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Topic: Baryogenesis

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  Baryogenesis - Wikipedia, the free encyclopedia
Baryogenesis is the generic designation for the physical processes that generate matter (more specifically, a class of fundamental particle called baryon) from an otherwise matter-empty state (such as it is generally believed to be the state of the Universe at its onset, the so-called Big Bang).
The fundamental difference between baryogenesis theories is the description of the interaction between fundamental particles.
The next step after baryogenesis, is the much better understood nucleosynthesis, the forming of atomic nuclei.
en.wikipedia.org /wiki/Baryogenesis   (1408 words)

 Big Bang - Wikipedia, the free encyclopedia
At a certain temperature, by an as-yet-unknown transition called baryogenesis, the quarks and gluons combined into baryons such as protons and neutrons, somehow producing the observed asymmetry between matter and antimatter.
The Big Bang theory predicted the existence of the cosmic microwave background radiation or CMB which is composed of photons emitted during baryogenesis.
Because the early universe was in thermal equilibrium, the temperature of the radiation and the plasma were equal until the plasma recombined.
en.wikipedia.org /wiki/Big_Bang   (5612 words)

 Research - Baryogenesis   (Site not responding. Last check: 2007-09-18)
In these type of scenarios the Universe undergoes a first order phase transition at the electroweak scale in which bubbles of the Higgs phase (in which particles are massive) nucleate in the sea of the hot phase (massless particles).
Baryogenesis is effective at the front of the growing bubbles.
Another attractive class of baryogenesis scenarios involves the physics of grand unification of fundamental forces, and it is typically based on out-of-equilibrium decays of heavy particles that violate either lepton or baryon numbers.
www.thphys.uni-heidelberg.de /home/cosmology/baryogen.html   (532 words)

 Baryogenesis   (Site not responding. Last check: 2007-09-18)
c - Baryogenesis occurred at the Electroweak Phase Transition (EWPT).
Thermal nonequilibrium is achieved during first-order phase transitions in the cooling early universe, such as the EWPT (at T = 100 GeV or so).
As bubbles of the "true vacuum" (with a nonzero Higgs vev) percolate and grow, baryogenesis can occur at or near the bubble walls.
www.ibiblio.org /lunar/school/library/barygens.html   (603 words)

 Research Interests for Kevin Kelley   (Site not responding. Last check: 2007-09-18)
Another issue that arises in the evolution of the cosmos is that of baryogenesis.
There are many different types of baryogenesis scenarios, ranging from GUT scale interactions to gravitational interactions which could possibly generate the matter asymmetry.
This is exciting from a phenomenological point of view, in that the energies at which such phase transitions may occur are within reach of the next generation of colliders, and could thus be probed experimentally.
moose.ucdavis.edu /research/interests.html   (2664 words)

 Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations   (Site not responding. Last check: 2007-09-18)
Baryogenesis during the electroweak phase transition is a plausible scenario for the origin of matter in the Universe.
Furthermore, it has the advantage over other scenarios in that one can imagine the much of the physics involved may be experimentally probed before long.
In this talk I give an overview of the standard picture, and discuss briefly the advances over the past year that suggest electroweak baryogenesis is a robust phenomenon.
www.osti.gov /energycitations/product.biblio.jsp?osti_id=58999   (170 words)

 DFS 2003 Astrophysics abstract   (Site not responding. Last check: 2007-09-18)
Antimatter, baryogenesis, and the anisotropies and polarization of the CMB radiation
We discuss the hypothesis that the cosmological baryon asymmetry and entropy were produced in the early Universe by phase transitions of scalar fields in the framework of spontaneous baryogenesis scenario.
It is assumed that the baryogenesis remnants in the form of baryon-antibaryon clouds survive to the present day as a new relic of the Universe.
www.nbi.dk /dfs/abs2003/aa10.html   (154 words)

 Citebase - Particle Physics Models, Topological Defects and Electroweak Baryogenesis
We demonstrate the viability of electroweak baryogenesis scenarios in which the necessary departure from equilibrium is realized by the evolution of a network of topological defects.
In each case we compare the strength of the model with that expected from scenarios in which baryogenesis proceeds with the propagation of critical bubbles.
We consider the effects of particle transport in the topological defect-mediated electroweak baryogenesis scenarios of Ref. 1.
citebase.eprints.org /cgi-bin/citations?archiveID=oai:arXiv.org:hep-ph/9412266   (1091 words)

 Microphysical mechanisms
An intuitive way to see this is to note that fl holes are fully described by their mass, their angular momentum and their entropy; quantum-gravitational interactions involving the exchange of virtual fl holes therefore have no knowledge of the interacting particles' other quantum numbers and can violate all of them.
Thus, it is possible that baryogenesis occurred at the GUT energy scale.
The Affleck-Dine scenario for baryogenesis notes that in supersymmetric theories, where each of the ordinary fermion fields from standard-model physics has a scalar partner, the early universe contained baryon- and lepton-number-carrying scalar fields.
www-cdf.lbl.gov /~jmuelmen/www/Microphysical_mechanisms.html   (1250 words)

 Citebase - Baryogenesis
We then discuss a generic scenario for electroweak baryogenesis relying on bubble wall dynamics.
Updated dependences of the baryon asymmetry on chargino mass parameters and the bubble wall velocity are shown.
Supersymmetric Electroweak Baryogenesis in the WKB approximation [ Abstract/Citations, PDF ]
citebase.eprints.org /cgi-bin/citations?id=oai:arXiv.org:hep-ph/0112020   (985 words)

 Learn more about Phase transition in the online encyclopedia.   (Site not responding. Last check: 2007-09-18)
For example, the electroweak transition broke the SU(2)×U(1) symmetry of the electroweak field into the U(1) symmetry of the present-day electromagnetic field.
This transition is important to understanding the asymmetry between the amount of matter and antimatter in the present-day universe (see electroweak baryogenesis.)
Continuous phase transitions are easier to study than first-order transitions due to the absence of latent heat, and they have been discovered to have many interesting properties.
www.onlineencyclopedia.org /p/ph/phase_transition.html   (1960 words)

 A Way to Reopen the Window for Electroweak Baryogenesis   (Site not responding. Last check: 2007-09-18)
These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major experimental constraints on four-dimensional gravity.
Such modification of cosmology at early times therefore reopens the parameter space allowing electroweak baryogenesis which had been reduced substantially given the new bound on the higgs mass imposed by LEP.
In contrast with previous attempts to turn around the sphaleron bound using alternative cosmologies, we are still considering that the electroweak phase transition takes place in a radiation dominated universe.
stacks.iop.org /1126-6708/2002/i=01/a=044   (394 words)

 Momentogenesis by He vortices: an experimental analogue of primordial baryogenesis.   (Site not responding. Last check: 2007-09-18)
Momentogenesis by He vortices: an experimental analogue of primordial baryogenesis.
He vortices: an experimental analogue of primordial baryogenesis.
The observed excess of matter over antimatter is believed to result from baryogenesis during phase transitions in the early universe [1, 2].
boojum.hut.fi /abstracts/lowtemp/LTL-96008.html   (240 words)

 The 42 faces of baryogenesis - Information Technology Services   (Site not responding. Last check: 2007-09-18)
In layman's terms, the real question here is why we have a universe which is full of matter and has very little anti-matter.
This little pet theory has virtue of both explaining the matter-antimatter imbalance and resolving the big question of what happened before the Big Bang, which becomes an event at the middle of time, instead of the beginning of time.
I admit that there are a great deal of models in the list of 42 that I haven't heard about before.
www.physicsforums.com /archive/topic/t-53648_The_42_faces_of_baryogenesis.html   (1055 words)

 Lee, Christopher (2005-05-25) Probing physics in the standard model and beyond with electroweak baryogenesis and ...
Lee, Christopher (2005-05-25) Probing physics in the standard model and beyond with electroweak baryogenesis and effective theories of the strong interactions.
First, we embark on an attempt to account for the abundance of matter in the present Universe if earlier in its history matter and antimatter were equally abundant.
We explore whether baryogenesis at the electroweak phase transition could successfully account for the observed density of baryons in the Universe, using the closed-time-path (CTP) formalism of quantum field theory to calculate the buildup and relaxation of particle densities during the phase transition.
etd.caltech.edu /etd/available/etd-05272005-162229   (321 words)

 Constraints on Electroweak Baryogenesis from CP Violation
[A2.02] Constraints on Electroweak Baryogenesis from CP Violation
It is argued that: (a) If the standard model had all its CP violation originating from the Cabibbo-Kobayashi-Maskawa matrix, then the existence of a baryogenesis mechanism is prohibited by the fast and incoherent quark-gluon interactions.
(b) If the standard model had other sources of CP violation, then the constraints are generically relaxed and the requirement of a successful baryogenesis becomes a numerical question which is parameter dependent.
flux.aps.org /meetings/BAPSMAY96/abs/S20002.html   (173 words)

 MCTP: Baryogenesis workshop, 2003   (Site not responding. Last check: 2007-09-18)
We are pleased to announce a workshop on Baryogenesis at the University of Michigan, Ann Arbor, from June 9 through June 27, 2003.
The aim of the workshop is to bring together a group of interested physicists to discuss outstanding theoretical questions as well as the phenomenological consequences of the different baryogenesis scenarios.
Initially, we will concentrate on technical aspects, including the foundations, issues of field theory at zero and finite temperature, and the derivation and solution of the Boltzmann equations necessary for the computation of the baryon asymmetry.
www.umich.edu /~mctp/events/baryogenesis2003   (295 words)

 Baryogenesis and galaxy formation.
Perhaps some galaxies don't have dark matter because there was another way for galaxies to form that didn't require them.
Then I remeber a page on Baryogenesis, and they explained GUT baryogenesis and electroweak baryogenesis.
And then it hit me. In electroweak baryogenesis the baryogenesis happens in 'bubbles', or boundaries.
www.pych-one.com /new-5122670-4396.html   (220 words)

 Baryogenesis: Why Are There More Protons Than Antiprotons?
Baryogenesis: Why Are There More Protons Than Antiprotons?
In 1967 Sakharov enumerated 3 necessary conditions for baryogenesis:
If baryon number (B) is conserved in all reactions, then the present baryon asymmetry can only reflect asymmetric initial conditions, and we are back to the first case in the previous list.
math.ucr.edu /home/baez/physics/ParticleAndNuclear/baryogenesis.html   (620 words)

 BARYOGENESIS   (Site not responding. Last check: 2007-09-18)
We work   mainly on a   baryogenesis model, based on the Afleck-Dine baryogenesis scenarion,   with a complex scalar field, which is a scalar superpartner of a colorless and electrically neutral combination of quark and lepton fields.
The model in brief: After inflation the field starts to oscillate with a decreasing amplitude, due to the Universe expansion and the particle production.
We are trying to provide more precise account for the particle creation processes, which were proved to play an essential role for baryogenesis.
www.astro.bas.bg /galaxies/galaxies_files/baryogenesis.html   (333 words)

 Supersymmetric electroweak baryogenesis   (Site not responding. Last check: 2007-09-18)
We re-examine the generation of the baryon asymmetry in the minimal supersymmetric standard model (MSSM) during the electroweak phase transition.
We find that the dominant source for baryogenesis arises from the chargino sector.
Controlled keywords: Baryogenesis, Cosmological Phase Transitions, Supersymmetric Standard Model, CP violation
stacks.iop.org /1126-6708/2000/i=07/a=018   (411 words)

 ScienceDaily -- Browse Topics: Science/Physics/Cosmology
Particle Aspects of Cosmology and Baryogenesis - An introduction to particle aspects of cosmology with particular reference to primordial nucleosynthesis, dark matter and baryogenesis is provided.
In particular, various scenarios-GUT baryogenesis, electroweak baryogenesis and baryogenesis through leptogenesis are reviewed.
Cosmology II: From Planck Time to BBN - Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.
www.sciencedaily.com /directory/Science/Physics/Cosmology   (1786 words)

 [No title]   (Site not responding. Last check: 2007-09-18)
15:00 Jan Smit: Tachyonic electroweak transition, CP violation and baryogenesis
15:25 Anders Tranberg: Baryogenesis from CP-violation at Electroweak Tachyonic Preheating (slides), and plots
18:10 Masahide Yamaguchi: Baryogenesis from a flat direction with only Peccei-Quinn charge
www.ippp.dur.ac.uk /cosmo03/BAUPT.html   (71 words)

 Theoretical Particle Physics - Electroweak Baryogenesis   (Site not responding. Last check: 2007-09-18)
Published papers have considered a general two Higgs doublet model, as well as the Minimal and Next to Minimal Supersymmetric Standard Model.
Electroweak baryogenesis requires additional sources of CP violation than are present in the Standard Model.
We have investigated a general version of the Next to Minimal Supersymmetric model which allows spontaneous CP violation.
www.physics.gla.ac.uk /~adavies/ElectBar   (340 words)

 Turning Around the Sphaleron Bound: Electroweak Baryogenesis in an Alternative Post-inflationary Cosmology   (Site not responding. Last check: 2007-09-18)
Turning Around the Sphaleron Bound: Electroweak Baryogenesis in an Alternative Post-inflationary Cosmology
The usual sphaleron bound and the statement of the impossibility of baryon production at a second order phase transition or analytic cross-over are reformulated in the first part of the paper as requirements of the expansion rate of the Universe at the electroweak scale.
In models with inflation driven by a second field and the usual mechanism of reheating (by decay of the inflaton) the required kinetic energy dominated cosmology is viable in both types of potential.
www.maths.tcd.ie /report_series/abstracts/tcdm9712.html   (295 words)

 Abstract the 14th Rencontres de Blois
Models of baryogenesis leading to astronomically significant amount of
It is recently shown that the possibility of small amount of
in the Universe in a non-GUT baryogenesis model with a scalar field
blois.in2p3.fr /2002/pages/abstract.html   (3501 words)

 Open Directory - Science: Physics: Cosmology
Cosmology from Topological Defects - Lecture Notes delivered at the Xth Brazilian School on Cosmology and Gravitation, Mangaratiba, Rio de Janeiro, July 29 - August 9, 2002.
The focus is on major features of N-body simulations: equations, main numerical techniques, effects of resolution, and methods of halo identification.
The Possible Geometries for Space - A short article on the possible structures for space in the Friedmann-Robertson-Walker model
dmoz.org /Science/Physics/Cosmology   (1326 words)

 MCTP: Baryogenesis workshop, 2003   (Site not responding. Last check: 2007-09-18)
Dark Matter and Baryogenesis at the QCD scale
The atmospheric neutrino mass scale from a leptogenesis point of view 4 PM Li (Institute for Advanced Study)
Electroweak Baryogenesis in the SUSY SU(3) x SU(2) X U(1) x U(1)' model
www.umich.edu /~mctp/events/baryogenesis2003/talkschedule.html   (159 words)

 Dr. Micha Berkooz, Weizmann Institute, Standard Model Baryogenesis with Horizontal Symmetries   (Site not responding. Last check: 2007-09-18)
Micha Berkooz, Weizmann Institute, Standard Model Baryogenesis with Horizontal Symmetries
Begin WebCam and audio for the whole talk: high bandwidth or medium bandwidth.
To begin viewing slides, click on the first slide below.
online.itp.ucsb.edu /online/strings03/berkooz   (54 words)

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