
	Where results make sense

Topic: W bosons

Related Topics

W and Z bosons

Higgs boson

gauge bosons

Z boson

W bosons

bosonic string theories

Goldstone boson

Interacting boson model

Nambu Goldstone boson

pseudo Goldstone boson

vector boson

bosonic particles

In the News (Wed 30 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	W and Z bosons - Wikipedia, the free encyclopedia
		In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force.
		The W and Z bosons are carrier particles that mediate the weak nuclear force, much like the photon is the carrier particle for the electromagnetic force.
		The exchange of a Z boson between particles, called a neutral current interaction, therefore leaves the interacting particles unaffected, except for a transfer of momentum.
	en.wikipedia.org /wiki/W_and_Z_bosons (942 words)

	W boson - Wikipedia
		The W Boson is an elementary particle; it is one of the carriers of the weak interaction.
		That the W and Z bosons have mass is somewhat of a conundrum.
		The W and Z are accurately described by a SU(2) Gauge theory, but the bosons in a gauge theory must be massless The photon is also massless because the photon and electromagnetism are described by a U(1) gauge theory.
	nostalgia.wikipedia.org /wiki/W_boson (417 words)

	Boson - Wikipedia, the free encyclopedia
		Bosons are also the only particles which can occupy the same state as another.
		Gauge bosons are elementary particles which act as the carriers of the fundamental forces such as the W vector bosons of the weak force, the gluons of the strong force, the photons of the electromagnetic force, and the graviton of the gravitational force.
		This explains the spectrum of fl-body radiation and the operation of lasers, the properties of superfluid helium-4 and the possibility of bosons to form Bose-Einstein condensates, a particular state of matter.
	en.wikipedia.org /wiki/Boson (285 words)

	W and Z bosons: Definition and Links by Encyclopedian.com - All about W and Z bosons (Site not responding. Last check: 2007-10-21)
		The W Boson is an elementary particle, having an electric charge of just ±1, a mass of 80.4110 GeV (about 80 times the proton's mass), and weak isospin of the same.
		The discovery of the W Boson occurred in 1983, during a series of SPS accelerator-based experiments being conducted by Carlo Rubbia and Simon Van der Meer[?], working at the CERN laboratory.
		The W and Z are accurately described by a SU(2) Gauge theory[?], but the bosons in a gauge theory must be massless.
	www.encyclopedian.com /z-/Z-boson.html (366 words)

	Electroweak Physics at LBL
		The experimental discovery of the Z and W bosons in 1983 by the UA1 and UA2 collaborations at CERN was a supreme vindication of the unified electroweak theory and earned Carlo Rubbia and Simon Van der Meer the Nobel Prize in 1984.
		A measurement of the W boson mass and a measurement of its decay width.
		The W width is measured by essentially counting the number of events at large values of the transverse mass, since predominantly it is the intrinsic width/lifetime of the W which determines the mass distribution at large values of the mass.
	www-cdf.lbl.gov /cdf_ewk/cdf_ewk.html (1180 words)

	Encyclopedia: W and Z bosons (Site not responding. Last check: 2007-10-21)
		Gauge bosons are bosonic particles which act as carriers of the fundamental forces of Nature.
		In particle physics, a squark is a hypothetical boson partner of a quark whose existence is implied by supersymmetry.
		In particle physics, a slepton is a hypothetical bosonic partner of a lepton whose existence is implied by supersymmetry.
	www.nationmaster.com /encyclopedia/W-and-Z-bosons (2417 words)

	W and Z bosons -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-10-21)
		In (The science of matter and energy and their interactions) physics, the W and Z bosons are the elementary particles that mediate the (Click link for more info and facts about weak nuclear force) weak nuclear force.
		Two kinds of W bosons exist with +1 and −1 elementary units of (The quantity of unbalanced electricity in a body (either positive or negative) and construed as an excess or deficiency of electrons) electric charge; the W
		The discovery of the W and Z particles themselves had to wait for the construction of a (A scientific instrument that increases the kinetic energy of charged particles) particle accelerator powerful enough to produce them.
	www.absoluteastronomy.com /encyclopedia/w/w/w_and_z_bosons.htm (1336 words)

	Meeting of The Divison of Particles and Fields of The American Physical Society
		Since the longitudinal $W$ boson is intimately related to the electroweak symmetry breaking mechanism, and the Standard Model gives a specific prediction for the fraction of longitudinal W bosons from top decays in nature, it is of particular interest for study.
		We present a preliminary measurement of $W$ boson polarization through an analysis of lepton angular distributions from top-quark candidate decays observed with the CDF II detector at the Tevatron.
		We present a preliminary measurement of $W$ boson polarization through an analysis of transverse momentum spectrum of charged leptons in top-quark candidate decays observed with the CDF II detector at the Tevatron.
	physics.ucr.edu /~billdbrk/Abstract.html?id=29 (228 words)

	The Particle Table
		The hypothetical "Higgs" boson, the presumed source of particle mass, probably belongs here with the other massive "metric" particles, although it is not an IVB (the Higgs has spin = 0 whereas the IVBs have spin = 1).
		Another advantage of the theory is that if the W is a metric particle, then it may also contain an element of time, which could be the source of its asymmetric character.
		This mechanism also raises another possibility: if the W has a "big brother" (the "X"), it might be powerful enough to squeeze the quarks of a baryon sufficiently to cause the color charge to vanish ("asymptotic freedom"), and initiate proton decay.
	www.people.cornell.edu /pages/jag8/partable.html (2555 words)

	Exchange Particles
		The W and Z particles are the massive exchange particles which are involved in the nuclear weak interaction, the weak force between electrons and neutrinos.
		The W and Z particles are called intermediate vector bosons and are the exchange particles for the weak interaction.
		The charged W bosons participate in the transformation of quarks in which the flavor of the quark is changed.
	hyperphysics.phy-astr.gsu.edu /hbase/particles/expar.html (1159 words)

	Theory: Weak Interaction Carrier Particles
		Processes where a W boson is emitted or absorbed are the only way that quark flavor can be changed.
		The Z boson has no electric charge and no other distinguishable quantum number so the antiparticle of a Z boson is a Z boson.
		Z bosons decay to produce either quark and its matching flavor antiquark or a lepton and its matching anti-lepton.
	www2.slac.stanford.edu /vvc/theory/weakbosons.html (218 words)

	sciforums.com - pi mesons decay
		I think that W and Z is not correctly to be called "intermediators" of the weak force, they are rather just intermediate state of the decayng particles.
		W and Z are the mediators of the weak force.
		the mediator boson (W or Z) is exchanged between the quark and the lepton.
	www.sciforums.com /showthread.php?t=28158 (3301 words)

	Hadronic decays of W bosons.
		We present evidence for hadronic W decays in $t\bar t\ \to$ lepton + neutrino + $\ge$ 4 jet events using a 109 pb$\sp{-1}$ data sample of $p\bar p$ collisions at $\sqrt s$ = 1.8 TeV collected with the Collider Detector at Fermilab (CDF).
		This peak is consistent with W decay but inconsistent with the predicted background shape by 2.9$\sigma$.
		We measure the W mass to be 78.3 $\pm$ 5.1 (stat) $\pm$ 3.0 (syst) GeV/$c\sp2$.
	repository.upenn.edu /dissertations/AAI9800939 (168 words)

	W Boson Decays
		is the azimuthal angle of the decay fermion in the W rest frame, as illustrated in figure 3.9.
		Knowing how the decay fermions couple to the W bosons of different helicity and also how the W bosons are produced in the W-pair through the helicity amplitudes, (3.18), an analytical expression for the differential cross-section of the process
		The subscripts on the D-functions, shown in equation 3.26, do not indicate the spins of the two separate W bosons, but rather are both for a single W boson.
	www.hep.ucl.ac.uk /~jpc/all/ulthesis/node45.html (552 words)

	CERN Courier - The W and Z at LEP - IOP Publishing - article
		In the first phase, between 1989 and 1995, 18 million Z bosons were collected, while in the second phase, from 1996 to 2000, some 80,000 W bosons were generated at energies gradually climbing from the W-pair threshold to the maximum of 209 GeV.
		The properties of the Z boson and the underlying electroweak theory were studied at LEP by measuring the overall formation cross-section, the forward-backward asymmetries of the leptons and quarks, and the polarization of tau leptons.
		From the steep increase of the excitation curve near the threshold and from the reconstruction of the W bosons in the leptonic and hadronic decay modes, the mass M
	www.cerncourier.com /main/article/44/4/15 (2374 words)

	CHART of INTERACTIONS
		Quarks and leptons are fermions with half spins, while mediators of interactions are full spin bosons: photon, graviton, gluon, W+, W-, Zo bosons.
		More precisely, the two W bosons have charge as well as mass, while the Z boson has only mass.
		W +, W-, Zo It can be seen that the weak interaction "sticks out" of line somehow - it is "irregular" - yet we should also notice its analogy with the pi mesons.
	www.geocities.com /CapeCanaveral/Galaxy/7386/chart.html (331 words)

	W and Z bosons at opensource encyclopedia (Site not responding. Last check: 2007-10-21)
		it:Bosoni W e Z sl:Bozoni W in Z In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force.
		Two kinds of W boson exist with +1 and −1 elementary units of electric charge; the W
		Their electroweak theory postulated not only the W bosons necessary to explain beta decay, but also a new Z boson that had never been observed before.
	wiki.tatet.com /W_and_Z_bosons.html (963 words)

	Individual W Polarised Cross-Sections
		Represented are the differential cross-sections for leptonically decaying W bosons and hadronically decaying W bosons, along with the sum of all W bosons.
		The polarisation of the leptonically and hadronically decaying W bosons in a W-pair were obtained independently of each other.
		The total fraction of longitudinal W bosons was calculated by taking the average of the leptonic and hadronic fractions.
	www.hep.ucl.ac.uk /~jpc/all/ulthesis/node100.html (321 words)

	ScienceWeek
		The mass of the Higgs boson is not specified in the SM, but the strength of the "coupling" of the Higgs boson to a given particle is proportional to that particle's mass, so that the Higgs boson decays preferentially to the most massive particles that are allowed by energy and momentum conservation.
		Indirect methods can also be used to constrain the mass of the Higgs boson, because it affects other observable quantities (for example, the mass of the W boson and some measurable properties of the Z boson).
		According to current physics, all particles in nature are either fermions or bosons, with fermions (always elementary particles) having half-integer spin (spin-states characterized by half-integer multiples of Planck's constant divided by 2[pi]), and bosons (all other particles) having integer spin (spin-states characterized by integer multiples of Planck's constant divided by 2[pi]).
	scienceweek.com /2004/sc040528-1.htm (1896 words)

	CERN Courier - LEP pursues Higgs boson and - IOP Publishing - article
		A fit to the LEP and SLC results on Z exchange, as well as the determinations of the W boson and top quark masses from LEP and the Tevatron, predict that the Higgs boson should be lighter than about 220 GeV, with a best fit at around 90 GeV.
		Via many of the same measurements that are used to constrain the Higgs boson indirectly, the experimenters (with a great deal of help from the theorists) have coaxed the Standard Model into predicting the mass of the W boson with an error of only 26 MeV (in 80 GeV).
		Now the challenge is to measure the W boson mass directly to the same accuracy, which will be a stringent test of the Standard Model.
	www.cerncourier.com /main/article/39/9/12 (962 words)

	London Student Issue 11 - futures Higgs bosons (Site not responding. Last check: 2007-10-21)
		Physicists hope that the Higgs boson will be able to explain how the cooling of the universe led to a plurality of forces, or bosons.
		The Higgs boson is then thought to have interacted with these massless bosons at several distinct stages of the universe’s expansion, to create each of the four, massive, force bosons.
		W bosons (weak nuclear bosons) result; furthermore, their mass is known.
	www.londonstudent.org.uk /11issue/futures/boson.htm (599 words)

	W and Z bosons - Hutchinson encyclopedia article about W and Z bosons (Site not responding. Last check: 2007-10-21)
		Member of a group of elementary particles, see intermediate vector boson.
		W (slang for George Walker Bush; the 43rd US president)
		This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.
	encyclopedia.farlex.com /W+and+Z+bosons (86 words)

	13.3.2.1 Anomalous Coupling of the W bosons
		is the angle of the W boson with respect to the beam axis.
		Figure 13.15 shows corrected number of W pairs as a function of their center-of-mass energy.
		are the number of W pairs, the luminosity and the cross section for J=0 and 2 in the i-th bin, respectively.
	acfahep.kek.jp /acfareport/node319.html (701 words)

	Physics Help and Math Help - Physics Forums - Do bosons anihilate?
		Photons with photons to produce electron-positron pairs (most commonly), gluons with gluons to produce quark-antiquark pairs, Z particles with Z particles to produce either lepton-antilepton pairs of quark-antiquark pairs, and W- with W+ to produce photons (generally, but sometimes Z particles).
		It is possible, since we have bosons that decay into leptonic pairs and quark pairs already, that we need some boson that can decay into neutrino pairs to complete the model.
		W- and W+ are very similar to electrons in this way; they too can be treated as just oppositely charged renditions of the same particle.
	www.physicsforums.com /printthread.php?t=10519&pp=40 (1673 words)

	Theory: Weak Interactions
		Later, higher energy experiments produced W and Z bosons and studied their decays.
		Carlo Rubbia and Simon van der Meer were awarded the 1984 Nobel Prize for their development of the facility at CERN which first produced and detected W and Z bosons, and for their leadership of the discovery experiment.
		The W boson then decays to produce an electron and an anti-electron type neutrino.
	www2.slac.stanford.edu /vvc/theory/weakinteract.html (481 words)

	Weak Mixing Angle Lab Writeup
		It relates the masses of the W and Z bosons and determines their relative couplings to matter.
		In this experiment, W bosons are only produced as virtual particles but higher energy experiments have produced real W bosons both individually and in pairs.
		bosons are willing to interact with both quarks and anti-quarks but have couplings that depend on the charge and helicity of the particle and involve the Weak Mixing Angle.
	www-e815.fnal.gov /wma-lab-web/writeup.html (3114 words)

	CDF HWW Dilepton Analysis - Public Access (Site not responding. Last check: 2007-10-21)
		In the Standard Model, when the mass of Higgs boson is greater than 135 GeV the predominant mode of Higgs decay is to a pair of W bosons.
		When the mass of the Higgs boson is greater than 136 GeV the predominant mode of Higgs decay is to a pair of on/off-shell W bosons.
		The Higgs boson is predicted to have zero spin in the Standard Model, which would make a Higgs event different from background in many ways, for example, small angular separation and small invariant mass of the two final-state leptons.
	www.hep.wisc.edu /~shanhuei/HWW (703 words)

	CCSD thèses-EN-ligne: Mesure des corrélations de Bose-Einstein dans les désintegrations de paires de bosons W avec ...
		The measurement of the W boson mass is a key issue of LEP2.
		In the W+ W- -> q1 q2bar q3 q4bar channel, a large systematic error comes from Bose-Einstein correlations, which could induced a non-independent fragmentation of the two W. This thesis deals with the measurement of these correlations in W boson pair decays.
		The model predictions are compared to results of measurements done in W+ W- decays observed at energies of collisions of 172, 183 and 189 GeV.
	tel.ccsd.cnrs.fr /documents/archives0/00/00/30/62/index.html (474 words)

Try your search on: Qwika (all wikis)