Rare $ B $ Decays as Tests of the Standard Model
... the FCNC interactions are encoded in Wilson coefficients of dimension-six operators that are made out of the
light SM fields, i.e. leptons, the five lightest quarks, photons and gluons. This not only allows to calculate
QCD corrections to weak decays perturbatively but is also useful when studying p ...
Measurement of the Top Quark Pair Production Cross Section with
... and µ+jets events recorded with the CDF II detector. The data correspond to 1.12
fb−1 of pp collisions with center-of-mass energy 1.96 TeV taken during Run 2 of the
Fermilab Tevatron. We identify tt candidate events by requiring at least one secondary
vertex b-tag, and we measure a production cross ...
Reconstruction of ttZ Events Using Kinematic Likelihood Fits at the
... matter, its constituents and the forces acting between them. Visible matter is formed by
spin-½ particles called fermions. They are separated into quarks and leptons, according
to their different coupling behaviour, each consisting of three families. For all twelve
fermions there exists an antiparti ...
Plasma_02 - StealthSkater
... Neutrinos were the "ghosts" of the particle world. Even if they really existed, scientists
saw no way to detect them.
[Jonas Schultz] (University of California, Irvine): They concluded that it was a practical impossibility - that no one would ever see these neutrinos. And I think that's what put pe ...
the unit nature of matter - Starlight Publishing Company
... the current (energy rotation) around the unit of matter generates a magnetic field, the
direction of which follows either the right hand rule or the left hand rule, depending on
the charge of the current.
The positive current of the positron generates a magnetic field that follows the right
hand rul ...
A search for the Higgs boson in the decay to b-quarks
... If a particle travels with the speed of light, left or right handedness is independent of its reference frame
(in Formula 1.1, the sign of helicity depends on the direction of p). Only mass-less particles travel with
the speed of light, but we neglect the mass of the neutrinos in this section. It gi ...
The Excitement of Neutrino Physics
... The lightest massive particles
A million times lighter than the electron
No direct mass measurement yet
The most weakly interacting particles
Invisible: do not interact with light
Stopping radiation with lead shielding:
Stopping α, β, γ radiation: 50 cm
Stopping neutrinos from the Sun: light years ! ...
The CKM Matrix and CP Violation
... the CKM matrix
• To date CP violation has been observed only in the quark sector
• Because we are dealing with quarks, which are only observed as bound states,
this is a fairly complicated subject. Here we will approach it in two steps:
• i) Consider particle – anti-particle oscillations without CP ...
Slides - indico.jinr.ru – Indico
... Following the PAC recommendation, in November 2016 another beam
measurements were fulfilled with a different tritium concentration
(0.08% tritium in the T/H mixture) and in two different detector geometries
Results (preliminary!) of the November run:
1. Predictions about the dependence of the react ...
the capture of magnetic inelastic dark matter in the sun.
... The nature of dark matter is one of the most intriguing mysteries in physics. One of our best
candidates to explain its properties is the WIMP, or Weakly Interacting Massive Particle. These
particles would be produced by thermal processes in the early universe, and freeze-out at their
present densit ...
pptx - Curtis A. Meyer
... Should we expect to see these?
MIT Bag Model – quarks confined to a finite space, add a TE gluon JPC=1+- .
This leads to four new nonets of “hybrid mesons” 1-- 0-+ 1-+ and 2-+ .
Automatic scanning of emulsion films for the OPERA - INFN
... In e+ e− collisions at SLAC was later found evidence for a third type of
lepton τ − to which was associated a third neutrino ντ .
During the sixties and seventies, electron and muon neutrinos of high
energy were used to probe the composition of nucleons. The experiments
gave evidence for quarks and ...
Search for Signatures of New Heavy Top Quark of the Fourth
... Z bosons decays, and 2 hadrons are produced from decaying the W boson and two b jets. We searched for
the t ′ by analyzing Monte Carlo data generated by MadGraph5, CalcHEP and Pythia8. The discoveries of the
top quark at the Tevatron have been many searches for a possible new generation of fermions. ...
... confirming evidence from earlier experiments, showed
the oscillation of muon neutrinos. This confirmation of
oscillations shook the neutrino world.
Super-Kamiokande also confirmed the observation
of the solar neutrino deficit first seen by Davis and
Bahcall. In the process, they took the first image ...
Finite-Volume Electromagnetic Corrections to the Masses of Mesons
... when the electromagnetic gauge field is subject to periodic boundary conditions (PBCs) [15–17].
However, a uniform background charge density can be introduced to circumvent this problem and
restore these laws. This is equivalent to removing the zero modes of the photon in a finite-volume
(FV) calcul ...
... dot-dash lines
... with several unknown parameters
=> an exciting experimental program for at least 25 years *)
including leptonic CP & T violations
Multi-Majoron Modes for Neutrinoless Double
... decays, provided we relax the conditions that are cast on the relevant masses by big bang
nucleosynthesis constraints. The estimated rate for the n = 7 decays appears to be too
small to be detectable.
This paper has the following organization. The next section computes the ββϕϕ decay
rate for the t ...
... The question of how neutrino masses arise has not been answered conclusively. In the Standard
Model of particle physics, fermions only have mass because of interactions with the Higgs field
(see Higgs boson). These interactions involve both left- and right-handed versions of the fermion
(see chirali ...
The quark model and deep inelastic scattering
... created in strong interactions — particles which did not fit into the two-quarkflavour model and were called ‘strange particles’. Bubble chamber experiments
were used to examine the properties of beams of strange particles and demonstrated
that the strange particles could travel macroscopic distance ...
The Weak Interaction - University of Warwick
... The nuclear β-decay caused a great deal of anxiety among physicists. Both α- and γ-rays are emitted
with discrete spectra, simply because of energy conservation. The energy of the emitted particle is
the same as the energy difference between the initial and final state of the nucleus. It was much
What does a spark chamber detect?
... little finger's nail every second, and their main source is thought to be from the
Sun. They are so unreactive, that if they were to travel through a light year worth
of lead, there would only be 50% change that it would hit anything along the way.
Much experimental work is currently being done to ...
... Just as for J/ψ, decay involves coupling to virtual photon.
The φ is ssbar: electric charge factor (-1/3)2
Both ρ and ω are mixtures of u.ubar and d.dbar, but there’s a factor of ~10
difference in leptonic width…
The u and d quarks play a special role in the strong interactions because
their masses ...
SEARCH FOR HEAVY LEPTONS FROM TIME
... Once Nino came to my office to tell me about his ideas of studying
lepton pair production at PS. I was still not Director General, but Research
Director at CERN. In addition to (ee) and () pairs, he wanted to
search for (e) pairs as a signature of a new lepton carrying its own lepton
The muon (/ˈmjuːɒn/; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with electric charge of −1 e and a spin of 1⁄2, but with a much greater mass (7002105700000000000♠105.7 MeV/c2). It is classified as a lepton, together with the electron (mass 6999511000000000000♠0.511 MeV/c2), the tau (mass 7003177682000000000♠1776.82 MeV/c2), and the three neutrinos (electron neutrino νe, muon neutrino νμ and tau neutrino ντ). As is the case with other leptons, the muon is not believed to have any sub-structure—that is, it is not thought to be composed of any simpler particles.The muon is an unstable subatomic particle with a mean lifetime of 6994220000000000000♠2.2 µs. Among all known unstable subatomic particles, only the neutron (lasting around 15 minutes) and some atomic nuclei have a longer decay lifetime; others decay significantly faster. The decay of the muon (as well as of the neutron, the longest-lived unstable baryon), is mediated by the weak interaction exclusively. Muon decay always produces at least three particles, which must include an electron of the same charge as the muon and two neutrinos of different types.Like all elementary particles, the muon has a corresponding antiparticle of opposite charge (+1 e) but equal mass and spin: the antimuon (also called a positive muon). Muons are denoted by μ− and antimuons by μ+. Muons were previously called mu mesons, but are not classified as mesons by modern particle physicists (see § History), and that name is no longer used by the physics community.Muons have a mass of 7002105700000000000♠105.7 MeV/c2, which is about 207 times that of the electron. Due to their greater mass, muons are not as sharply accelerated when they encounter electromagnetic fields, and do not emit as much bremsstrahlung (deceleration radiation). This allows muons of a given energy to penetrate far more deeply into matter than electrons, since the deceleration of electrons and muons is primarily due to energy loss by the bremsstrahlung mechanism. As an example, so-called ""secondary muons"", generated by cosmic rays hitting the atmosphere, can penetrate to the Earth's surface, and even into deep mines.Because muons have a very large mass and energy compared with the decay energy of radioactivity, they are never produced by radioactive decay. They are, however, produced in copious amounts in high-energy interactions in normal matter, in certain particle accelerator experiments with hadrons, or naturally in cosmic ray interactions with matter. These interactions usually produce pi mesons initially, which most often decay to muons.As with the case of the other charged leptons, the muon has an associated muon neutrino, denoted by νμ, which is not the same particle as the electron neutrino, and does not participate in the same nuclear reactions.