise theory of gravity confirmed in all experiments up to date. The WEP states the equivalence of the inertial, m, and gravitational, mg, masses and was tested in numerous occasions with normal matter at relatively low energies. However, there is no confirmation for the matter and antimatter at high energies. For the antimatter the situation is even less clear – current direct observations of trapped antihydrogen suggest the limits −65antimatter by Earth. Here we demonstrate an indirect bound 0.96

Antimatter

CERN Multimedia

CERN. Geneva. Audiovisual Unit; Landua, Rolf

2002-01-01

Antiparticles are a crucial ingredient of particle physics and cosmology. More than 70 years after Dirac's bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: as a tool in accelerators; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on the experimental 'antimatter' programme at the Antiproton Decelerator (AD), with special emphysis on antihydrogen production and spectroscopy. The lecture will conclude with an outlook on present and potential future applications of antiparticles in science and our daily life.

More Sci- than Fi, Physicists Create Antimatter

CERN Multimedia

Overbye, Dennis

2002-01-01

Physicists working in Europe announced yesterday that they had passed through nature's looking glass and had created atoms made of antimatter, or antiatoms, opening up the possibility of experiments in a realm once reserved for science fiction writers (5 pages)

Traps for antimatter and antihydrogen production

International Nuclear Information System (INIS)

Holzscheiter, M.H.

1994-01-01

Even though positrons have been captured and stored in ion traps for precision measurements, the recent trapping and cooling of antiprotons may be considered as the beginning of a new era in antimatter research. For the first time all the ingredients to produce the first atom of the antimatter world, the antihydrogen atom, are at hand, and several groups have entered an active discussion on the feasibility of producing antihydrogen as well as on the possibility to perform precision tests on CPT and gravity. At the same time, the trapping of reasonable large numbers of antiprotons has opened up the way for a variety of exciting physics with ultra-low energy antiprotons, ranging from atomic physics issues to nuclear physics and medical applications. I will describe the current status of the work on trapping antiprotons and positrons, discuss possible physics applications of this technique, and describe the two most promising routes to produce antihydrogen for precision spectroscopy. Towards the end a few comments on storing the produced antihydrogen and on utilizing antihydrogen for gravity measurements and for CPT tests are given

Antimatter and 20th Century Science

Science.gov (United States)

Williams, Gary

2005-01-01

This article gives an outline of the history of antimatter from the concept first introduced in 1898 up to the present day and is intended to complement the article "Antihydrogen on Tap" on page 229 [of this issue of "Physics Education"]. It is hoped that it will provide enough historical background material along with interesting snippets of…

Looking for the origin of the matter-antimatter asymmetry. Recent results from the Belle experiment

International Nuclear Information System (INIS)

Katayama, Nobuhiko

2006-01-01

Why is our Universe made of matter and not antimatter? It might be explained if the laws that govern matter and antimatter are different. In 1964, matter-antimatter asymmetry was discovered in the weak decays of elementary particles called Kaons. At the KEKB B factory we have discovered CP violations in B meson decays and have thus established the Kobayashi-Maskawa model of CP violation. The present article reviews the history of CP violation, focusing on recent results from the B factories and prospects in this field. (author)

Measuring gravitational effects on antimatter in space

Directory of Open Access Journals (Sweden)

Piacentino Giovanni Maria

2017-01-01

Full Text Available A direct measurement of the gravitational acceleration of antimatter has never been performed to date. Recently, such an experiment has been proposed, using antihydrogen with an atom interferometer and an antihydrogen confinament has been realized at CERN. In alternative we propose an experimental test of the gravitational interaction with antimatter by measuring the branching fraction of the CP violating decay of KL in space. In fact, even if the theoretical Standard Model explains the CPV with the presence of pure phase in the KMC Kobaiashi-Maskava-Cabibbo matrix, ample room is left for contributions by other interactions and forces to generate CPV in the mixing of the neutral K and B mesons. Gravitation is a good candidate and we show that at the altitude of the International Space Station, gravitational effects may change the level of CP violation such that a 5 sigma discrimination may be obtained by collecting the KL produced by the cosmic proton flux within a few years.

Cosmic ray neutrino tests for heavier weak bosons and cosmic antimatter

Science.gov (United States)

Brown, R. W.; Stecker, F. W.

1981-01-01

A program for using high energy neutrino astronomy with large neutrino detectors to directly test for the existence of heavier weak intermediate vector bosons (ivb) and cosmic antimatter is described. Such observations can provide a direct test of baryon symmetric cosmologies. Changes in the total cross section for nu(N) yields mu(X) due to additional propagators are discussed and higher mass resonances in the annihilation channel bar-nu sub e e(-) yields X are analyzed. The annihilation channel is instrumental in the search for antimatter, partcularly if heavier IVB's exist.

Constraining antimatter domains in the early universe with big bang nucleosynthesis.

Science.gov (United States)

Kurki-Suonio, H; Sihvola, E

2000-04-24

We consider the effect of a small-scale matter-antimatter domain structure on big bang nucleosynthesis and place upper limits on the amount of antimatter in the early universe. For small domains, which annihilate before nucleosynthesis, this limit comes from underproduction of 4He. For larger domains, the limit comes from 3He overproduction. Since most of the 3He from &pmacr; 4He annihilation are themselves annihilated, the main source of primordial 3He is the photodisintegration of 4He by the electromagnetic cascades initiated by the annihilation.

New interpretation of matter-antimatter asymmetry based on branes and possible observational consequences

International Nuclear Information System (INIS)

Cai Ronggen; Li Tong; Li Xueqian; Wang Xun

2007-01-01

Motivated by the alpha-magnetic-spectrometer (AMS) project, we assume that after the big bang or inflation epoch, antimatter was repelled onto one brane which is separated from our brane where all the observational matter resides. It is suggested that CP may be spontaneously broken, the two branes would correspond to ground states for matter and antimatter, respectively. Generally a complex scalar field which is responsible for the spontaneous CP violation, exists in the space between the branes. The matter and antimatter on the two branes attract each other via gravitational force, meanwhile the scalar field causes a Casimir effect to result in a repulsive force against the gravitation. We find that the Casimir force is much stronger than the gravitational force, as long as the separation of the two branes is small. Thus at early epoch after the big bang, the two branes were closer and then have been separated by the Casimir repulsive force from each other. The trend will continue until the separation is sufficiently large and then the gravitational force observed in our four-space would obviously deviate from the Newton's universal gravitational law. We suppose that there is a potential barrier at the brane boundary, which is similar to the surface tension for a water membrane. The barrier prevents the matter (antimatter) particles from entering the space between two branes and jump from one brane to another. However, by the quantum tunneling, a sizable antimatter flux may come to our brane and be observed by the AMS. In this work by considering two possible models, i.e. the naive flat space-time and Randall-Sundrum models, and using the observational data on the visible matter in our universe as inputs, we derive the antimatter flux which comes to our detector in the nonrelativistic approximation and make a rough numerical estimate of possible numbers of antihelium at AMS

A position sensitive silicon detector for AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy)

CERN Multimedia

Gligorova, A

2014-01-01

The AEḡIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is located at the Antiproton Decelerator (AD) at CERN and studies antimatter. The main goal of the AEḡIS experiment is to carry out the first measurement of the gravitational acceleration for antimatter in Earth’s gravitational field to a 1% relative precision. Such a measurement would test the Weak Equivalence Principle (WEP) of Einstein’s General Relativity. The gravitational acceleration for antihydrogen will be determined using a set of gravity measurement gratings (Moiré deflectometer) and a position sensitive detector. The vertical shift due to gravity of the falling antihydrogen atoms will be detected with a silicon strip detector, where the annihilation of antihydrogen will take place. This poster presents part of the development process of this detector.

Possible evidence for the existence of antimatter on a cosmological scale in the universe.

Science.gov (United States)

Stecker, F. W.; Morgan, D. L., Jr.; Bredekamp, J.

1971-01-01

Initial results of a detailed calculation of the cosmological gamma-ray spectrum from matter-antimatter annihilation in the universe. The similarity between the calculated spectrum and the present observations of the gamma-ray background spectrum above 1 MeV suggests that such observations may be evidence of the existence of antimatter on a large scale in the universe.

Study of the concordance of a matter-antimatter symmetric Dirac-Milne Universe

International Nuclear Information System (INIS)

Benoit-Levy, A.

2009-09-01

This thesis is devoted to the study of the Dirac-Milne Universe, a cosmological model in which matter and antimatter are present in equal quantities and where antimatter, as suggested by general relativity through the properties of the Kerr-Newman solutions, is supposed to have a negative active gravitational mass. Supposing such hypothesis removes the necessity to invoke inflation, Dark Energy and Dark matter as mandatory components. Matter (with positive mass) and antimatter (with negative mass) being present in equal quantities, the scale factor evolves linearly with time. After a short summary of basic properties of standard cosmology, some consequences of this linear evolution are studied. The full study of primordial nucleosynthesis within the framework of the Dirac-Milne universe reveals that deuterium can be produced by residual annihilations between matter and antimatter shortly before recombination. Even though Dirac-Milne universe does not present any recent acceleration of the expansion, it is shown that this model is in good agreement with the cosmological test of type Ia supernovae. It is also shown that the position of the acoustic scale of the Cosmic Microwave Background (CMB) naturally appears at the degree scale. The full study of the CMB spectrum and the coherence of the notion of negative mass remain to be investigated, but this work exhibits a original model that could potentially give an alternative description of our Universe. (author)

Gravitational matter-antimatter asymmetry and four-dimensional Yang-Mills gauge symmetry

Science.gov (United States)

Hsu, J. P.

1981-01-01

A formulation of gravity based on the maximum four-dimensional Yang-Mills gauge symmetry is studied. The theory predicts that the gravitational force inside matter (fermions) is different from that inside antimatter. This difference could lead to the cosmic separation of matter and antimatter in the evolution of the universe. Moreover, a new gravitational long-range spin-force between two fermions is predicted, in addition to the usual Newtonian force. The geometrical foundation of such a gravitational theory is the Riemann-Cartan geometry, in which there is a torsion. The results of the theory for weak fields are consistent with previous experiments.

Antimatter performs optical gymnastics

Energy Technology Data Exchange (ETDEWEB)

Eades, John [University of Tokyo (Japan); CERN, Geneva (Switzerland)

2005-03-01

Lasers have been used for the first time to create antihydrogen, which could allow precise spectroscopic measurements of anti-atoms. The philosopher William James once said that 'if you wish to upset the law that all crows are black, you must not seek to show that none of them are - it is enough to produce a single white crow'. Likewise, if you wish to test the so-called CPT theorem, according to which a world constructed of antimatter behaves exactly the same as one constructed of matter, you do not need to create an entire 'antiworld'. It would be quite sufficient to show that the frequency of just one transition in a simple anti-atom differs from the value of the same transition in the corresponding ordinary atom. The question is, by how much? Any gross violations of the CPT theorem - which, more formally, states that a system remains unchanged under the combined operations of charge conjugation, parity reversal and time reversal - have already been ruled out experimentally. As a result, nobody expects any difference between matter and antimatter to be anything other than minute, if, indeed, there is a difference at all. The laser-spectroscopy tools that have made it possible to measure transition frequencies in ordinary hydrogen to extraordinarily high precision should also be applicable to antihydrogen. This makes hydrogen anti-atoms excellent candidates to test the CPT theorem. Now, researchers in the ATRAP collaboration at CERN have taken an important step along the obstacle-strewn path towards this goal by using lasers to control the production of antihydrogen atoms. (U.K.)

The Role of Antimatter in Big-Bang Cosmology

Science.gov (United States)

Stecker, Floyd W.

1974-01-01

Discusses theories underlying man's conceptions of the universe, including Omnes' repulsive separation mechanism, the turbulence theory of galaxy formation, and the author's idea about gamma ray spectra in cosmological matter-antimatter annihilation. Indicates that the Apollo data provide encouraging evidence by fitting well with his theoretical…

ELENA prepares a bright future for antimatter research

CERN Multimedia

CERN Bulletin

2011-01-01

At its recent session in June, the CERN Council approved the construction of the Extra Low ENergy Antiproton ring (ELENA) – an upgrade of the existing Antiproton Decelerator. ELENA will allow the further deceleration of antiprotons, resulting in an increased number of particles trapped downstream in the experimental set-ups. This will give an important boost to antimatter research in the years to come.   Layout of the AD experimental hall: the Antiproton Decelerator ring (purple); the ALPHA, ASACUSA, and ATRAP experiments (green); the ACE experiment (not pictured); and the new ELENA ring (blue). The Antiproton Decelerator (AD) is CERN’s widely recognized facility for the study of antimatter properties. The recent successes of the AD experiments are just the latest in a long list of important scientific results that started with LEAR (Low Energy Antiproton Ring). The scientific demand for low-energy antiprotons at the AD continues to grow. There are now four experiments runnin...

MASS-SAT: Matter-antimatter space spectrometer on satellite

CERN Document Server

Basini, G; Massimo Brancaccio, F; Ricci, M; Bocciolini, M; Spillantini, P; Wang, Y F; Bongiorno, F; de Pascale, M P; Morselli, A; Picozza, P; de Marzo, C; Erriquez, O; Barbiellini, G; Vacchi, A; Galeotti, P; Ballocchi, G; Simon, M; Carlson, P; Goret, P; Golden, R L

The MASS-SAT Experiment (Matter-Antimatter Space Spectrometer on SATellite) presented here is conceived to search for an experimental answer to many open problems related to both Astrophysics and Physics, through the detection of positrons, antiprotons, nuclei and, overall, antinuclei if they exist. Among these problems there are the hypothesized presence of antigalaxies in the Universe (the matter-antimatter symmetry problem), the existence of black holes as possible antiproton sources (the Hawking effect), the existence of photinos as antiproton sources (related to the dark-matter problem), the understanding of the mechanism of cosmic-ray acceleration in the interstellar medium, the determination of the relative abundancies of isotopes in cosmic rays and many others. The choice of an orbit expecially appropriate for that (geostationary or polar orbit) as well as the choice of an apparatus composed only of solid-state detectors and permanent magnets (no gas and no liquid helium on board, avoiding complexity ...

A new “culprit” for matter-antimatter asymmetry

CERN Multimedia

Antonella Del Rosso

2013-01-01

In our matter-dominated Universe, the observation of new processes showing matter-antimatter asymmetry allows scientists to test their theories and, possibly, to explore new territories. The LHCb collaboration has recently observed matter-antimatter asymmetries in the decays of the B0s meson, which thus becomes the fourth particle known to present such behaviour.   The VELO detector: a crucial element for particle identifiation in LHCb. Almost all physics processes known to scientists show perfect symmetry if a particle is interchanged with its antiparticle (C symmetry), and then if left and right are swapped (P symmetry). So it becomes very hard to explain why the Universe itself does not conform to this symmetry and, instead, shows a huge preference for matter. Processes that violate this symmetry are rare and of great interest to scientists. Violation of the CP symmetry in neutral kaons was first observed by Nobel Prize Laureates James Cronin and Val Fitch in the 1960s. About 40 years la...

Matter-antimatter and matter-matter interactions at intermediate energies

International Nuclear Information System (INIS)

Santos, Antonio Carlos Fontes dos

2002-01-01

This article presents some of the recent experimental advances on the study on antimatter-matter and matter-matter interactions, and some of the subtle differences stimulated a great theoretical efforts for explanation of the results experimentally observed

Undergraduate Laboratory Experiment: Measuring Matter Antimatter Asymmetries at the Large Hadron Collider

CERN Document Server

Parkes, Chris; Gutierrez, J

2015-01-01

This document is the student manual for a third year undergraduate laboratory experiment at the University of Manchester. This project aims to measure a fundamental difference between the behaviour of matter and antimatter through the analysis of data collected by the LHCb experiment at the Large Hadron Collider. The three-body dmecays $B^\\pm \\rightarrow h^\\pm h^+ h^-$, where $h^\\pm$ is a $\\pi^\\pm$ or $K^\\pm$ are studied. The inclusive matter antimatter asymmetry is calculated, and larger asymmetries are searched for in localized regions of the phase-space.

Emerging science and technology of antimatter plasmas and trap-based beams

International Nuclear Information System (INIS)

Surko, C.M.; Greaves, R.G.

2004-01-01

Progress in the ability to accumulate and cool positrons and antiprotons is enabling new scientific and technological opportunities. The driver for this work is plasma physics research - developing new ways to create and manipulate antimatter plasmas. An overview is presented of recent results and near-term goals and challenges. In atomic physics, new experiments on the resonant capture of positrons by molecules provide the first direct evidence that positrons bind to 'ordinary' matter (i.e., atoms and molecules). The formation of low-energy antihydrogen was observed recently by injecting low-energy antiprotons into a cold positron plasma. This opens up a range of new scientific opportunities, including precision tests of fundamental symmetries such as invariance under charge conjugation, parity, and time reversal, and study of the chemistry of matter and antimatter. The first laboratory study of electron-positron plasmas has been conducted by passing an electron beam through a positron plasma. The next major step in these studies will be the simultaneous confinement of electron and positron plasmas. Although very challenging, such experiments would permit studies of the nonlinear behavior predicted for this unique and interesting plasma system. The use of trap-based positron beams to study transport in fusion plasmas and to characterize materials is reviewed. More challenging experiments are described, such as the creation of a Bose-condensed gas of positronium atoms. Finally, the future of positron trapping and beam formation is discussed, including the development of a novel multicell trap to increase by orders of magnitude the number of positrons trapped, portable antimatter traps, and cold antimatter beams (e.g., with energy spreads ≤1 meV) for precision studies of positron-matter interactions

The Janus Cosmological Model (JCM) : An answer to the missing cosmological antimatter

Science.gov (United States)

D'Agostini, Gilles; Petit, Jean-Pierre

2017-01-01

Cosmological antimatter absence remains unexplained. Twin universes 1967 Sakarov's model suggests an answer: excess of matter and anti-quarks production in our universe is balanced by equivalent excess of antimatter and quark in twin universe. JCM provides geometrical framework, with a single manifold , two metrics solutions of two coupled field equations, to describe two populations of particles, one with positive energy-mass and the other with negative energy-mass : the `twin matter'. In a quantum point of view, it's a copy of the standard matter but with negative mass and energy. The matter-antimatter duality holds in both sectors. The standard and twin matters do not interact except through the gravitational coupling expressed in field equations. The twin matter is unobservable from matter-made apparatus. Field equations shows that matter and twin matter repel each other. Twin matter surrounding galaxies explains their confinement (dark matter role) and, in the dust universe era, mainly drives the process of expansion of the positive sector, responsible of the observed acceleration (dark energy role).

Val L. Fitch, the CP Violation, and Antimatter

Science.gov (United States)

dropdown arrow Site Map A-Z Index Menu Synopsis Val L. Fitch, the CP Violation, and Antimatter Resources ) 'to verify a fundamental tenet of physics, known as CP [charge-parity] symmetry, by showing that two into two pi mesons. Cronin and Fitch had found an example of CP violation. The discovery's

Is the Universe matter-antimatter symmetric

International Nuclear Information System (INIS)

Alfven, H.

1976-09-01

According to the symmetric cosmology there should be antimatter regions in space which are equally as large as the matter regions. The regions of different kind are separated by Leidenfrost layers, which may be very thin and not observable from a distance. This view has met resistance which in part is based on the old view that the dilute interstellar and intergalactic medium is more or less homogeneous. However, through space research in the magnetosphere and interplanetary space we know that thin layers, dividing space into regions of different magnetisation, exist and based on this it is concluded that space in general has a cellular structure. This result may break down the psychological resistance to the symmetric theory. The possibility that every second star in our galaxy consists of antimatter is discussed, and it is shown that this view is not in conflict with any observations. As most stars are likely to be surrounded by solar systems of a structure like our own, it is concluded that collisions between comets and antistars (or anticomets and stars) would be rather frequent. Such collisions would result in phenomena of the same type as the observed cosmic γ-ray bursts. Another support for the symmetric cosmology is the continuous X-ray background radiation. Also many of the observed large energy releases in cosmos are likely to be due to annihilation

Measurement of matter-antimatter differences in beauty baryon decays

NARCIS (Netherlands)

Dufour, L.; Mulder, M; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.; van Veghel, M.

Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined chargeconjugation and parity transformations, known as CP

Radio Frequency (RF) Trap for Confinement of Antimatter Plasmas Using Rotating Wall Electric Fields

Science.gov (United States)

Sims, William Herbert, III; Pearson, J. Boise

2004-01-01

Perturbations associated with a rotating wall electric field enable the confinement of ions for periods approaching weeks. This steady state confinement is a result of a radio frequency manipulation of the ions. Using state-of-the-art techniques it is shown that radio frequency energy can produce useable manipulation of the ion cloud (matter or antimatter) for use in containment experiments. The current research focuses on the improvement of confinement systems capable of containing and transporting antimatter.

Measurement of matter-antimatter differences in beauty baryon decays

NARCIS (Netherlands)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; Everse, LA; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J.E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Carvalho Akiba, K.; Coco, V.; David, P. N.Y.; De Bruyn, K.; Ferro-Luzzi, M.; Ketel, T.; Koopman, R. F.; Van Leerdam, J.; Merk, M.; Onderwater, C. J.G.; Raven, G.; Schiller, M.; Serra, N.; Snoek, H.; Storaci, B.; Syropoulos, V.; Van Tilburg, J.; Tolk, S.; Tsopelas, P.; Tuning, N.

Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP

Prospects for Studies of the Free Fall and Gravitational Quantum States of Antimatter

Directory of Open Access Journals (Sweden)

G. Dufour

2015-01-01

Full Text Available Different experiments are ongoing to measure the effect of gravity on cold neutral antimatter atoms such as positronium, muonium, and antihydrogen. Among those, the project GBAR at CERN aims to measure precisely the gravitational fall of ultracold antihydrogen atoms. In the ultracold regime, the interaction of antihydrogen atoms with a surface is governed by the phenomenon of quantum reflection which results in bouncing of antihydrogen atoms on matter surfaces. This allows the application of a filtering scheme to increase the precision of the free fall measurement. In the ultimate limit of smallest vertical velocities, antihydrogen atoms are settled in gravitational quantum states in close analogy to ultracold neutrons (UCNs. Positronium is another neutral system involving antimatter for which free fall under gravity is currently being investigated at UCL. Building on the experimental techniques under development for the free fall measurement, gravitational quantum states could also be observed in positronium. In this contribution, we report on the status of the ongoing experiments and discuss the prospects of observing gravitational quantum states of antimatter and their implications.

Origin of the matter-antimatter asymmetry

International Nuclear Information System (INIS)

Dine, Michael; Kusenko, Alexander

2004-01-01

Although the origin of matter-antimatter asymmetry remains unknown, continuing advances in theory and improved experimental limits have ruled out some scenarios for baryogenesis, for example, sphaleron baryogenesis at the electroweak phase transition in the Standard Model. At the same time, the success of cosmological inflation and the prospects for discovering supersymmetry at the Large Hadron Collider have put some other models in sharper focus. We review the current state of our understanding of baryogenesis with emphasis on those scenarios that we consider most plausible

Why is the universe more partial to mater than antimatter?

CERN Multimedia

2006-01-01

"B factory experiments at the Stanford Linear Accelerator (SLAC) in the USA and at the High Energy Accelerator Research Organization (KEK) in Japan have reached a new milestone in the quest to understand the matter-antimatter imbalance in our universe.

Atom optical tools for antimatter experiments

Energy Technology Data Exchange (ETDEWEB)

Braeunig, Philippe H.M.

2014-12-17

The direct measurement of the gravitational acceleration of antimatter in the earth's field, which represents a test of the weak equivalence principle, is in the focus of several ongoing experimental attempts. This thesis investigates tools and techniques known from the field of atom optics that can be utilised for such a measurement with antihydrogen atoms as envisioned by the AEgIS collaboration. A first experimental step is presented, in which a detection due to an electromagnetic force acting on antiprotons is measured with a Moire deflectometer. This device, which can be described with classical particle trajectories, consists of two gratings and a spatially resolving detector. Key elements of this measurement are the use of an emulsion detector with high spatial resolution and an absolute reference technique based on an interferometric fringe pattern of light, which is not deflected by forces. For future realisations, a new detection and evaluation scheme to measure gravity based on a three-grating system enclosed by a vertex-reconstructing detector is discussed. This allows the use of a grating periodicity that is smaller than the resolution of the detector while making efficient use of the particle flux. Smaller periodicities are favourable to increase the inertial sensitivity of the measurement apparatus but require to take effects of diffraction into account. To explore this near-field regime with antimatter, a Talbot-Lau interferometer for antiprotons is proposed and its possible experimental implementation is discussed.

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

Energy Technology Data Exchange (ETDEWEB)

Surko, Clifford M. [U. C. San Diego

2013-10-02

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.

Experiments with low-energy antimatter

Directory of Open Access Journals (Sweden)

Consolati G.

2015-01-01

Full Text Available Investigations on antimatter allow us to shed light on fundamental issues of contemporary physics. The only antiatom presently available, antihydrogen, is produced making use of the Antiproton Decelerator (AD facility at CERN. International collaborations currently on the floor (ALPHA, ASACUSA and ATRAP have succeeded in producing antihydrogen and are now involved in its confinement and manipulation. The AEGIS experiment is currently completing the commissioning of the apparatus which will generate and manipulate antiatoms. The present paper, after a report on the main results achieved with antihydrogen physics, gives an overview of the AEGIS experiment, describes its current status and discusses its first target.

Matter reflects Antimatter

CERN Document Server

Bianconi, A.; Cristiano, A.; Leali, M.; Lodi Rizzini, E.; Venturelli, L.; Zurlo, N.

2008-01-01

It is common belief that the interaction between antimatter and ordinary solid matter is dominated by annihilation. However, non-destructive processes may play a relevant role too. One century ago E. Rutherford wrote about the "diffuse reflection" of alpha and beta particles by thin layers of different metals: "The observations ... of Geiger and Marsden on the scattering of alpha rays indicate that some of the alpha particles must suffer a deflexion of more than a right angle at a single encounter.... It will be shown that the main deductions from the theory are independent of whether the central charge is supposed to be positive or negative". Although the theory of electromagnetic scattering is in first approximation independent of the relative sign of the colliding particles, in the case where projectile antiprotons are shot against a wall of solid matter the Rutherford diffuse reflection mechanism competes with the annihilation process. So it is not obvious at all that a relevant part of an antiproton beam...

Cosmic Ray Antimatter

CERN Multimedia

CERN. Geneva

2017-01-01

Over the last decade, space-born experiments have delivered new measurements of high energy cosmic-ray (CR) antiprotons and positrons, opening new frontiers in energy reach and precision. While being a promising discovery tool for new physics or exotic astrophysical phenomena, an irreducible background of antimatter comes from CR collisions with interstellar matter in the Galaxy. Understanding this irreducible source or constraining it from first principles is an interesting challenge: a game of hide-and-seek where the objective is to identify the laws of basic particle physics among the forest of astrophysical uncertainties. I describe an attempt to obtain such understanding, combining information from a zoo of CR species including massive nuclei and relativistic radioisotopes. I show that: (i) CR antiprotons most likely come from CR-gas collisions; (ii) positron data is consistent with, and suggestive of the same astrophysical production mechanism responsible for antiprotons and dominated by proton-proton c...

Some aspects of matter-antimatter asymmetry and states in the Universe

International Nuclear Information System (INIS)

Braghin, Fabio L.

2011-01-01

Full text: Matter-antimatter asymmetry observed in our Universe is discussed considering different aspects. The usual baryogenesis mechanism proposed by Sakharov is described and and few other mechanisms are analyzed. Furthermore, the possibility of the existence of antimatter islands is discussed in view of different observational results and plans for future observations. For the different mechanisms of producing such asymmetry, besides the breaking of CP, particular attention is given to CPT , considering both its possible breakdown in different systems and the framework of the CPT theorem, and to few other different effects which are (or might be) present in the (extended) phase diagram of strong interacting systems and which might not rely on non-equilibrium conditions. Some ideas of relevance for finite (anti)baryonic density systems are discussed as well. (author)

Using antimatter in modern medicine

OpenAIRE

Machado, A.C.B.; Pleitez, V.; Tijero, M.C.

2006-01-01

Neste artigo, fazemos uma breve exposição de como um dos conceitos fundamentais da física moderna, a existência de antimatéria, tem aplicação na medicina, na chamada tomografia por emissão de pósitrons (PET na sigla em inglês). Ela consiste na produção de imagens tomográficas digitais do organismo que são obtidas pela detecção da radiação produzida na aniquilação do pósitron com o elétron. In this paper we discuss how the existence of antimatter, one of the main concepts of modern physics,...

Cosmic ray antimatter: Is it primary or secondary?

Science.gov (United States)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1981-01-01

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic ray antiprotons, including the low energy measurement of Buffington, were examined. It is concluded that the cosmic ray antiproton data may be strong evidence for antimatter galaxies and baryon symmetric cosmology. The present antiproton data are consistent with a primary extragalactic component having antiproton/proton approximately equal to .0032 + or - 0.7.

Measurement of gravitational acceleration of antimatter

International Nuclear Information System (INIS)

Rouhani, S.

1989-12-01

The minute yet effective impact of gravitational potential in the central region of a long tube magnetic container of non-neutral plasmas can be utilized for the measurement of the gravitational acceleration of antimatter particles. The slight change in distribution of plasma particles along the gravitational field affects the internal electric field of the plasma, which in turn affects the frequency of the magnetron motion of its particles. Thus, a rather straightforward relation is established between the gravitational acceleration of the particles and their magnetron frequencies, which is measurable directly, determining the value of the gravitational acceleration. (author). 7 refs, 3 figs

The antimatter. Press breakfast 23 may 2000; L'antimatiere. Petit dejeuner de presse 23 mai 2000

Energy Technology Data Exchange (ETDEWEB)

Spiro, M; Dejardin, M; Debu, P; Aleksan, R [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France)

2000-05-01

This document brings together the subjects discussed during the Press breakfast of 23 may 2000 on the antimatter, with scientists of the CEA and the CNRS. It presents the research programs and the experiments on the antimatter and the symmetry violation: the CP LEAR and the NA48 experiments at CERN, the BaBar detector at SLAC, the fundamental research at the CEA and the impacts on the energy policy. It provides also links for more detailed inquiries. (A.L.B.)

On the random geometry of a symmetric matter antimatter universe

International Nuclear Information System (INIS)

Aldrovandi, R.; Goto, M.

1977-05-01

A statistical analysis is made of the randon geometry of an early symmetric matter-antimatter universe model. Such a model is shown to determine the total number of the largest agglomerations in the universe, as well as of some special configurations. Constraints on the time development of the protoagglomerations are also obtained

The Symmetry, or Lack of it, Between Matter and Antimatter

International Nuclear Information System (INIS)

Quinn, Helen R

2001-01-01

The subject of antimatter and its relationship to matter began with Dirac, with the publication of his famous equation in 1928.[1] Today it remains an active area of particle physics. The dominant issue for a number of major experimental programs is to decipher the nature of the difference in the laws of physics for matter and for antimatter. This has been a central issue of my work in the past few years, and a recurring theme in earlier work. Hence when I was asked to review a subject of my choice for this conference, this was the obvious choice for me; a very different focus from any other talk here. (Also, it allows me along the way make reference to both pieces of work for which I was cited in my Dirac award, though neither is central to this story.) Given this opportunity, I decided to start with the early history of the subject, both in honor of Dirac and his essential role in it, and because it is fascinating to look back and see how understanding evolves

Euro-led research team creates first ever reaction between matter and antimatter

CERN Multimedia

2006-01-01

"An EU-funded team of international researchers has produced the first ever reaction between matter and antimatter, creating protonium. Protonium is a unique type of atom that consists of a proton and an antiproton orbiting around each other." (1 page)

Local gamma ray events as tests of the antimatter theory of gamma ray bursts

International Nuclear Information System (INIS)

Sofia, S.; Wilson, R.E.

1976-01-01

Nearby examples of the antimatter 'chunks' postulated by Sofia and Van Horn to explain the cosmic gamma ray bursts may produce detectable gamma ray events when struck by solar system meteoroids. These events would have a much shorter time scale and higher energy spectrum than the bursts already observed. In order to have a reasonably high event rate, the local meteoroid population must extend to a distance from the Sun of the order of 0.1 pc, but the required distance could become much lower if the instrumental threshold is improved. The expected gamma ray flux for interaction of the antimatter bodies with the solar wind is also examined, and found to be far below present instrumental capabilities. (Auth.)

Gravitationally neutral dark matter-dark antimatter universe crystal with epochs of decelerated and accelerated expansion

Science.gov (United States)

Gribov, I. A.; Trigger, S. A.

2016-11-01

A large-scale self-similar crystallized phase of finite gravitationally neutral universe (GNU)—huge GNU-ball—with spherical 2D-boundary immersed into an endless empty 3D- space is considered. The main principal assumptions of this universe model are: (1) existence of stable elementary particles-antiparticles with the opposite gravitational “charges” (M+gr and M -gr), which have the same positive inertial mass M in = |M ±gr | ≥ 0 and are equally presented in the universe during all universe evolution epochs; (2) the gravitational interaction between the masses of the opposite charges” is repulsive; (3) the unbroken baryon-antibaryon symmetry; (4) M+gr-M-gr “charges” symmetry, valid for two equally presented matter-antimatter GNU-components: (a) ordinary matter (OM)-ordinary antimatter (OAM), (b) dark matter (DM)-dark antimatter (DAM). The GNU-ball is weightless crystallized dust of equally presented, mutually repulsive (OM+DM) clusters and (OAM+DAM) anticlusters. Newtonian GNU-hydrodynamics gives the observable spatial flatness and ideal Hubble flow. The GNU in the obtained large-scale self-similar crystallized phase preserves absence of the cluster-anticluster collisions and simultaneously explains the observable large-scale universe phenomena: (1) the absence of the matter-antimatter clusters annihilation, (2) the self-similar Hubble flow stability and homogeneity, (3) flatness, (4) bubble and cosmic-net structures as 3D-2D-1D decrystallization phases with decelerative (a ≤ 0) and accelerative (a ≥ 0) expansion epochs, (5) the dark energy (DE) phenomena with Λ VACUUM = 0, (6) the DE and DM fine-tuning nature and predicts (7) evaporation into isolated huge M±gr superclusters without Big Rip.

Gravitationally neutral dark matter–dark antimatter universe crystal with epochs of decelerated and accelerated expansion

International Nuclear Information System (INIS)

Gribov, I A; Trigger, S A

2016-01-01

A large-scale self-similar crystallized phase of finite gravitationally neutral universe (GNU)—huge GNU-ball—with spherical 2D-boundary immersed into an endless empty 3D- space is considered. The main principal assumptions of this universe model are: (1) existence of stable elementary particles-antiparticles with the opposite gravitational “charges” ( M + gr and M -gr ), which have the same positive inertial mass M in = | M ±gr | ≥ 0 and are equally presented in the universe during all universe evolution epochs; (2) the gravitational interaction between the masses of the opposite charges” is repulsive; (3) the unbroken baryon-antibaryon symmetry; (4) M +gr -M -gr “charges” symmetry, valid for two equally presented matter-antimatter GNU-components: (a) ordinary matter (OM)-ordinary antimatter (OAM), (b) dark matter (DM)-dark antimatter (DAM). The GNU-ball is weightless crystallized dust of equally presented, mutually repulsive (OM+DM) clusters and (OAM+DAM) anticlusters. Newtonian GNU-hydrodynamics gives the observable spatial flatness and ideal Hubble flow. The GNU in the obtained large-scale self-similar crystallized phase preserves absence of the cluster-anticluster collisions and simultaneously explains the observable large-scale universe phenomena: (1) the absence of the matter-antimatter clusters annihilation, (2) the self-similar Hubble flow stability and homogeneity, (3) flatness, (4) bubble and cosmic-net structures as 3D-2D-1D decrystallization phases with decelerative (a ≤ 0) and accelerative (a ≥ 0) expansion epochs, (5) the dark energy (DE) phenomena with Λ VACUUM = 0, (6) the DE and DM fine-tuning nature and predicts (7) evaporation into isolated huge M ±gr superclusters without Big Rip. (paper)

Can the new Neutrino Telescopes and LHC reveal the gravitational proprieties of antimatter?

CERN Document Server

Hajdukovic, Dragan Slavkov

2011-01-01

What are the gravitational proprieties of antimatter is still not known. One possibility is the gravitational repulsion between matter and antimatter (in short we call it antigravity). We point out two possible signatures of the assumed existence of antigravity. First, the supermassive black hole in the center of our Galaxy (Southern Sky)and in the center of the Andromeda Galaxy (Northern Sky)may produce a flux of antineutrinos measurable with the new generation of the neutrino telescopes; like the IceCube Neutrino Detector under construction at the South Pole, and the future one cubic kilometer telescope in Mediterranean Sea. Second, if microscopic black holes are successfully produced at the Large Hadron Collider (LHC) at CERN, their thermal (Hawking's) radiation should be dominated by a non-thermal radiation caused by antigravity.

Dissecting the Science of 'Angels and Demons' or Antimatter and Other Matters (Vernon W. Hughes Memorial Lecture)

International Nuclear Information System (INIS)

Gordon, Howard

2009-01-01

Howard Gordon, a physicist from the U.S. Department of Energy's Brookhaven National Laboratory, and local educators will separate the science facts from the science fiction of 'Angels and Demons,' a major motion picture based on Dan Brown's best-selling novel. The film, which opens nationally in theaters today, focuses on a plot to destroy the Vatican using antimatter stolen from the Large Hadron Collider (LHC) at the European particle physics laboratory CERN. Speakers will explain the real science of the LHC, including antimatter - oppositely charged cousins of ordinary matter with intriguing properties.

Development and data analysis of a position detector for AE$\\bar{g}$IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy)

CERN Document Server

Gligorova, Angela; Doser, Michael; Pacifico, Nicola

2015-03-13

AE$\\mathrm{\\bar{g}}$IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an antimatter experiment based at CERN, the European Organization for Nuclear Research, whose goal is to carry out the first direct measurement of the Earth’s gravitational acceleration on antimatter. The outcome of such measurement would be the first precision test of the Weak Equivalence Principle in a completely new area. According to WEP, all bodies fall with the same acceleration regardless of their mass and composition. AE$\\mathrm{\\bar{g}}$IS will attempt to achieve its aim by measuring the gravitational acceleration ($\\bar{g}$) for antihydrogen with 1$\\%$ relative precision. The first step towards the final goal is the formation of a pulsed, cold antihydrogen beam, which will be performed by a charge exchange reaction between laser excited (Rydberg) positronium and cold (100 mK) antiprotons. The antihydrogen atoms will be accelerated by an inhomogeneous electric field (Stark acceleration) to form a beam whose fr...

Matter-antimatter separation in the early universe by rotating black holes

Science.gov (United States)

Leahy, D. A.

1981-01-01

Consideration of the effect of rotating black holes evaporating early in the universe shows that they would have produced oppositely directed neutrino and antineutrino currents, which push matter and antimatter apart. This separation mechanism is, however, too feeble to account for a present baryon-to-photon ratio of 10 to the -9th, and has no significant observational consequences.

Black Holes and Gravitational Properties of Antimatter

CERN Document Server

Hajdukovic, D

2006-01-01

We speculate about impact of antigravity (i.e. gravitational repulsion between matter and antimatter) on the creation and emission of particles by a black hole. If antigravity is present a black hole made of matter may radiate particles as a black body, but this shouldn't be true for antiparticles. It may lead to radical change of radiation process predicted by Hawking and should be taken into account in preparation of the attempt to create and study mini black holes at CERN. Gravity, including antigravity is more than ever similar to electrodynamics and such similarity with a successfully quantized interaction may help in quantization of gravity.

Atomic physics of the antimatter explored with slow antiprotons

International Nuclear Information System (INIS)

Torii, Hiroyuki A.

2010-01-01

Frontiers of antimatter physics are reviewed, with a focus on our ASACUSA collaboration, doing research on 'Atomic Spectroscopy And Collisions Using Slow Antiprotons' at the 'Antiproton Decelerator' facility at CERN. Antiprotonic helium atoms give a unique test ground for testing CPT invariance between particles and antiparticles. Laser spectroscopy of this exotic atom has reached a precision of a few parts per billion in determation of the antiproton mass. We also have developed techniques to decelerate antiprotons and cool them to sub-eV energies in an electromagnetic trap at ultra-high vacuum and extract them as an ultra-slow beam at typically 250 eV. This unique low-energy beam opens up the possibility to study ionization and formation of antiprotonic atoms. The antihydrogen has been synthesized at low temperature in nested Penning traps by ATRAP and ATHENA(presently ALPHA) collaborations. Confinement of this neutral anti-atoms in a trap with magnetic field gradient is being studied, with an aim of 1S-2S laser spectroscopy in the future. ASACUSA has prepared a cusp trap for production of antihydrogen atoms, and aims at microwave spectroscopy between the hyperfine states of spin-polarized antihydrogen. A wide variety of low-energy antiproton physics also includes measurement of nuclear scattering, radiational biological effects, and gravity test of antimatter. (author)

Dissecting the Science of "Angels and Demons" or Antimatter and Other Matters (Vernon W. Hughes Memorial Lecture)

Energy Technology Data Exchange (ETDEWEB)

Gordon, Howard

2009-05-27

Howard Gordon, a physicist from the U.S. Department of Energy’s Brookhaven National Laboratory, and local educators will separate the science facts from the science fiction of “Angels & Demons,” a major motion picture based on Dan Brown’s best-selling novel. The film, which opens nationally in theaters today, focuses on a plot to destroy the Vatican using antimatter stolen from the Large Hadron Collider (LHC) at the European particle physics laboratory CERN. Speakers will explain the real science of the LHC, including antimatter – oppositely charged cousins of ordinary matter with intriguing properties.

The creation of high energy densities with antimatter beams

International Nuclear Information System (INIS)

Gibbs, W.R.; Kruk, J.W.; Rice Univ., Houston, TX

1989-01-01

The use of antiprotons (and antideuterons) for the study of the behavior of nuclear matter at high energy density is considered. It is shown that high temperatures and high energy densities can be achieved for small volumes. Also investigated is the strangeness production in antimatter annihilation. It is found that the high rate of Lambda production seen in a recent experiment is easily understood. The Lambda and K-short rapidity distributions are also reproduced by the model considered. 11 refs., 6 figs

The development and performance of the EXAM detector to search for extragalactic antimatter

International Nuclear Information System (INIS)

Coan, T.E.

1989-01-01

The design and development of a practical balloon borne instrument capable of detecting heavy (Z approximately equal to -26) antimatter in the cosmic rays are described. Emphasis is placed on describing the essential physics of the EXAM (extragalactic antimatter) instrument's individual detectors that make such a detection possible. In particular, it is shown that the responses from a plastic scintillator, a Cerenkov radiation detector, dielectric track detectors, and proportional drift tube arrays can be used to uniquely determine the speed, charge magnitude, and charge sign of a cosmic ray nucleus. This novel nonmagnetic detection scheme permits the construction of a relatively light weight (approximately 2,000 kg) detector with a large collecting power (approximately 10 sq m sr). The profound cosmological and elementary particle physics implications of the detection of just a single heavy antimatter nucleus are discussed in chapter one, along with arguments that imply that such a detected antinucleus must necessarily be extragalactic in origin. Chapters two through six describe the response of EXAM's individual detectors to the passage of heavily ionizing charged particles. Chapter seven is an overview of the mechanical construction of the entire instrument. Details of the measurement of the light collection efficiency of EXAM's Cerenkov detector and primary scintillator using sea-level muons and how this will be used to assist in the flight data analysis are contained in chapter eight. This chapter also includes a description of the instrument's electronic configuration and its data acquisition system. Finally, there are two appendices summarizing some important mechanical stress calculations that were required to actually build the instrument

Academic Training - Studying Anti-Matter

CERN Multimedia

Françoise Benz

2006-01-01

ACADEMIC TRAINING LECTURE SERIES 24, 25, 26 April from 11:00 to 12:00 - Main Auditorium, bldg. 500 Main Auditorium, bldg. 500 on 14, 15 March, Council Room on 13, 16 March Studying Anti-Matter R. LANDUA / DSU Antiparticles are a crucial ingredient of particle physics and cosmology. Almost 80 years after Dirac's bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? When and how were they discovered? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: their production, their use in colliders; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on results and challenges of the '...

Studying antimatter with laser precision

CERN Multimedia

Katarina Anthony

2012-01-01

The next generation of antihydrogen trapping devices, ALPHA-2, is moving into CERN’s Antiproton Decelerator (AD) hall. This brand-new experiment will allow the ALPHA collaboration to conduct studies of antimatter with greater precision. ALPHA spokesperson Jeffrey Hangst was recently awarded a grant by the Carlsberg Foundation, which will be used to purchase equipment for the new experiment.   A 3-D view of the new magnet (in blue) and cryostat. The red lines show the paths of laser beams. LHC-type current leads for the superconducting magnets are visible on the top-right of the image. The ALPHA collaboration has been working to trap and study antihydrogen since 2006. Using antiprotons provided by CERN’s Antiproton Decelerator (AD), ALPHA was the first experiment to trap antihydrogen and to hold it long enough to study its properties. “The new ALPHA-2 experiment will use integrated lasers to probe the trapped antihydrogen,” explains Jeffrey Hangst, ALP...

The Matter-Antimatter Concept Revisited

Directory of Open Access Journals (Sweden)

Marquet P.

2010-04-01

Full Text Available In this paper, we briefly review the theory elaborated by Louis de Broglie who showed that in some circumstances, a particle tunneling through a dispersive refracting material may reverse its velocity with respect to that of its associated wave (phase velocity: this is a consequence of Rayleigh's formula defining the group velocity. Within his Double Solution Theory, de Broglie re-interprets Dirac's aether concept which was an early attempt to describe the matter-antimatter symmetry. In this new approach, de Broglie suggests that the (hidden sub-quantum medium required by his theory be likened to the dispersive and refracting material with identical properties. A Riemannian generalization of this scheme restricted to a space-time section, and formulated within an holonomic frame is here considered. This procedure is shown to be founded and consistent if one refers to the extended formulation of General Relativity (EGR theory, wherein pre-exists a persistent field.

The Matter-Antimatter Concept Revisited

Directory of Open Access Journals (Sweden)

Marquet P.

2010-04-01

Full Text Available In this paper, we briefly review the theory elaborated by Louis de Broglie who showed that in some circumstances, a particle tunneling through a dispersive refracting material may reverse its velocity with respect to that of its associated wave (phase velocity: this is a consequence of Rayleigh’s formula defining the group velocity. Within his “Double Solution Theory”, de Broglie re-interprets Dirac’s aether concept which was an early attempt to describe the matter-antimatter symmetry. In this new approach, de Broglie suggests that the (hidden sub-quantum medium required by his theory be likened to the dispersive and refracting material with identical properties. A Riemannian generalization of this scheme restricted to a space-time section, and formulated within an holonomic frame is here considered. This procedure is shown to be founded and consistent if one refers to the extended formulation of General Relativity (EGR theory, wherein pre-exists a persistent field.

Unified picture for Dirac neutrinos, dark matter, dark energy and matter–antimatter asymmetry

OpenAIRE

Gu, Pei-Hong

2008-01-01

We propose a unified scenario to generate the masses of Dirac neutrinos and cold dark matter at the TeV scale, understand the origin of dark energy and explain the matter-antimatter asymmetry of the universe. This model can lead to significant impact on the Higgs searches at LHC.

Separated matter and antimatter domains with vanishing domain walls

Energy Technology Data Exchange (ETDEWEB)

Dolgov, A.D.; Godunov, S.I.; Rudenko, A.S.; Tkachev, I.I., E-mail: dolgov@fe.infn.it, E-mail: sgodunov@itep.ru, E-mail: a.s.rudenko@inp.nsk.su, E-mail: tkachev@ms2.inr.ac.ru [Physics Department and Laboratory of Cosmology and Elementary Particle Physics, Novosibirsk State University, Pirogova st. 2, Novosibirsk, 630090 (Russian Federation)

2015-10-01

We present a model of spontaneous (or dynamical) C and CP violation where it is possible to generate domains of matter and antimatter separated by cosmologically large distances. Such C(CP) violation existed only in the early universe and later it disappeared with the only trace of generated baryonic and/or antibaryonic domains. So the problem of domain walls in this model does not exist. These features are achieved through a postulated form of interaction between inflaton and a new scalar field, realizing short time C(CP) violation.

York University atomic scientist contributes to new breakthrough in the production of antimatter

CERN Multimedia

2002-01-01

Physicists working in Europe, including Canada Research Chair in Atomic Physics at York University, Prof. Eric Hessels, have succeeded in capturing the first glimpse of the structure of antimatter. The ATRAP group of scientists at CERN have managed to examine the internal states of anti-hydrogen atoms (1/2 page).

High Energy Antimatter Telescope (HEAT) Balloon Experiment

Science.gov (United States)

Beatty, J. J.

1995-01-01

This grant supported our work on the High Energy Antimatter Telescope(HEAT) balloon experiment. The HEAT payload is designed to perform a series of experiments focusing on the cosmic ray positron, electron, and antiprotons. Thus far two flights of the HEAT -e+/- configuration have taken place. During the period of this grant major accomplishments included the following: (1) Publication of the first results of the 1994 HEAT-e+/- flight in Physical Review Letters; (2) Successful reflight of the HEAT-e+/- payload from Lynn Lake in August 1995; (3) Repair and refurbishment of the elements of the HEAT payload damaged during the landing following the 1995 flight; and (4) Upgrade of the ground support equipment for future flights of the HEAT payload.

Cosmic ray antimatter and baryon symmetric cosmology

Science.gov (United States)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1982-01-01

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p=/equiv 1+/- 3.2/0.7x10 = to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha =/equiv 10 to the -5, within range of future cosmic ray detectors.

Search for antimatter in 1012 eV cosmic rays using Artemis method and interpretation of the cosmic rays spectrum

International Nuclear Information System (INIS)

Pomarede, D.

1999-04-01

This thesis is divided into three parts. The first part is a review of the present knowledge of the antimatter and of the cosmic rays. Theoretical and experimental aspects are presented. It is demonstrated that a measurement of the antimatter abundance in TeV cosmic rays is of fundamental interest, and would establish the symmetric or asymmetric nature of the Universe. The second part is dedicated to the method of antimatter research through the Earth Moon ion spectrometer (ARTEMIS). The account is given of the winter 1996-97 41-nights observation campaign undertaken at the Whipple Observatory in Arizona (USA). A 109 photomultiplier camera is operated on the 40 meter telescope to detect by Cherenkov imaging the cosmic ray initiated showers. We describe the performance of an optical filter used to reduce the noise. The development and the utilization of a simulation program are described. The main work is the analysis of the data: data characterization, understanding of the apparatus, understanding of the noise and its influence, calibration, search for signals by different methods. Subtle systematic effects are uncovered. The simulations establish that the amount of data is insufficient to reveal a shadow effect in the cosmic ray flux. The conclusion of this work is that the experimental setup was not suitable, and we propose important improvements of the method based on a bigger focal plane that would allow to reach a one percent sensitivity on the antimatter content of the cosmic rays. In the third part of the thesis, an interpretation of the total cosmic ray spectrum is proposed and discussed. (author)

Star Trek meets the Big Bang curiosity is leading scientists on a mission to explain antimatter

CERN Multimedia

Cookson, C

1998-01-01

Next year, scientists at CERN will inaugurate the world's first 'antimatter factory'. The 'Antiproton Decelerator' will make more than 2000 atoms of anti-hydrogen an hour and contain them in a magnetic trap within a vacuum (1 page).

Mathematical Descriptions of Axially Varying Penning Traps for the Antimatter Experiment: gravity, Interferometry, and Spectroscopy

CERN Document Server

Stephanie, Brown

2015-01-01

Antimatter, though proposed in 1933, is still not well understood. AEgIS aims to study the interaction of antihydrogen with the earth's gravitational field. This information will add to our understanding of the matter-antimatter asymmetry present in our universe. This paper discusses a Penning-Malmberg with a magnetic mirror that will hold $C_{2}^{-}$ that will be used for sympathetic cooling of antiprotons before the antihydrogen is created. The trap, which is critical to the cooling process of the antihydrogen, can be characterized by the separatrix between trapped and untrapped particles. This paper applies analytical processes used to define the separatrix of pure electron plasmas to a molecular plasma. Our work is based on the desire conditions (density, particle number, field strength, trap size) of the high field region. The initial application of a semi-analytical method applied to our trap defines the trap potential difference at \\~ 0.6V. The separatrix is defined in both the high and low fiel...

Frontiers in propulsion research: Laser, matter-antimatter, excited helium, energy exchange thermonuclear fusion

Science.gov (United States)

Papailiou, D. D. (Editor)

1975-01-01

Concepts are described that presently appear to have the potential for propulsion applications in the post-1990 era of space technology. The studies are still in progress, and only the current status of investigation is presented. The topics for possible propulsion application are lasers, nuclear fusion, matter-antimatter annihilation, electronically excited helium, energy exchange through the interaction of various fields, laser propagation, and thermonuclear fusion technology.

Domain Walls and Matter-Antimatter Domains in the Early Universe

Directory of Open Access Journals (Sweden)

Dolgov A.D.

2017-01-01

Full Text Available We suggest a scenario of spontaneous (or dynamical C and CP violation according to which it is possible to generate domains of matter and antimatter separated by cosmologically large distances. Such C(CP violation existed only in the early universe and later it disappeared with the only trace of generated matter and antimatter domains. So this scenario does not suffer from the problem of domain walls. According to this scenario the width of the domain wall should grow exponentially to prevent annihilation at the domain boundaries. Though there is a classical result obtained by Basu and Vilenkin that the width of the wall tends to the one of the stationary solution (constant physical width. That is why we considered thick domain walls in a de Sitter universe following paper by Basu and Vilenkin. However, we were interested not only in stationary solutions found therein, but also investigated the general case of domain wall evolution with time. When the wall thickness parameter, δ0 , is smaller than H−1/2 where H is the Hubble parameter in de Sitter space-time, then the stationary solutions exist, and initial field configurations tend with time to the stationary ones. However, there are no stationary solutions for δ0>H−1/2 We have calculated numerically the rate of the wall expansion in this case and have found that the width of the wall grows exponentially fast for δ0≫H−1 An explanation for the critical value δ0c=H−1/2 is also proposed.

How to build an antimatter rocket for interstellar missions - systems level considerations in designing advanced propulsion technology vehicles

Science.gov (United States)

Frisbee, Robert H.

2003-01-01

This paper discusses the general mission requirements and system technologies that would be required to implement an antimatter propulsion system where a magnetic nozzle is used to direct charged particles to produce thrust.

Prospects for comparison of matter and antimatter gravitation with ALPHA-g

Science.gov (United States)

Bertsche, W. A.

2018-03-01

The ALPHA experiment has recently entered an expansion phase of its experimental programme, driven in part by the expected benefits of conducting experiments in the framework of the new AD + ELENA antiproton facility at CERN. With antihydrogen trapping now a routine operation in the ALPHA experiment, the collaboration is leading progress towards precision atomic measurements on trapped antihydrogen atoms, with the first excitation of the 1S-2S transition and the first measurement of the antihydrogen hyperfine spectrum (Ahmadi et al. 2017 Nature 541, 506-510 (doi:10.1038/nature21040); Nature 548, 66-69 (doi:10.1038/nature23446)). We are building on these successes to extend our physics programme to include a measurement of antimatter gravitation. We plan to expand a proof-of-principle method (Amole et al. 2013 Nat. Commun. 4, 1785 (doi:10.1038/ncomms2787)), first demonstrated in the original ALPHA apparatus, and perform a precise measurement of antimatter gravitational acceleration with the aim of achieving a test of the weak equivalence principle at the 1% level. The design of this apparatus has drawn from a growing body of experience on the simulation and verification of antihydrogen orbits confined within magnetic-minimum atom traps. The new experiment, ALPHA-g, will be an additional atom-trapping apparatus located at the ALPHA experiment with the intention of measuring antihydrogen gravitation. This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'.

Light element abundances in a matter-antimatter model of the universe

International Nuclear Information System (INIS)

Aly, J.J.

1978-01-01

This paper is devoted to the problem of light element synthesis in a baryon symmetric Big-Bang cosmology, in which the universe is constituted at the end of the leptonic era by a nucleon-antinucleon emulsion. If the initial typical size of the matter or antimatter regions is sufficiently high to avoid significant neutron annihilation, nucleosynthesis can proceed in this kind of model in the same way as in the conventional Big-Bang. But the abundances of the created light elements can be modified at a later time by interaction of the nuclei with the high energy particles and photons resulting from annihilation. In this article, we consider two specific mechanisms able to change the abundances: a 4 He 'nucleodisruption' process (proposed by Combes et al., 1975), which leads to deuterium production, and 4 He photodisintegration by annihilation γ-rays, which leads to an increase of the 3 He and D production. General relations are established which allow one to compute the abundances of the so created elements when the size l of the matter or antimatter regions and the annihilation rate are given as function of time. These relations are applied to the Omnes model, in which the size l grows by a coalescence mechanism. It is shown that in this model the D and 3 He abundances are much greater than the limits on primordial abundances deduced from the present observations. (orig.) [de

Prospects for comparison of matter and antimatter gravitation with ALPHA-g.

Science.gov (United States)

Bertsche, W A

2018-03-28

The ALPHA experiment has recently entered an expansion phase of its experimental programme, driven in part by the expected benefits of conducting experiments in the framework of the new AD + ELENA antiproton facility at CERN. With antihydrogen trapping now a routine operation in the ALPHA experiment, the collaboration is leading progress towards precision atomic measurements on trapped antihydrogen atoms, with the first excitation of the 1S-2S transition and the first measurement of the antihydrogen hyperfine spectrum (Ahmadi et al. 2017 Nature 541 , 506-510 (doi:10.1038/nature21040); Nature 548 , 66-69 (doi:10.1038/nature23446)). We are building on these successes to extend our physics programme to include a measurement of antimatter gravitation. We plan to expand a proof-of-principle method (Amole et al. 2013 Nat. Commun. 4 , 1785 (doi:10.1038/ncomms2787)), first demonstrated in the original ALPHA apparatus, and perform a precise measurement of antimatter gravitational acceleration with the aim of achieving a test of the weak equivalence principle at the 1% level. The design of this apparatus has drawn from a growing body of experience on the simulation and verification of antihydrogen orbits confined within magnetic-minimum atom traps. The new experiment, ALPHA-g, will be an additional atom-trapping apparatus located at the ALPHA experiment with the intention of measuring antihydrogen gravitation.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Authors.

Matter and antimatter

International Nuclear Information System (INIS)

Schopper, H.

1989-01-01

For many years the physicist Herwig Schopper has been contributing in leading positions - either as director of DESY in Hamburg or as general director of CERN in Geneva - to the development of a fascinating field of modern physics. His book is the first comprehensive presentation of experimental particle physics for non-physicists. The search for the smallest constituents of matter, i.e. the exploration of the microcosmos, apart from the advance of the man into space belongs to the most exciting scientific-technical adventures of our century. Contrarily to the stars, atoms, atomic nuclei, and quarks cannot be seen. How objects are studied which are by thousands smaller than the smallest atomic nucleus? Can matter be decomposed in ever smaller constituents, or does there exist a limit? What is matter, and what is of consequence for the mysterious antimatter. Do the laws of the infinitely small also determine the development of the universe since its origin? Such and other questions - expressions of human curiosity - Schopper wants to answer with his generally understandable book. Thereby the 'machines' and the experiments of high-energy physics play a decicive role in the presentation. The author describes the development of the accelerators - in Europe, as well as in the Soviet Union, Japan, or in the USA -, and he shows, why for the investigation of the smallest immense experimental facilities - the 1989 finished LEP storage ring at CERN has a circumference of 27 kilometers - are necessary. Schopper explains how the 'machines' work and how the single experiments run. His book satisfies the curiosity of all those, who want to know more about the world of the quarks. (orig.) With 96 figs [de

Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy

Science.gov (United States)

Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V.; Jackson Kimball, Derek F.; Kozlov, Mikhail G.; Stadnik, Yevgeny V.; Budker, Dmitry

2018-05-01

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

Direct observation limits on antimatter gravitation

International Nuclear Information System (INIS)

Fischler, Mark; Lykken, Joe; Roberts, Tom; Fermilab

2008-01-01

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

Matter-antimatter and matter-matter interactions at intermediate energies; Interacao materia-antimateria e materia-materia a energias intermediarias

Energy Technology Data Exchange (ETDEWEB)

Santos, Antonio Carlos Fontes dos [Missouri Univ., Rolla, MO (United States). Dept. of Physics]. E-mail: antoniocfs@hotmail.com

2002-07-01

This article presents some of the recent experimental advances on the study on antimatter-matter and matter-matter interactions, and some of the subtle differences stimulated a great theoretical efforts for explanation of the results experimentally observed.

The story of antimatter matter's vanished twin

CERN Document Server

Borissov, Guennadi

2018-01-01

Each elementary particle contained within every known substance has an almost identical twin called its antiparticle. Existing data clearly indicate that equal numbers of particles and antiparticles were initially created soon after the birth of the universe. Despite this, all objects around us, as well as all the stars in all the known galaxies, are made of particles, while antiparticles have almost completely vanished. The reasons behind this disappearance are not yet fully known. Uncovering them will allow us to not only penetrate much deeper into the structure of matter, but also to understand the secret mechanisms that determine the genesis and development of our immense universe. That is why explaining the mystery of the missing antimatter is currently considered to be one of the main tasks of particle physics. This book tells the story of all the achievements in solving the problem of the missing antiparticles including the latest developments in the field. It is written by Prof. Guennadi Borissov, an...

Chemical reaction between matter and antimatter realized for the first time: it brings about the formation of protonium

CERN Multimedia

2006-01-01

"Matter and antimatter particles run into each other and they annihilate into a small flash of energy: it happened at the first light of the Universe and it happens every day in the particles accelerators throughout the world." (1 page)

A trip to Rome—thanks to antimatter

CERN Multimedia

Alizée Dauvergne

2010-01-01

The Angels and Demons exhibition created by the PH Department’s Education Group came to an end last summer. The exhibition was accompanied by a competition, with a first prize of a flight to Rome. Now we know the winner’s name. An exhibit of the Angels&Demons - the science behind the story exhibition She is Sarah Manton, and she is from Scotland. In September Sarah will fly to Rome with her husband to retrace the Angels and Demons street itinerary. “We are looking forward to visiting the usual tourist sights, including all the places that feature in Angels and Demons such as the Pantheon,” she said in answer to a question from the exhibition organisers. The couple was touring CERN when, intrigued by the Globe and the name of the exhibition, they decided to do a visit and participate in the competition. Five correct answers on antimatter later—and several months on—Sarah got a pleasant surprise: “I decided to have a go at the quiz an...

Matter antimatter domains: A possible solution to the CP domain wall problem in the early universe

Science.gov (United States)

Mohanty, A. K.; Stecker, F. W.

1984-01-01

An SU(5) grand unified theory model is used to show how the degeneracy between vacua with different spontaneously broken charge parity can be dynamically lifted by a condensate of heavy fermion pairs. This drives a phase transition to a unique vacuum state with definite charge parity. The transition eliminates the domain walls in a matter antimatter symmetric domain cosmology.

New experiment to gain unparalleled insight into antimatter

CERN Multimedia

Katarina Anthony

2013-01-01

At last week’s Research Board meeting, the Baryon Antibaryon Symmetry Experiment (BASE) was approved for installation at CERN. The experiment will be diving into the search for matter-antimatter asymmetry, as it aims to take ultra-high precision measurements of the antiproton magnetic moment.   CERN's AD Hall: the new home of the BASE double Penning trap set-up. The BASE collaboration will be setting up shop in the AD Hall this September with its first CERN-based experimental set-up. Using the novel double-Penning trap set-up developed at the University of Mainz, GSI Darmstadt and the Max Plank Institute for Nuclear Physics (Germany), the BASE team will be able to measure the antiproton magnetic moment with hitherto unreachable part-per-billion precision. “We constructed the first double-Penning trap at our companion facility in Germany, and made the first ever direct observations of single spin flips of a single proton,” explains Stefan Ulmer from RIKE...

Matter-antimatter asymmetry induced by a running vacuum coupling

Energy Technology Data Exchange (ETDEWEB)

Lima, J.A.S. [Universidade de Sao Paulo, Departamento de Astronomia, Sao Paulo (Brazil); Singleton, D. [California State University Fresno, Department of Physics, Fresno, CA (United States); Institute of Experimental and Theoretical Physics Al-Farabi KazNU, Almaty (Kazakhstan)

2017-12-15

We show that a CP-violating interaction induced by a derivative coupling between the running vacuum and a non-conserving baryon current may dynamically break CPT and trigger baryogenesis through an effective chemical potential. By assuming a non-singular class of running vacuum cosmologies which provides a complete cosmic history (from an early inflationary de Sitter stage to the present day quasi-de Sitter acceleration), it is found that an acceptable baryon asymmetry is generated for many different choices of the model parameters. It is interesting that the same ingredient (running vacuum energy density) addresses several open cosmological questions/problems: avoids the initial singularity, provides a smooth exit for primordial inflation, alleviates both the coincidence and the cosmological constant problems, and, finally, is also capable of explaining the generation of matter-antimatter asymmetry in the very early Universe. (orig.)

The instrument PAMELA for antimatter and dark matter search in space

International Nuclear Information System (INIS)

Picozza, Piergiorgio; Sparvoli, Roberta

2010-01-01

The PAMELA satellite experiment is dedicated to the study of charged particles in cosmic radiation, with a particular focus on antiparticles for the search of antimatter and signals of dark matter, in the energy window from 100 MeV to some hundreds of GeV. PAMELA is installed on board of the Resurs DK1 satellite that was launched from the Baikonur cosmodrome on June 15th, 2006. The PAMELA apparatus comprises a magnetic spectrometer, a time-of-flight system, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows antiparticles to be reliably identified from a large background of other charged particles.

Jeans instability and antiscreening in the system of matter-antimatter with antigravitation

International Nuclear Information System (INIS)

Trigger, S A; Gribov, I A

2015-01-01

The hypothesis of antigravitational interaction of elementary particles and antiparticles is applied to the simple two-component hydrodynamic model Λ-CDM (Lambda cold-dark matter) with gravitational repulsion and attraction. An increase in the Jeans instability rate, the presence of antiscreening, and the dominant role of the gravitational repulsion as a possible mechanism of spatial separation of matter and antimatter in the Universe are shown, as well as the observable acceleration of far galaxies. The sound wave is found for the two-component gravitational-antigravitational system. The suggested approach permits to reestablish the idea about baryon symmetry of the Universe, causing its steady large-scale flatness and accelerated Universe expansion. (paper)

Soft CP violation and the global matter-antimatter symmetry of the universe

Science.gov (United States)

Senjanovic, G.; Stecker, F. W.

1980-01-01

Scenarios for baryon production are considered within the context of SU(5) and SO(10) grand unified theories where CP violation arises spontaneously. The spontaneous CP symmetry breaking then results in a matter-antimatter domain structure in the universe. Two possible, distinct types of theories of soft CP violation are defined. In the first type the CP nonconservation originates only from the breaking of SU(2) sub L X U(1) symmetry, and in the second type, even at the unification temperature scale, CP violation can emerge as a result of symmetry breaking by the vacuum expectation values of the superheavy Higgs sector scalars.

Large-scale anisotropy in the extragalactic gamma-ray background as a probe for cosmological antimatter

Science.gov (United States)

Gao, Yi-Tian; Stecker, Floyd W.; Gleiser, Marcelo; Cline, David B.

1990-01-01

Intrinsic anisotropies in the extragalactic gamma-ray background (EGB), which should be detectable with the forthcoming Gamma Ray Observatory, can be used to examine some of the mechanisms proposed to explain its origin, one of which, the baryon-symmetric big bang (BSBB) model, is investigated here. In this simulation, large domains containing matter and antimatter galaxies produce gamma rays by annihilation at the domain boundaries. This mechanism can produce mountain-chain-shaped angular fluctuations in the EGB flux.

Experimental considerations for testing antimatter antigravity using positronium 1S-2S spectroscopy

Science.gov (United States)

Crivelli, P.; Cooke, D. A.; Friedreich, S.

2014-05-01

In this contribution to the WAG 2013 workshop we report on the status of our measurement of the 1S-2S transition frequency of positronium. The aim of this experiment is to reach a precision of 0.5 ppb in order to cross check the QED calculations. After reviewing the current available sources of Ps, we consider laser cooling as a route to push the precision in the measurement down to 0.1 ppb. If such an uncertainty could be achieved, this would be sensitive to the gravitational redshift and therefore be able to assess the sign of gravity for antimatter.

Can the New Neutrino Telescopes Reveal the Gravitational Properties of Antimatter?

Directory of Open Access Journals (Sweden)

Dragan Slavkov Hajdukovic

2011-01-01

Full Text Available We argue that the hypothesis of the gravitational repulsion between matter and antimatter can be tested at the Ice Cube, a neutrino telescope, recently constructed at the South Pole. If there is such a gravitational repulsion, the gravitational field, deep inside the horizon of a black hole, might create neutrino-antineutrino pairs from the quantum vacuum. While neutrinos must stay confined inside the horizon, the antineutrinos should be violently ejected. Hence, a black hole (made from matter should behave as a point-like source of antineutrinos. Our simplified calculations suggest that the antineutrinos emitted by supermassive black holes in the centre of the Milky Way and Andromeda Galaxy could be detected by the new generation of neutrino telescopes.

LS1 Report: antimatter research on the starting blocks

CERN Multimedia

Antonella Del Rosso

2014-01-01

The consolidation work at the Antiproton Decelerator (AD) has been very intensive and the operators now have a basically new machine to “drive”. Thanks to the accurate preparation work still ongoing, the machine will soon deliver its first beam of antiprotons to the experiments. The renewed efficiency of the whole complex will ensure the best performance of the whole of CERN’s antimatter research programme in the long term.   The test bench for the new Magnetic Horn stripline. On the left, high voltage cables are connected to the stripline, which then feeds a 6 kV 400 kA pulse to the Horn. The Horn itself (the cylindrical object on the right) can be seen mounted on its chariot. The consolidation programme at the AD planned during LS1 has involved some of the most vital parts of the decelerator such as the target area, the ring magnets, the stochastic cooling system, vacuum system, control system and various aspects of the instrumentation. In addit...

Elementary process theory: a formal axiomatic system with a potential application as a foundational framework for physics supporting gravitational repulsion of matter and antimatter

International Nuclear Information System (INIS)

Cabbolet, M.J.T.F.

2010-01-01

Theories of modern physics predict that antimatter having rest mass will be attracted by the earth's gravitational field, but the actual coupling of antimatter with gravitation has not been established experimentally. The purpose of the present research was to identify laws of physics that would govern the universe if antimatter having rest mass would be repulsed by the earth's gravitational field. As a result, a formalized axiomatic system was developed together with interpretation rules for the terms of the language: the intention is that every theorem of the system yields a true statement about physical reality. Seven non-logical axioms of this axiomatic system form the elementary process theory (EPT): this is then a scheme of elementary principles describing the dynamics of individual processes taking place at supersmall scale. It is demonstrated how gravitational repulsion functions in the universe of the EPT, and some observed particles and processes have been formalized in the framework of the EPT. Incompatibility of quantum mechanics (QM) and General Relativity (GR) with the EPT is proven mathematically; to demonstrate applicability to real world problems to which neither QM nor GR applies, the EPT has been applied to a theory of the Planck era of the universe. The main conclusions are that a completely formalized framework for physics has been developed supporting the existence of gravitational repulsion and that the present results give rise to a potentially progressive research program. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Postinflationary Higgs relaxation and the origin of matter-antimatter asymmetry.

Science.gov (United States)

Kusenko, Alexander; Pearce, Lauren; Yang, Louis

2015-02-13

The recent measurement of the Higgs boson mass implies a relatively slow rise of the standard model Higgs potential at large scales, and a possible second minimum at even larger scales. Consequently, the Higgs field may develop a large vacuum expectation value during inflation. The relaxation of the Higgs field from its large postinflationary value to the minimum of the effective potential represents an important stage in the evolution of the Universe. During this epoch, the time-dependent Higgs condensate can create an effective chemical potential for the lepton number, leading to a generation of the lepton asymmetry in the presence of some large right-handed Majorana neutrino masses. The electroweak sphalerons redistribute this asymmetry between leptons and baryons. This Higgs relaxation leptogenesis can explain the observed matter-antimatter asymmetry of the Universe even if the standard model is valid up to the scale of inflation, and any new physics is suppressed by that high scale.

Lie-admissible invariant treatment of irreversibility for matter and antimatter at the classical and operator levels

International Nuclear Information System (INIS)

Santilli, R.M.

2006-01-01

It was generally believed throughout the 20th century that irreversibility is a purely classical event without operator counterpart. however, a classical irreversible system cannot be consistently decomposed into a finite number of reversible quantum particles (and. vive versa), thus establishing that the origin of irreversibility is basically unknown at the dawn of the 21-st century. To resolve this problem. we adopt the historical analytical representation of irreversibility by Lagrange and Hamilton, that with external terms in their analytic equations; we show that, when properly written, the brackets of the time evolution characterize covering Lie-admissible algebras; we prove that the formalism has fully consistent operator counterpart given by the Lie-admissible branch of hadronic mechanics; we identify mathematical and physical inconsistencies when irreversible formulations are treated with the conventional mathematics used for reversible systems; we show that when the dynamical equations are treated with a novel irreversible mathematics, Lie-admissible formulations are fully consistent because invariant at both the classical and operator levels; and we complete our analysis with a number of explicit applications to irreversible processes in classical mechanics, particle physics and thermodynamics. The case of closed-isolated systems verifying conventional total conservation laws, yet possessing an irreversible structure, is treated via the simpler Lie-isotopic branch of hadronic mechanics. The analysis is conducted for both matter and antimatter at the classical and operator levels to prevent insidious inconsistencies occurring for the sole study of matter or, separately, antimatter

arXiv Measurement of matter-antimatter differences in beauty baryon decays

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

2017-01-30

Differences in the behaviour of matter and antimatter have been observed in $K$ and $B$ meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as $C\\!P$ violation. Using data from the LHCb experiment at the Large Hadron Collider, a search is made for $C\\!P$-violating asymmetries in the decay angle distributions of $\\Lambda^0_b$ baryons decaying to $p\\pi^-\\pi^+\\pi^-$ and $p\\pi^-K^+K^-$ final states. These four-body hadronic decays are a promising place to search for sources of $C\\!P$ violation both within and beyond the Standard Model of particle physics. We find evidence for $C\\!P$ violation in $\\Lambda^0_b$ to $p\\pi^-\\pi^+\\pi^-$ decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for $C\\!P$ violation in the baryon sector.

Measurement of matter-antimatter differences in beauty baryon decays at LHCb

CERN Multimedia

Merli, Andrea

2017-01-01

Differences in the behaviour of matter and antimatter have been observed in $K$ and $B$ meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as $C\\!P$ violation. Using data from the LHCb experiment at the Large Hadron Collider, a search is made for $C\\!P$-violating asymmetries in the decay angle distributions of $\\Lambda_b^0$ baryons decaying to $p\\pi^-\\pi^+\\pi^-$ and $p\\pi^-K^+K^-m$ final states. These four-body hadronic decays are a promising place to search for sources of $C\\!P$ violation both within and beyond the Standard Model of particle physics. We find evidence for $C\\!P$ violation in $\\Lambda_b^0$ to $p\\pi^-\\pi^+\\pi^-$ decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for $C\\!P$ violation in the baryon sector.

AEgIS experiment: Towards antihydrogen beam production for antimatter gravity measurements

CERN Document Server

Mariazzi, Sebastiano; Amsler, Claude; Ariga, Akitaka; Ariga, Tomoko; Belov, Alexandre S; Bonomi, Germano; Bräunig, Philippe; Brusa, Roberto S; Bremer, Johan; Cabaret, Louis; Canali, Carlo; Caravita, Ruggero; Castelli, Fabrizio; Cerchiari, Giovanni; Cialdi, Simone; Comparat, Daniel; Consolati, Giovanni; Dassa, Luca; Derking, Jan Hendrik; Di Domizio, Sergio; Di Noto, Lea; Doser, Michael; Dudarev, Alexey; Ereditato, Antonio; Ferragut, Rafael; Fontana, Andrea; Genova, Pablo; Giammarchi, Marco; Gligorova, Angela; Gninenko, Sergei N; Hogan, Stephen D; Haider, Stefan; Jordan, Elena; Jørgensen, Lars V; Kaltenbacher, Thomas; Kawada, Jiro; Kellerbauer, Alban; Kimura, Mitsuhiro; Knecht, Andreas; Krasnický, Daniel; Lagomarsino, Vittorio; Lehner, Sebastian; Malbrunot, Chloe; Matveev, Viktor A; Merkt, Frederic; Moia, Fabio; Nebbia, Giancarlo; Nédélec, Patrick; Oberthaler, Markus K; Pacifico, Nicola; Petráček, Vojtech; Pistillo, Ciro; Prelz, Francesco; Prevedelli, Marco; Regenfus, Christian; Riccardi, Cristina; Røhne, Ole; Rotondi, Alberto; Sandaker, Heidi; Scampoli, Paola; Storey, James; Subieta Vasquez, Martin A.; Spaček, Michal; Czech Technical U. in Prague - FNSPE - B\\oehova 7 - 11519 - Praha 1 - Czech Aff25 Testera, Gemma; Vaccarone, Renzo; Villa, Fabio; Widmann, Eberhard; Zavatarelli, Sandra; Zmeskal, Johann

2014-01-01

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an experiment that aims to perform the first direct measurement of the gravitational acceleration g of antihydrogen in the Earth’s field. A cold antihydrogen beam will be produced by charge exchange reaction between cold antiprotons and positronium excited in Rydberg states. Rydberg positronium (with quantum number n between 20 and 30) will be produced by a two steps laser excitation. The antihydrogen beam, after being accelerated by Stark effect, will fly through the gratings of a moir ́ e deflectometer. The deflection of the horizontal beam due to its free fall will be measured by a position sensitive detector. It is estimated that the detection of about 10 3 antihydrogen atoms is required to determine the gravitational acceleration with a precision of 1%. In this report an overview of the AEgIS experiment is presented and its current status is described. Details on the production of slow positronium and its excitation with lasers ar...

Probing antimatter gravity – The AEGIS experiment at CERN

Directory of Open Access Journals (Sweden)

Kellerbauer A.

2016-01-01

Full Text Available The weak equivalence principle states that the motion of a body in a gravitational field is independent of its structure or composition. This postulate of general relativity has been tested to very high precision with ordinary matter, but no relevant experimental verification with antimatter has ever been carried out. The AEGIS experiment will measure the gravitational acceleration of antihydrogen to ultimately 1% precision. For this purpose, a pulsed horizontal antihydrogen beam with a velocity of several 100 m s−1 will be produced. Its vertical deflection due to gravity will be detected by a setup consisting of material gratings coupled with a position-sensitive detector, operating as a moiré deflectometer or an atom interferometer. The AEGIS experiment is installed at CERN’s Antiproton Decelerator, currently the only facility in the world which produces copious amounts of low-energy antiprotons. The construction of the setup has been going on since 2010 and is nearing completion. A proof-of-principle experiment with antiprotons has demonstrated that the deflection of antiparticles by a few μm due to an external force can be detected. Technological and scientific development pertaining to specific challenges of the experiment, such as antihydrogen formation by positronium charge exchange or the position-sensitive detection of antihydrogen annihilations, is ongoing.

Neutrinos in the Early Universe, Kalb-Ramond Torsion and Matter-Antimatter Asymmetry

Directory of Open Access Journals (Sweden)

Mavromatos Nick E.

2014-04-01

Full Text Available The generation of a matter-antimatter asymmetry in the universe may be induced by the propagation of fermions in non-trivial, spherically asymmetric (and hence Lorentz violating gravitational backgrounds. Such backgrounds may characterise the epoch of the early universe. The key point in these models is that the background induces di_erent dispersion relations, hence populations, between fermions and antifermions, and thus CPT Violation (CPTV appears in thermal equilibrium. Species populations may freeze out leading to leptogenesis and baryogenesis. We consider here a string-inspired scenario, in which the CPTV is associated with a cosmological background with torsion provided by the Kalb-Ramond (KR antisymemtric tensor field of the string gravitational multiplet. In a four-dimensional space time this field is dual to a pseudoscalar “axionlike” field. The mixing of the KR field with an ordinary axion field can lead to the generation of a Majorana neutrino mass.

Matter-antimatter accounting, thermodynamics, and black-hole radiation

International Nuclear Information System (INIS)

Toussaint, D.; Treiman, S.B.; Wilczek, F.; Zee, A.

1979-01-01

We discuss several issues bearing on the observed asymmetry between matter and antimatter in the content of the universe, in particular, the possible role in this of Hawking radiation from black holes, with allowance for weak C- and T-violating interactions. We show that the radiation, species by species, can be asymmetric between baryons and antibaryons. However, if baryon number is microscopically conserved there cannot be a net flux of baryon number in the radiation. Black-hole absorption from a medium with net baryon number zero can drive the medium to an asymmetric state. On the other hand, if baryon conservation is violated, a net asymmetry can develop. This can arise through asymmetric gravitational interactions of the radiated particles, and conceivably, by radiation of long-lived particles which decay asymmetrically. In the absence of microscopic baryon conservation, asymmetries can also arise from collision processes generally,say in the early stages of the universe as a whole. However, no asymmetries can develop (indeed any ''initial'' ones are erased) insofar as the baryon-violating interactions are in thermal equilibrium, as they might well be in the dense, high-temperature stages of the very early universe. Thus particle collisions can generate asymmetries only when nonequilibrium effects driven by cosmological expansion come into play. A scenario for baryon-number generation suggested by superunified theories is discussed in some detail. Black-hole radiation is another highly nonequilibrium process which is very efficient in producing asymmetry, given microscopic C, T, and baryon-number violation

Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS

Science.gov (United States)

Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.;

The electrosphere of macroscopc ""nuclei"": diffuse emissions in the MeV band from dark antimatter

Energy Technology Data Exchange (ETDEWEB)

Forbes, Michael Mcneil [Los Alamos National Laboratory; Lawson, Kyle [CANADA; Zhitnitsky, Ariel R [CANADA

2009-01-01

Using a Thomas-Fermi model, we calculate the structure of the electrosphere of the quark antimatter nuggets postulated to comprise much of the dark matter. This provides a single self-consistent density profile from ultra-rel ativistic densities to the non-relativistic Boltzmann regime. We use this to present a microscopically justified calculation of several properties of the nuggets, including their net charge, and the ratio of MeV to 511 keV emissions from electron annihilation. We find that the calculated parameters agree with previous phenomenological estimates based on the observational supposition that the nuggets are a source of several unexplained diffuse emissions from the galaxy. This provides another nontrivial verification of the dark matter proposal. The structure of the electrosphere is quite general and will also be valid at the surface of strange-quark stars, should they exist.

Cosmic ray antiproton measurements in the 4-19 GeV energy range using the NMSU/WiZard-matter antimatter superconducting spectrometer 2 (MASS2)

Energy Technology Data Exchange (ETDEWEB)

Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Brunetti, M.T.; Codini, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Hof, M. [Siegen Univ. (Germany). Fachbereich Physik; Golden, R.L.; Stochaj, S.J. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.M. [Florence Univ. (Italy)]|[INFN, Florence (Italy)

1995-09-01

The p/p-ratio from 4 to 19 GeV has been measured using the NMSU/WiZard balloon borne matter antimatter superconducting spectrometer (MASS2) instrument. This is the first confirmation of the cosmic ray antiproton component made in this energy range since their discovery in 1979. The MASS2 instrument is an updated version of the instrument flown in 1979. The p/p- ratio is 1.52x10{sup -}4.

The Discovery of Anti-Matter The Autobiography of Carl David Anderson, the Youngest Man to Win the Nobel Prize

CERN Document Server

1999-01-01

In 1936, at age 31, Carl David Anderson became the second youngest Nobel laureate for his discovery of antimatter when he observed positrons in a cloud chamber.He is responsible for developing rocket power weapons that were used in World War II.He was born in New York City in 1905 and was educated in Los Angeles. He served for many years as a physics professor at California Institute of Technology. Prior to Oppenheimer, Anderson was offered the job of heading the Los Alamos atomic bomb program but could not assume the role because of family obligations.He was a pioneer in studying cosmic rays

Antimatter and Dark Matter Search in Space: BESS-Polar Results

Science.gov (United States)

Mitchell, John W.; Yamamoto, Akira

2009-01-01

The apex of the Balloon-borne Experiment with a Superconducting Spectrometer program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier anti-nuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of anti-deuterons and anti-helium, The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

Reviews Book: The Age of Wonder Equipment: Portoscope DVD: Around the World in 80 Images Book: Four Laws that Drive the Universe Book: Antimatter Equipment: Coffee Saver Starter Set Equipment: Graphite Levitation Kit Book: Critical Reading Video: Science Fiction-Science Fact Web Watch

Science.gov (United States)

2009-03-01

WE RECOMMEND The Age of Wonder This book tells the stories of inspiring 19th-century scientists Antimatter A fast read that gives an intriguing tour of the antimatter world Science Fiction-Science Fact A video from a set of resources about the facts in science fiction WORTH A LOOK Portoscope Lightweight ×30 microscope that is easy on the purse Four Laws that Drive the Universe In just 124 pages Peter Atkins explains thermodynamics Coffee Saver Starter Kit A tool that can demonstrate the effect of reduced air pressure Graphite Levitation Kit Compact set that demonstrates diamagnetic behaviour Critical Reading A study guide on how to read scientific papers HANDLE WITH CARE Around the World in 80 Images Navigate through images from Envistat, country by country WEB WATCH This month's issue features real-time simulation program Krucible 2.0, which enables learners to run virtual experiments

The BESS Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter

Science.gov (United States)

Mitchell, John; Yamamoto, Akira

2009-01-01

The apex of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

An SO(10) × SO(10)' model for common origin of neutrino masses, ordinary and dark matter-antimatter asymmetries

International Nuclear Information System (INIS)

Gu, Pei-Hong

2014-01-01

We propose an SO(10) × SO(10)' model to simultaneously realize a seesaw for Dirac neutrino masses and a leptogenesis for ordinary and dark matter-antimatter asymmetries. A (16 × 1-bar 6-bar ') H scalar crossing the SO(10) and SO(10)' sectors plays an essential role in this seesaw-leptogenesis scenario. As a result of lepton number conservation, the lightest dark nucleon as the dark matter particle should have a determined mass around 15 GeV to explain the comparable fractions of ordinary and dark matter in the present universe. The (16 × 1-bar 6-bar ') H scalar also mediates a U(1) em × U(1)' em kinetic mixing after the ordinary and dark left-right symmetry breaking so that we can expect a dark nucleon scattering in direct detection experiments and/or a dark nucleon decay in indirect detection experiments. Furthermore, we can impose a softly broken mirror symmetry to simplify the parameter choice

Particle tracking at 4K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

CERN Document Server

Storey, J; Ahlén, O; Amsler, C; Ariga, A; Ariga, T; Belov, A.S; Bonomi, G; Bräunig, P; Bremer, J; Brusa, R.S; Burghart, G; Cabaret, L; Canali, C; Carante, M; Caravita, R; Castelli, F; Cerchiari, G; Cialdi, S; Comparat, D; Consolati, G; Dassa, L; Di Domizio, S; Di Noto, L; Doser, M; Dudarev, A; Ereditato, A; Ferragut, R; Fontana, A; Genova, P; Giammarchi, M; Gligorova, A; Gninenko, S.N; Haider, S; Hogan, S.D; Huse, T; Jordan, E; Jørgensen, L.V; Kaltenbacher, T; Kawada, J; Kellerbauer, A; Kimura, M; Knecht, A; Krasnický, D; Lagomarsino, V; Magnani, A; Mariazzi, S; Matveev, V.A; Merkt, F; Moia, F; Nebbia, G; Nédélec, P; Oberthaler, M.K; Pacifico, N; Petrácek, V; Pistillo, C; Prelz, F; Prevedelli, M; Regenfus, C; Riccardi, C; Røhne, O; Rotondi, A; Sandaker, H; Scampoli, P; Spacek, M; Subieta Vasquez, M.A; Testera, G; Trezzi, D; Vaccarone, R; Zavatarelli, S

2013-01-01

The AEgIS experiment is an international collaboration with the main goal of performing the fi rst direct measurement of the Earth ' s gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen ( H) atoms. The FACT detector is used to measure the production and temperature of the H atoms and for establishing the formation of a H beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H production, operate at 4 K inside a 1 T solenoidal fi eld and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fi bres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fi bres are coupled to clear fi bres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear ampli fi er and a fast discriminator, the out...

An SO(10) × SO(10)' model for common origin of neutrino masses, ordinary and dark matter-antimatter asymmetries

Energy Technology Data Exchange (ETDEWEB)

Gu, Pei-Hong, E-mail: peihong.gu@sjtu.edu.cn [Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2014-12-01

We propose an SO(10) × SO(10)' model to simultaneously realize a seesaw for Dirac neutrino masses and a leptogenesis for ordinary and dark matter-antimatter asymmetries. A (16 × 1-bar 6-bar '){sub H} scalar crossing the SO(10) and SO(10)' sectors plays an essential role in this seesaw-leptogenesis scenario. As a result of lepton number conservation, the lightest dark nucleon as the dark matter particle should have a determined mass around 15 GeV to explain the comparable fractions of ordinary and dark matter in the present universe. The (16 × 1-bar 6-bar '){sub H} scalar also mediates a U(1){sub em} × U(1)'{sub em} kinetic mixing after the ordinary and dark left-right symmetry breaking so that we can expect a dark nucleon scattering in direct detection experiments and/or a dark nucleon decay in indirect detection experiments. Furthermore, we can impose a softly broken mirror symmetry to simplify the parameter choice.

Ion Storage Tests with the High Performance Antimatter Trap (HiPAT)

Science.gov (United States)

Martin, James J.; Lewis, Raymond A.; Chakrabarti, Suman; Pearson, Boise; Schafer, Charles (Technical Monitor)

2002-01-01

The NASA/Marshall Space Flight Centers (NASA/MSFC) Propulsion Research Center (PRC) is evaluating an antiproton storage system, referred to as the High Performance Antiproton Trap (HiPAT). This interest stems from the sheer energy represented by matter/antimatter annihilation process with has an energy density approximately 10 order of magnitude above that of chemical propellants. In other terms, one gram of antiprotons contains the equivalent energy of approximately 23 space shuttle external tanks or ET's (each ET contains roughly 740,000 kgs of fuel and oxidizer). This incredible source of stored energy, if harnessed, would be an enabling technology for deep space mission where both spacecraft weight and propulsion performance are key to satisfying aggressive mission requirements. The HiPAT hardware consists of a 4 Tesla superconductor system, an ultra high vacuum test section (vacuum approaching 10(exp -12) torr), and a high voltage confinement electrode system (up to 20 kvolts operation). The current laboratory layout is illustrated. The HiPAT designed objectives included storage of up to 1 trillion antiprotons with corresponding lifetimes approaching 18 days. To date, testing has centered on the storage of positive hydrogen ions produced in situ by a stream of high-energy electrons that passes through the trapping region. However, due to space charge issues and electron beam compression as it passes through the HiPAT central field, current ion production is limited to less then 50,000 ions. Ion lifetime was determined by counting particle populations at the end of various storage time intervals. Particle detection was accomplished by destructively expelling the ions against a micro-channel plate located just outside the traps magnetic field. The effect of radio frequency (RF) stabilization on the lifetime of trapped particles was also examined. This technique, referred to as a rotating wall, made use of a segmented electrode located near the center of the trap

Rigidity spectrum of z greater than or equal to 3 cosmic-ray nuclei in the range 4-285 GV and a search for cosmic antimatter

Science.gov (United States)

Golden, R. L.; Adams, J. H., Jr.; Marar, T. M. K.; Deney, C. L.; Badhwar, G. D.; Heckman, H. H.; Lindstrom, P. J.

1974-01-01

A measurement, using the magnetic emulsion spectrometer system, of the differential rigidity spectrum of Z greater than or equal to 3 nuclei of the galactic cosmic radiation is presented. The system was flown on Aug. 22, 1969, from Palestine, Texas. The instrument floated above 125,000 feet for eight hours. The data in the rigidity range 8-285 GV can be represented by a power-law spectrum in rigidity, J(rho) = A rho to the minus gamma power, with the exponent gamma = 2.6 plus or minus 0.10. The spectrum in the range 15-285 GV is also described by the same exponent, gamma = 2.6 plus or minus 0.25. The data below 8 GV cannot be described by the same power law without invoking solar modulation. A set of nonunique parameters for modulation are given. Upper limit for the fraction of antimatter in the rigidity range 4-125 GV is .005 with 95% confidence limit.

反物質エネルギーの利用可能性の追求

OpenAIRE

増田, 正美

1992-01-01

Antimatter possesses a highly condensed energy and the mass converts completely to the energy by an annihilation process. Therefore, the use of antimatter for a rocket engine has been investigated as a reality than the scientific fiction. In this paper, the possibility of usage of antimatter energy is investigated and the methods to produce and to store the antimatter fuels are discussed.

New light on the dark side of matter

International Nuclear Information System (INIS)

Salt, David

2006-01-01

Mention antimatter in public and it'll be assumed you're either a sci-fi fan or a theoretical boffin. That's because most people see antimatter as an abstract concept with little place in the real world. And yet the truth is a bit different. Antimatter is a commonly used substance with many important applications. PET scans, for example, are a common form of diagnostic imaging used to detect tumours, and it works by releasing antimatter in our bodies. As another example, firing antimatter at the surface of materials is a technique used to characterise those surfaces. Indeed, antimatter plays a number of roles in the real world and its value in materials science, medicine and biology is only set to increase

Collective effects in diffuse ambiplasma

International Nuclear Information System (INIS)

Rogers, S.H.

1981-01-01

All laboratory evidence to date indicates that particles materialize from energy only in matter-antimatter pairs and, conversely, disappear only when such pairs annihilate. This observed law suggests that early in the Big Bang, when material and radiation were in equilibrium, the universe contained equal amounts of matter and antimatter. Since the earth, the solar system, and the neighboring stars, as implied by cosmic ray data, appear to be exclusively matter, their antimatter counterparts should by all rights exist elsewhere. Astronomical observations, however, have revealed no signs of antimatter on a large scale; in particular, the energetic gamma rays that would originate in the boundaries between matter and antimatter are not observed. The dilemma is resolved if the laboratory law is violated even minutely, a possibility that is now being tested by experiment. On the other hand, the dilemma disappears if the matter and antimatter exist in separate regions without, in effect, interacting. In this case there must be a repulsive force between the matter and antimatter that prevents them from mixing; in particular, such a force is crucial to the coexistence of large, diffuse regions akin to the galactic interstellar clouds. Predictions of the outcome of matter-antimatter contact are usually based entirely on binary collisions. This disseration explores the possibility that collective effects dominate interactions between diffuse matter and antimatter and give rise to the necessary repulsive force. Some years ago, a mechanism was proposed in which a thin, magnetized layer of ambiplasma kept matter and antimatter plasmas separated with the energy released in occasional annihilation

Production of antimatter 5,6Li nuclei in central Au+Au collisions at sNN=200 GeV

Directory of Open Access Journals (Sweden)

Kai-Jia Sun

2015-12-01

Full Text Available Combining the covariant coalescence model and a blast-wave-like analytical parametrization for (anti-nucleon phase–space freezeout configuration, we explore light (anti-nucleus production in central Au+Au collisions at sNN=200 GeV. Using the nucleon freezeout configuration (denoted by FO1 determined from the measured spectra of protons (p, deutrons (d and 3He, we find the predicted yield of 4He is significantly smaller than the experimental data. We show this disagreement can be removed by using a nucleon freezeout configuration (denoted by FO2 in which the nucleons are assumed to freeze out earlier than those in FO1 to effectively consider the effect of large binding energy value of 4He. Assuming the binding energy effect also exists for the production of 5Li, Li‾5, 6Li and Li‾6 due to their similar binding energy values as 4He, we find the yields of these heavier (anti-nuclei can be enhanced by a factor of about one order, implying that although the stable (anti-6Li nucleus is unlikely to be observed, the unstable (anti-5Li nucleus could be produced in observable abundance in Au+Au collisions at sNN=200 GeV where it may be identified through the p–4He (p‾–He‾4 invariant mass spectrum. The future experimental measurement on (anti-5Li would be very useful to understand the production mechanism of heavier antimatter.

Golden Jubilee Photos: A Universal Imbalance

CERN Multimedia

2004-01-01

http://www.cern.ch/cern50/ View along the NA48 beamline with the detector in the distance. No one is sure why the Universe wound up the way it has: all matter and no antimatter. According to prevailing theories, the early universe had equal amounts of matter and antimatter. However, whenever such opposites meet, they annihilate and become a burst of energy. This would seem to leave the Universe with neither matter nor antimatter - and thus no stars, planets, or physicists. If nature shows a bias for matter over antimatter, this could explain why the Universe is all matter. To see what might be missing from the theories, physicists search for the rare cases in which matter and antimatter behave differently. One such imbalance, called direct CP violation, showed up in the NA 31 experiment at CERN. The results from this experiment, first presented in 1993, showed that when K mesons and their antimatter cousins decay, they show a slight preference for matter over antimatter. Later experiments with neutral K mes...

Emergence of Space-Time Localization and Cosmic Decoherence:. More on Irreversible Time, Dark Energy, Anti-Matter and Black-Holes

Science.gov (United States)

Magnon, Anne

2005-04-01

A non geometric cosmology is presented, based on logic of observability, where logical categories of our perception set frontiers to comprehensibility. The Big-Bang singularity finds here a substitute (comparable to a "quantum jump"): a logical process (tied to self-referent and divisible totality) by which information emerges, focalizes on events and recycles, providing a transition from incoherence to causal coherence. This jump manufactures causal order and space-time localization, as exact solutions to Einstein's equation, where the last step of the process disentangles complex Riemann spheres into real null-cones (a geometric overturning imposed by self-reference, reminding us of our ability to project the cosmos within our mental sphere). Concepts such as antimatter and dark energy (dual entities tied to bifurcations or broken symmetries, and their compensation), are presented as hidden in the virtual potentialities, while irreversible time appears with the recycling of information and related flow. Logical bifurcations (such as the "part-totality" category, a quantum of information which owes its recycling to non localizable logical separations, as anticipated by unstability or horizon dependence of the quantum vacuum) induce broken symmetries, at the (complex or real) geometric level [eg. the antiselfdual complex non linear graviton solutions, which break duality symmetry, provide a model for (hidden) anti-matter, itself compensated with dark-energy, and providing, with space-time localization, the radiative gravitational energy (Bondi flux and related bifurcations of the peeling off type), as well as mass of isolated bodies]. These bifurcations are compensated by inertial effects (non geometric precursors of the Coriolis forces) able to explain (on logical grounds) the cosmic expansion (a repulsion?) and critical equilibrium of the cosmic tissue. Space-time environment, itself, emerges through the jump, as a censor to totality, a screen to incoherence (as

From Russia with krypton Exhibition Science Bringing Nations Together

CERN Multimedia

2000-01-01

The CERN experiment NA48 studies the matter-antimatter imbalance by measuring the decay of particles called neutral kaons and antikaons, their antimatter counterparts. These particles decay in several ways, and careful study gives an accurate handle on nature's apparent preference for matter over antimatter.

Golden Jubilee Photos: How slow can they go?

CERN Multimedia

2004-01-01

A technician installs a magnet in CERN's Antimatter Decelerator (AD) ring in 1998.Antimatter isn't normally just sitting around, waiting to be studied. As far as scientists know, hardly any antiparticles—the mirror-image versions of regular particles, with the same mass but opposite electric charge—exist in the Universe. This absence of antimatter is somehow mysterious and motivates physicists to look for tiny differences between particles and antiparticles. One way to do this is by studying antimatter very precisely. The simplest antimatter atom, antihydrogen, is made from an antiproton and a positron (an anti-electron). The first nine atoms of antihydrogen emerged from particle collisions at CERN in 1995, but they moved at nearly the speed of light. To produce slow-moving antihydrogen atoms, better suited for precision studies, scientists have gone against the prevailing methods at CERN. Instead of smashing together highly-accelerated particles, they built the Antimatter Decelerator (AD) to put th...

Antihydrogen Beams

Science.gov (United States)

Yamazaki, Yasunori; Doser, Michael; Pérez, Patrice

2018-03-01

Why does our universe consist purely of matter, even though the same amount of antimatter and matter should have been produced at the moment of the Big Bang 13.8 billion years ago? One of the most potentially fruitful approaches to address the mystery is to study the properties of antihydrogen and antiprotons. Because they are both stable, we can in principle make measurement precision as high as we need to see differences between these antimatter systems and their matter counterparts, i.e. hydrogen and protons. This is the goal of cold antihydrogen research. To study a fundamental symmetry-charge, parity, and time reversal (CPT) symmetry-which should lead to identical spectra in hydrogen and antihydrogen, as well as the weak equivalence principle (WEP), cold antihydrogen research seeks any discrepancies between matter and antimatter, which might also offer clues to the missing antimatter mystery. Precision tests of CPT have already been carried out in other systems, but antihydrogen spectroscopy offers the hope of reaching even higher sensitivity to violations of CPT. Meanwhile, utilizing the Earth and antihydrogen atoms as an experimental system, the WEP predicts a gravitational interaction between matter and antimatter that is identical to that between any two matter objects. The WEP has been tested to very high precision for a range of material compositions, but no such precision test using antimatter has yet been carried out, offering hope of a telltale inconsistency between matter and antimatter. In this Discovery book, we invite you to visit the frontiers of cold antimatter research, focusing on new technologies to form beams of antihydrogen atoms and antihydrogen ions, and new ways of interrogating the properties of antimatter.

Antimatter

International Nuclear Information System (INIS)

Kalmus, P.I.P.

1990-01-01

The two broad aims of particle physics, to study the ultimate constituents of matter: to find the smallest building blocks out of which we and the rest of the universe are made, and to study the nature of the forces through which these particles interact are discussed. In the early 1930s scientists had a relatively simple picture of elementary particles. Nuclei consisted of clusters of positively charged protons and uncharged neutrons having dimensions of around 10 -15 m. The nucleus was surrounded by a cloud of orbiting electrons, equal in number to the protons, to make an atom whose dimensions were around 10 -10 m. In addition the photon, the packet or quantum of light, was recognised as having particle-like properties. The idea that there might be antiparticles came not from experiment but from theoretical reasoning. The reasoning and the experiments which confirmed the theories put forward over the next decades are recounted. These culminated in the experiments at CERN in 1982 and 1983 to discover the W and Z particles. (author)

Trapping and accumulation of positrons from a pulsed beam produced by a linear accelerator for gravitational interaction of antimatter study

International Nuclear Information System (INIS)

Grandemange, Pierre

2013-01-01

The Gravitational Behaviour of Anti-hydrogen at Rest experiment - GBAR - is designed to perform a direct measurement of the weak equivalence principle on antimatter by measuring the acceleration (g-bar) of anti-hydrogen atoms in free fall. Its originality is to produce H-bar + ions and use sympathetic cooling to achieve μK temperature. H-bar + ions are produced by the reactions: p-bar + Ps → H-bar + e - , and H-bar + Ps → H-bar + + e - , where p-bar is an antiproton, Ps stands for positronium (the bound-state of a positron and an electron), H-bar is the anti-hydrogen and H-bar + the anti-ion associated. To produce enough Ps atoms, 2*10 10 positrons must be impinged on a porous SiO 2 target within 100 ns. Such an intense flux requires the accumulation (collection and cooling) of the positrons in a particle trap. This thesis describes the injector being commissioned at CEA Saclay for GBAR. It consists of a Penning-Malmberg trap (moved from RIKEN) fed by a slow positron beam. A 4.3 MeV linear accelerator shooting electrons on a tungsten target produces the pulsed positron beam, which is moderated by a multi-grid tungsten moderator. The slow positron flux is 10 4 e + /pulse, or 2*10 6 e + /s at 200 Hz. This work presents the first ever accumulation of low-energy positrons produced by an accelerator (rather than a radioactive source) and their cooling by a prepared reservoir of 2*10 10 cold electrons. (author) [fr

NA48 experiment : view along the NA48 beamline with the detector in the distance.

CERN Multimedia

Hans Taureg

1996-01-01

Photo 02: Side view of the NA48 experiment showing the LKR calorimeter cryostat No one is sure why the Universe wound up the way it has: all matter and no antimatter. According to prevailing theories, the early universe had equal amounts of matter and antimatter. To see what might be missing from the theories, physicists search for the rare cases in which matter and antimatter behave differently. One such imbalance, called direct CP violation, showed up in the NA 31 experiment at CERN. The results from this experiment, first presented in 1993, showed that when K mesons and their antimatter cousins decay, they show a slight preference for matter over antimatter. Later experiments with neutral K mesons, including NA48 at CERN and KTeV at Fermilab in the United States, showed direct CP violation is real.

The unknowns in particles physics

International Nuclear Information System (INIS)

Spiro, M.

1996-01-01

The author presents the historical quest of particles since Democrite's time. Some particles are very difficult to identify as for instance neutrinos and antiparticles. Nine anti-hydrogen atoms have just being manufactured in the CERN. This successful result is the last episode of a long history. This achievement is the first step in the elaboration of antimatter too. The enigma of the antimatter created at the universe dawn is perennial. Why is the universe made of matter and not of antimatter? Is there any slight difference in the physical law of antimatter and matter? That's why the study of antimatter is so important. The question of the missing mass of our galaxy leads to another quest: the Higgs's particles. The graviton is another target. That could lead to the unification theory, may be another proof of the unreasonable efficiency of mathematics. (O.M.). 2 figs

Particle tracking at 4 K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

Energy Technology Data Exchange (ETDEWEB)

Storey, J., E-mail: james.storey@cern.ch [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern, 3012 Bern (Switzerland); Canali, C. [University of Zurich, Physics Institute, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Aghion, S. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Milano, Via Celoria 16, 20133 Milano (Italy); Ahlén, O. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Amsler, C.; Ariga, A.; Ariga, T. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern, 3012 Bern (Switzerland); Belov, A.S. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312 (Russian Federation); Bonomi, G. [University of Brescia, Department of Mechanical and Industrial Engineering, Via Branze 38, 25133 Brescia (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia (Italy); Bräunig, P. [University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Bremer, J. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Brusa, R.S. [Dipartimento di Fisica, Università di Trento and INFN, Gruppo Collegato di Trento, Via Sommarive 14, 38050 Povo, Trento (Italy); Burghart, G. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Cabaret, L. [Laboratoire Aimé Cotton, CNRS, Université Paris Sud, ENS Cachan, Bâtiment 505, Campus d' Orsay, 91405 Orsay Cedex (France); Carante, M. [Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia (Italy); Caravita, R. [University of Milano, Department of Physics, Via Celoria 16, 20133 Milano (Italy); and others

2013-12-21

The AEgIS experiment is an international collaboration with the main goal of performing the first direct measurement of the Earth's gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen (H{sup ¯}) atoms. The FACT detector is used to measure the production and temperature of the H{sup ¯} atoms and for establishing the formation of a H{sup ¯} beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H{sup ¯} production, operate at 4 K inside a 1 T solenoidal field and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fibres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fibres are coupled to clear fibres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear amplifier and a fast discriminator, the outputs of which are sampled continuously by Field Programmable Gate Arrays (FPGAs). In the course of the developments for the FACT detector we have established the performance of scintillating fibres at 4 K by means of a cosmic-ray tracker operating in a liquid helium cryostat. The FACT detector was installed in the AEgIS apparatus in December 2012 and will be used to study the H{sup ¯} formation when the low energy antiproton physics programs resume at CERN in the Summer of 2014. This paper presents the design requirements and construction methods of the FACT detector and provides the first results of the detector commissioning.

Particle tracking at 4 K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

International Nuclear Information System (INIS)

Storey, J.; Canali, C.; Aghion, S.; Ahlén, O.; Amsler, C.; Ariga, A.; Ariga, T.; Belov, A.S.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R.S.; Burghart, G.; Cabaret, L.; Carante, M.; Caravita, R.

2013-01-01

The AEgIS experiment is an international collaboration with the main goal of performing the first direct measurement of the Earth's gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen (H ¯ ) atoms. The FACT detector is used to measure the production and temperature of the H ¯ atoms and for establishing the formation of a H ¯ beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H ¯ production, operate at 4 K inside a 1 T solenoidal field and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fibres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fibres are coupled to clear fibres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear amplifier and a fast discriminator, the outputs of which are sampled continuously by Field Programmable Gate Arrays (FPGAs). In the course of the developments for the FACT detector we have established the performance of scintillating fibres at 4 K by means of a cosmic-ray tracker operating in a liquid helium cryostat. The FACT detector was installed in the AEgIS apparatus in December 2012 and will be used to study the H ¯ formation when the low energy antiproton physics programs resume at CERN in the Summer of 2014. This paper presents the design requirements and construction methods of the FACT detector and provides the first results of the detector commissioning

CP and T violations: new results leave open questions

International Nuclear Information System (INIS)

Quinn, H.; Hewett, J.

1999-01-01

A steady stream of new results on the violation of charge-parity symmetry has improved our understanding of the difference between matter and antimatter, and will have important consequences for a new generation of particle-physics experiments. Symmetry is one of the most powerful concepts in modern physics and it underlies many fundamental laws, such as the conservation of energy and momentum. However, there is a very obvious lack of symmetry all around us: why is the universe made of matter rather than antimatter? The big bang is thought to have created equal amounts of matter and antimatter but, to the best of our knowledge, all the antimatter has disappeared, along with most of the matter. How can this be explained? The answer is not yet known, but the clues lie in understanding the symmetry, or the lack of it, between the basic interactions of matter and antimatter. In this article the authors describe the search for antisymmetry in particle physics. (UK)

An antinucleus detector with unprecedented collecting power and resolution

International Nuclear Information System (INIS)

Ahlen, S.P.; Price, P.B.; Salamon, M.H.; Tarle, G.; California Univ., Berkeley

1982-01-01

We describe the details of a novel technique to detect the presence of antimatter in cosmic rays by taking advantage of the presence of higher order quantum electrodynamic effects involving the interactions of relativistic, heavily ionizing particles with plastic scintillators, track etch detectors and Cherenkov counters. We review the relevant physics, summarize the experimental status involving the response mechanisms of the different types of particle detectors, and give a detailed description of the construction and anticipated performance characteristics of the instrument. By extending the sensitivity of previous antimatter searches by two orders of magnitude, this experiment should be the first to be sensitive to extragalactic antimatter, should the universe contain substantial quantities of antimatter. (orig.)

Baryon symmetric big bang cosmology

Science.gov (United States)

Stecker, F. W.

1978-01-01

Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.

Ecology and Space – Backbone Directions of Human Civilization Development

Directory of Open Access Journals (Sweden)

Evgenii P. Prokopiev

2013-01-01

Full Text Available The article briefly describes the features and possible ways of space technologies development (special attention is attached to the problematic issues of physics, chemistry and antimatter technology; the problem of positron annihilation in matter (positronium, including positron processes, positron states and annihilation process, which is the component of fundamental and practical important problem of antimatter. The space technologies of the future – the most important problems of antimatter application are considered on the basis of Internet data.

Studying antimatter

CERN Multimedia

CERN. Geneva

2006-01-01

Antiparticles are a crucial ingredient of particle physics and cosmology. Almost 80 years after Dirac’s bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? When and how were they discovered? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: their production, their use in colliders; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on results and challenges of the “antimatter” programme at the Antiproton Decelerator (AD), with special emphasis on antihydrogen production, trapping and precision measurements.

AEgIS Experiment: Status & Outlook

CERN Document Server

Lansonneur, P; Amsler, C; Bonomi, G; Brusa, R S; Caccia, M; Caravita, R; Castelli, F; Cerchiari, G; Comparat, D; Consolati, G; Demetrio, A; Di Noto, L; Doser, M; Evans, C; Ferragut, R; Fesel, J; Fontana, A; Gerber, S; Giammarchi, M; Gligorova, A; Guatieri, F; Haider, S; Hinterberger, A; Holmestad, H; Kellerbauer, A; Khalidova, O; Krasnicky, D; Lagomarsino, V; Lebrun, P; Malbrunot, C; Mariazzi, S; Marton, J; Matveev, V; Mazzotta, Z; Müller, S R; Nebbia, G; Nedelec, P; Oberthaler, M; Pacico, N; Pagano, D; Penasa, L; Petracek, V; Prelz, F; Prevedelli, M; Ravelli, L; Rienaecker, B; Robert, J; Rhøne, O M; Rotondi, A; Sacerdoti, M; Sandaker, H; Santoro, R; Simon, M; Smestad, L; Sorrentino, F; Testera, G; Tietje, I C; Widmann, E; Yzombard, P; Zimmer, C; Zmeska, J; Zurlo, N

2017-01-01

The AEGIS experiment 1 (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is planned to perform the first measurement of the gravitational acceleration on antimatter by observing the free fall of antihydrogen atoms. By combining techniques based on recent developments in the production of positronium and its laser excitation to Rydberg states, such a study seems indeed to be feasible for neutral antimatter. We present here some of the experimental techniques involved in the experiment as well as the status of the detector test envisioned for the gravity measurement.

De aartsvijand van de materie

CERN Multimedia

De Decker, Kris

2002-01-01

An international team of scientists a few weeks ago in the European laboratory for Paqrticle Physics (CERN) in Geneva created antimatter into relative great quantity. The Antimatter plays an essential part in the theory of the big-bang

Characterization of the 1S–2S transition in antihydrogen

DEFF Research Database (Denmark)

Ahmadi, M.; Alves, B. X. R.; Baker, C. J.

2018-01-01

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles—antimatter. The existence of particles...... of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3–7, including tests of fundamental symmetries such as charge...... of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees...

Scientists seek to explain how Big Bang let us live

CERN Multimedia

Hawke, N

2000-01-01

Scientists at CERN have opened an antimatter factory, the Antiproton Decelerator. They hope to discover why, in the Big Bang, the amount of matter and antimatter produced was not equal, so allowing the universe to exist at all (1 page).

Putting the brakes on antihydrogen

CERN Multimedia

2002-01-01

"Researchers at the European Organization for Nuclear Research (CERN) in Geneva have now made the first slow-moving atoms of antimatter. By studying them, scientists may more closely compare matter and antimatter and possibly explain the latter's glaring absence" (1/2 page).

In viaggio con l'antimateria

CERN Multimedia

Parolini, Giuditta

2007-01-01

From mathematical intuition to fuel for interstellar travels. Antimatter has made much road in little less than a century. The ultimate stage, at least for the moment, is marked from the speculations of New Scientist on the spaceships fed to antimatter. (1/2 page)

Antiproton-nucleus experiments at LEAR and KAON

International Nuclear Information System (INIS)

Yavin, A.I.

1989-12-01

Antimatter and matter-antimatter systems are briefly discussed. Results of the antiproton-nucleus scattering experiments at LEAR are described, with the emphasis on unfinished experiments and on proposed experiments yet untouched. A few remarks on antiproton and antideuteron experiments at KAON are then presented

Relativistic Tsiolkovsky equation -- a case study in special relativity

Science.gov (United States)

Redd, Jeremy; Panin, Alexander

2011-10-01

A possibility of using antimatter in future space propulsion systems is seriously discussed in scientific literature. Annihilation of matter and antimatter is not only the energy source of ultimate density 9x10^16 J/kg (provided that antimatter fuel is available on board or can be collected along the journey) but also potentially allows to reach ultimate exhaust speed -- speed of light c. Using relativistic rocket equation we discuss the feasibility of achieving relativistic velocities with annihilation powered photon engine, as well as the advantages and disadvantages of interstellar travel with relativistic and ultrarelativistic velocities.

A New Form of Matter — Unmatter, Composed of Particles and Anti-Particles

Directory of Open Access Journals (Sweden)

Smarandache F.

2005-04-01

Full Text Available Besides matter and antimatter there must exist unmatter (as a new form of matter in accordance with the neutrosophy theory that between an entity and its opposite there exist intermediate entities . Unmatter is neither matter nor antimatter, but something in between. An atom of unmatter is formed either by (1: electrons, protons, and antineutrons, or by (2: antielectrons, antiprotons, and neutrons. At CERN it will be possible to test the production of unmatter. The existence of unmatter in the universe has a similar chance to that of the antimatter, and its production also difficult for present technologies.

Tests of fundamental symmetries with trapped antihydrogen

DEFF Research Database (Denmark)

Rasmussen, Chris Ørum

2016-01-01

Antihydrogen is the simplest pure antimatter atomic system, and it allows for direct tests of CPT symmetry as well as the weak equivalence principle. Furthermore the study of antihydrogen may provide clues to the matter- antimatter asymmetry observed in the universe - one of the major unanswered...

Antihydrogen beams

CERN Document Server

Yamazaki, Yasunori; Pérez, Patrice

2018-01-01

Why does our universe consist purely of matter, even though the same amount of antimatter and matter should have been produced at the moment of the Big Bang 13.8 billion years ago? One of the most potentially fruitful approaches to address the mystery is to study the properties of antihydrogen and antiprotons. Because they are both stable, we can in principle make measurement precision as high as we need to see differences between these antimatter systems and their matter counterparts, i.e. hydrogen and protons. This is the goal of cold antihydrogen research. To study a fundamental symmetry—charge, parity, and time reversal (CPT) symmetry—which should lead to identical spectra in hydrogen and antihydrogen, as well as the weak equivalence principle (WEP), cold antihydrogen research seeks any discrepancies between matter and antimatter, which might also offer clues to the missing antimatter mystery. Precision tests of CPT have already been carried out in other systems, but antihydrogen spectroscopy offers t...

Unmatter Plasma revisited

Science.gov (United States)

Smarandache, Florentin

2017-10-01

Unmmatter Plasma is a novel form of plasma, exclusively made of matter and its antimatter counterpart. The electron-positron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted since 2004) really exists. That is the electron-positron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter. Unmatter is formed by combinations of matter and antimatter that bind together, or by long-range mixture of matter and antimatter forming a weakly-coupled phase. Binding and bound state means that the interaction is sufficiently strong to tie together the particles of a system, therefore hindering them from becoming free. For example, a usual liquid is a bound state of molecules, while a gas is an un-bounded where the molecules can move freely in successive collisions.

Swiss Science Festival - Science et Cité Science - It's magic!

CERN Multimedia

2001-01-01

CERN's new antimatter factory, the Antiproton Decelerator (AD), will allow precision studies of antihydrogen. From Saturday 5 May for a week in ten Swiss towns, the 'Science et Cité' Festival will be bringing science to the public. The festival aims to be a bridge between the concerns of the public at large and those of scientists, so naturally CERN is involved. The Laboratory is organising special visits on the theme of antimatter. Following a presentation by Rolf Landua, spokesman of the ATHENA collaboration, visitors will discover two machines indispensable for the study of antimatter - LEIR, which as LEAR was where the first atoms of antihydrogen were created, and the new antimatter factory, the Antiproton Decelerator, AD. As well as these visits, CERN guides will become show people on the stand 'Magicians? Physicists!' at the old SIP building, where the majority of the Geneva events will take place. Disguised as magicians, our guides will amaze and astound their audience with a series of rema...

Characterization of the 1S-2S transition in antihydrogen.

Science.gov (United States)

Ahmadi, M; Alves, B X R; Baker, C J; Bertsche, W; Capra, A; Carruth, C; Cesar, C L; Charlton, M; Cohen, S; Collister, R; Eriksson, S; Evans, A; Evetts, N; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Johnson, M A; Jones, J M; Jones, S A; Jonsell, S; Khramov, A; Knapp, P; Kurchaninov, L; Madsen, N; Maxwell, D; McKenna, J T K; Menary, S; Momose, T; Munich, J J; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sacramento, R L; Sameed, M; Sarid, E; Silveira, D M; Stutter, G; So, C; Tharp, T D; Thompson, R I; van der Werf, D P; Wurtele, J S

2018-05-01

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter 3-7 , including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 10 15 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10 -12 -two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10 -20 GeV.

La antimateria es eficaz contra el cáncer

CERN Multimedia

2006-01-01

Following a study made at CERN in Geneva, the antimatter appeared much more effective to fight the cancer. Nuclear medicine has been applying for half century therapies that destroys cancerigene cells thanks to proton irradiation. Now, it has been discovered that antimatter cells are four times more effective to destroy these cells. (2 pages)

Live Webcast from CERN - Mission Impossible 3?

CERN Document Server

2000-01-01

It is a beautiful sunny autumn day, 21 November 2000. The place is CERN's Microcosm exhibition where around 50 pupils from the International School in Geneva and the Collège du Leman have gathered to dive into the mystery of antimatter production and take part in CERN's second Live Webcast of the series 'The Antimatter Factory'. The first was broadcast on 18 November. The webcast is played in the mood of Mission Impossible with music and teasers from this famous television and cinema series. The mission here is not to save the planet but to understand how and why antimatter is produced at CERN. In the Webcast studio, Paola Catapano, Rolf Landua and Mick Storr answer questions posed by students in Italy and Finland thanks to video-conferencing. Paola Catapano, Visit and Exhibitions group leader, dressed like a Bond girl Rolf Landua, spokesman of the ATHENA experiment and Mick Storr Head of Technical Training lead the show. The place starts buzzing and we peep into the antimatter factory (AD) and a...

What would be outcome of a Big Crunch?

CERN Document Server

Hajdukovic, Dragan Slavkov

2010-01-01

I suggest the existence of a still undiscovered interaction: repulsion between matter and antimatter. The simplest and the most elegant candidate for such a force is gravitational repulsion between particles and antiparticles. I argue that such a force may give birth to a new Universe; by transforming an eventual Big Crunch of our universe, to an event similar to Big Bang. In fact, when a collapsing Universe is reduced to a supermassive black hole of a small size, a very strong field of the conjectured force may create particle-antiparticle pairs from the surrounding vacuum. The amount of the antimatter created from the physical vacuum is equal to the decrease of mass of "black hole Universe" and violently repelled from it. When the size of the black hole is sufficiently small the creation of antimatter may become so huge and fast, that matter of our Universe may disappear in a fraction of the Planck time. So fast transformation of matter to antimatter may look like a Big Bang with the initial size about 30 o...

George Smoot talks to the Bulletin

CERN Multimedia

CERN Bulletin

2011-01-01

Antimatter, dark matter, dark energy, the nature of space and time… The Nobel Laureate George Smoot answers Paola Catapano’s questions about his career and the many issues about the Universe that are still open.   You started your scientific career as a particle physicist, but soon you moved to astrophysics and in particular the Big Bang theory and cosmology. What motivated your interest in the Big Bang theory? After I graduated from MIT, I went to Berkeley to work with particle physicist Luis Alvarez. He knew I was interested in many areas and said, “tell me what you would like to do and we’ll try and work on that”. I saw astrophysics as a new field, with a lot of new and exciting opportunities. I started doing experiments looking for antimatter, which eventually led to the idea of ASTROMAG and later to AMS. Studying antimatter, we found that it was in less than one part in 10,000. I thought: “There’s no antimatter around us ...

Antimatter gravity experiment

International Nuclear Information System (INIS)

Brown, R.E.; Camp, J.B.; Darling, T.W.

1990-01-01

An experiment is being developed to measure the acceleration of the antiproton in the gravitational field of the earth. Antiprotons of a few MeV from the LEAR facility at CERN will be slowed, captured, cooled to a temperature of about 10 K, and subsequently launched a few at a time into a drift tube where the effect of gravity on their motion will be determined by a time-of-flight method. Development of the experiment is proceeding at Los Alamos using normal matter. The fabrication of a drift tube that will produce a region of space in which gravity is the dominant force on moving ions is of major difficulty. This involves a study of methods of minimizing the electric fields produced by spatially varying work functions on conducting surfaces. Progress in a number of areas is described, with stress on the drift-tube development

First antimatter chemistry

CERN Multimedia

2006-01-01

"The Athena collaboration, an experimental group working at the CERN laboratory in Geneva, has measured chemical reactions involving antiprotonic hydrogen, a bound object consisting of a negatively charged antiproton paired with a positively charged proton." (1 page)

Baryogenesis model suggesting antigalaxies

International Nuclear Information System (INIS)

Kirilova, D.P.

1998-12-01

A non-GUT baryogenesis model, according to which our Universe may contain clusters of antigalaxies is discussed. A mechanism of separation of vast quantities of matter from such of antimatter is described. The provided analysis showed that for a natural range of model parameters a sufficient separation between matter and antimatter regions, required from observational data, can be obtained. (author)

Antimateria, la otra realidad

CERN Multimedia

González, Gabriel

2005-01-01

If, according to the history of cosmos, there is the same quantity of matter and antimatter; if, for every particle there is an antiparticle, why do we live in an universe composed exclusively by matter? Where is gone the antimatter? Is it possible that parallel antiuniverses exist? Such questions are not a wild imagining. The answer worries the physicists of the whole world (3 ½ pages)

Prospects for testing Lorentz and CPT symmetry with antiprotons

Science.gov (United States)

Vargas, Arnaldo J.

2018-03-01

A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

Une Web-émission sur l'antimatière en direct du CERN

CERN Multimedia

CERN Press Office. Geneva

2000-01-01

Dive into the anti-world from the Web ! On 18 and 21 November, you will be able to discover antimatter thanks to a Webcast live from CERN*. An hour long show for the general public broadcast through the Internet will show you how and why CERN's antimatter factory is producing anti-particles. Interviews, video clips and questions from the public are on the programme.

Physics at the AD/PS/SPS (4/4)

CERN Multimedia

CERN. Geneva

2012-01-01

Lecture 4: Physics with Antimatter at the Antiproton Decelerator The Antiproton Decelerator (AD) is a unique facility - the world's only source of low energy antiprotons for fundamental studies of the physics of antimatter. I will discuss the physics at the AD, with an emphasis on studies of antihydrogen, the only antimatter atom that we can produce in the laboratory. Recently we have been able to capture antihydrogen, store it for more than 15 minutes, and make the first measurements of its structure. The idea is to compare it to hydrogen, to see if atom and anti-atom behave identically, as required by the Standard Model. The AD was the inspiration for Dan Brown's 'Angels and Demons'; we can also take a look at the science fiction in the book.

Cooking Up Hot Quark Soup

Science.gov (United States)

Walsh, Karen McNulty

2011-03-28

Near-light-speed collisions of gold ions provide a recipe for in-depth explorations of matter and fundamental forces. The Relativistic Heavy Ion Collider (RHIC) has produced the most massive antimatter nucleus ever discovered?and the first containing an anti-strange quark. The presence of strange antimatter makes this antinucleus the first to be entered below the plane of the classic Periodic Table of Elements, marking a new frontier in physics.

Prospects for testing Lorentz and CPT symmetry with antiprotons.

Science.gov (United States)

Vargas, Arnaldo J

2018-03-28

A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Author(s).

Annihilation model of quasi-stellar objects

International Nuclear Information System (INIS)

Alfven, H.

1979-01-01

The possibility that annihilation is a major source of energy in cosmic physics is discussed. Since Klein suggested that the Universe might be matter-antimatter symmetric over two decades ago, there have been a significant number of papers developing the consequences of this view. These, however, have been largely ignored in the general literature. There have also been a number of papers claiming to prove that there cannot be antimatter anywhere in the observable Universe. In the first part of this paper an assessment of the differing views is given, and it is shown that none of the arguments against antimatter is convincing. The existence of antimatter is not in conflict with any observational fact. The reason for the negative attitude towards the existence of antimatter seems to be that this view is in conflict with a number of speculative but 'generally accepted' theories. However, recent magnetospheric and heliospheric research, including in situ measurements of cosmic plasmas, is now drastically changing cosmic plasma physics in a way that leads to growing scepticism about quite a few of the speculative theories. An attempt is made to develop a simple phenomenological model of QSOs based on star-antistar collisions. This model can account for such basic observational properties as the acceleration to very large (non-cosmological) velocities, the existence of broad emission lines, and at the same time narrow absorption lines with different redshifts. The absence of blueshifts is also explained. The model predicts that relatively young QSOs should be at cosmological distances whereas the old ones may very well be much closer to us than indicated by their redshift. (Auth.)

Leptogenesis from loop effects in curved spacetime

Energy Technology Data Exchange (ETDEWEB)

McDonald, Jamie I.; Shore, Graham M. [Department of Physics, Swansea University,Singleton Park, Swansea, SA2 8PP (United Kingdom)

2016-04-05

We describe a new mechanism — radiatively-induced gravitational leptogenesis — for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C and CP violating theories cause matter and antimatter to propagate differently in the presence of gravity, and prove this is forbidden in flat space by CPT and translation symmetry. This generates a curvature-dependent chemical potential for leptons, allowing a matter-antimatter asymmetry to be generated in thermal equilibrium in the early Universe. The time-dependent dynamics necessary for leptogenesis is provided by the interaction of the virtual self-energy cloud of the leptons with the expanding curved spacetime background, which violates the strong equivalence principle and allows a distinction between matter and antimatter. We show here how this mechanism is realised in a particular BSM theory, the see-saw model, where the quantum loops involve the heavy sterile neutrinos responsible for light neutrino masses. We demonstrate by explicit computation of the relevant two-loop Feynman diagrams how the size of the radiative corrections relevant for leptogenesis becomes enhanced by increasing the mass hierarchy of the sterile neutrinos, and show how the induced lepton asymmetry may be sufficiently large to play an important rôle in determining the baryon-to-photon ratio of the Universe.

Antihydrogen spectroscopy and fundamental symmetry tests

DEFF Research Database (Denmark)

Ximenez Rodrigues Alves, Bruno

2018-01-01

The baryon asymmetry remains an important unanswered question in physics nowadays. The Standard Model of Particle Physics predicts that matter and antimatter should have been created in equal amounts in early stages of the universe. However, our universe seems to be pretty much empty of antimat......- ter. This discrepancy between theory and observation triggers scientists to investigate the properties of antimatter. A comparison between matter and antimatter properties constitutes a test of the charge conjugation-parity-time reversal (CPT) symmetry and any violation of this symmetry can open...... the doors for new physics and a possible explanation for the baryon asymmetry. Antihydrogen, the bound state of a positron and an antiproton, is the simplest anti-atom one can make. This thesis reports on the measurement of the resonance frequency of the 1S–2S transition in magnetically trapped antihydrogen...

Experiments on the CMB Spectrum, Big Jets Model and Their Implications for the Missing Half of the Universe

Directory of Open Access Journals (Sweden)

Hsu Leonardo

2018-01-01

Full Text Available Based on the limiting continuation of Lorentz-Poincaré invariance, we propose an alternative formulation of the generalized Planck distribution for inertial and noninertial frames. The Lorentz invariant Planck distribution law leads to a new physical interpretation of the dipole anisotropy of the Cosmic Microwave Background. The Big Jets model predicts a distant ‘antimatter blackbody,’ whose radiations could make 50% of the sky very slightly warmer than the isotropic CMB temperature TCMB with a cosine function. The other 50% of the sky has the same isotropic temperature TCMB. Thus, we could have a pseudo-dipole anisotropy because the microwaves emitted from the antimatter blackbody are totally absorbed by our matter blackbody. We suggest that accurate data of satellite experiments might be used to search for the pseudo-dipole anisotropy and the missing half of the antimatter universe.

Neutrino masses, dark matter and leptogenesis with U(1) B - L gauge symmetry

Science.gov (United States)

Geng, Chao-Qiang; Okada, Hiroshi

2018-06-01

We propose a model with an U(1) B - L gauge symmetry, in which small neutrino masses, dark matter and the matter-antimatter asymmetry in the Universe can be simultaneously explained. In particular, the neutrino masses are generated radiatively, while the matter-antimatter asymmetry is led by the leptogenesis mechanism, at TeV scale. We also explore allowed regions of the model parameters and discuss some phenomenological effects, including lepton flavor violating processes.

Antiproton interaction with 4He as a test of GUT cosmology

International Nuclear Information System (INIS)

Chechetkin, V.M.; Khlopov, M.Yu.; Zeldovich, Ya.B.

1982-01-01

A new possibility of checking some GUT models is suggested, basing on the analysis of their cosmological consequences and the experimental study of the anti p 4 He interaction. The study of annihilation of antiprotons with 4 He may provide limits on the possible amount of antimatter in the early Universe, limits on the probability of formation of primordial black holes and restrictions on the GUT parameters determining the properties of domains of antimatter

Physics with ultra-low energy antiprotons

International Nuclear Information System (INIS)

Holtkamp, D.B.; Holzscheiter, M.H.; Hughes, R.J.

1989-01-01

The experimental observation that all forms of matter experience the same gravitational acceleration is embodied in the weak equivalence principle of gravitational physics. However no experiment has tested this principle for particles of antimatter such as the antiproton or the antihydrogen atom. Clearly the question of whether antimatter is in compliance with weak equivalence is a fundamental experimental issue, which can best be addressed at an ultra-low energy antiproton facility. This paper addresses the issue. 20 refs

Matter-antimeter annihilation and the cosmic gamma-ray bursts

International Nuclear Information System (INIS)

Vincent, J.R.

1976-12-01

A review of the argument for matter-antimatter symmetry in the universe is given. It is found that based on known physical laws and processes the universe should be symmetric. In particular there in no known process to create the major elementary particles that does not involve the creation of an equal number of antiparticles. The cosmology of such a universe is discussed without reference to assumed initial conditions of the postulation of new physical laws. In a review of arguments against the existence of large quantities of antimatter it is shown that there is no observational evidence that preclude matters symmetrry, in fact we are unable to say whether or not the nearest star is matter or antimatter. The second section deals with the observation of cosmic gamma-ray bursts, and provides a brief history, implications on the nature of these events, and a summary of some of the proposed theories. Finally, it is suggested that these events are the result of matter-antimatter collisions and the case of an anticomment falling in to a Koinostar is discussed. It is shown that the mass/energy, collisional frequency and spatial distribution is in agreement with current observational data. Further calculations are in progress in which it is felt that the time scale and spectrum of such a collision may also fit the observations.(author)

Fundamental Physics with Antihydrogen

Science.gov (United States)

Hangst, J. S.

Antihydrogen—the antimatter equivalent of the hydrogen atom—is of fundamental interest as a test bed for universal symmetries—such as CPT and the Weak Equivalence Principle for gravitation. Invariance under CPT requires that hydrogen and antihydrogen have the same spectrum. Antimatter is of course intriguing because of the observed baryon asymmetry in the universe—currently unexplained by the Standard Model. At the CERN Antiproton Decelerator (AD) [1], several groups have been working diligently since 1999 to produce, trap, and study the structure and behaviour of the antihydrogen atom. One of the main thrusts of the AD experimental program is to apply precision techniques from atomic physics to the study of antimatter. Such experiments complement the high-energy searches for physics beyond the Standard Model. Antihydrogen is the only atom of antimatter to be produced in the laboratory. This is not so unfortunate, as its matter equivalent, hydrogen, is one of the most well-understood and accurately measured systems in all of physics. It is thus very compelling to undertake experimental examinations of the structure of antihydrogen. As experimental spectroscopy of antihydrogen has yet to begin in earnest, I will give here a brief introduction to some of the ion and atom trap developments necessary for synthesizing and trapping antihydrogen, so that it can be studied.

Antimatter could fight cancer

CERN Multimedia

2006-01-01

A pioneering experiment at CERN with potential future applications in cancer therapy has produced its first results. Researchers found that antiprotons are four times more effective than protons for cell irradiation.

ANTIMATTER - THE ULTIMATE MIRROR

CERN Multimedia

Gordon FRASER - ETT

2000-01-01

This new 200-page popular science book by CERN Courier Editor Gordon Fraser, published by Cambridge University Press, focuses on the 1995 synthesis of antihydrogen atoms at CERN and the implications of this physics. It is now available from the Reception Shop, Building 33, price SFr 30,and from the User Support Bookshop in Bldg 513 1-022, http://consult.cern.ch/service/bookshop/, for purchase via tid, edh or cash.

Radiatively-induced gravitational leptogenesis

Energy Technology Data Exchange (ETDEWEB)

McDonald, J.I., E-mail: pymcdonald@swansea.ac.uk; Shore, G.M., E-mail: g.m.shore@swansea.ac.uk

2015-12-17

We demonstrate how loop effects in gravitational backgrounds lead to a difference in the propagation of matter and antimatter, and show this is forbidden in flat space due to CPT and translation invariance. This mechanism, which is naturally present in beyond the standard model (BSM) theories exhibiting C and CP violation, generates a curvature-dependent chemical potential for leptons in the low-energy effective Lagrangian, allowing a matter–antimatter asymmetry to be generated in thermodynamic equilibrium, below the BSM scale.

Radiatively-induced gravitational leptogenesis

Directory of Open Access Journals (Sweden)

J.I. McDonald

2015-12-01

Full Text Available We demonstrate how loop effects in gravitational backgrounds lead to a difference in the propagation of matter and antimatter, and show this is forbidden in flat space due to CPT and translation invariance. This mechanism, which is naturally present in beyond the standard model (BSM theories exhibiting C and CP violation, generates a curvature-dependent chemical potential for leptons in the low-energy effective Lagrangian, allowing a matter–antimatter asymmetry to be generated in thermodynamic equilibrium, below the BSM scale.

Getting to grips with antihydrogen

CERN Multimedia

Katarina Anthony

2012-01-01

In June 2011, the ALPHA Collaboration announced that they had successfully managed to trap and hold atoms of antimatter for 1000 seconds. Last week they announced that their success in changing the internal state of antihydrogen and made the first ever measurement of its spectrum. The Collaboration is now installing an all-new experimental set-up – ALPHA-2 – and shows no signs of slowing down its investigations into the anti-world.   The ALPHA experiment hall. Newspapers and magazines around the world described the recent ALPHA announcement as the first step towards explaining why antimatter and matter did not cancel each other out in the first instances of creation, that is, why our universe of matter exists. Understanding the behaviour of matter and antimatter can help scientists solve this conundrum. With this in mind, the ALPHA collaboration has begun the study of the antihydrogen spectrum. So far, the Collaboration has been focused on proving that they can alter the ...

LHCb is trying to crack the Standard Model

CERN Multimedia

2011-01-01

LHCb will reveal new results tomorrow that will shed more light on the possible CP-violation measurement reported recently by the Tevatron experiments, different from Standard Model predictions. Quantum Diaries blogger for CERN, Pauline Gagnon, explains how.   LHCb, one of the Large Hadron Collider (LHC) experiments, was designed specifically to study charge-parity or CP violation. In simple words, its goal is to explain why more matter than antimatter was produced when the Universe slowly cooled down after the Big Bang, leading to a world predominantly composed of matter. This is quite puzzling since in laboratory experiments we do not measure a preference for the creation of matter over antimatter. Hence the CP-conservation law in physics that states that Nature should not have a preference for matter over antimatter. So why did the Universe evolve this way? One of the best ways to study this phenomenon is with b quarks. Since they are heavy, they can decay (i.e break down into smaller parts) ...

Observation of the 1S–2S transition in trapped antihydrogen

CERN Document Server

Ahmadi, M.; Baker, C.J.; Bertsche, W.; Butler, E.; Capra, A.; Carruth, C.; Cesar, C.L.; Charlton, M.; Cohen, S.; Collister, R.; Eriksson, S.; Evans, A.; Evetts, N.; Fajans, J.; Friesen, T.; Fujiwara, M.C.; Gill, D.R.; Gutierrez, A.; Hangst, J. S.; Hardy, W.N.; Hayden, M.E.; Isaac, C.A.; Ishida, A.; Johnson, M.A.; Jones, S.A.; Jonsell, S.; Kurchaninov, L.; Madsen, N.; Mathers, M.; Maxwell, D.; McKenna, J.T.K.; Menary, S.; Michan, J.M.; Momose, T.; Munich, J.J.; Nolan, P.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C.Ø.; Robicheaux, F.; Sacramento, R.L.; Sameed, M.; Sarid, E.; Silveira, D.M.; Stracka, S.; Stutter, G.; So, C.; Tharp, T.D.; Thompson, J.E.; Thompson, R.I.; van der Werf, D.P.; Wurtele, J.S.

2016-01-01

The spectrum of the hydrogen atom has played a central part in fundamental physics in the past 200 years. Historical examples of its significance include the wavelength measurements of absorption lines in the solar spectrum by Fraunhofer, the identification of transition lines by Balmer, Lyman et al., the empirical description of allowed wavelengths by Rydberg, the quantum model of Bohr, the capability of quantum electrodynamics to precisely predict transition frequencies, and modern measurements of the 1S–2S transition by Hänsch1 to a precision of a few parts in 1015. Recently, we have achieved the technological advances to allow us to focus on antihydrogen—the antimatter equivalent of hydrogen2,3,4. The Standard Model predicts that there should have been equal amounts of matter and antimatter in the primordial Universe after the Big Bang, but today’s Universe is observed to consist almost entirely of ordinary matter. This motivates physicists to carefully study antimatter, to see if there is a small ...

Antiproton tagging and vertex fitting in a Timepix3 detector

CERN Document Server

Aghion, S.; The AEGIS collaboration; Antonello, M.; Belov, A.; Bonomi, G.; Brusah, R. S.; Caccia, M.; Camper, A.; Caravita, R.; Castelli, F.; Cerchiari, G.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Evans, C.; Fanì, M.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Hackstock, P.; Haider, S.; Hinterberger, A.; Holmestad, H.; Kellerbauer, A.; Khalidova, O.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lebrun, P.; Malbrunot, C.; Mariazzi, S.; Marton, J.; Matveev, V.; Müller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Pagano, D.; Penasa, L.; Petracek, V.; Prelz, F.; Prevedelli, M.; Rienaecker, B.; Robert, J.; Røhne, O. M.; Rotondi, A.; Sandaker, H.; Santoro, R.; Smestad, L.; Sorrentino, F.; Testera, G.; Tietje, I. C.; Widmann, E.; Yzombard, P.; Zimmer, C.; Zmeskal, J.; Zurlo, N.

2018-01-01

Studies of antimatter are important for understanding our universe at a fundamental level. There are still unsolved problems, such as the matter-antimatter asymmetry in the universe. The AEgIS experiment at CERN aims at measuring the gravitational fall of antihydrogen in order to determine the gravitational force on antimatter. The proposed method will make use of a position-sensitive detector to measure the annihilation point of antihydrogen. Such a detector must be able to tag the antiproton, measure its time of arrival and reconstruct its annihilation point with high precision in the vertical direction. This work explores a new method for tagging antiprotons and reconstructing their annihilation point. Antiprotons from the Antiproton Decelerator at CERN was used to obtain data on direct annihilations on the surface of a silicon pixel sensor with Timepix3 readout. These data were used to develop and verify a detector response model for annihilation of antiprotons in this detector. Using this model and the a...

The AEgIS antihydrogen gravity experiment

Energy Technology Data Exchange (ETDEWEB)

Jorgensen, Lars V., E-mail: lars.varming.jorgensen@cern.ch [CERN, Department of Physics (Switzerland); Collaboration: AEGIS Collaboration

2012-12-15

The experimental program of the AEgIS experiment at CERN's AD complex aims to perform the first measurement of the gravitational interaction of antimatter, initially to a precision of about 1%, to ascertain the veracity of Einstein's Weak Equivalence Principle for antimatter. As gravity is very much weaker than electromagnetic forces, such an experiment can only be done using neutral antimatter. The antihydrogen atoms also need to be very cold for the effects of gravity to be visible above the noise of thermal motion. This makes the experiment very challenging and has necessitated the introduction of several new techniques into the experimental field of antihydrogen studies, such as pulsed formation of antihydrogen via 3-body recombination with excited state positronium and the subsequent acceleration of the formed antihydrogen using electric gradients (Stark acceleration). The gravity measurement itself will be performed using a classical Moire deflectometer. Here we report on the present state of the experiment and the prospects for the near future.

Cooling of electrically insulated high voltage electrodes down to 30 mK Kühlung von elektrisch isolierten Hochspannungselektroden bis 30 mK

CERN Document Server

Eisel, Thomas; Bremer, J

2011-01-01

The Antimatter Experiment: Gravity, Interferometry, Spectroscopy (AEGIS) at the European Organization for Nuclear Research (CERN) is an experiment investigating the influence of earth’s gravitational force upon antimatter. To perform precise measurements the antimatter needs to be cooled to a temperature of 100 mK. This will be done in a Penning trap, formed by several electrodes, which are charged with several kV and have to be individually electrically insulated. The trap is thermally linked to a mixing chamber of a 3He-4He dilution refrigerator. Two link designs are examined, the Rod design and the Sandwich design. The Rod design electrically connects a single electrode with a heat exchanger, immersed in the helium of the mixing chamber, by a copper pin. An alumina ring and the helium electrically insulate the Rod design. The Sandwich uses an electrically insulating sapphire plate sandwiched between the electrode and the mixing chamber. Indium layers on the sapphire plate are applied to improve the ther...

An improved limit on the charge of antihydrogen from stochastic acceleration

CERN Document Server

Ahmadi, M; Bertsche, W; Butler, E; Capra, A; Carruth, C; Cesar, C L; Charlton, M; Charman, A E; Eriksson, S; Evans, L T; Evetts, N; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Ishida, A; Jones, S A; Jonsell, S; Kurchaninov, L; Madsen, N; Maxwell, D; McKenna, J T K; Menary, S; Michan, J M; Momose, T; Munich, J J; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sacramento, R L; Sameed, M; Sarid, E; Silveira, D M; So, C; Tharp, T D; Thompson, R I; van der Werf, D P; Wurtele, J S; Zhmoginov, A I

2016-01-01

Antimatter continues to intrigue physicists because of its apparent absence in the observable Universe. Current theory requires that matter and antimatter appeared in equal quantities after the Big Bang, but the Standard Model of particle physics offers no quantitative explanation for the apparent disappearance of half the Universe. It has recently become possible to study trapped atoms of antihydrogen to search for possible, as yet unobserved, differences in the physical behaviour of matter and antimatter. Here we consider the charge neutrality of the antihydrogen atom. By applying stochastic acceleration to trapped antihydrogen atoms, we determine an experimental bound on the antihydrogen charge, Qe, of |Q| < 0.71 parts per billion (one standard deviation), in which e is the elementary charge. This bound is a factor of 20 less than that determined from the best previous measurement of the antihydrogen charge. The electrical charge of atoms and molecules of normal matter is known to be no greater than...

Observation of the 1S–2S transition in trapped antihydrogen

CERN Document Server

Ahmadi, M.; Baker, C.J.; Bertsche, W.; Butler, E.; Capra, A.; Carruth, C.; Cesar, C.L.; Charlton, M.; Cohen, S.; Collister, R.; Eriksson, S.; Evans, A.; Evetts, N.; Fajans, J.; Friesen, T.; Fujiwara, M.C.; Gill, D.R.; Gutierrez, A.; Hangst, J. S.; Hardy, W.N.; Hayden, M.E.; Isaac, C.A.; Ishida, A.; Johnson, M.A.; Jones, S.A.; Jonsell, S.; Kurchaninov, L.; Madsen, N.; Mathers, M.; Maxwell, D.; McKenna, J.T.K.; Menary, S.; Michan, J.M.; Momose, T.; Munich, J.J.; Nolan, P.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C.Ø.; Robicheaux, F.; Sacramento, R.L.; Sameed, M.; Sarid, E.; Silveira, D.M.; Stracka, S.; Stutter, G.; So, C.; Tharp, T.D.; Thompson, J.E.; Thompson, R.I.; van der Werf, D.P.; Wurtele, J.S.

2017-01-01

The spectrum of the hydrogen atom has played a central part in fundamental physics in the past 200 years. Historical examples of its significance include the wavelength measurements of absorption lines in the solar spectrum by Fraunhofer, the identification of transition lines by Balmer, Lyman et al., the empirical description of allowed wavelengths by Rydberg, the quantum model of Bohr, the capability of quantum electrodynamics to precisely predict transition frequencies, and modern measurements of the 1S–2S transition by Hänsch1 to a precision of a few parts in 1015. Recently, we have achieved the technological advances to allow us to focus on antihydrogen—the antimatter equivalent of hydrogen2,3,4. The Standard Model predicts that there should have been equal amounts of matter and antimatter in the primordial Universe after the Big Bang, but today’s Universe is observed to consist almost entirely of ordinary matter. This motivates physicists to carefully study antimatter, to see if there is a small ...

Ein Moiré-Deflektometer als Gravimeter für Antiwasserstoff

CERN Document Server

Haupert, Fabienne Cathérine

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) – one of the experiments carried out at CERN – aims to examine fundamental physical properties of antimatter, in order to promote knowledge about the incompatibility of gravitation with other forces. As part of achieving this knowledge, the experiment will measure in its first phase the gravitational acceleration g of antihydrogen with a precision of 1% and hence, provide data for a deeper understanding of antimatter in general. A Moiré-deflectometer is applied as gravimeter for this measurement. Its design and construction are carried out in Heidelberg. In order to test and characterise this deflectometer to its best achieveable sensitivity, a high-flux source of metastable argon atoms as well as a Faraday cup to detect these atoms are built. An additional optical Mach-Zehnder interferometer controls the stability of the apparatus. The major components of the deflectometer, the deflection gratings, are manufactured out of six-inch sili...

50 years of positrons

International Nuclear Information System (INIS)

Anon.

1982-01-01

This year marks the 50th anniversary of one of the major landmarks of modern physics - the discovery of the positron, the antimatter counterpart of the electron. This provided the first evidence for antimatter, and it was also unprecedented for the existence of a new particle to have been predicted by theory. The positron and the concepts behind it were to radically change our picture of Nature. It led to the rapid advancement or our understanding, culminating some fifteen years later with the formulation of quantum electrodynamics as we now know it. (orig./HSI).

Electron-cooled accumulation of $4 × 10^9$ positrons for production and storage of antihydrogen atoms

CERN Document Server

Fitzakerley, DW; Hessels, E A; Skinner, T D G; Storry, C H; Weel, M; Gabrielse, G; Hamley, C D; Jones, N; Marable, K; Tardiff, E; Grzonka, D; Oelert, W; Zielinski, M

2016-01-01

Four billion positrons (e+) are accumulated in a Penning–Ioffe trap apparatus at 1.2 K and <6 × 10−17 Torr. This is the largest number of positrons ever held in a Penning trap. The e+ are cooled by collisions with trapped electrons (e−) in this first demonstration of using e− for efficient loading of e+ into a Penning trap. The combined low temperature and vacuum pressure provide an environment suitable for antihydrogen ($\\bar{{\\rm{H}}}$) production, and long antimatter storage times, sufficient for high-precision tests of antimatter gravity and of CPT.

BAKSAN: Solar neutrinos more of a problem

International Nuclear Information System (INIS)

Anon.

1992-01-01

Jets - narrow clusters of particles produced in violent collisions - provide a very effective window on the elusive interactions of the quarks and gluons hidden deep inside strongly interacting particles. ; In 1964, Val Fitch and Jim Cronin's team at Brookhaven discovered something new in neutral kaon decays. Called CP-violation, this effect is now an integral part of today's particle physics dogma, and could be related to deep questions of cosmology, particularly why the Universe, governed by equations symmetric between matter and antimatter, appears to have almost no antimatter in it

Antihydrogen Production in $ \\bar{p} $ Z - interaction

CERN Multimedia

2002-01-01

% PS210 \\\\ \\\\ The production of the antihydrogen atom $ \\bar {H}^0 \\equiv \\bar{p}e $ as the simplest atomic bound state of antimatter has been studied. Nine $ \\bar {H}^0 $ have been observed.\\\\ \\\\ The production of $ \\bar {H}^0 $ is predominantly mediated by the two-photon mechanism in the antiproton-nucleus interaction. In principle $ \\bar {H}^0 $ is well suited for investigations of fundamental CPT violation studies under different forces, however, in the present experiment we concentrated on the production of this antimatter object, since so far it never had been observed.

Discovery Mondays: The very early Universe

CERN Multimedia

2003-01-01

Copyright NASARetracing the very early Universe to understand why there is "something rather than nothing" is one of the challenges facing astrophysics today. It is also the theme of the third Discovery Monday, to be held in the Microcosm on 7 July, where you will be welcomed by a number of scientists. A professional astronomer will allow you to look through his telescope and explain how it works. A cosmologist will talk to you about the very early Universe and a CERN physicist will show you how it's possible to trap antimatter. The mirror of matter, antimatter should have existed in the same quantities as matter in the very early stages of the Universe but today it seems to have virtually disappeared. Perhaps the research being done at CERN will one day explain how an infinitesimal predominance of matter over antimatter resulted in such a richly structured Universe. Come along to the Microcosm on Monday, 7 July between 7.30 p.m. and 9.00 p.m. Entrance is free http://www.cern.ch/microcosm N.B.: The Discove...

Cosmology [2011 European School of High-Energy Physics

Energy Technology Data Exchange (ETDEWEB)

Rubakov, V A [Moscow, INR (Russian Federation)

2014-07-01

In these lectures we first concentrate on the cosmological problems which, hopefully, have to do with the new physics to be probed at the LHC: the nature and origin of dark matter and generation of matter-antimatter asymmetry. We give several examples showing the LHC cosmological potential. These are WIMPs as cold dark matter, gravitinos as warm dark matter, and electroweak baryogenesis as a mechanism for generating matter-antimatter asymmetry. In the remaining part of the lectures we discuss the cosmological perturbations as a tool for studying the epoch preceeding the conventional hot stage of the cosmological evolution.

Search for Antihelium in the Cosmic Radiation

DEFF Research Database (Denmark)

Streitmatter, R.E.; Barbier, L.M.; Christian, E.R.

1996-01-01

The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba Canada on July 16-17, 1992. Sixteen hours of data were taken. Measurements of multiple dE/dX, rigidity, and time of flight were used to search for antihelium in the cosmic radiation. A report on the r......The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba Canada on July 16-17, 1992. Sixteen hours of data were taken. Measurements of multiple dE/dX, rigidity, and time of flight were used to search for antihelium in the cosmic radiation. A report...

A testing time for antimatter

NARCIS (Netherlands)

Ubachs, Wim

2016-01-01

Spectroscopy is the most accurate branch of science. Optical transition frequencies in isolated atoms and molecules can nowadays be measured to many-digit accuracies by applying the tools developed in the atomic physics community: ultrastable lasers, locked via frequency-comb lasers to atomic

Search for cosmic-ray antimatter

International Nuclear Information System (INIS)

Smoot, G.F.; Buffington, A.; Orth, C.D.

1975-01-01

In a sample of 1.5times10 4 helium and 4.0times10 4 higher-charged nuclei, obtained with balloon-borne superconducting magnetic spectrometers, we find the ratio of antinuclei to nuclei in the cosmic rays to be less than 8times10 -5 for rigidities (momentum/charge) between 4 and 33 GV/c and less than 10 -2 between 33 and 100 GV/c, at the 95% confidence level. (auth)

Matter-antimatter interactions involving antihydrogen

Energy Technology Data Exchange (ETDEWEB)

Armour, E.A.G. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)]. E-mail: edward.armour@nottingham.ac.uk; Jonsell, S. [Department of Physics, Umeaa University, SE-90187 Umeaa (Sweden); Liu, Y. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Todd, A.C. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2006-06-15

We review theoretical results for low-energy scattering of antihydrogen and atomic hydrogen and helium. Various inelastic channels, such as rearrangement and annihilation, as well as elastic scattering, are considered. In particular we give a progress report on our He-H-bar calculations and give preliminary results for the low-energy cross section for rearrangement into positronium and antiprotonic helium. As far as we are aware, this is the first time that these cross sections have been calculated.

Search for Antimatter in Space

CERN Document Server

2002-01-01

PAMELA is a cosmic ray space experiment that will be installed on board of the Russian satellite Resurs-DK1 whose launch is scheduled at the end of 2002. The duration of the mission will be at least three years in a high latitude orbit at an altitude ranging between 350 and 600 Km. \\\\ The observational objectives of the PAMELA experiment are the measurement of the spectra of antiprotons, positrons, particles and nuclei in a wide range of energies, the search for antinuclei and the study of the cosmic ray fluxes during a portion of a solar cycle. The main scientific objectives can be schematically summarized as follows: \\\\ \\\\ a) measurement of the antiproton spectrum in the energy range 80 MeV-190 GeV;\\\\ b) measurement of the positron spectrum in the energy range 50 MeV-270 GeV;\\\\ c) search for antinuclei with a sensitivity of the order $10^{-8}$ in the $\\overline{He}/He$ ratio;\\\\ d) measurement of the nuclei spectra (from H to C) in the energy range 100 MeV/n - 200 GeV/n;\\\\ e) energy spectrum of the electroni...

Matter-antimatter: balancing the scales

CERN Multimedia

CERN Bulletin

2011-01-01

Using its innovative experimental set-up, the Japanese-European ASACUSA collaboration recently succeeded in measuring the mass of the antiprotons with an unprecedented accuracy. This has been made possible by applying extremely high-precision laser techniques.   ASACUSA physicist, Masaki Hori, adjusts the optical system of laser beams. The antiproton is not something you could weigh by putting it on a pair of scales. Besides, it is not its “weight” (i.e. the Earth’s gravitational force on it) that scientists aim to measure but rather its “mass”. In addition, the yardstick against which the antiproton mass was measured is not the familiar kilogram, but the electron’s mass. Technically speaking, this is no easy task, especially when an unprecedented precision is requested. In the ASACUSA experiment, two counter-propagating ultra-sharp laser beams simultaneously hit an antiprotonic helium atom, where an antiproton orbits around the nuc...

The GBAR antimatter gravity experiment

Energy Technology Data Exchange (ETDEWEB)

Pérez, P., E-mail: patrice.perez@cea.fr [Institut de Recherches sur les lois Fondamentales de l’Univers (France); Banerjee, D. [Institute for Particle Physics, ETH Zürich (Switzerland); Biraben, F. [UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Laboratoire Kastler Brossel, Collège de France (France); Brook-Roberge, D. [Institut de Recherches sur les lois Fondamentales de l’Univers (France); Charlton, M. [Swansea University, Department of Physics (United Kingdom); Cladé, P. [UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Laboratoire Kastler Brossel, Collège de France (France); Comini, P. [Institut de Recherches sur les lois Fondamentales de l’Univers (France); Crivelli, P. [Institute for Particle Physics, ETH Zürich (Switzerland); Dalkarov, O. [P. N. Lebedev Physical Institute (Russian Federation); Debu, P. [Institut de Recherches sur les lois Fondamentales de l’Univers (France); Douillet, A. [Université d’Evry Val d’Essonne, UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Laboratoire Kastler Brossel, Collége de France (France); Dufour, G. [UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Laboratoire Kastler Brossel, Collège de France (France); and others

2015-08-15

The GBAR project (Gravitational Behaviour of Anti hydrogen at Rest) at CERN, aims to measure the free fall acceleration of ultracold neutral anti hydrogen atoms in the terrestrial gravitational field. The experiment consists preparing anti hydrogen ions (one antiproton and two positrons) and sympathetically cooling them with Be{sup +} ions to less than 10 μK. The ultracold ions will then be photo-ionized just above threshold, and the free fall time over a known distance measured. We will describe the project, the accuracy that can be reached by standard techniques, and discuss a possible improvement to reduce the vertical velocity spread.

Antimatter propulsion, status and prospects

Science.gov (United States)

Howe, Steven D.; Hynes, Michael V.

1986-01-01

The use of advanced propulsion techniques must be considered if the currently envisioned launch date of the manned Mars mission were delayed until 2020 or later. Within the next thirty years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of antiprotons to become feasible. A propulsion system with an ISP of around 5000 s would allow the currently envisioned mission module to fly to Mars in 3 months and would require about one million pounds to be assembled in Earth orbit. Of the possible methods to achieve this, the antiproton mass-conversion reaction offers the highest potential, the greatest problems, and the most fascination. Increasing the production rates of antiprotons is a high priority task at facilities around the world. The application of antiprotons to propulsion requires the coupling of the energy released in the mass-conversion reaction to thrust-producing mechanisms. Recent proposals entail using the antiprotons to produce inertial confinement fusion or to produce negative muons which can catalyze fusion. By increasing the energy released per antiproton, the effective cost, (dollars/joule) can be reduced. These proposals and other areas of research can be investigated now. These short term results will be important in assessing the long range feasibility of an antiproton powered engine.

Observation of an Antimatter Hypernucleus

Czech Academy of Sciences Publication Activity Database

Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B.D.; Arkhipkin, D.; Averichev, G. S.; Badyal, S. K.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D.R.; Bellwied, R.; Benedosso, F.; Betancourt, M.J.; Betts, R. R.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielčík, Jaroslav; Bielčíková, Jana; Biritz, B.; Bland, L.C.; Bnzarov, I.; Bombara, M.; Bonner, B.E.; Bouchet, J.; Braidot, E.; Brandin, A.V.; Bruna, E.; Bueltmann, S.; Burton, T.P.; Bysterský, Michal; Cai, X.Z.; Caines, H.; Calderon, M.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M.C.; Chajecki, Z.; Chaloupka, Petr; Chattopadhyay, S.; Chen, H.F.; Chen, J.H.; Chen, J.Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K.E.; Christie, W.; Clarke, R.F.; Codrington, M.J.M.; Corliss, R.; Cormier, T.M.; Cosentino, M.R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Dash, S.; Daugherity, M.; De Silva, L.C.; Dedovich, T. G.; DePhillips, M.; Derevschikov, A.A.; de Souza, R.D.; Didenko, L.; Djawotho, P.; Dogra, S.M.; Dong, X.; Drachenberg, J.L.; Draper, J. E.; Dunlop, J.C.; Mazumdar, M.R.D.; Efimov, L.G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L. (ed.); Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gaillard, L.; Gangaharan, D.R.; Ganti, M.S.; Garcia-Solis, E.J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y.N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S.M.; Guimaraes, K.S.F.F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Hofman, D.J.; Hollis, R.S.; Huang, H.Z.; Humanic, T.J.; Huo, L.; Igo, G.; Lordanova, A.; Jacobs, P.; Jacobs, W.W.; Jakl, Pavel; Jena, C.; Jin, F.; Jones, C.L.; Jones, P.G.; Joseph, J.; Judd, E.G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitán, Jan; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V.Yu.; Kikola, D.P.; Kiryluk, J.; Kisiel, A.; Klein, S.R.; Knospe, A.G.; Kocoloski, A.; Koetke, D.D.; Konzer, J.; Kopytine, M.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kushpil, Vasilij; Kravtsov, P.; Kravtsov, V.I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M.A.C.; Landgraf, J.M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednický, Richard; Lee, Ch.; Lee, J.H.; Leight, W.; LeVine, M.J.; Li, C.; Li, N.; Li, Y.; Lin, G.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W.J.; Longacre, R.S.; Love, W.A.; Lu, Y.; Ludlam, T.; Ma, G.L.; Ma, Y.G.; Mahapatra, D.P.; Majka, R.; Mall, O.I.; Mangotra, L.K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H.S.; Matulenko, Yu.A.; McDonald, D.; McShane, T.S.; Meschanin, A.; Millner, R.; Minaev, N.G.; Mioduszewski, S.; Mischke, A.; Mohanty, B.; Mondal, M.M.; Morozov, D.A.; Munhoz, M. G.; Nandi, B.K.; Nattrass, C.; Nayak, T. K.; Nelson, J.M.; Netrakanti, P.K.; Ng, M.J.; Nogach, L.V.; Nurushev, S.B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B.S.; Pal, S.K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S.C.; Pile, P.; Planinic, M.; Ploskon, M.A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A.M.; Potukuchi, B.V.K.S.; Prindle, D.; Pruneau, C.; Pruthi, N.K.; Pujahari, P.R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R.L.; Redwine, R.; Reed, R.; Ridiger, A.; Ritter, H.G.; Roberts, J.B.; Rogachevskiy, O.V.; Romero, J.L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M.J.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R.P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S.S.; Shi, X.H.; Sichtermann, E.P.; Simon, F.; Singaraju, R.N.; Skoby, M.J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H.M.; Srivastava, B.; Stanislaus, T.D.S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A.A.P.; Suarez, M.C.; Subba, N.L.; Šumbera, Michal; Sun, X.M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T.J.M.; de Toledo, A. S.; Takahashi, J.; Tang, A.H.; Tang, Z.; Tarini, L.H.; Tarnowsky, T.; Thein, D.; Thomas, J.H.; Tian, J.; Timmins, A.R.; Timoshenko, S.; Tlustý, David; Tokarev, M. V.; Trainor, T.A.; Tram, V.N.; Trattner, A.L.; Trentalange, S.; Tribble, R. E.; Tsai, O.D.; Ulery, J.; Ullrich, T.; Underwood, D.G.; Van Buren, G.; van Leeuwen, M.; van Nieuwenhuizen, G.; Vanfossen, J.A.; Varma, R.; Vasconcelos, G.M.S.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S.E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S.A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J.S.; Wang, Q.; Wang, X.; Wang, X.L.; Wang, Y.; Webb, G.; Westfall, G.D.; Whitten, C.; Wieman, H.; Wissink, S.W.; Witt, R.; Wu, Y.; Xie, W.; Xu, N.; Xu, Q.H.; Xu, Y.; Xu, Z.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, K.-Y.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, S.; Zhang, W.M.; Zhang, X.P.; Zhang, Y.; Zhang, Z.P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zhu, X.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zuo, J.X.

2010-01-01

Roč. 328, č. 5974 (2010), s. 58-62 ISSN 0036-8075 R&D Projects: GA ČR GA202/07/0079; GA MŠk LA09013 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z10100502 Keywords : QUARK-GLUON-PLASMA * LIGHT HYPERNUCLEI * STRANGENESS Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 31.364, year: 2010

Observation of an antimatter hypernucleus

NARCIS (Netherlands)

Abelev, B.I.; Braidot, E; Mischke, A.; Peitzmann, T.; van Leeuwen, M.

2010-01-01

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—comprising an antiproton, an antineutron, and an

Antimatter interferometry for gravity measurements.

Science.gov (United States)

Hamilton, Paul; Zhmoginov, Andrey; Robicheaux, Francis; Fajans, Joel; Wurtele, Jonathan S; Müller, Holger

2014-03-28

We describe a light-pulse atom interferometer that is suitable for any species of atom and even for electrons and protons as well as their antiparticles, in particular, for testing the Einstein equivalence principle with antihydrogen. The design obviates the need for resonant lasers through far-off resonant Bragg beam splitters and makes efficient use of scarce atoms by magnetic confinement and atom recycling. We expect to reach an initial accuracy of better than 1% for the acceleration of the free fall of antihydrogen, which can be improved to the part-per million level.

The GBAR antimatter gravity experiment

Energy Technology Data Exchange (ETDEWEB)

Perez, Patrice [IRFU, CEA Saclay (France)

2015-07-01

The GBAR project (Gravitational Behaviour of Antihydrogen at Rest) at CERN, will measure the free fall acceleration of ultracold neutral antihydrogen atoms in the terrestrial gravitational field. The experiment consists in preparing antihydrogen ions (one antiproton and two positrons) and sympathetically cool them with Be{sup +} ions to a few 10 microK. The ultracold ions will then be photo-ionized just above threshold, and the free-fall time over a known distance measured. I describe the project, the accuracy that can be reached by standard techniques, and with possible improvements using quantum reflection of antihydrogen on surfaces.

Observation of an antimatter hypernucleus.

Science.gov (United States)

Abelev, B I; Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Anderson, B D; Arkhipkin, D; Averichev, G S; Balewski, J; Barnby, L S; Baumgart, S; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Bonner, B E; Bouchet, J; Braidot, E; Brandin, A V; Bridgeman, A; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Calderon, M; Catu, O; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, P; Clarke, R F; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; DePhillips, M; Derevschikov, A A; Derradi de Souza, R; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Dunlop, J C; Dutta Mazumdar, M R; Efimov, L G; Elhalhuli, E; Elnimr, M; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Evdokimov, O; Fachini, P; Fatemi, R; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Ganti, M S; Garcia-Solis, E J; Geromitsos, A; Geurts, F; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Gupta, A; Gupta, N; Guryn, W; Haag, B; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heinz, M; Heppelmann, S; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jena, C; Jin, F; Jones, C L; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kajimoto, K; Kang, K; Kapitan, J; Kauder, K; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Konzer, J; Kopytine, M; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kouchpil, V; Kravtsov, P; Krueger, K; Krus, M; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lee, J H; Leight, W; Levine, M J; Li, C; Li, L; Li, N; Li, W; Li, X; Li, Y; Li, Z; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mal, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Masui, H; Matis, H S; Matulenko, Yu A; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mischke, A; Mitrovski, M K; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okada, H; Okorokov, V; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Pile, P; Planinic, M; Ploskon, M A; Pluta, J; Plyku, D; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Sahoo, R; Sakai, S; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sangaline, E; Schambach, J; Scharenberg, R P; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Staszak, D; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbaek, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wingfield, E; Wissink, S W; Witt, R; Wu, Y; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, J; Zhong, C; Zhou, J; Zhou, W; Zhu, X; Zhu, Y H; Zoulkarneev, R; Zoulkarneeva, Y

2010-04-02

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--comprising an antiproton, an antineutron, and an antilambda hyperon--produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons ((Lambda)(3)-H) and 157 +/- 30 hypertritons (Lambda3H). The measured yields of Lambda3H ((Lambda)(3)-H) and 3He (3He) 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 of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

Antiprotons are another matter

International Nuclear Information System (INIS)

Hynes, M.V.

1987-01-01

Theories of gravity abound, whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer these properties from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster, and that normal matter will fall with a small Baryon-number dependance in the earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to ∼4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H - ions which simulates the electromagnetic behavior of the antiproton, yet is a baryon to ∼0.1%. To extract the gravitational acceleration of the antiproton relative to the H - ion with a statistical precision of 1% will require the release of ∼10 6 to 10 7 particles

Antiprotons are another matter

International Nuclear Information System (INIS)

Hynes, M.V.

1988-01-01

Theories of gravity abound whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer this property from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster and that normal matter will fall with a small Baryon-number dependence in the Earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to ≅ 4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H - ions which simulate the electromagnetic behavior of the antiproton yet are baryons to ≅ 0.1%. To extract the gravitational acceleration of the antiproton relative to the H - ion with a statistical precision of 1% will require the release of ≅ 10 6 -10 7 particles. (orig.)

Angels and Demons: The Science Behind the Scenes

Energy Technology Data Exchange (ETDEWEB)

Graf, Norman

2009-05-12

Does antimatter really exist? How and why do scientists produce and use it? Does CERN exist and is there an underground complex deep beneath the Swiss/French border? Is truth stranger than fiction? Find out at the coming public lecture. On Tuesday, May 12, SLAC physicist Norman Graf will discuss the real science behind Angels & Demons, Dan Brown's blockbuster novel and the basis of an upcoming Tom Hanks movie. Graf's' talk is one in a series of public lectures across the U.S., Canada and Puerto Rico to share the science of antimatter and the Large Hadron Collider, and the excitement of particle physics research.

Angels and Demons: The Science Behind the Scenes

International Nuclear Information System (INIS)

Graf, Norman

2009-01-01

Does antimatter really exist? How and why do scientists produce and use it? Does CERN exist and is there an underground complex deep beneath the Swiss/French border? Is truth stranger than fiction? Find out at the coming public lecture. On Tuesday, May 12, SLAC physicist Norman Graf will discuss the real science behind Angels and Demons, Dan Brown's blockbuster novel and the basis of an upcoming Tom Hanks movie. Graf's' talk is one in a series of public lectures across the U.S., Canada and Puerto Rico to share the science of antimatter and the Large Hadron Collider, and the excitement of particle physics research.

Gravitational leptogenesis, C, CP and strong equivalence

International Nuclear Information System (INIS)

McDonald, Jamie I.; Shore, Graham M.

2015-01-01

The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

High precision Standard Model Physics

International Nuclear Information System (INIS)

Magnin, J.

2009-01-01

The main goal of the LHCb experiment, one of the four large experiments of the Large Hadron Collider, is to try to give answers to the question of why Nature prefers matter over antimatter? This will be done by studying the decay of b quarks and their antimatter partners, b-bar, which will be produced by billions in 14 TeV p-p collisions by the LHC. In addition, as 'beauty' particles mainly decay in charm particles, an interesting program of charm physics will be carried on, allowing to measure quantities as for instance the D 0 -D-bar 0 mixing, with incredible precision.

A successful start to preparations for the BaBar experiment

CERN Document Server

Green, M

1997-01-01

In June this year, the first part of new collider called PEP-II was commissioned. It will be used in an experiment to observe a rare effect in particle physics that could explain why there appears to be only matter and not antimatter in the Universe. The effect is called CPviolation, and the experiment will measure for the first time subtle differences in the way fundamental particles called Bmesons and their antiparticles decay. According to theory, particles and their antimatter partners should behave like exact mirror images of each other. However, the Bmesons and their antiparticles are predicted to break this mirror symmetry by a tiny amount.

Gravitational leptogenesis, C, CP and strong equivalence

Energy Technology Data Exchange (ETDEWEB)

McDonald, Jamie I.; Shore, Graham M. [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

2015-02-12

The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

Observation of the hyperfine spectrum of antihydrogen

Science.gov (United States)

Ahmadi, M.; Alves, B. X. R.; Baker, C. J.; Bertsche, W.; Butler, E.; Capra, A.; Carruth, C.; Cesar, C. L.; Charlton, M.; Cohen, S.; Collister, R.; Eriksson, S.; Evans, A.; Evetts, N.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Gutierrez, A.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Isaac, C. A.; Ishida, A.; Johnson, M. A.; Jones, S. A.; Jonsell, S.; Kurchaninov, L.; Madsen, N.; Mathers, M.; Maxwell, D.; McKenna, J. T. K.; Menary, S.; Michan, J. M.; Momose, T.; Munich, J. J.; Nolan, P.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C. Ø.; Robicheaux, F.; Sacramento, R. L.; Sameed, M.; Sarid, E.; Silveira, D. M.; Stracka, S.; Stutter, G.; So, C.; Tharp, T. D.; Thompson, J. E.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.

2017-08-01

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 1013 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger’s relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen—the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 104. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Observation of the hyperfine spectrum of antihydrogen.

Science.gov (United States)

Ahmadi, M; Alves, B X R; Baker, C J; Bertsche, W; Butler, E; Capra, A; Carruth, C; Cesar, C L; Charlton, M; Cohen, S; Collister, R; Eriksson, S; Evans, A; Evetts, N; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Ishida, A; Johnson, M A; Jones, S A; Jonsell, S; Kurchaninov, L; Madsen, N; Mathers, M; Maxwell, D; McKenna, J T K; Menary, S; Michan, J M; Momose, T; Munich, J J; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sacramento, R L; Sameed, M; Sarid, E; Silveira, D M; Stracka, S; Stutter, G; So, C; Tharp, T D; Thompson, J E; Thompson, R I; van der Werf, D P; Wurtele, J S

2017-08-02

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 10 13 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 10 4 . This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Theoretical motivation for gravitation experiments on ultra-low energy antiprotons and antihydrogen

International Nuclear Information System (INIS)

Nieto, M.M.

1995-01-01

It is known that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when one tries to combine these theories, one must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wonder about not understood phenomena, such as the dark matter problem. This all has led some open-quotes intrepidclose quotes theorists to consider a new gravitational regime, that of antimatter. Even more open-quotes daringclose quotes experimentalists are attempting, or considering attempting, the measurement of the gravitational force on antimatter, including low-energy antiprotons and, perhaps most enticing, antihydrogen

Experimental limit on the ratio of the gravitational mass to the inertial mass of antihydrogen

Science.gov (United States)

Fajans, Joel; Wurtele, Jonathan; Charman, Andrew; Zhmoginov, Andrey

2012-10-01

Physicists have long wondered if the gravitational interactions between matter and antimatter might be different from those between matter and itself. While there are many indirect indications that no such differences exist, i.e., that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. By searching for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap, we have determined that we can reject ratios of the gravitational mass to the inertial mass of antihydrogen greater than about 100 at a statistical significance level of 5%. A similar search places somewhat lower limits on a negative gravitational mass, i.e., on antigravity.

The Dirac-Milne cosmology

Science.gov (United States)

Benoit-Lévy, Aurélien; Chardin, Gabriel

2014-05-01

We study an unconventional cosmology, in which we investigate the consequences that antigravity would pose to cosmology. We present the main characteristics of the Dirac-Milne Universe, a cosmological model where antimatter has a negative active gravitational mass. In this non-standard Universe, separate domains of matter and antimatter coexist at our epoch without annihilation, separated by a gravitationally induced depletion zone. We show that this cosmology does not require a priori the Dark Matter and Dark Energy components of the standard model of cosmology. Additionally, inflation becomes an unnecessary ingredient. Investigating this model, we show that the classical cosmological tests such as primordial nucleosynthesis, Type Ia supernovæ and Cosmic Microwave Background are surprisingly concordant.

Unmatter Entities inside Nuclei, Predicted by the Brightsen Nucleon Cluster Model

Directory of Open Access Journals (Sweden)

Smarandache F.

2006-01-01

Full Text Available Applying the R. A. Brightsen Nucleon Cluster Model of the atomic nucleus we discuss how unmatter entities (the conjugations of matter and antimatter may be formed as clusters inside a nucleus. The model supports a hypothesis that antimatter nucleon clusters are present as a parton (sensu Feynman superposition within the spatial confinement of the proton (1H1, the neutron, and the deuteron (1H2. If model predictions can be confirmed both mathematically and experimentally, a new physics is suggested. A proposed experiment is connected to othopositronium annihilation anomalies, which, being related to one of known unmatter entity, orthopositronium (built on electron and positron, opens a way to expand the Standard Model.

A Moire-deflectometer as gravimeter for antihydrogen

Energy Technology Data Exchange (ETDEWEB)

Haupert, Fabienne Catherine

2012-02-02

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) - one of the experiments carried out at CERN - aims to examine fundamental physical properties of antimatter, in order to promote knowledge about the incompatibility of gravitation with other forces. As part of achieving this knowledge, the experiment will measure in its first phase the gravitational acceleration g of antihydrogen with a precision of 1% and hence, provide data for a deeper understanding of antimatter in general. A Moire-deflectometer is applied as gravimeter for this measurement. Its design and construction are carried out in Heidelberg. In order to test and characterise this deflectometer to its best achieveable sensitivity, a high-flux source of metastable argon atoms as well as a Faraday cup to detect these atoms are built. An additional optical Mach-Zehnder interferometer controls the stability of the apparatus. The major components of the deflectometer, the deflection gratings, are manufactured out of six-inch silicon wafers. Their prototypes together with the entire apparatus are designed and built with due care to account for the experimental conditions given by the apparatus at CERN. A first gravitational measurement with the test setup at Heidelberg yields g=(9.5{+-}1.9)(m)/(s{sup 2}) and opens up a huge number of potential improvements.

Motivations for antigravity in General Relativity

International Nuclear Information System (INIS)

Chardin, G.

1997-01-01

We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as 'supermirrors' reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP' violation observed in the neutral kaon system

Imaging antimatter with a Micromegas detector

Science.gov (United States)

Mäckel, V.; Radics, B.; Dupre, P.; Higaki, H.; Kanai, Y.; Kuroda, N.; Matsuda, Y.; Nagata, Y.; Tajima, M.; Widmann, E.; Yamazaki, Y.

2018-05-01

The ASACUSA collaboration aims at measuring the ground state hyperfine splitting of antihydrogen for probing fundamental symmetries. A cryogenic trap for mixing antiprotons and positrons serves as an antihydrogen source for in-flight spectroscopy. In order to be able to monitor the antihydrogen formation process, a dedicated Micromegas tracking detector has been designed and built to record the annihilation distribution in the trap. In this paper, we present the first results from antiproton annihilation data recorded with the Micromegas, together with a description of the event reconstruction algorithm.

Atomic processes in matter-antimatter interactions

International Nuclear Information System (INIS)

Morgan, D.L.

1988-01-01

Atomic processes dominate antiproton stopping in matter at nearly all energies of interest. They significantly influence or determine the antiproton annihilation rate at all energies around or below several MeV. This article reviews what is known about these atomic processes. For stopping above about 10 eV the processes are antiproton-electron collisions, effective at medium keV through high MeV energies, and elastic collisions with atoms and adiabatic ionization of atoms, effective from medium eV through low keB energies. For annihilation above about 10 eV is the enhancement of the antiproton annihilation rate due to the antiproton-nucleus coulomb attraction, effective around and below a few tens of MeV. At about 10 eV and below, the atomic rearrangement/annihilation process determines both the stopping and annihilation rates. Although a fair amount of theoretical and some experimental work relevant to these processes exist, there are a number of energy ranges and material types for which experimental data does not exist and for which the theoretical information is not as well grounded or as accurate as desired. Additional experimental and theoretical work is required for accurate prediction of antiproton stopping and annihilation for energies and material relevant to antiproton experimentation and application

Focusing an antimatter beam with matter

CERN Document Server

CERN. Geneva

2000-01-01

An experiment at the Stanford Linear Accelerator Center has recently focused positron beams by means of a plasma lens. This is the first time this process has been observed. The process started with a positron beam from the SLAC PEP-II positron source. This was sent through a damping ring and then accelerated to 28.5 GeV in the SLAC linac with a bunch intensity of 1-2*10/sup 10/. The beam was delivered to the Final Focus Test Beam Facility (FFTB) at a rate of 1 or 10 Hz. At the focal point of the FFTB transport, a special plasma chamber contains a 3 mm diameter pulsed gas nozzle through which either hydrogen or nitrogen gas is "puffed" into the ultrahigh vacuum system at plenum gas pressures up to 75 atm with a discharge time of 800 mu s. The gas is pumped off by a Roots-type pump. On either side of the central chamber are differential pumping sections semi- isolated from each other by thin titanium windows with small (2-5 mm diameter) apertures for the positron beams to pass through. These sections are evacu...

Particle physics: Matter and antimatter scrutinized

NARCIS (Netherlands)

Jungmann, Klaus Peter

2015-01-01

A search for differences in the charge-to-mass ratio of protons and antiprotons, conducted at unprecedented levels of precision, results in stringent limits to the validity of fundamental physical symmetries.

Particle detector goes on line soon in Japan

CERN Multimedia

1998-01-01

Belle, a detector intended to explain the imbalance between matter and antimatter in the universe is scheduled to be moved to the collision point of KEK's new electron-positron collider in February 1999.

Fulltext PDF

Indian Academy of Sciences (India)

Particle physics has taught us that matter and antimatter behave essentially .... extremely accurate at electroweak temperatures, baryogenesis cannot occur at such low scales ..... Here I will provide just one concrete example. Pramana - J.

Do positrons and antiprotons respect the weak equivalence principle?

International Nuclear Information System (INIS)

Hughes, R.J.

1990-01-01

We resolve the difficulties which Morrison identified with energy conservation and the gravitational red-shift when particles of antimatter, such as the positron and antiproton, do not respect the weak equivalence principle. 13 refs

Some insight into gravitational red-shift: is antigravity really to be ruled out

Energy Technology Data Exchange (ETDEWEB)

Molteni, D. (Palermo Univ. (Italy). Ist. di Fisica); Ziino, G. (Dipartimento di Fisica dell' Universita della Calabria, Arcavacata, Cosenza (Italy))

1978-11-25

It is pointed out that, strictly speaking, there is no energy exchange between photon and gravitational field. From this, recalling virtual electron-positron production, the reliability of an antigravitational behaviour of antimatter is inferred.

Thousands of cold anti-atoms produced at CERN

CERN Multimedia

2002-01-01

The antimatter factory delivers its first major results. ATHENA has just produced thousands of anti-atoms. This is the result of techniques developed by ATRAP and ATHENA, the two collaborations aiming to study antihydrogen.

Leptogenesis, Dark Energy, Dark Matter and the neutrinos

International Nuclear Information System (INIS)

Sarkar, Utpal

2007-01-01

In this review we discuss how the models of neutrino masses can accommodate solutions to the problem of matter-antimatter asymmetry in the universe, dark energy or cosmological constant problem and dark matter candidates. The matter-antimatter asymmetry is explained by leptogenesis, originating from the lepton number violation associated with the neutrino masses. The dark energy problem is correlated with a mass varying neutrinos, which could originate from a pseudo-Nambu-Goldstone boson. In some radiative models of neutrino masses, there exists a Higgs doublet that does not acquire any vacuum expectation value. This field could be inert and the lightest inert particle could then be a dark matter candidate. We reviewed these scenarios in connection with models of neutrino masses with right-handed neutrinos and with triplet Higgs scalars

Motivations for anti-gravity in general relativity

International Nuclear Information System (INIS)

Chardin, G.

1996-05-01

Arguments are presented showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, a property of perfect stigmatism through Kerr wormholes which allows general relativity to mimic anti-gravity is conjectured. Kerr wormholes would then act as 'super-mirrors' reversing the C, P and T images of an object seen through it. This interpretation is subjected to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP'-violation observed in the neutral kaon system. (K.A.)

Jagiellonian University Advances in Ps Manipulations and Laser Studies in the AEgIS Experiment

CERN Document Server

Caravita, R; Amsler, C; Bonomi, G; Brusa, R S; Caccia, M; Castelli, F; Cerchiari, G; Comparat, D; Consolati, G; Demetrio, A; Di Noto, L; Doser, M; Evans, C; Ferragut, R; Fesel, J; Fontana, A; Gerber, S; Giammarchi, M; Gligorova, A; Guatieri, F; Haider, S; Hinterberger, A; Holmestad, H; Kellerbauer, A; Khalidova, O; Krasnický, D; Lagomarsino, V; Lansonneur, P; Lebrun, P; Malbrunot, C; Mariazzi, S; Marton, J; Matveev, V; Mazzotta, Z; Müller, S R; Nebbia, G; Nedelec, P; Oberthaler, M; Pacifico, N; Pagano, D; Penasa, L; Petracek, V; Prelz, F; Prevedelli, M; Ravelli, L; Rienäcker, B; Robert, J; Røhne, O M; Rotondi, A; Sandaker, H; Santoro, R; Smestad, L; Sorrentino, F; Testera, G; Tietje, I; Widmann, E; Yzombard, P; Zimmer, C; Zmeskal, J; Zurlo, N

2017-01-01

Positronium (Ps), the unstable bound state of electron and positron, is a valuable system for neutral antimatter spectroscopic studies and for antihydrogen production. Forming a pulsed beam cold antihydrogen using charge-exchange with the Rydberg Ps is the goal of the AEgIS Collaboration, which aims to measure gravity on neutral antimatter. Recent results achieved in producing, manipulating and studying Ps are summarized. Ps has been first produced with mesoporous silica targets in a reflection geometry. Spectroscopy of Ps n = 3 state has been conducted, yielding as a byproduct an independent estimate of the produced Ps temperature. Efficient laser excitation to the Rydberg levels was then achieved, validating the proof-of-concept of AEgIS. Subsequently, production of Ps from a new class of transmission targets was also achieved, opening the possibility for future experiments.

Motivations for antigravity in General Relativity

Energy Technology Data Exchange (ETDEWEB)

Chardin, G. [DSM/DAPNIA/SPP, CEN-Saclay (France)

1997-08-15

We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as 'supermirrors' reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP' violation observed in the neutral kaon system.

Motivations for anti-gravity in general relativity

Energy Technology Data Exchange (ETDEWEB)

Chardin, G. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

1996-05-01

Arguments are presented showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, a property of perfect stigmatism through Kerr wormholes which allows general relativity to mimic anti-gravity is conjectured. Kerr wormholes would then act as `super-mirrors` reversing the C, P and T images of an object seen through it. This interpretation is subjected to several experimental tests and able to provide an explanation, without any free parameter, of the `CP`-violation observed in the neutral kaon system. (K.A.). 37 refs.

Des bâtisseurs d'univers créent au CERN de minuscules antimondes

CERN Multimedia

Augereau, Jean-François

2003-01-01

For a long time, users of particle accelerators have known how to produce the elementary bricks of antimatter: anti-electrons and antiprotons. But to build anti-atoms from such elements, is another thing! (2 pages)

Physicists observe subatomic quick-change artist

CERN Multimedia

Halber, Deborah

2006-01-01

Physicists have announced the observation of a subatomic particle known as the Bs (pronounced "B sub s") meson switching between matter and antimatter states at a mind-boggling 3 trillion times per second (1 page)

Some insight into gravitational red-shift: is antigravity really to be ruled out

International Nuclear Information System (INIS)

Molteni, D.

1978-01-01

It is pointed out that, strictly speaking, there is no energy exchange between photon and gravitational field. From this, recalling virtual electron-positron production, the reliability of an antigravitational behaviour of antimatter is inferred. (author)

View of the CERN Antiproton Decelerator (AD) and portrait of Prof. Tommy Eriksson, in charge of the AD machine.

CERN Multimedia

Maximilien Brice

2011-01-01

The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory in Geneva. It started operation in 2000. It decelerates antiprotons before sending them to several experiments studying antimatter : ALPHA, ASACUSA, ATRAP and ACE.

Black Holes Physicists could soon be creating black holes in the Laboratory

CERN Multimedia

Carr, Bernard

2005-01-01

Ever sinc physicists invented particle accelerators, nearly 80 years ago, they have used them for such exotic tasks as splitting atoms, transmuting elements, producing antimatter and creating particles not previoulsy observed in nature (7 pages)

Physicists produce first antiatom

CERN Multimedia

Watson, A

1996-01-01

Researchers at the European Center for Particle Physics (CERN) created 11 atoms of antihydrogen using the Low-Energy Antiproton Ring. Physicists forecast that the creation of the first antiatoms will aid in the understanding of antimatter.

Paul Dirac

Science.gov (United States)

Pais, Abraham; Jacob, Maurice; Olive, David I.; Atiyah, Michael F.

2005-09-01

Preface Peter Goddard; Dirac memorial address Stephen Hawking; 1. Paul Dirac: aspects of his life and work Abraham Pais; 2. Antimatter Maurice Jacob; 3. The monopole David Olive; 4. The Dirac equation and geometry Michael F. Atiyah.

Il protonio nasce dall'antimateria Assomiglia sia ad un atomo di idrogeno che a uno di anti-idrogeno

CERN Multimedia

2006-01-01

For the fist time in the history, a chemical reaction has been realized between matter and antimatter; from this reaction is born the "new born" protonio, made of one ion of hydrogen and one of anti-hydrogen

Through the looking glass

CERN Multimedia

Hellemans, A

2000-01-01

Over the next few months two international collaborations, ATHENA and ATRAP will use the AD to try to combine positrons and antiprotons to produce antimatter. A third team, ASACUSA, is aiming to create 'antiprotonic' atoms (4 pages).

"Dark energy" in the Local Void

Science.gov (United States)

Villata, M.

2012-05-01

The unexpected discovery of the accelerated cosmic expansion in 1998 has filled the Universe with the embarrassing presence of an unidentified "dark energy", or cosmological constant, devoid of any physical meaning. While this standard cosmology seems to work well at the global level, improved knowledge of the kinematics and other properties of our extragalactic neighborhood indicates the need for a better theory. We investigate whether the recently suggested repulsive-gravity scenario can account for some of the features that are unexplained by the standard model. Through simple dynamical considerations, we find that the Local Void could host an amount of antimatter (˜5×1015 M ⊙) roughly equivalent to the mass of a typical supercluster, thus restoring the matter-antimatter symmetry. The antigravity field produced by this "dark repulsor" can explain the anomalous motion of the Local Sheet away from the Local Void, as well as several other properties of nearby galaxies that seem to require void evacuation and structure formation much faster than expected from the standard model. At the global cosmological level, gravitational repulsion from antimatter hidden in voids can provide more than enough potential energy to drive both the cosmic expansion and its acceleration, with no need for an initial "explosion" and dark energy. Moreover, the discrete distribution of these dark repulsors, in contrast to the uniformly permeating dark energy, can also explain dark flows and other recently observed excessive inhomogeneities and anisotropies of the Universe.

Testing existence of antigravity

CERN Document Server

Hajdukovic, D

2006-01-01

After a brief review of arguments in favor of antigravity (as gravitational repulsion between matter and antimatter) we present a simple idea for an experimental test using antiprotons. Different experimental realizations of the same basic idea are considered

They do it with lasers

CERN Multimedia

Wright, Alison

2005-01-01

The antihydrogen quest continues. C.H. Storry et al. present a laser-controlled process for creating these anti-atoms, each of which comprises an antiproton and a positron, and is hence the antimatter mirror or hydrogen (¼ page)

CERN result provides definite answer to one of nature's most subtle secrets

CERN Multimedia

CERN Press Office. Geneva

2001-01-01

At a seminar at CERN on 10 May the NA48 collaboration announced its final result on one of nature's best-kept secrets : direct Charge Parity (CP)-violation. This subtle effect explains nature's preference for matter over antimatter.

Pentalenes--from highly reactive antiaromatics to substrates for material science.

Science.gov (United States)

Hopf, Henning

2013-11-18

Antimatter: Once studied primarily for their antiaromatic properties, pentalenes are rapidly becoming important π-systems for novel electronic materials. Recent developments in this area are summarized. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CERN: LEP delivers; Looking deeper at spin; Handling low energy antiprotons

Energy Technology Data Exchange (ETDEWEB)

Anon.

1990-03-15

One year ago, with the world catalogue of Z particles - the electrically neutral carrier of the weak nuclear force - containing a few hundred examples, it sounded extravagant when proponents of CERN's new LEP electron-positron collider promised a hundred thousand Zs by Christmas 1989. The first round of experiments in the North Area of CERN's SPS proton synchrotron included a considerable investment in studies using high energy muon beams. This paid off with important contribuions to physics, particularly in the measurement of the quark/gluon content (structure functions) of nucleons. ; The LEAR low energy antiproton ring at CERN takes its antimatter beams down to very low kinetic energies - less than 10 MeV - for a unique range of physics studies. However even these modest energies are too high for a series of experiments aiming to explore the effects of gravity on antimatter.

Broken symmetries at the origin of matter, at the origin of life and at the origin of culture

International Nuclear Information System (INIS)

Klinken, J. van

1998-01-01

In earliest cosmic history the universe started with matter and not with antimatter. Shortly after the beginning the electroweak interaction - prominent in nuclear β decay - acted as a left-hander. Much later, in pre biotic evolution, optically left-handed amino acids determined the unique signature of following terrestrial organic life. Again ae- ons later, homo sapiens appears as predominantly right handed and creates cultures with many broken symmetries. Along these pathways of history it was essential that choices were made - left or right, matter or antimatter - but on several instances it seemed less relevant which choice were made. We think that biochirality occurred by global chance; perhaps by local necessity, but without causal links to the PCT theorem. In other cases - e.g. the standardization to right-handed screws - the choice will have been made by causal necessity. (author)

Measuring g with a beam of antihydrogen (AEgIS)

CERN Document Server

Canali, C

2011-01-01

The gravitational interaction between matter and antimatter has never been tested experimentally. According to some attempts to unify gravity with the other forces, the possibility that $g(p) 6= g\\bar{(p)}$ cannot be excluded 1 . The AEGIS experiment 2 intends to measure for the first time the gravitational acceleration of antimatter using cold antihydrogen atoms. Antihydrogen atoms will be obtained trough a charge exchange process between Rydberg positronium atoms and antiprotons. Once $\\bar{H}$ are accelerated to form a horizontal beam, they travel through a Moire deflectometer, able to measure the vertical displacement of atoms due to gravity. Knowing the velocity of the antiatoms from the time of flight measurement and the length of the flight path allows to estimate the gravity acceleration g for antihydrogen. With this setup an initial precision on the measure of g of 1% is expected.

La bomba A (antimateria) Viaggio ai confini della fisica

CERN Multimedia

Giorgetti, Giorgio

2005-01-01

In Dan Brown's last book, it threatened to destroy Vatican. The antimatter is not a literary invention, but one of the more burning topics of modern physics to such a degree that some scientists call it "antiuniverse" (5 pages)

Empirical limits to antigravity

International Nuclear Information System (INIS)

Ericson, T.E.O.; Richter, A.

1990-01-01

An upper bound of one part in 10 6 /10 7 is derived for the violation of the equivalence principle for antimatter in the form of antiprotons based on existing data for bulk matter, electrons, positrons, neutrons and protons

On a perdu la moitié du monde

CERN Multimedia

Vos, Anton

2005-01-01

Antimatter, mirror of the ordinary matter, would have been produced in the same quantity as the matter at the time of the big bang. But, scientists do not find it and wonder what became this half of the Universe

Empirical limits to antigravity

Energy Technology Data Exchange (ETDEWEB)

Ericson, T.E.O. (European Organization for Nuclear Research, Geneva (CH)); Richter, A. (Technische Hochschule Darmstadt (DE). Inst. fuer Kernphysik)

1990-02-01

An upper bound of one part in 10{sup 6}/10{sup 7} is derived for the violation of the equivalence principle for antimatter in the form of antiprotons based on existing data for bulk matter, electrons, positrons, neutrons and protons.

Heat transfer at a sapphire - Indium interface in the 30 mK - 300 mK temperature range

NARCIS (Netherlands)

Liberadzka, J.; Koettig, T.; Bremer, J.; Van Der Post, C. C.W.; Ter Brake, H. J.M.

2017-01-01

Within the framework of the AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) project a direct measurement of the Earth's gravitational acceleration on antihydrogen will be carried out. In order to obtain satisfactory precision of the measurement, the thermal movement of the

Dialogo tra arte e tecnologia in una mostra al Vittoriano

CERN Document Server

Greco, Anna Maria

2001-01-01

The connection between art and science is the subject of a unique exhibition: art has tried to understand nature and to interpret the laws of physics; matter and antimatter, relativity and quanta, protons and neutrons became tools of a new creativity (1 page)

LHCb brochure (French version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb studies a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

LHCb brochure (English version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb studies a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

LHCb brochure (Italian version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb studies a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

Has the Universe always been very regular

Energy Technology Data Exchange (ETDEWEB)

Aly, J J [Cambridge Univ. Inst. of Astronomy (UK)

1979-11-01

The previously published argument that the finiteness of the entropy per baryon in the Universe today limits the amount of initial chaos to a moderate value is shown to be inconclusive if some matter-antimatter symmetry breaking occurs in the hot primordial radiation.

Testing antigravity effects

International Nuclear Information System (INIS)

Ericson, T.E.O.; Richter, A.

1990-01-01

In this paper an upper bound of one part in 10 6 -10 7 is derived for the violation of the equivalence principle for antimatter in the form of antiprotons based on existing data for bulk matter, electrons, positrons, neutrons and protons

As the antiworld turns probing the secrets of atoms, new experiments may sharpen lasers, aid doctors and - some say - fuel starships

CERN Multimedia

Hughes, J

1999-01-01

Experiments due to begin soon at CERN will produce large amounts of antihydrogen to compare matter and antimatter so physicists can gain a better understanding of the universe. Additionally, through the experiments they will generate new analytic instruments and technological innovations (4 pages).

CERN: End of an era; Scintillating fibre tracking in action

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-01-15

After twelve years, the UA1 experiment at CERN's proton-antiproton collider is over. The idea of a big detector to provide information on all emerging particles was an integral part of Carlo Rubbia's bold 1976 proposal to harness antimatter for research.

Broken symmetries at the origin of matter, at the origin of life and at the origin of culture

NARCIS (Netherlands)

van Klinken, J.

1998-01-01

In earliest cosmic history the university started with matter and not with antimatter. Shortly after the beginning the electroweak interaction prominent in nuclear beta decay - acted as a lefthander. Much later, in prebiotic evolution, optically left-handed amino acids determined the unique

Design and Testing of 100 mK High-voltage Electrodes for AEgIS (Proc. 25th ICEC & ICMC2014 conference)

NARCIS (Netherlands)

Derking, J.H.; Liberadzka, Joanna; Koettig, T.; Bremer, J.

2015-01-01

The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment at CERN has as main goal to perform the first direct measurement of the Earth's gravitational acceleration on antihydrogen atoms within 1% precision. To reach this precision, the antihydrogen should be cooled down to

Fundamental physics in particle traps

International Nuclear Information System (INIS)

Quint, Wolfgang; Vogel, Manuel

2014-01-01

The individual topics are covered by leading experts in the respective fields of research. Provides readers with present theory and experiments in this field. A useful reference for researchers. This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

LEP : four building blocks of matter ... times three Conference MT17

CERN Multimedia

2001-01-01

The four building blocks of everyday matter form a family composed of the up-quark, the down-quark, the electron and the electron-neutrino. Similar particles, heavier but otherwise identical, are known to exist - grouped together in two further families. By measuring the number of neutrino types that exist, LEP has shown that there are no more fam-ilies of particles. Nature has chosen the number three. This is an intriguing result, and the reason why there are neither more nor fewer than three particle families is one of the greatest mysteries of modern physics. One important consequence is that we exist. Had there been any fewer than three families of matter particles, the phenomenon known as CP violation - which led to matter dominating anti-matter in the early Universe - would not have occurred. All the matter and antimatter created in the Big Bang would have annihilated.

CERN: LEP delivers; Looking deeper at spin; Handling low energy antiprotons

International Nuclear Information System (INIS)

Anon.

1990-01-01

One year ago, with the world catalogue of Z particles - the electrically neutral carrier of the weak nuclear force - containing a few hundred examples, it sounded extravagant when proponents of CERN's new LEP electron-positron collider promised a hundred thousand Zs by Christmas 1989. The first round of experiments in the North Area of CERN's SPS proton synchrotron included a considerable investment in studies using high energy muon beams. This paid off with important contribuions to physics, particularly in the measurement of the quark/gluon content (structure functions) of nucleons. ; The LEAR low energy antiproton ring at CERN takes its antimatter beams down to very low kinetic energies - less than 10 MeV - for a unique range of physics studies. However even these modest energies are too high for a series of experiments aiming to explore the effects of gravity on antimatter

Polish Acadaemy of Sciences Positronium for Antihydrogen Production in the AEGIS Experiment

CERN Document Server

Consolati, G; Amsler, C; Bonomi, G; Brusa, R S; Caccia, M; Caravita, R; Castelli, F; Cerchiari, G; Comparat, D; Demetrio, A; Di Noto, L; Doser, M; Evans, C; Fanì, M; Ferragut, R; Fesel, J; Fontana, A; Gerber, S; Giammarchi, M; Gligorova, A; Guatieri, F; Haider, S; Hinterberger, A; Holmestad, H; Kellerbauer, A; Khalidova, O; Krasnicky, D; Lagomarsino, V; Lansonneur, P; Lebrun, P; Malbrunot, C; Mariazzi, S; Marton, J; Matveev, V; Mazzotta, Z; Müller, S R; Nebbia, G; Nedelec, P; Oberthaler, M; Pacifico, N; Pagano, D; Penasa, L; Petracek, V; Prelz, F; Prevedelli, M; Ravelli, L; Rienaecker, B; Robert, J; Røhne, O M; Rotondi, A; Sandaker, H; Santoro, R; Smestad, L; Sorrentino, F; Testera, G; Tietje, I C; Widmann, E; Yzombard, P; Zimmer, C; Zmeskal, J; Zurlo, N

2017-01-01

The primary goal of the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEGIS) collaboration is to measure for the first time precisely the gravitational acceleration of antihydrogen, H¯ , a fundamental issue of contemporary physics, using a beam of antiatoms. Indeed, although indirect arguments have been raised against a different acceleration of antimatter with respect to matter, nevertheless some attempts to formulate quantum theories of gravity, or to unify gravity with the other forces, consider the possibility of a non-identical gravitational interaction between matter and antimatter. We plan to generate H¯ through a charge-exchange reaction between excited Ps and antiprotons coming from the Antiproton Decelerator facility at CERN. It offers the advantage to produce sufficiently cold antihydrogen to make feasible a measurement of gravitational acceleration with reasonable uncertainty (of the order of a few percent). Since the cross-section of the above reaction increases with n 4 , n b...

From calorimetry to medical imaging: a shining example of successful transfer!

CERN Multimedia

Caroline Duc

2012-01-01

A team at CERN has drawn inspiration from calorimetry methods developed for high-energy physics to create a new positron-emission tomography system for use in medical imaging, which they’ve dubbed AX-PET. With support from European and American laboratories*, the project is reaching fruition, as initial tests confirm its promise.   Snapshot of a “phantom”, a test object, surrounded by the AX-PET photon detectors. Positron-emission tomography (PET) is a medical imaging technique based on the matter-antimatter interaction that can provide a three-dimensional representation of the metabolic activity of an organ. To do so, radioactive marker molecules are first injected into the subject. As the marker decays, it emits positrons (antimatter particles), which are annihilated upon encountering electrons in the surrounding environment. The resulting flash, consisting of two photons, is detected by the PET machine. In conventional PET systems, it is impossible to improv...

Broken symmetries at the origin of matter, at the origin of life and at the origin of culture

Energy Technology Data Exchange (ETDEWEB)

Klinken, J. van [Kernfysisch Versneller Instituut, University of Groningen, Groningen (Netherlands)

1998-01-01

In earliest cosmic history the universe started with matter and not with antimatter. Shortly after the beginning the electroweak interaction - prominent in nuclear {beta} decay - acted as a left-hander. Much later, in pre biotic evolution, optically left-handed amino acids determined the unique signature of following terrestrial organic life. Again ae- ons later, homo sapiens appears as predominantly right handed and creates cultures with many broken symmetries. Along these pathways of history it was essential that choices were made - left or right, matter or antimatter - but on several instances it seemed less relevant which choice were made. We think that biochirality occurred by global chance; perhaps by local necessity, but without causal links to the PCT theorem. In other cases - e.g. the standardization to right-handed screws - the choice will have been made by causal necessity. (author) 14 refs, 8 figs, 1 tab

High nuclear temperatures by antimatter-matter annihilation

International Nuclear Information System (INIS)

Gibbs, W.R.; Strottman, D.

1985-01-01

It is suggested that the quark-gluon phase be created through the use of antiproton or antideuteron beams. The first advantage to this method, using higher energy antiprotons than 1.5 GeV/c, is that the higher momenta antiprotons penetrate more deeply so that mesons produced are more nearly contained within the nucleus. Another advantage is that the annihilation products are very forward-peaked and tend to form a beam of mesons so that the energy density does not disperse very rapidly. Calculations were performed using the intranuclear cascade to try to follow the process of annihilation in some detail. The intranuclear cascade type calculation method is compared to the hydrodynamic approach. 8 refs., 8 figs

NASA declares no room for antimatter experiment

CERN Multimedia

Law??, Andrew

2007-01-01

"The Alpha Magnetic Spectrometer (AMS) is a model of international cooperation, led by a dynamic Nobel Prize winner, and promises to do impressive science in space. But it may never get a chance to do its thing." (1 page)

Polarizing matter and antimatter: A new method

International Nuclear Information System (INIS)

Onel, Y.

1992-02-01

Several years ago a self-polarization effect for stored (anti)- protons and ions was investigated theoretically. The effect is based on the well-known Stern-Gerlach effect in gradient fields. The aim of the ongoing measurements at the Indiana University Cyclotron Facility (IUCF) is to verify experimentally the various assumptions on which this effect is based. The final goal is to demonstrate this new polarization effect. The proposed effect could be a powerful tool to produce polarized stored hadron beams both in the low-energy range and at SSC and LHC energies. In this progress report we will describe our progress in three parts: (A) Experimental work at IUCF Cooler Ring; (B) Our extensive computer simulations of the spin stability for the IUCF Cooler Ring; and (C) Theoretical studies

Facts about real antimatter collide with fiction

CERN Multimedia

Siegfried, Tom

2004-01-01

When science collides with fiction, sometimes a best seller emerges from the debris. Take Dan Brown's Angels & Demons, for instance, a murder mystery based on science at CERN, the European nuclear research laboratory outside Geneva

Observation of the antimatter helium-4 nucleus

Czech Academy of Sciences Publication Activity Database

Agakishiev, C.; Aggarwal, M. M.; Ahammed, Z.; Bielčík, J.; Bielčíková, Jana; Chaloupka, Petr; Chung, P.; Kapitán, Jan; Kouchpil, V.; Rusnak, J.; Šumbera, Michal; Tlustý, David

2011-01-01

Roč. 473, č. 7347 (2011), s. 353-356 ISSN 0028-0836 R&D Projects: GA MŠk LA09035 Institutional research plan: CEZ:AV0Z10480505 Keywords : QUARK-GLUON PLASMA * ANTIPROTONS * COLLISIONS * ELECTRON Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 36.280, year: 2011

En route to matter-antimatter pair plasmas

Energy Technology Data Exchange (ETDEWEB)

Stenson, Eve V.; Hergenhahn, Uwe; Paschkowski, Norbert; Saitoh, Haruhiko; Stanja, Juliane [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Schweikhard, Lutz [Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Hugenschmidt, Christoph [Technische Universitaet Muenchen, Garching (Germany); Danielson, James R.; Surko, Clifford M. [University of California, San Diego, La Jolla (United States)

2015-05-01

The APEX and PAX projects have as their overarching goal the laboratory creation and confinement of the world's first positron-electron pair plasma. Plasmas of this type have been the subject of hundreds of theoretical investigations and are also believed to play a role in various astrophysical environments. In order to achieve this goal in an experimentally accessible volume (e.g., 10 liters), a record number (≥ 10{sup 10}) of cold (∝ 1 eV) positrons are to be accumulated and combined with a corresponding population of electrons. Notable requirements include a high-intensity positron beam (such as NEPOMUC), a suitable magnetic confinement device for the pair plasma (such as a levitated dipole), high-efficiency tools for bridging the two (i.e., means by which the positrons can be efficiently cooled, trapped, and injected across flux surfaces), and diagnostics not only for the pair plasma, but also for the positron beam and for intermediary non-neutral plasmas. This talk will summarize the project as a whole and recent work by the APEX/PAX team on its various elements.

Cosmic-ray antimatter - A primary origin hypothesis

Science.gov (United States)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1983-01-01

The present investigation is concerned with the possibility that the observed cosmic-ray protons are of primary extragalactic origin, taking into account the significance of the current antiproton data. Attention is given to questions regarding primary antiprotons, antihelium fluxes, and the propagation of extragalactic cosmic rays. It is concluded that the primary origin hypothesis should be considered as a serious alternative explanation for the cosmic-ray antiproton fluxes. Such extragalactic primary origin can be considered in the context of a baryon symmetric domain cosmology. The fluxes and propagation characteristics suggested are found to be in rough agreement with the present antiproton data.

LHCb brochure (German version)

CERN Multimedia

Lefevre, C

2008-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb will study a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

LHCb brochure (German version)

CERN Multimedia

Lefevre, Christiane

2012-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb will study a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

LHCb brochure (Spanish version)

CERN Multimedia

Lefevre, C

2008-01-01

LHCb is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. LHCb will study a phenomenon which could partly explain why the Universe is all matter and practically no antimatter.

James Cronin, CP Violation, and the Pierre Auger Observatory

Science.gov (United States)

dropdown arrow Site Map A-Z Index Menu Synopsis James Cronin, CP Violation and the Pierre Auger Observatory matter over antimatter."1 "The experiment uncovered the CP [charge-parity] violation, or a with Additional Information Additional information about James Cronin and the charge-parity (CP

Confinement of antihydrogen for 1,000 seconds

DEFF Research Database (Denmark)

Bruun Andresen, Gorm; Ashkezari, M.D.; Baquero-Ruiz, M.

2011-01-01

Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter–antimatter symmetry. We have recently...

Experimental tests of fundamental symmetries

NARCIS (Netherlands)

Jungmann, K. P.

2014-01-01

Ongoing experiments and projects to test our understanding of fundamental inter- actions and symmetries in nature have progressed significantly in the past few years. At high energies the long searched for Higgs boson has been found; tests of gravity for antimatter have come closer to reality;

Looking for charming asymmetries

CERN Multimedia

Stefania Pandolfi

2016-01-01

New results presented by the LHCb collaboration on the decay of particles containing a “charm” quark delve deeper into the mystery of matter-antimatter asymmetry.   A view of the LHCb experimental cavern. (Photo: Maximilien Brice/CERN) One of the biggest challenges in physics is to understand why everything we see in our universe seems to be formed only of matter, whereas the Big Bang should have created equal amounts of matter and antimatter. CERN’s LHCb experiment is one of the best hopes for physicists looking to solve this longstanding mystery. At the VIII International Workshop on Charm Physics, which took place in Bologna earlier this month, the LHCb Collaboration presented the most precise measurement to date of a phenomenon called Charge-Parity (CP) violation among particles that contain a charm quark. CP symmetry states that laws of physics are the same if a particle is interchanged with its anti-particle (the “C” part) and if its spatia...

To Mars and beyond, fast! how plasma propulsion will revolutionize space exploration

CERN Document Server

Chang Díaz, Franklin

2017-01-01

As advanced space propulsion moves slowly from science fiction to achievable reality, the Variable Specific Impulse Magnetoplasma Rocket, or VASIMR, is a leading contender for making 'Mars in a month' a possibility. Developed by Ad Astra Rockets, which was founded by astronaut Franklin Chang-Diaz and backed by NASA, its first commercial tests are imminent. VASIMR heats plasma to extreme temperatures using radio waves. Strong magnetic fields then funnel this plasma out the back of the engine, creating thrust. The continuous propulsion may place long, fast interplanetary journeys within reach in the near future. While scientists dream of the possibilities of using fusion or well-controlled matter-antimatter interactions to propel spacecraft fast and far, that goal is still some way over the horizon. VASIMR provides a more attainable propulsion technology that is based on the matter-antimatter concept. The book describes a landmark technology grounded in plasma physics and offering a practical technological solu...

Golden Jubilee photos: LEAR

CERN Multimedia

2004-01-01

Extraction lines that carried the antiprotons from LEAR to the experiments. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously. Particle physicists don't always need ever more powerful accelerators to study interesting physics. LEAR, the Low Energy Antiproton Ring, was designed to help explore the properties of antimatter, with the annihilation of protons and antiprotons becoming the main theme. LEAR was commissioned in 1983 and contributed to more than 30 experiments with great success. LEAR took part in the discovery of a 'glueball', a particle composed entirely of gluons, the carriers of the strong nuclear force. LEAR also observed that neutral kaons and antikaons decay at a slightly different rate, offering physicists another insight into the mystery about why matter prevails over antimatter in the Universe. Uniquely, LEAR combined both the electron and stochastic beam cooling techniques, used to control and refine the beams. It also pioneered a technique usin...

ELENA’s International Collaboration is born

CERN Multimedia

Antonella Del Rosso

2012-01-01

On 13 June, ten institutes signed a Memorandum of Understanding (MoU) for the construction of the Extra Low ENergy Antiproton ring (ELENA). Allowing the further deceleration of antiprotons from the Antimatter Decelerator, ELENA will significantly increase the number of particles trapped downstream in the experimental set-ups. This will give an important boost to antimatter research in the years to come.   Electrostatic triplet lenses - a device that will transport antiprotons from ELENA to the experiments. The electrostatic device was successfully tested with the ASACUSA experiment two weeks ago. ELENA - an upgrade of the existing Antiproton Decelerator (AD) - was approved by the CERN Council last year under the condition that external user institutions would contribute to its construction. On 13 June, the foundation stone of the new international collaboration was laid with the signature of the MoU. ELENA is a small magnetic decelerator ring 30 m in circumference that will fit inside the ...

Development of a buffer gas trap for the confinement of positrons and study of positronium production in the GBAR experiment

CERN Document Server

AUTHOR|(CDS)2101248; van der Werf, Dirk

The GBAR experiment relies on the production of antihydrogen positive ions to achieve its goal of measuring the gravitational acceleration of antimatter at rest. The ANTION project, included in the GBAR enterprise, is responsible for the production of these antimatter ions. Moreover, it also aims to measure the cross section of antihydrogen production throughout the collision of antiprotons and positronium atoms, as well as the matter cross sections of hydrogen and the hydrogen negative ion. These experiments imply the formation of a very dense positronium cloud, thus a large amount of positrons will be implanted on a positron/positronium converter material. This thesis reports the construction of a three stage buffer gas trap with the goal of trapping and accumulating positrons for the ANTION project. The combination of the Penning-type trap with a LINAC source constitutes a unique experimental setup. The trap was commissioned and optimized and is now fully operational. Trapping protocols were studied and...

Sixfold improved single particle measurement of the magnetic moment of the antiproton

CERN Document Server

Nagahama, H; Sellner, S; Harrington, J; Higuchi, T; Borchert, M J; Tanaka, T; Besirli, M; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-01-01

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

arXiv Status of rates and rate equations for thermal leptogenesis

CERN Document Server

Biondini, Simone; Brambilla, Nora; Garny, Mathias; Ghiglieri, Jacopo; Hohenegger, Andreas; Laine, Mikko; Mendizabal, Sebastian; Millington, Peter; Salvio, Alberto; Vairo, Antonio

2018-02-28

In many realizations of leptogenesis, heavy right-handed neutrinos play the main role in the generation of an imbalance between matter and antimatter in the early Universe. Hence, it is relevant to address quantitatively their dynamics in a hot and dense environment by taking into account the various thermal aspects of the problem at hand. The strong washout regime offers an interesting framework to carry out calculations systematically and reduce theoretical uncertainties. Indeed, any matter-antimatter asymmetry generated when the temperature of the hot plasma $T$ exceeds the right-handed neutrino mass scale $M$ is efficiently erased, and one can focus on the temperature window $T \\ll M$. We review recent progresses in the thermal field theoretic derivation of the key ingredients for the leptogenesis mechanism: the right-handed neutrino production rate, the CP asymmetry in the heavy-neutrino decays and the washout rates. The derivation of evolution equations for the heavy-neutrino and lepton-asymmetry number...

Status of rates and rate equations for thermal leptogenesis

Science.gov (United States)

Biondini, S.; Bödeker, D.; Brambilla, N.; Garny, M.; Ghiglieri, J.; Hohenegger, A.; Laine, M.; Mendizabal, S.; Millington, P.; Salvio, A.; Vairo, A.

2018-02-01

In many realizations of leptogenesis, heavy right-handed neutrinos play the main role in the generation of an imbalance between matter and antimatter in the early Universe. Hence, it is relevant to address quantitatively their dynamics in a hot and dense environment by taking into account the various thermal aspects of the problem at hand. The strong washout regime offers an interesting framework to carry out calculations systematically and reduce theoretical uncertainties. Indeed, any matter-antimatter asymmetry generated when the temperature of the hot plasma T exceeds the right-handed neutrino mass scale M is efficiently erased, and one can focus on the temperature window T ≪ M. We review recent progress in the thermal field theoretic derivation of the key ingredients for the leptogenesis mechanism: the right-handed neutrino production rate, the CP asymmetry in the heavy-neutrino decays and the washout rates. The derivation of evolution equations for the heavy-neutrino and lepton-asymmetry number densities, their rigorous formulation and applicability are also discussed.

The ELENA project at CERN

CERN Document Server

Oelert, W

2015-01-01

CERN has a longstanding tradition of pursuing fundamental physics on extreme low and high energy scales. The present physics knowledge is successfully described by the Standard Model and the General Relativity. In the anti-matter regime many predictions of this established theory still remain experimentally unverified and one of the most fundamental open problems in physics concerns the question of asymmetry between particles: why is the observable and visible universe apparently composed almost entirely of matter and not of anti-matter? There is a huge interest in the very compelling scientiic case for anti-hydrogen and low energy anti-proton physics, here to name especially the Workshop on New Opportunities in the Physics Landscape at CERN which was convened in May 2009 by the CERN Directorate and culminated in the decision for the final approval of the construction of the Extra Low ENergy Antiproton (ELENA) ring by the Research Board in June 2011. ELENA is a CERN project aiming to construct a small 30 m ci...

Antihydrogen Formation, Dynamics and Trapping

CERN Document Server

Butler, Eoin; Charlton, Michael

2011-01-01

Antihydrogen, the simplest pure-antimatter atomic system, holds the promise of direct tests of matter-antimatter equivalence and CPT invariance, two of the outstanding unanswered questions in modern physics. Antihydrogen is now routinely produced in charged-particle traps through the combination of plasmas of antiprotons and positrons, but the atoms escape and are destroyed in a minuscule fraction of a second. The focus of this work is the production of a sample of cold antihydrogen atoms in a magnetic atom trap. This poses an extreme challenge, because the state-of-the-art atom traps are only approximately 0.5 K deep for ground-state antihydrogen atoms, much shallower than the energies of particles stored in the plasmas. This thesis will outline the main parts of the ALPHA experiment, with an overview of the important physical processes at work. Antihydrogen production techniques will be described, and an analysis of the spatial annihilation distribution to give indications of the temperature and binding ene...

ACADEMIC TRAINING

CERN Multimedia

Françoise Benz

2002-01-01

24, 25, 26 April LECTURE SERIES from 11.00 to 12.00 hrs - Auditorium, bldg. 500 Anti-Matter by R. LANDUA /CERN-EP Antiparticles are a crucial ingredient of particle physics and cosmology. More than 70 years after Dirac's bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: as a tool in accelerators; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on the experimental 'antimatter' programme at the Antiproton Decelerator (AD), with special emphysis on antihydrogen production and spectroscopy. The lecture will conclude with an outl...

A parts-per-billion measurement of the antiproton magnetic moment

CERN Document Server

Smorra, C; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-01-01

Precise comparisons of the fundamental properties of matter–antimatter conjugates provide sensitive tests of charge–parity–time (CPT) invariance1, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons2, leptons3, 4 and baryons5, 6 have compared different properties of matter–antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level7, 8: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron3. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic ...

A measurement of the gravitational acceleration of the anti-proton

CERN Document Server

Holzscheiter, M H

1990-01-01

A fundamental experiment in gravity proposed by us, is the measurement of the gravitational force on antimatter. This measurement would constitute the first direct test of the Weak Equivalence Principle (WEP) for antimatter. The availability of low-energy antiprotons at CERN has made such an experiment feasible, and a proposal to carry out such a measurement has been accepted by the CERN Program Committee. We plan to use a time-of-flight technique similar to that pioneered by Fairbank and Witteborn in their measurement of the gravitational force on an electron. Very slow particles are launched into a vertical drift tube and the time-of-flight spectrum of these particles is recorded. This spectrum will exhibit a cut-off point directly related to the gravitational acceleration of the particles. Obtaining very slow antiprotons involves several stages of deceleration. Antiprotons from LEAR will be initially decelerated from 2 MeY to tens of kilovolts by passing them through a thin foil. After capture and cooling ...

AEgIS installation completed

CERN Multimedia

Katarina Anthony

2012-01-01

Gravity. Despite first being described over three centuries ago, it remains one of the least understood of the fundamental forces explored by physicists. At CERN’s recently completed AEgIS experiment, a team has set out to examine the effect of gravity on an as-yet-uncharted realm: antimatter.   The complete AEgIS set-up. Located in the AD hall, the AEgIS experiment plans to  make the first direct measurement of Earth’s gravitation effect on antimatter. By sending a beam of antihydrogen atoms through very thin gratings, the experiment will be able to measure how far the antihydrogen atoms fall and in how much time – giving the AEgIS team a measurement of the gravitational coupling. “By the end of 2012, we had finished by putting all the elements of the experiment together,” explains Michael Doser, AEgIS Spokesperson. “Now we have to show that they can all work together and, unfortunately, we will have no antiproton beams fo...

Description and first application of a new technique to measure the gravitational mass of antihydrogen

Science.gov (United States)

Alpha Collaboration; Amole, C.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Butler, E.; Capra, A.; Cesar, C. L.; Charlton, M.; Eriksson, S.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Gutierrez, A.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Isaac, C. A.; Jonsell, S.; Kurchaninov, L.; Little, A.; Madsen, N.; McKenna, J. T. K.; Menary, S.; Napoli, S. C.; Nolan, P.; Olin, A.; Pusa, P.; Rasmussen, C. Ø.; Robicheaux, F.; Sarid, E.; Silveira, D. M.; So, C.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.; Zhmoginov, A. I.; Charman, A. E.

2013-04-01

Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen >75 at a statistical significance level of 5% worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regime.

Description and first application of a new technique to measure the gravitational mass of antihydrogen

CERN Document Server

Charman, A E; Menary, S; Capra, A; Baquero-Ruiz, M; Fajans, J; Ashkezari, M D; Bertsche, W; Butler, E; Cesar, C L; Charlton, M; Eriksson, S; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Napoli, S C; Nolan, P; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Thompson, R I; Van der Werf, D P; Wurtele, J S; Zhmoginov, A I

2013-01-01

Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen >75 at a statistical significance level of 5%; worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regim...

Resonant quantum transitions in trapped antihydrogen atoms

CERN Document Server

Amole, C; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Donnan, P H; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Shields, C R; Silveira, D M; Stracka, S; So, C; Thompson, R I; van der Werf, D P; Wurtele, J S

2012-01-01

The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom’s stature lies in its simplicity and in the accuracy with which its spectrum can be measured1 and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and—by comparison with measurements on its antimatter counterpart, antihydrogen—the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state2, 3 of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave...

Study of b-hadron decays into two hadrons and a photon at LHCb and first observation of b-baryon radiative decays

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00357276; Calvo, Miriam

The Standard Model (SM) of particle physics, a set of theories that were developed during the 20th century, aims to explain three of the four fundamental forces of nature: electromagnetism, strong and weak interactions. From a theoretical point of view, the SM was finished during the 1970s, but it was not until 2012 when its last piece, the Higgs boson, was experimentally confirmed. Despite having been proved to be a very successful theory with many experimental observations, the SM fails to explain crucial phenomena that would make it a complete theory. Its main shortcomings are the inclusion of gravity as described by general relativity, the existence and properties of dark matter and dark energy and neutrino oscillations. It also fails to explain the different abundances of matter and antimatter that are observed in the Universe. In particular, $CP$ violation is related to the last of these problems as it is a necessary condition to the asymmetrical matter-antimatter abundances to appear from a symmetrical...

Observation of the Crab Nebula with cosmic rays in the UV, or 'gamma astronomy at the moonlight'

International Nuclear Information System (INIS)

Sarazin, Xavier

1994-01-01

The aim of ARTEMIS (Antimatter Research Through the Earth Moon Ion Spectrometer) is to detect extragalactic antimatter at Very High (TeV) Energies in cosmic rays. The Earth's magnetic field is used as deflector of these ions, the moon serves as an absorber, and the atmosphere as a giant calorimeter. The cosmic rays are detected by Cerenkov imaging in the atmosphere. This Cerenkov flash must be detected in the UV because of the presence of moonlight, necessitating the construction of a novel UV camera. This is the first time Cerenkov imaging has been performed in the UV. The Crab Nebula, which has become a reference source for Very High Energy Gamma-ray Astronomy, enabled evaluation of the UV method in low moonlight. Our detection of a signal from the Crab validates, on the one hand, the Cerenkov imaging technique in the UV and, on the other hand, offers the possibility of uninterrupted nightly observations of a source, regardless of the moon's phase. (author) [fr

Lepton asymmetry rate from quantum field theory: NLO in the hierarchical limit

Energy Technology Data Exchange (ETDEWEB)

Bödeker, D.; Sangel, M., E-mail: bodeker@physik.uni-bielefeld.de, E-mail: msangel@physik.uni-bielefeld.de [Fakultät für Physik, Universität Bielefeld, 33501 Bielefeld (Germany)

2017-06-01

The rates for generating a matter-antimatter asymmetry in extensions of the Standard Model (SM) containing right-handed neutrinos are the most interesting and least trivial co\\-efficients in the rate equations for baryogenesis through thermal leptogenesis. We obtain a relation of these rates to finite-temperature real-time correlation functions, similar to the Kubo formulas for transport coefficients. Then we consider the case of hierarchical masses for the sterile neutrinos. At leading order in their Yukawa couplings we find a simple master formula which relates the rates to a single finite temperature three-point spectral function. It is valid to all orders in g , where g denotes a SM gauge or quark Yukawa coupling. We use it to compute the rate for generating a matter-antimatter asymmetry at next-to-leading order in g in the non-relativistic regime. The corrections are of order g {sup 2}, and they amount to 4% or less.

The Point Mass Concept

Directory of Open Access Journals (Sweden)

Lehnert B.

2011-04-01

Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the spec- ulation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

One Antimatter— Two Possible Thermodynamics

Directory of Open Access Journals (Sweden)

Alexander Y. Klimenko

2014-02-01

Full Text Available Conventional thermodynamics, which is formulated for our world populated by radiation and matter, can be extended to describe physical properties of antimatter in two mutually exclusive ways: CP-invariant or CPT-invariant. Here we refer to invariance of physical laws under charge (C, parity (P and time reversal (T transformations. While in quantum field theory CPT invariance is a theorem confirmed by experiments, the symmetry principles applied to macroscopic phenomena or to the whole of the Universe represent only hypotheses. Since both versions of thermodynamics are different only in their treatment of antimatter, but are the same in describing our world dominated by matter, making a clear experimentally justified choice between CP invariance and CPT invariance in context of thermodynamics is not possible at present. This work investigates the comparative properties of the CP- and CPT-invariant extensions of thermodynamics (focusing on the latter, which is less conventional than the former and examines conditions under which these extensions can be experimentally tested.

The Point Mass Concept

Directory of Open Access Journals (Sweden)

Lehnert B.

2011-04-01

Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the speculation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

Life, the universe ... and nothing?; Science still can't explain what happened to half of everything

CERN Multimedia

Davidson, K

2002-01-01

New measurements at the Stanford Linear Accelerator Centre have refined measurements of sub-atomic particles that explain why there is a dominance of matter over antimatter in the Universe. The results partially confirm an announcement made last year that describes the imbalance in these physical opposites (1 page).

The Future of Our Physics

Science.gov (United States)

Zichichi, Antonino

The following sections are included: * Physics Problems * The Whole of our Knowledge * The Future * Appendices * Appendix A: Dirac - Antiparticles & Antimatter * Appendix B: Blackett - The discovery of the "Vacuum Polarization" (1932) [the 1st example of radiative effect: pre-the Lamb-shift (1947)] * Appendix C: The New Manhattan Project * References

Muse at CERN

CERN Multimedia

CERN Bulletin

2016-01-01

On 19 July, the world-famous, English rock band, Muse, visited CERN before taking centre-stage at Nyon’s Paléo Festival. They toured some of CERN’s installations, including the Synchrocyclotron and the Microcosm exhibition, and also looked in on CMS and the Antimatter Factory.    

Symmetry breaking. Particles, antiparticles, and the small difference; Symmetriebrechung. Teilchen, Antiteilchen und der kleine Unterschied

Energy Technology Data Exchange (ETDEWEB)

Uwer, Ulrich [Heidelberg Univ. (Germany). Physikalisches Inst.; Albrecht, Johannes [Technische Univ. Dortmund (Germany). Emmy-Noether Gruppe

2018-04-01

With precise measurements on subatomic particles and their antiparticles physicists search at CERN for new physical phenomena. They hope for last but not least better for answers to the question, why we live in a world of matter, where matter and antimatter in the universe must have arisen alike.

An improved limit on the charge of antihydrogen from stochastic acceleration.

Science.gov (United States)

Ahmadi, M; Baquero-Ruiz, M; Bertsche, W; Butler, E; Capra, A; Carruth, C; Cesar, C L; Charlton, M; Charman, A E; Eriksson, S; Evans, L T; Evetts, N; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Ishida, A; Jones, S A; Jonsell, S; Kurchaninov, L; Madsen, N; Maxwell, D; McKenna, J T K; Menary, S; Michan, J M; Momose, T; Munich, J J; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sacramento, R L; Sameed, M; Sarid, E; Silveira, D M; So, C; Tharp, T D; Thompson, R I; van der Werf, D P; Wurtele, J S; Zhmoginov, A I

2016-01-21

Antimatter continues to intrigue physicists because of its apparent absence in the observable Universe. Current theory requires that matter and antimatter appeared in equal quantities after the Big Bang, but the Standard Model of particle physics offers no quantitative explanation for the apparent disappearance of half the Universe. It has recently become possible to study trapped atoms of antihydrogen to search for possible, as yet unobserved, differences in the physical behaviour of matter and antimatter. Here we consider the charge neutrality of the antihydrogen atom. By applying stochastic acceleration to trapped antihydrogen atoms, we determine an experimental bound on the antihydrogen charge, Qe, of |Q| < 0.71 parts per billion (one standard deviation), in which e is the elementary charge. This bound is a factor of 20 less than that determined from the best previous measurement of the antihydrogen charge. The electrical charge of atoms and molecules of normal matter is known to be no greater than about 10(-21)e for a diverse range of species including H2, He and SF6. Charge-parity-time symmetry and quantum anomaly cancellation demand that the charge of antihydrogen be similarly small. Thus, our measurement constitutes an improved limit and a test of fundamental aspects of the Standard Model. If we assume charge superposition and use the best measured value of the antiproton charge, then we can place a new limit on the positron charge anomaly (the relative difference between the positron and elementary charge) of about one part per billion (one standard deviation), a 25-fold reduction compared to the current best measurement.

Looking back to understand the future Does CERN exist?"

CERN Document Server

Gillies, James D

2007-01-01

"From the moment that Dan Brown wrote in his novel "Angels and Demons" of antimatter being stolen from CERN, the European Organization for Nuclear Research, was immediately cast into the focus of a broader public. James Gillies, Head of Communications at CERN, presents the institution." (2 pages - english and german)

Connecting QGP-Heavy Ion Physics to the Early Universe

Energy Technology Data Exchange (ETDEWEB)

Rafelski, Johann

2013-10-15

We discuss properties and evolution of quark-gluon plasma in the early Universe and compare to laboratory heavy ion experiments. We describe how matter and antimatter emerged from a primordial soup of quarks and gluons. We focus our discussion on similarities and differences between the early Universe and the laboratory experiments.

AD-7/GBAR status report for the 2017 CERN SPSC

CERN Document Server

Lunney, D

2017-01-01

The first components of the GBAR (Gravitational Behavior of Antimatter at Rest) experiment will arrive at CERN in early 2017 for installation on the ELENA extraction line LNE50 and inside the newly constructed bunker in the AD hall. We report the installation plan and progress of all GBAR components.

Measurement of 0.25-3.2 GeV antiprotons in the cosmic radiation

DEFF Research Database (Denmark)

Mitchell, J.W.; Barbier, L.M.; Christian, E.R.

1996-01-01

The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba, Canada on 16-17 July 1992. Using velocity and magnetic rigidity to determine mass, we have directly measured the abundances of cosmic ray antiprotons and protons in the energy range from 0.25 to 3.2 ...

Some aspects of symmetrical relativistic cosmology

International Nuclear Information System (INIS)

Goto, M.

1977-01-01

A qualitative study of the cosmological model of Omnes is presented, as well as some numerical results. Studies are made in a chronological or historical way involving several subjects like matter and anti-matter emulsions, density of galactic clusters, the annihilation problem, quasars, etc. One solution for the matter diffusion equation is presented

Baryogenesis in an inflationary universe

International Nuclear Information System (INIS)

Dodelson, S.

1988-01-01

The existence of matter in our universe today is a result of fundamental processes in the early universe. This matter is the remnant of an asymmetry between matter and anti-matter. How that asymmetry developed is the focus of this thesis. A statistical mechanical analysis is given of baryogenesis after an inflationary era

Exotic power and propulsion concepts

International Nuclear Information System (INIS)

Forward, R.L.

1990-01-01

The status of some exotic physical phenomena and unconventional spacecraft concepts that might produce breakthroughs in power and propulsion in the 21st Century are reviewed. The subjects covered include: electric, nuclear fission, nuclear fusion, antimatter, high energy density materials, metallic hydrogen, laser thermal, solar thermal, solar sail, magnetic sail, and tether propulsion

Links between neutrino oscillations, leptogenesis, and proton decay ...

Indian Academy of Sciences (India)

accounts for the observed baryon asymmetry of the Universe by utilizing the process ... since the discoveries (confirmations) of the atmospheric [1] and solar neutrino oscil- lations [2,3] ... origin of their tiny masses may be at the root of the origin of matter-antimatter ..... Quite to the contrary, the minimal Higgs system provides.

A naturally occurring trap for antiprotons

International Nuclear Information System (INIS)

Eades, J.; Morita, N.; Ito, T.M.

1993-05-01

The phenomenon of delayed annihilation of antiprotons in helium is the first instance of a naturally occurring trap for antimatter in ordinary matter. Recent studies of this effect at CERN are summarized, and plans are described for laser excitation experiments to test its interpretation in terms of metastable exotic helium atom formation. (author)

From Kaonic Nuclei to Multikaonic Hypernuclei

Czech Academy of Sciences Publication Activity Database

Mareš, Jiří

2010-01-01

Roč. 186, NFQCD (2010), s. 343-350 ISSN 0375-9687. [Conference on NFQCD. Kyoto, 18.01.2010-19.03.2010] R&D Projects: GA ČR GA202/09/1441 Institutional support: RVO:61389005 Keywords : antimatter * charge particle reactions * Kaon reactions Subject RIV: BE - Theoretical Physics Impact factor: 1.017, year: 2010

Physics of antimatter-matter reactions for interstellar propulsion

International Nuclear Information System (INIS)

Morgan, D.L. Jr.

1986-01-01

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ ≅ 1000 to 2000 s) and very high I/sub sp/ (3 x 10 7 s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is on the order of or larger than atomic areas due to a rearrangement reaction, but it is very low at high energy where its value is closer to nuclear areas

Towards a gravity measurement on cold antimatter atoms

CERN Document Server

Caravita, R; Amsler, C; Ariga, A; Ariga, T; Bonomi, G; Bräunig, P; Bremer, J; Brusa, R S; Cabaret, L; Caccia, M; Castelli, F; Cerchiari, G; Chlouba, K; Cialdi, S; Comparat, D; Consolati, G; Demetrio, A; Di Noto, L; Doser, M; Dudarev, A; Ereditato, A; Evans, C; Ferragut, R; Fesel, J; Fontana, A; Forslund, O K; Gerber, S; Giammarchi, M; Gligorova, A; Gninenko, S; Guatieri, F; Haider, S; Holmestad, H; Huse, T; Jernelv, I L; Jordan, E; Kaltenbacher, T; Kellerbauer, A; Kimura, M; Koetting, T; Krasnicky, D; Lagomarsino, V; Lansonneur, P; Lebrun, P; Lehner, S; Liberadzka, J; Malbrunot, C; Mariazzi, S; Marx, L; Matveev, V; Mazzotta, Z; Nebbia, G; Nedelec, P; Oberthaler, M; Pacifico, N; Pagano, D; Penasa, L; Petracek, V; Pistillo, C; Prelz, F; Prevedelli, M; Ravelli, L; Resch, L; Rienäcker, B; Røhne, O M; Rosenberger, S; Rotondi, A; Sacerdoti, M; Sandaker, H; Santoro, R; Scampoli, P; Sorrentino, F; Spacek, M; Storey, J; Strojek, I M; Testera, G; Tietje, I; Vamosi, S; Widmann, E; Yzombard, P; Zavatarelli, S; Zmeskal, J

2016-01-01

The present status of the AEGIS experiment at CERN (AD-06), on the way of forming anti-hydrogen for a first gravity measurement, is reviewed. Recent results in trapping and cooling positrons and antiprotons in the main electromagnetic traps are presented, including the storage time measurement obtained during the 2014 run with antiprotons, the observation of centrifugal separation of a mixed antiproton/electron plasma and positron accumulation and transfer results obtained during 2015.

The production of anti-matter in our galaxy

Energy Technology Data Exchange (ETDEWEB)

Chardonnet, P.; Orloff, J.; Salati, P. [Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique Theorique

1997-12-31

A coalescence model is applied to assess the amount of anti-deuterium and anti-helium {sup 3}He present in cosmic rays together with anti-protons. The propagation of cosmic rays in the galaxy is described through a two-zone diffusion model which correctly describes the observed abundances. The {sup 3}He/p abundance does not exceed {approx} 4 x 10{sup -13}. Heavier anti-nuclei are even further suppressed. (author). 12 refs.

Baryon symmetric big-bang cosmology. [matter-antimatter symmetry

Science.gov (United States)

Stecker, F. W.

1978-01-01

The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.

Binding in some few-body systems containing antimatter

International Nuclear Information System (INIS)

Armour, E.A.G.

2009-01-01

It is well known that the system made up of a fixed proton and antiproton and an electron (or a positron) has no bound states if the internuclear distance R 0 . In this paper, I consider the more complicated system in which the electron and the positron are both present and investigate the possibility of obtaining a lower bound on the value of R for which the system has no bound states. I also investigate the implications of the existence of bound states of the simpler, one light particle system regarding bound states of the more complicated system. This article is based on the presentation by E. A. G. Armour at the Fifth Workshop on Critical Stability, Erice, Sicily. (author)

The production of anti-matter in our galaxy

International Nuclear Information System (INIS)

Chardonnet, P.; Orloff, J.; Salati, P.

1997-01-01

A coalescence model is applied to assess the amount of anti-deuterium and anti-helium 3 He present in cosmic rays together with anti-protons. The propagation of cosmic rays in the galaxy is described through a two-zone diffusion model which correctly describes the observed abundances. The 3 He/p abundance does not exceed ∼ 4 x 10 -13 . Heavier anti-nuclei are even further suppressed. (author)

Antimatter Plasmas in a Multipole Trap for Antihydrogen

CERN Document Server

Andresen, G B; Boston, A; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Chartier, M; Deutsch, A; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Gomberoff, K; Hangst, J S; Hayano, R S; Hydomako, R; Jenkins, M J; Jørgensen, L V; Kurchaninov, L; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Robicheaux, F; Sarid, E; Silveira, D M; Storey, J W; Telle, H H; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki, Y

2007-01-01

We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies.

Antiproton cell experiment: antimatter is a better killer

CERN Multimedia

2006-01-01

"European Organization for Nuclear Research is reporting that results from a three year study of antiprotons for neoplasm irrdiation showed a better cellular killer with a smaller lethal dose." (1,5 page)

Antimatter plasmas in a multipole trap for antihydrogen.

Science.gov (United States)

Andresen, G; Bertsche, W; Boston, A; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Chartier, M; Deutsch, A; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Gomberoff, K; Hangst, J S; Hayano, R S; Hydomako, R; Jenkins, M J; Jørgensen, L V; Kurchaninov, L; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Robicheaux, F; Sarid, E; Silveira, D M; Storey, J W; Telle, H H; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki, Y

2007-01-12

We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies.

Binding matter with antimatter: the covalent positron bond.

Science.gov (United States)

Charry, Jorge Alfonso; Varella, Marcio T Do N; Reyes, Andrés

2018-05-16

We report sufficient theoretical evidence of the energy stability of the e⁺H₂²⁻ molecule, formed by two H⁻ anions and one positron. Analysis of the electronic and positronic densities of the latter compound undoubtedly points out the formation of a positronic covalent bond between the otherwise repelling hydride anions. The lower limit for the bonding energy of the e⁺H₂²⁻ molecule is 74 kJ/mol (0.77 eV), accounting for the zero-point vibrational correction. The formation of a non electronic covalent bond is fundamentally distinct from positron attachment to stable molecules, as the latter process is characterized by a positron affinity, analogous to the electron affinity. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antibodies and antimatter: the resurgence of immuno-PET.

Science.gov (United States)

Wu, Anna M

2009-01-01

The completion of the human genome, coupled with parallel major research efforts in proteomics and systems biology, has led to a flood of information on the roles of individual genes and proteins in normal physiologic processes and their disruptions in disease. In practical terms, this information has opened the door to increasingly targeted therapies as specific molecular markers are identified and validated. The ongoing transition from empiric to molecular medicine has engendered a need for corresponding molecular diagnostics, including noninvasive molecular imaging. Convergence of knowledge regarding key biomarkers that define normal biologic processes and disease with protein and imaging technology makes this an opportune time to revisit the combination of antibodies and PET, or immuno-PET.

Antimatter Driven P-B11 Fusion Propulsion System

Science.gov (United States)

Kammash, Terry; Martin, James; Godfroy, Thomas

2002-01-01

One of the major advantages of using P-B11 fusion fuel is that the reaction produces only charged particles in the form of three alpha particles and no neutrons. A fusion concept that lends itself to this fuel cycle is the Magnetically Insulated Inertial Confinement Fusion (MICF) reactor whose distinct advantage lies in the very strong magnetic field that is created when an incident particle (or laser) beam strikes the inner wall of the target pellet. This field serves to thermally insulate the hot plasma from the metal wall thereby allowing thc plasma to burn for a long time and produce a large energy magnification. If used as a propulsion device, we propose using antiprotons to drive the system which we show to be capable of producing very large specific impulse and thrust. By way of validating the confinement propenies of MICF we will address a proposed experiment in which pellets coated with P-B11 fuel at the appropriate ratio will be zapped by a beam of antiprotons that enter the target through a hole. Calculations showing the density and temperature of the generated plasma along with the strength of the magnetic field and other properties of the system will be presented and discussed.

On the chemical reaction of matter with antimatter.

Science.gov (United States)

Lodi Rizzini, Evandro; Venturelli, Luca; Zurlo, Nicola

2007-06-04

A chemical reaction between the building block antiatomic nucleus, the antiproton (p or H- in chemical notation), and the hydrogen molecular ion (H2+) has been observed by the ATHENA collaboration at CERN. The charged pair interact via the long-range Coulomb force in the environment of a Penning trap which is purpose-built to observe antiproton interactions. The net result of the very low energy collision of the pair is the creation of an antiproton-proton bound state, known as protonium (Pn), together with the liberation of a hydrogen atom. The Pn is formed in a highly excited, metastable, state with a lifetime against annihilation of around 1 micros. Effects are observed related to the temperature of the H2+ prior to the interaction, and this is discussed herein.

Intensity-Frontier Antiproton Physics with The Antiproton Annihilation Spectrometer (TAPAS) at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Apollinari, Giorgio; /Fermilab; Asner, David M.; /PNL, Richland; Baldini, Wander; /INFN, Ferrara; Bartoszek, Larry; Broemmelsiek, Daniel R.; Brown, Charles N.; /Fermilab; Chakravorty, Alak; /St. Xavier U., Chicago; Colas, Paul; /Saclay; Derwent, Paul; /Fermilab; Drutskoy, Alexey; /Moscow, ITEP; Fortner, Michael; /Northern Illinois U. /Saclay /Indian Inst. Tech., Hyderabad

2011-11-01

The Fermilab Antiproton Source is the world's most intense source of antimatter. With the Tevatron program now behind us, this unique facility can help make the case for Fermilab's continued accelerator operations. The Antiproton Source can be used for unique, dedicated antimatter studies, including medium-energy {bar p}-annihilation experiments. We propose to assemble a powerful, yet cost-effective, solenoidal magnetic spectrometer for antiproton-annihilation events, and to use it at the Fermilab Antiproton Accumulator to measure the charm production cross section, study rare hyperon decays, search for hyperon CP asymmetry, precisely measure the properties of several charmonium and nearby states, and make the first measurements of the Drell-Yan continuum in medium-energy antiproton annihilation. Should the charm production cross section be as large as some have proposed, we will also be able to measure D{sup 0}-{bar D}{sup 0} mixing with high precision and discover (or sensitively limit) charm CP violation. The observation of charm or hyperon CP violation would be evidence for physics beyond the Standard Model, with possible implications for the origin of the baryon asymmetry of the universe - the question of what happened to all the antimatter that must have been produced in the Big Bang. The experiment will be carried out by an international collaboration and will require some four years of running time. As possibly the sole hadron experiment in progress at Fermilab during that time, it will play an important role in maintaining a broad particle physics program at Fermilab and in the U.S. It will thus help us to continue attracting creative and capable young people into science and technology, and introducing them to the important technologies of accelerators, detectors, and data acquisition and analysis - key roles in society that accelerator-based particle physics has historically played.

Track calorimeter (TCAL) of alpha magnetic spectrometer (AMS) (a particle physics experiment on the international space station alpha)

International Nuclear Information System (INIS)

Anosov, V.; Baranov, S.; Bednyakov, V.

1999-01-01

Based on the simulation and R and D results the JINR project - to supplement AMS with a finely granulated scintillator calorimeter (TCAL) - is discussed. The project cost is about 1 million USD. TCAL would essentially increase the AMS potential in the studies of antimatter, matter and missing matter in the experiments in outer space

Comment le CERN profite du star-system hollywoodien

CERN Document Server

Comby, Geneviève

2009-01-01

The very serious european center for nuclear research did not hesitate to team up with the kings of the entertainement. Tom Hanks and Ron Howard in head, on the occasion of the release of the american spectacular "Angels and Demons" in which a bomb of antimatter stolen at CERN threatens the Vatican. (2 pages)

Looking at the antiworld

International Nuclear Information System (INIS)

Eades, John

1992-01-01

A popular pastime among amateur scientific historians is tracing key concepts in twentieth century physics back to their origins. Participants at the Antihydrogen Workshop in Munich on July 30-31 were astonished to hear 1989 Nobel prizewinner Wolfgang Paul mention in his introductory remarks that W. Nernst referred to antimatter as far back as 1897

ATLAS experiment : mapping the secrets of the universe

CERN Multimedia

ATLAS Outreach

2010-01-01

This 4 page color brochure describes ATLAS and the LHC, the ATLAS inner detector, calorimeters, muon spectrometer, magnet system, a short definition of the terms "particles," "dark matter," "mass," "antimatter." It also explains the ATLAS collaboration and provides the ATLAS website address with some images of the detector and the ATLAS collaboration at work.

CP violations in the Universe

Science.gov (United States)

Auriemma, Giulio

2003-12-01

The origin of the asymmetry between matter and antimatter that is evident in our part of the Universe is one of the open questions in cosmology, because the CPT symmetry between matter and antimatter seems to be absolutely conserved at microscopic level. We repeat here the classical proofs which exclude the viability of a Universe baryon symmetric on the average, or the observed asymmetry as an initial conditions. The current understanding is that the asymmetry should have been dynamically generated before nucleosynthesis, by B, C, and CP violating processes, acting out of thermodynamical equilibrium, as suggested by Sakharov in the 70's. The physical realizations of these conditions would be possible, in principle, also in the framework of the Standard Model of elementary particles, but the present limits on the mass of the higgs particle exclude this possibility. Finally we present the model of baryogenesis through leptogenesis, which is allowed by a minimal extension of the Standard Model, which has the appeal of being testable in future long-baseline neutrino oscillation experiments.

Models of baryogenesis

Science.gov (United States)

Auriemma, G.

2005-06-01

The origin of the asymmetry between matter and antimatter that is evident in our part of the Universe is one of the open questions in cosmology, because the CPT symmetry between matter and antimatter seems to be absolutely conserved at microscopic level. We repeat here the classical proofs which exclude the viability of a Universe baryon symmetric on the average, or the observed asymmetry as an initial condition. The current understanding is that the asymmetry should have been dynamically generated before nucleosynthesis, by B, C, and CP-violating processes, acting out of thermodynamical equilibrium, as suggested by Sakharov in the 70's. The physical realizations of these conditions would be possible, in principle, also in the framework of the Standard Model of elementary particles, but the present limits on the mass of the Higgs particle exclude this possibility. Finally we present the model of baryogenesis through leptogenesis, which is allowed by a minimal extension of the Standard Model, which has the appeal of being testable in future long-baseline neutrino oscillation experiments.

Positronium formation in porous materials for antihydrogen production

International Nuclear Information System (INIS)

Ferragut, R; Calloni, A; Dupasquier, A; Consolati, G; Giammarchi, M G; Quasso, F; Trezzi, D; Egger, W; Ravelli, L; Petkov, M P; Jones, S M; Wang, B; Yaghi, O M; Jasinska, B; Chiodini, N; Paleari, A

2010-01-01

Positronium (Ps) formation measurements in several porous materials as: Vycor, germanate Xerogel, Metal-Organic Frameworks MOF-177 and Aerogel with two densities (20 and 150 mg/cm 3 ), were performed by means of a variable energy positron beam provided with a Ge detector and a positron lifetime spectrometer. An efficient formation of cooled Ps atoms is a requisite for the production of antihydrogen, with the aim of a direct measurement of the Earth gravitational acceleration g of antimatter, which is a primary scientific goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy). Porous materials are necessary to form a high yield of Ps atoms as well as to cool Ps through collisions with the inner walls of the pores. The different materials were characterized and produce Ps into the pores. Lifetime measurements give an estimation of the typical pores dimension of the substances. A comparative study of the positron lifetime and the Ps fraction values in the above mentioned materials indicates that silica Aerogel, with the appropriate density, is an excellent candidate for an efficient formation of cold Ps atoms for the AEGIS project.

NA48 unravels one of nature's most subtle secrets

CERN Multimedia

2001-01-01

NA48 has just announced its final results confirming direct CP-violation with great precision. This phenomenon helps us to understand the imbalance between matter and antimatter in the Universe. At a seminar at CERN on 10 May Guillaume Unal of the Laboratory's NA48 collaboration announced NA48's final result on one of nature's best-kept secrets. Direct CP-violation, as it is called, is a subtle effect that betrays nature's preference for matter over antimatter, the reason why we are here. In 1993, an earlier CERN experiment, NA31, and the E731 experiment at Fermi National Accelerator Laboratory (Fermilab) in the USA published the first precise results on direct CP-violation. The CERN result suggested that direct CP-violation was a real effect. The Fermilab result, while not excluding the effect, was also compatible with no direct CP-violation. More precise measurements were clearly needed, and ambitious new experiments at the two laboratories - NA48 and KTeV - soon rose to the challenge. Both have now measure...

Summer Students

CERN Multimedia

2005-01-01

SUMMER STUDENT LECTURE PROGRAMME Main Auditorium, bldg. 500 DATE TIME LECTURER TITLE Monday 11 July 09:15 - 10:00 L. Di Lella (CERN) Introduction to Particle Physics (4/4) 10:15 - 11:00 P. Chomaz (GANIL / CERN) Introduction to Nuclear Physics (3/3) 11:15 - 12:00 G. ROLANDI (CERN) How an experiment is designed (2/2) 12:00 Discussion Session Tuesday 12 July  09:15 - 11:00 O. BrÜning (CERN) Accelerators (1-2/5) 11:15 - 12:00 O. ULLALAND (CERN) Detectors (1/5) 12:00 Discussion Session Wednesday 13 July 09:15 - 10:00 O. BrÜning (CERN) Accelerators (3/5) 10:15 - 11:00 R. LANDUA (CERN) Antimatter in the Lab (1/2) 11:15 - 12:00 O. ULLALAND (CERN) Detectors (2/5) 12:00 Discussion Session Thursday 14 July 09:15 - 10:00 O. ULLALAND (CERN) Detectors (3/5) 10:15 - 11:00 G. ROLANDI (CERN) Antimatter in the Lab (2/2) 11:15 - 12:00 O. BrÜning (CERN) Accelerators (4/5) 12:00 Discussion Session Friday 1...

The AEGIS experiment at CERN

Energy Technology Data Exchange (ETDEWEB)

Kellerbauer, A., E-mail: a.kellerbauer@cern.ch [Max Planck Institute for Nuclear Physics (Germany); Allkofer, Y.; Amsler, C. [University of Zurich, Physics Institute (Switzerland); Belov, A. S. [Institute for Nuclear Research of the Russian Academy of Sciences (Russian Federation); Bonomi, G. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Braeunig, P. [University of Heidelberg, Kirchhoff Institute for Physics (Germany); Bremer, J. [European Organisation for Nuclear Research, Physics Department (Switzerland); Brusa, R. S. [University of Trento, Department of Physics (Italy); Burghart, G. [European Organisation for Nuclear Research, Physics Department (Switzerland); Cabaret, L. [Centre national de la recherche scientifique, Laboratoire Aime Cotton (France); Canali, C. [University of Zurich, Physics Institute (Switzerland); Castelli, F. [University of Milano, Department of Physics (Italy); Chlouba, K. [Czech Technical University in Prague, Department of Physics (Czech Republic); Cialdi, S. [University of Milano, Department of Physics (Italy); Comparat, D. [Centre national de la recherche scientifique, Laboratoire Aime Cotton (France); Consolati, G. [Politecnico di Milano, Department of Physics (Italy); Dassa, L. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Noto, L. Di [University of Trento, Department of Physics (Italy); Donzella, A. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Doser, M. [European Organisation for Nuclear Research, Physics Department (Switzerland); Collaboration: AEGIS Collaboration; and others

2012-05-15

After the first production of cold antihydrogen by the ATHENA and ATRAP experiments ten years ago, new second-generation experiments are aimed at measuring the fundamental properties of this anti-atom. The goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is to test the weak equivalence principle by studying the gravitational interaction between matter and antimatter with a pulsed, cold antihydrogen beam. The experiment is currently being assembled at CERN's Antiproton Decelerator. In AEGIS, antihydrogen will be produced by charge exchange of cold antiprotons with positronium excited to a high Rydberg state (n > 20). An antihydrogen beam will be produced by controlled acceleration in an electric-field gradient (Stark acceleration). The deflection of the horizontal beam due to its free fall in the gravitational field of the earth will be measured with a moire deflectometer. Initially, the gravitational acceleration will be determined to a precision of 1%, requiring the detection of about 10{sup 5} antihydrogen atoms. In this paper, after a general description, the present status of the experiment will be reviewed.

Events at the Globe of Science and Innovation

CERN Document Server

2006-01-01

CERN is organising a series of lectures based on the exhibition «A des années-lumière» Thursday 16 November, 8.00 p.m. (in French): Antimatter in the Milky Way Jacques Paul, scientific advisor to the European Space Agency's INTEGRAL mission Every second, more than ten billion tonnes of antimatter destroys itself in our galaxy, the Milky Way. This surprising phenomenon was observed by telescopes on board the INTEGRAL satellite, the European Space Agency's latest giant space observatory. During his lecture the speaker will illustrate the strong link between astronomy and particle physics using the concepts of astroparticles, electron-positron annihilation, the galaxy bulge and dark matter. Tuesday 21 November, 8.00 p.m. (in French): The shape of space, from black holes to the crumpled universe Jean-Pierre Luminet, Research Director at the CNRS Black holes, the shape of the universe, the structure of space-time... Describing the shape of space has always involved a myriad of geometric models, each one wi...

Precision tests of CPT invariance with single trapped antiprotons

Energy Technology Data Exchange (ETDEWEB)

Ulmer, Stefan [RIKEN, Ulmer Initiative Research Unit, Wako, Saitama (Japan); Collaboration: BASE-Collaboration

2015-07-01

The reason for the striking imbalance of matter and antimatter in our Universe has yet to be understood. This is the motivation and inspiration to conduct high precision experiments comparing the fundamental properties of matter and antimatter equivalents at lowest energies and with greatest precision. According to theory, the most sensitive tests of CPT invariance are measurements of antihydrogen ground-state hyperfine splitting as well as comparisons of proton and antiproton magnetic moments. Within the BASE collaboration we target the latter. By using a double Penning trap we performed very recently the first direct high precision measurement of the proton magnetic moment. The achieved fractional precision of 3.3 ppb improves the currently accepted literature value by a factor of 2.5. Application of the method to a single trapped antiproton will improve precision of the particles magnetic moment by more than a factor of 1000, thus providing one of the most stringent tests of CPT invariance. In my talk I report on the status and future perspectives of our efforts.

Technology FANTASY

CERN Multimedia

2008-01-01

The secret weapon of Dan Brown's book may be lurking out there is space, says S Ananthanarayanan DAN Brown's Da Vinci Code created interest in the legends about the life of Christ. His earlier book, Angels and Demons, was set in the Vatican City and dealt with the crisis of a piece of antimatter falling into the wrong hands.

BaBar Detector

CERN Multimedia

2006-01-01

"B factory experiments at the Stanford Linear Accelerator (SLAC) in the USA and at the High Energy Accelerator Research Organization (KEK) in Japan have reached a new milestone in the quest to understand the matter-antimatter imbalance in our universe. These experiments are used by scientists from around the world, including the UK, to probe such fundamental questions."

Black Holes and the Large Hadron Collider

Science.gov (United States)

Roy, Arunava

2011-01-01

The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

Fundamental symmetry tests with antihydrogen

International Nuclear Information System (INIS)

Hughes, R.J.

1992-01-01

The prospects for testing CPT invariance and the weak equivalence principle (WEP) for antimatter with spectroscopic measurements on antihydrogen are discussed. The potential precisions of these tests are compared with those from other measurements. The arguments involving energy conservation, the behavior of neutral kaons in a gravitational field and the equivalence principle for antiparticles are reviewed in detail

Quirky quarks a cartoon guide to the fascinating realm of physics

CERN Document Server

Bahr, Benjamin; Piccolo, Rina

2016-01-01

Do you love quantum physics, cosmology, and the humor behind the popular television show The Big Bang Theory? Have you been on the lookout for a fun, non-technical explanation of the science behind things like time travel, wormholes, antimatter, and dark energy? You’ll find all of that, and more, inside this fact-filled, cartoon-packed book.

Antiproton-nucleus interaction

International Nuclear Information System (INIS)

Gibbs, W.R.

1984-01-01

Several facets of antinucleon-nucleus interactions are explored. The topics treated are: coherent interactions, production of unusual states and particles in the nuclear medium, and the creation of extreme states of matter by antimatter annihilation. It is found that temperatures of the magnitude necessary to achieve the predicted quark-gluon phase transition are obtained. 20 references

A summary view of the symmetric cosmological model

International Nuclear Information System (INIS)

Aldrovandi, R.

1975-01-01

A brief analysis of cosmological models is done, beginning with the standard model and following with the symmetric model of Omnes. Some attempts have been made for the phase transition in thermal radiation at high temperatures, to the annihilation period and to coalescence. One model with equal amounts of matter and antimatter seems to be reasonable [pt

The CAPRICE RICH detector

Energy Technology Data Exchange (ETDEWEB)

Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

1995-09-01

A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

Que reste-t-il à découvrir?

CERN Multimedia

Bonneau, Cécile; Grousson, Mathieu; Pajot, Philippe

2007-01-01

What is the nature of the black matter? And the one of the dark energy? and antimatter? Extraterrestrial life? All these questions, and some others, put today the physicians at the challenge. Because it's the last enigma of the Universe and the matter. But also because they threaten the mots fundamental certainties of the physics. Should we thus talk of crisis? (13 pages)

Model PET Scan Activity

Science.gov (United States)

Strunk, Amber; Gazdovich, Jennifer; Redouté, Oriane; Reverte, Juan Manuel; Shelley, Samantha; Todorova, Vesela

2018-05-01

This paper provides a brief introduction to antimatter and how it, along with other modern physics topics, is utilized in positron emission tomography (PET) scans. It further describes a hands-on activity for students to help them gain an understanding of how PET scans assist in detecting cancer. Modern physics topics provide an exciting way to introduce students to current applications of physics.

CERN result provides answer to one of nature's most subtle secrets

CERN Multimedia

CERN Press Office. Geneva

1999-01-01

At a seminar at CERN on 18 June Pascal Debu, spokesman of the Laboratory's NA48 experiment, announced its preliminary result, after analysis of 10% of the expected data, on one of nature's best-kept secrets. Direct CP-violation, as it is called, is a subtle effect that betrays nature's preference for matter over antimatter, the reason why we are here.

Antihydrogen Experiment Gravity Interferometry Spectroscopy

CERN Multimedia

Trezzi, D; Dassa, L; Rienacker, B; Khalidova, O; Ferrari, G; Krasnicky, D; Perini, D; Cerchiari, G; Belov, A; Boscolo, I; Sacerdoti, M G; Ferragut, R O; Nedelec, P; Hinterberger, A; Al-qaradawi, I; Malbrunot, C L S; Brusa, R S; Prelz, F; Manuzio, G; Riccardi, C; Fontana, A; Genova, P; Haider, S; Haug, F; Turbabin, A; Castelli, F; Testera, G; Lagomarsino, V E; Doser, M; Penasa, L; Gninenko, S; Cataneo, F; Zenoni, A; Cabaret, L; Comparat, D P; Zmeskal, J; Scampoli, P; Nesteruk, K P; Dudarev, A; Kellerbauer, A G; Mariazzi, S; Carraro, C; Zavatarelli, S M

The AEGIS experiment (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) has the aim of carrying out the first measurement of the gravitational interaction of antimatter to a precision of 1%, by applying techniques from atomic physics, laser spectroscopy and interferometry to a beam of antihydrogen atoms. A further goal of the experiment is to carry out spectroscopy of the antihydrogen atoms in flight.

Baryogenesis via Elementary Goldstone Higgs Relaxation

DEFF Research Database (Denmark)

Gertov, Helene; Pearce, Lauren; Sannino, Francesco

2016-01-01

We extend the relaxation mechanism to the Elementary Goldstone Higgs framework. Besides studying the allowed parameter space of the theory we add the minimal ingredients needed for the framework to be phenomenologically viable. The very nature of the extended Higgs sector allows to consider very ...... but radiatively generated, it is possible to generate the observed matter-antimatter asymmetry via the relaxation mechanism....

Unmatter Plasma Discovered (Letters to Progress in Physics

Directory of Open Access Journals (Sweden)

Smarandache F.

2015-07-01

Full Text Available The electron-positron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted a decade ago really exists. That is the electron-positron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter.

The origin of matter

International Nuclear Information System (INIS)

Cline, J.

2004-01-01

The author presents the issue of how matter triumphed over anti-matter in the formation of the universe. Theories focus on the nature of asymmetry that might have created an excess of matter over anti-matter. Sakharov and Kuzmin listed 3 conditions that must be met for baryogenesis to take place. First the baryon number must not be conserved: there must be some interactions that change the number of baryons, baryon-number violation can rise from an interaction between quarks and leptons. Secondly, 2 symmetries that relate particles to antiparticles must be violated. The CP violation in Kaon decay is too weak to create enough baryon asymmetry, so physicists believe that larger sources of CP violation await discovery. Thirdly, there must be the loss of thermal equilibrium of the universe. In thermal equilibrium, baryons are decaying but inverse processes are also taking place, quarks are fusing to form baryons, rates being equal no baryon asymmetry is generated. But if thermal equilibrium is broken, to say temperature is decreasing, at a certain temperature a pair of quarks will no longer have enough energy to produce a heavy particle which generates baryon asymmetry. (A.C.)

Antihydrogen production and precision experiments

International Nuclear Information System (INIS)

Nieto, M.M.; Goldman, T.; Holzscheiter, M.H.

1996-01-01

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 16 , offers in principle the possibility to directly compare matter and antimatter properties at a level of 1 part in 10 16

The identity card of particles

International Nuclear Information System (INIS)

2009-11-01

For each particle, this publication briefly and simply indicates its properties, recalls how it has been discovered, describes how it can be observed, and its role in sub-atomic physics. The presented particles are: antimatter, W"+ and W"- bosons, Z boson, electron, gluon, graviton, muon, electronic neutrino, muon neutrino, tau neutrino, atomic nucleus, photon, quark, top quark, U and D quarks, S and C quarks, and tau