CDF's Particle Physics Results Explained 

as seen in Fermilab Today's "Result of the Week" 

CDF II


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Every Thursday, a new Fermilab Result of the Week appears in Fermilab Today, Fermilab's daily email publication for employees, users and subscribers. Results of the Week highlight science from Fermilab experiments. Each Result of the Week is a showcase of the scientific research and results achieved at Fermilab. Featured here are results from the CDF Collaboration. Also, check out plain english summaries  of published results.

Article Title 
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Physics Title  Description  Date Published 
2008  See photos and pictures for 2008 
Expect the unexpected Search for new physics in the di-photon plus lepton signature CDF physicist searched, in a model independent way, for excesses in the final states containing two photons and a lepton. No excesses were observed.
April, 3, 2008
The Tevatron's Higgs highway Tevatron Higgs combination and future expectations A new Tevatron Higgs combination shows that the excluded cross-sections are very close to the expected SM limits. Extrapolations to the data expected until the end of 2010 show that we can expect to exclude most of the mass range and have a change at seeing evidence in some mass regions.
March, 21, 2008
CDF seeks sexy singles Evidence for single top quark production Single top quark production is sensitive to the weak force but it is very difficult to extract from a huge background of other Standard Model processes. Three sophisticated analysis are used and their results combined.
March, 20, 2008
Finding needles in a haystack of collisions CDF L2 Upgrade An upgrade to the CDF L2 trigger system was performed which reduces the number of unwanted events at high luminosity.
March, 6, 2008
Shedding light onto other dimensions Search for extra dimensions CDF physcisits searches for events with only a single photon and missing energy. This signature has only very little Standard Model background and is expected to be sensitive to extra dimensions. No excess is observed.
February, 14, 2008
CDF scientists create a buZZ Evidence of ZZ production For the first time at the Tevatron, CDF researchers have observed events produced in proton-antiproton collisions that resulted in the production of two Z bosons.
February, 1, 2008
Searching for the missing link using missing energy SM Higgs Seach using jets and missing energy One way the Higgs boson can be produced is with a Z boson. The Higgs boson can decay to a pair of b-quarks, which each produce a jet. The Z boson can decay to neutrinos, which are invisible to collider detectors.
January, 31, 2008
Strangely beautiful - beautifully strange CP-violation in the Bs meson CP violation in the Bs system is only in marginal agreement with the Standard Model prediction
January, 17, 2008
CDF scientists see strange in a proton? Meausrement of the W+c-jet cross-section Physicists at CDF measure the W+c-jet production cross-section, a world first. This process is sensitive to the strange quark content of the proton.
January, 3, 2008
2007  See photos and pictures for 2007 
Does top choose the road less traveled? Measurement of Afb in top production Physicists at CDF seek to measure the forward-backward asymmetry in top production. A large asymmetry in top quark production could be evidence of new physics. So significant deviation from the Standard Model expectations is observed.
December, 13, 2007
Never trust billiard ball b-quark physics Measurement of b-quark production angles In more complicated theories, B quarks are not produced back to back because of other particles produced. This measurement confirms these models.
November 29, 2007
Closing in on the Higgs Search for Higgs produced with W bosons The standard model Higgs boson can be produced at the Tevatron at the same time as W bosons. This search for W + Higgs continues to get more sensitive as techniques are improved.
November 8, 2007
CDF confirms the charming nature of particle oscillations Evidence of charm mixing in D0 meson CDF presents evidence for D0 mesons oscillation into their own antiparticles.
October 25, 2007
Getting a charge from asymmetry W charge asymmetry If one wants to know what a proton and antiproton look like inside at really high energies, one can study which direction the W bosons are produced in Tevatron collisions.
October 11, 2007
Does the top quark have a weight problem? Simultaneous top mass and cross-section measurement in dilepton channel In the past, we have measured the top quark mass in many ways, and also the number of top quarks produced. Here we describe a measurment of the top quark mass which uses the number of top quarks produced to try to get a better answer..
September 27, 2007
Searching for 23 percent of the universe at the Tevatron B_s to muon+muon search This particular B meson decay is very sensitive to supersymmetry, and if the rate is found to be higher than predicted by the standard mdoel, it would be evidence of new physics.
September 13, 2007
A beautiful road to the Higgs Search for supersymmetric Higgs to b quarks If supersymmetry is correct, then the Higgs boson can be produced at a much higher rate than in the standard model, and can decay to b quarks. In this search we find a slight excess of data, which we will continue to monitor as data comes in..

August 30, 2007
Summer to begin for CDF 54 new CDF summer results Since winter, CDF has produced over 54 new measurements, many of which will be presented at summer conferences.
August 16, 2007
Looking at CP violation from another angle Steps toward measuring CP angle gamma using B_s to D_s K decays CP violation is the difference between matter and antimatter. A new physics process found by CDF can allow CP violation to be studied in a different way, to further understand the sources for CP violation.
August 2, 2007
If the top lost its bottom, would it still have charm? Flavor changing neutral currents in top quark decay In the standard model, the top quark decays almost 100% of the time to a W boson and a b quark. In some theoretical extensions to the standard model, the top quark may decay to a Z boson and a charm quark. Here is a search for the latter.
July 19, 2007
Leptons and quarks: Are they related ? Search for leptoquarks There are 3 generations of quarks, and 3 generations of leptons. This CDF search looks to see if there is a reason for this by search for particles which are part lepton and part quark.
July 5, 2007
Top crosses 10,000 Most precise top quark cross-section measurement With a huge number of top quarks recorded at CDF, we measure the cross-section to produce top quarks with the most precise measurement to date.
June 21, 2007
CDF leaves no stone unturned Global searches (Vista and Sleuth) Here we describe a global search for new physics at CDF using a large number of types of events.
June 7, 2007
The strong, the weak, and the invisible Measurement of Z + jets cross-sections This measurement is of the Z boson cross-section produced with jets. This physics process is a background for Higgs events and supersymmetric processes.
May 24, 2007
CHAMP sent to corner Search for CHAMPs CHAMPs, or "charged massive stable particles", are possible new phenomenon, which could explain the missing mass in the universe. CDF has searched for these particles at CDF by measuring the time it takes particles to traverse the CDF detector.
May 10, 2007
Charged on top Measurement of ABC Here we describe a measurement of the charge of the top quark, using its decay products.
April 26, 2007
CDF lowers the roof on Higgs Search for Higgs decaying to two W bosons For Higgs boson masses above 135 GeV, the Higgs boson prefers to decay to two W bosons. Here we describe a search for this Higgs decay, and see that we are getting very close to either finding evidence or excluding Higgs boson masses at 160 GeV, which is twice the mass of the W boson.
April 12, 2007
The weak force: How fast does it decay ? W width measurement By careful study of the range of masses the W boson can have, we can measure top W boson width and its lifetime.
March 29, 2007
The black orchids of particle physics Search for rare b decays Special decays of b hadrons can be indirectly affected by heavier particles, such as those from new phenomenon. Here we describe a search for new phenomenon using the decays of b quarks.
March 15, 2007
Not all top quarks are created equal Top quark production mechanisms Top quarks can be produced either by gluons or quarks in collisions of protons and antiprotons. Here we describe two different types of methods for distinguishing them.
March 1, 2007
New data, new questions Search for new physics with leptons, photons, and MET Some interesting events with leptons, photons, and missing transverse energy were seen at the Tevatron in its "Run I" in the 1990's. Here we describe dedicated searches for this type of phenomenon in order to test for new physics.
February 15, 2007
Tautal Excess Search for supersymmetric Higgs decaying to tau leptons If supersymmetry is correct, then the Higgs boson can be produced at a much higher rate than in the standard model, and can decay to tau leptons. In this search we find a slight excess of data, which we will continue to monitor as data comes in..
February 1, 2007
The W weighs in again Single best W mass measurement An important parameter in the standard model is the W mass, which amongst other things, provides an estimate of the Higgs mass. Here we describe the single best W mass measurement to date.
January 18, 2007
A relatively simple idea Measurement of top mass using LXY The top quark decays to several particles including a b quark. Because the b quark has a lifetime, and because time moves slower for faster moving objects due to relativity, one can measure the top quark mass by measuring how far the b quark travels before decaying.
January 4, 2007
2006  See photos and pictures for 2006 
Life on the edge of the top quark Search for Single top quark production The top quark was discovered in 1995 at the Tevatron. Many measurements have been made for the case when the top quark is produced in pairs by the QCD interaction. The electroweak theory states that the top quark can be produced by the electroweak force also, but only one at a time. Here we describe a search for the not yet observed single top quark production.
December 7, 2006
WZ couple: Discovering a match made in heavies Observation of WZ production A W boson and Z boson can be produced in the same interaction, but with an extremely small probability (or cross-section). Here we describe the first observation of this process. This achievement is a milestone for searching for undiscovered phenomenon.
November 16, 2006
The leaning tower of B mesons Observation of Bs->K pion This new decay mode will allow new studies of CP asymmetries. CP (Charge Parity) asymmetries are when antimatter is not the mirror image of matter, and contribute to why our universe is filled with only with matter rather than both.
November 2, 2006
Discover one, get three free Discovery of four new Σbbaryons These are new particles composed of 3 quarks, one of which is a b quark. A measurement of their properties will help theorists study how quarks form into composite particles.
October 23, 2006
What tops top? Search for a heavy top-quark like particle The top quark is the heaviest particle. We describe here a search for a hypothetical, heavier one.
October 5, 2006
Photons shed light on higher dimensions Search for Graviton decaying to two photons If there are extra dimensions in our universe, gravitons could decay to photons. Her we search for this process.
September 21, 2006
A charming mystery Measuring the polarization of J/Ψ particles We measure the spin orientation of 2-quark particles called J/Ψs (charm quark & anti-charm quark). The result disproves a popular theory that had tried to explain some strange physics seen 10 years ago.
September 7, 2006
Using your brain to find the Higgs Search for Higgs bosons produced with Z bosons We describe a search for the Higgs boson using a technique called artificial neural networks.
August 24, 2006
Weighting a firecracker The most precise single measurement of the top quark mass to date The top quark is the heaviest, and most unstable particle. Here we describe a measurement of its mass to 1.5% accuracy.
August 10, 2006
CDF and DZero: Working together to find the Higgs A combined search for Higgs using multiple analyses from CDF and DZero The Higgs can be searched for in multiple channels at the Tevatron. By combining two experiments, we can double the data, and be more sensitive to finding the Higgs.
August 3, 2006
Wicked W Bosons in Top Quark Decays? Measurement of W helicity in top quark decays Since the top quark is the heaviest particle, does it have different interactions ? Here we describe a measurement of top quark decay which tests for new physics.
July 27, 2006
Looking for Delayed Photons Search for Neutralino decaying to photons If a certain long-lived particle candidate for dark matter exists, it could produce a signature where two photons arrive at the detector at different times. Her we search for this scenario.
July 13, 2006
CDF turns to the Dark Side Search for Charginos and Neutralinos in multi-lepton data We search for supersymmetric particle decays which produce multiple leptons and missing energy due to creation of a dark-matter candidate.
June 29, 2006
Avoiding a breakup Search for exclusive diphotons Protons and antiprotons can glance off each other and produce particles without breaking up. Here we describe a search for such events where photons are produced.
June 15, 2006
Tough Top: Nothing but Jet Top mass measurement in all-jets mode The top quark always decays into a W boson and b quark, but the W can decay into leptons or quarks. Historically, it has been challenging to measure the top quark when both Ws decay to quarks. Now we are reaching the precision era in this decay mode.
June 1, 2006
Beauty and charm are fleeting Measurement of lifetime of Bc particle The Bc particle is composed of a b quark and a c quark and is one of the heaviest 2-quark states. Here we measure its lifetime.
May 18, 2006
At the bottom of everything... Measurement of b quark fragmentation functions A b quark cannot exist by itself. It must excitet a quark out of the vacuum. Her we measure how often different quarks are yanked out of the vacuum.
May 4, 2006
Search for "brand Y" Supersymmetry Search for R-parity violating Supersymmetry Here we describe a search for a type of Supersymmetry (SUSY) in which new SUSY particles interact more freely with known standard model particles.
April 20, 2006
Over the Top Combined measurement of top quark mass Here we describe a precise measurement of the top quark mass by combining multiple top quark decay modes.
April 6, 2006
The last meson shows its full beauty and charm! Observation of fully reconstructed Bc, the last meson Here we describe a measurement of a new channel of the last "ground-state" 2-quark meson. This particle is composed of a b quark and a c quark. "Ground state" means that the particle is not excited.
March 24, 2006
CDF: Looking at Mass Bumps from a Different Angle Search for New particles decaying to electrons Here we look for a bump in the mass spectrum of two-electron data. This analysis not only checks the mass for a bump, but also the relative angles of the electrons produced in the decay.
March 9, 2006
First 1 fb-1 Physics Results at a Hadron Collider Z mass distribution with 1 fb-1 of data We celebrate a milestone of achieving 1 fb-1 of data by examining the mass of the Z boson.
February 23, 2006
Strange Beautiful Meson has a new charming mode Observation of Bs decay to J/Ψ(2S) φ The Bs is a particle composed of a b quark and an s quark. Here we observe its decay into the second excited state (called "2S") of a J/Ψ particle. This measurement indicates that, as in other Bs, these decay about 60% of the time into the "2S" state as the "1S" or first excited state.
January 26, 2006
When heavy Photons decay to Taus Measurement of
Z -> ττ cross-section
A tau (τ) particle is like a heavy, more unstable version of an electron. Taus are more difficult to measure than electrons, and here we describe a precision measurement of the decay of Z bosons to taus.
January 12, 2006
2005 (under construction)  See photos and pictures for 2005 
Missing Energy to Hit the Top Measurement of top quark cross-section in missing energy plus jets channel This new analysis measures the top quark in events which were previously inaccessible for top quark analysis. The trick is to search for missing energy due to the neutrino in the top decay.
December 22, 2005
CDF Gets the LED Out Search for large extra dimensions in missing energy plus jet data If there are large extra dimensions in our universe, we may be able to find them by searching for events where a particle appears to recoil against nothing. That "nothing" is the graviton, which can't be detected, but is expected to exist and be responsible for the force of gravity.
December 8, 2005
Double Jeopardy! Searching for Doubly-Charged Higgs Bosons at CDF Searching for Doubly-Charged Higgs Bosons at CDF In certain exotic models, there can be multiple Higgs particles. Here we search for a Higgs particle with a charge of +2 or -2, twice the charge of a proton or electron.
November 17, 2005
Pushing the World Limit: B Flavor Oscillations at CDF Search for Bs oscillations This is a flagship analysis of the Tevatron. Here we describe how we are getting closer to making this measurement which constrains our knowledge of the asymmetry of matter and antimatter in the universe.
November 3, 2005
What do Z's and b's Tell us About the Higgs Boson? Measurement of Z plus b quark production A Z boson can be produced with a b quark. Knowing the rate of this process is important since it is a background to the sought after process where a Z boson is produced with a Higgs boson, which then decays to b quarks.
October 20, 2005
Getting Ready for Take Two: B0s Mixing at CDF Updates in the search for Bs mixing, which which constrains our knowledge of the asymmetry of matter and antimatter in the universe.
October 6, 2005
Six Jets to the Top Measurement of top quark production cross-section in the all-jets channel The top quark will always decay to a W boson and a b quark. When the W decays to leptons, the signature is more noticeable. However, when the W decays to quarks, which then fragment into sprays of energy called "jets" the measurement is more difficult.
Some Month, XX, 2007
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2007
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2007
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2007
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2007
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
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2004 (under construction)  See photos and pictures for 2004 
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2004
2003 (under construction)  See photos and pictures for 2003 
Title X Measurement of ABC ABC is hypothesized to exist. Here we describe a search for ABC.
Some Month, XX, 2003


CDF result editor
Ben Kilminster