This article is an autobiography or has been extensively edited by the subject or by someone connected to the subject.(February 2024) |
Pekka K. Sinervo is an experimental particle physicist who has studied quarks, [1] gluons [2] and vector bosons [3] [4] [5] [6] using high-energy electron and proton collisions. He is a professor of physics at University of Toronto, where he has taught and pursued research since 1990.
He is known for his contributions to the discovery of the top quark [7] and studies of its properties (see, e.g., [8] [9] [10] ), along with collaborators in the CDF (Collider Detector at Fermilab) and ATLAS experiments. He was also a member of one of the teams that discovered the Higgs boson. [11] His earlier work involved the study of mesons with charm quarks and strange quarks, and hadrons with bottom quarks (see, e.g., [12] [13] [14] ). He is currently working on searches for new particles (see, e.g., [15] [16] ) and dark matter [17] at the SNOLAB Underground Laboratory, as a member of the SuperCDMS Collaboration. [18] Sinervo served as dean of the Faculty of Arts and Science at the University of Toronto [19] from 2003 to 2008, and as senior vice-president, research at the Canadian Institute for Advanced Research [20] from 2009 to 2015. He has written on international research collaborations, science and Judaism, and popular science (see, e.g.,
[21] [22] ). He is a member of the Reform Jewish Community of Canada, [23] serving as its president from 2017 to 2021, and has served in leadership roles in the Union for Reform Judaism [24] and the World Union for Progressive Judaism. [25] He has been recognized for his contributions with appointments to numerous scientific societies [Note 1] with fellowships in the American Physical Society and the Royal Society of Canada recognizing his contributions to the discovery of the top quark. He was appointed a member of the Order of Canada in 2018 [26] for his contributions to the discoveries of the top quark and Higgs boson, and his leadership in the Canadian Jewish community.
A gluon is a type of massless elementary particle that mediates the strong interaction between quarks, acting as the exchange particle for the interaction. Gluons are massless vector bosons, thereby having a spin of 1. Through the strong interaction, gluons bind quarks into groups according to quantum chromodynamics (QCD), forming hadrons such as protons and neutrons.
The Standard Model of particle physics is the theory describing three of the four known fundamental forces in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, through the work of many scientists worldwide, with the current formulation being finalized in the mid-1970s upon experimental confirmation of the existence of quarks. Since then, proof of the top quark (1995), the tau neutrino (2000), and the Higgs boson (2012) have added further credence to the Standard Model. In addition, the Standard Model has predicted various properties of weak neutral currents and the W and Z bosons with great accuracy.
The charm quark, charmed quark, or c quark is an elementary particle found in composite subatomic particles called hadrons such as the J/psi meson and the charmed baryons created in particle accelerator collisions. Several bosons, including the W and Z bosons and the Higgs boson, can decay into charm quarks. All charm quarks carry charm, a quantum number. This second-generation particle is the third-most-massive quark, with a mass of 1.27±0.02 GeV/c2 as measured in 2022, and a charge of +2/3 e.
The top quark, sometimes also referred to as the truth quark, is the most massive of all observed elementary particles. It derives its mass from its coupling to the Higgs boson. This coupling yt is very close to unity; in the Standard Model of particle physics, it is the largest (strongest) coupling at the scale of the weak interactions and above. The top quark was discovered in 1995 by the CDF and DØ experiments at Fermilab.
The bottom quark, beauty quark, or b quark, is an elementary particle of the third generation. It is a heavy quark with a charge of −1/3 e.
In particle physics, a tetraquark is an exotic meson composed of four valence quarks. A tetraquark state has long been suspected to be allowed by quantum chromodynamics, the modern theory of strong interactions. A tetraquark state is an example of an exotic hadron which lies outside the conventional quark model classification. A number of different types of tetraquark have been observed.
The
J/ψ
(J/psi) meson is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium" or psions. The
J/ψ
is the most common form of charmonium, due to its spin of 1 and its low rest mass. The
J/ψ
has a rest mass of 3.0969 GeV/c2, just above that of the
η
c, and a mean lifetime of 7.2×10−21 s. This lifetime was about a thousand times longer than expected.
The Underground Area 2 (UA2) experiment was a high-energy physics experiment at the Proton-Antiproton Collider — a modification of the Super Proton Synchrotron (SPS) — at CERN. The experiment ran from 1981 until 1990, and its main objective was to discover the W and Z bosons. UA2, together with the UA1 experiment, succeeded in discovering these particles in 1983, leading to the 1984 Nobel Prize in Physics being awarded to Carlo Rubbia and Simon van der Meer. The UA2 experiment also observed the first evidence for jet production in hadron collisions in 1981, and was involved in the searches of the top quark and of supersymmetric particles. Pierre Darriulat was the spokesperson of UA2 from 1981 to 1986, followed by Luigi Di Lella from 1986 to 1990.
A conformal anomaly, scale anomaly, trace anomaly or Weyl anomaly is an anomaly, i.e. a quantum phenomenon that breaks the conformal symmetry of the classical theory.
Two-photon physics, also called gamma–gamma physics, is a branch of particle physics that describes the interactions between two photons. Normally, beams of light pass through each other unperturbed. Inside an optical material, and if the intensity of the beams is high enough, the beams may affect each other through a variety of non-linear effects. In pure vacuum, some weak scattering of light by light exists as well. Also, above some threshold of this center-of-mass energy of the system of the two photons, matter can be created.
Exotic hadrons are subatomic particles composed of quarks and gluons, but which – unlike "well-known" hadrons such as protons, neutrons and mesons – consist of more than three valence quarks. By contrast, "ordinary" hadrons contain just two or three quarks. Hadrons with explicit valence gluon content would also be considered exotic. In theory, there is no limit on the number of quarks in a hadron, as long as the hadron's color charge is white, or color-neutral.
This is a timeline of subatomic particle discoveries, including all particles thus far discovered which appear to be elementary given the best available evidence. It also includes the discovery of composite particles and antiparticles that were of particular historical importance.
In particle physics, flavor-changing neutral currents or flavour-changing neutral currents (FCNCs) are hypothetical interactions that change the flavor of a fermion without altering its electric charge.
The Drell–Yan process occurs in high energy hadron–hadron scattering. It takes place when a quark of one hadron and an antiquark of another hadron annihilate, creating a virtual photon or Z boson which then decays into a pair of oppositely-charged leptons. Importantly, the energy of the colliding quark-antiquark pair can be almost entirely transformed into the mass of new particles. This process was first suggested by Sidney Drell and Tung-Mow Yan in 1970 to describe the production of lepton–antilepton pairs in high-energy hadron collisions. Experimentally, this process was first observed by J. H. Christenson et al. in proton–uranium collisions at the Alternating Gradient Synchrotron.
The DØ experiment was a worldwide collaboration of scientists conducting research on the fundamental nature of matter. DØ was one of two major experiments located at the Tevatron Collider at Fermilab in Batavia, Illinois. The Tevatron was the world's highest-energy accelerator from 1983 until 2009, when its energy was surpassed by the Large Hadron Collider. The DØ experiment stopped taking data in 2011, when the Tevatron shut down, but data analysis is still ongoing. The DØ detector is preserved in Fermilab's DØ Assembly Building as part of a historical exhibit for public tours.
CLEO was a general purpose particle detector at the Cornell Electron Storage Ring (CESR), and the name of the collaboration of physicists who operated the detector. The name CLEO is not an acronym; it is short for Cleopatra and was chosen to go with CESR. CESR was a particle accelerator designed to collide electrons and positrons at a center-of-mass energy of approximately 10 GeV. The energy of the accelerator was chosen before the first three bottom quark Upsilon resonances were discovered between 9.4 GeV and 10.4 GeV in 1977. The fourth Υ resonance, the Υ(4S), was slightly above the threshold for, and therefore ideal for the study of, B meson production.
In particle physics phenomenology, chiral color is a speculative model which extends quantum chromodynamics (QCD), the generally accepted theory for the strong interactions of quarks. QCD is a gauge field theory based on a gauge group known as color SU(3)C with an octet of colored gluons acting as the force carriers between a triplet of colored quarks.
In particle physics, W′ and Z′ bosons refer to hypothetical gauge bosons that arise from extensions of the electroweak symmetry of the Standard Model. They are named in analogy with the Standard Model W and Z bosons.
Luigi Di Lella is an Italian experimental particle physicist. He has been a staff member at CERN for over 40 years, and has played an important role in major experiments at CERN such as CAST and UA2. From 1986 to 1990 he acted as spokesperson for the UA2 Collaboration, which, together with the UA1 Collaboration, discovered the W and Z bosons in 1983.
Color transparency is a phenomenon observed in high-energy particle physics, where hadrons created in a nucleus propagate through that nucleus with less interaction than expected. It suggests that hadrons are first created with a small size in the nucleus, and then grow to their nominal size. Here, color refers to the color charge, the property of quarks and gluons that determines how strongly they interact through the nuclear strong force.
This article needs additional or more specific categories .(July 2024) |