Hadrons  

In General > s.a. atomic; Bag Model; constants; neutron; particle physics; QCD phenomenology; Skyrme Model.
* Idea: Mesons and baryons (and pentaquarks).
* Types and classification: The known mesons (singlets and octets) and baryons (singlets, octets and decuplets) belong to representations which are explained as made up from the fundamental representation of flavor SU(6):

q-qbar = 3 3bar = 1 8 ;   qqq = 3 3 3 = 1 8 8 10 .

* Pions, : The isovector fundamental representation of isospin SU(2); The "mesons" postulated by H Yukawa in 1935, discovered by C Powell in emulsions exposed to cosmic rays in 1947.
* Kaons, K: Mesons containing strange quarks; > s.a. CP violation, CPT.
* Baryons: Hadrons composed of three (valence) quarks; They include p, n, and the heavier, unstable ones, or hyperons; In the large Nc limit of QCD, baryons can be modeled as solitons, for instance, as Skyrmions.
* Pentaquarks: 2002–2003, Discovered in Japan and confirmed by others, thought to be made up of five quarks; 2004–2005, More claimed detections [@ news pw(04)mar, charmed], but not seen in further, higher-energy experiments, and considered by some to be a mistake.
@ General references: Chew et al SA(64)feb; Jaffe PT(95)sep [p spin]; Rajeev ht/99 [structure functions]; Alkofer & von Smekal PRP(01) [IR Green functions]; Jaffe hp/01-in [spin distribution]; Gogohia PLB(05)ht/04, ht/06 [mass gap]; Belotsky et al hp/04 [4th generation, bounds]; Afonin IJMPA(07) [parity doubling].
@ Mesons: Choi et Belle PRL(03)he + pw(03)nov [X(3872) mystery meson – tetraquark?]; Particle Data Group PLB(04); Choi et al PRL(05) + pw(05)may [hybrid]; Swanson PRP(06) [new heavy]; news pw(07)nov [tetraquark?].
@ Baryons: Particle Data Group PLB(04); Cherman & Cohen JHEP(06)ht [and large Nc limit]; news pn(06)oct, png(06) [periodic table]; news SFN(06)nov [b discovered by CDF, heaviest baryons known].
@ Pentaquarks: Diakonov et al ZPA(97) [prediction]; Nakano et al PRL(03) + pw(03)jul [evidence]; Zhu PRL(03) [in QCD], IJMPA(04) [rev]; Carlson et al PLB(04); Jaffe & Wilczek EPJC(04)hp-in, pw(04)jun; Close pw(05)feb; news Nat(05)apr [doubts]; Karliner IJMPA(05); Stancu IJMPA(05); Hicks IJMPA(05); Seth IJMPA(05) [status]; Wei et al JHEP(05) [spin-3/2]; Gupta IJMPA(05) [tetraquarks]; Close CP(06) [rev].

Proton
* General properties: Mass mp = 1.6726 × 10–27 kg; uud valence quarks + sea quarks, which give the right charge, but valence quarks account for less than 1% of the proton's mass! Momentum distribution is 30% valence quarks, 50% gluons, 20% virtual particles.
@ Magnetic moment: Belinfante PR(53) [and neutron]; Kumar pw(05)sep.
@ Structure: Jaffe PT(95)sep ["spin crisis"]; Rith & Schäfer SA(99)jul [internal structure]; Thomas & Weise 01 [r PT(02)jun]; Bass RMP(05), 08 [spin structure in QCD]; Ellis & Karliner MPLA(06) [gluon polarization]; news pn(06)may [HAPPEx results]; Bass & Aidala IJMPA(06) [rev]; Bass 07, Fritzsch NPPS(07) [spin structure]; Myhrer & Thomas PLB(08) [possible solution to spin problem].
@ Decay: Horwitz & Katznelson PRL(83) [inhibition inside a nucleus]; Nath & Fileviez PRP(07) [rev, in GUTs, strings and branes]; > s.a. black hole formation, GUTs.
@ Decay, and quantum gravity: Harnik et al NPB(04)hp; Danielsson gq/05; Bambi & Freese a0803 [from minimal length].

Parton Models > s.a. QCD [quarks].
* Parton models: Treat hadrons as composite particles; Feynman came up with the idea, but in the currently accepted QCD picture, the partons are Gell-Mann's quarks.
@ References: Kogut & Susskind PRP(73); Drell & Yan AP(00) [hep applications]; Kim & Noz qp/02-in [relating quarks and Feynman's partons]; Kancheli hp/02 [and transplanckian collisions]; Diehl PRP(03), Belitsky & Radyushkin PRP(05) [generalized parton distributions].

Quarks > s.a. astronomical objects [quark stars]; HEP experiments [search for fractional charges]; QCD phenomenology.
* Idea: Basic building blocks of hadronic matter, which interact by exchange of gluons (and gamma's, gravitons, ...).
* History: The first indications of hadron properties that led to the idea of quarks was the isospin symmetry, under an SU(2) that was to become a subgroup of SU(n); The proposal of the first three quarks was made by Gell-Mann in 1964, as mathematical objects belonging to the fundamental (triplet) representation of (flavor) SU(3), an (approximate) symmetry of strong interactions; 1996, It is believed that there are 6 flavors, that fill the fundamental representation of flavor SU(6) (not a symmetry) and physically make up hadrons.
* Top: Discovered in 1995; m = 177 GeV (CDF) or 172 GeV (D0) in 1997; 2004, 178.0 4.3 GeV, from D0 results.
* Mass: It is subtle to define, since quark confinement does not allow the measurement in isolation; The short-distance (current algebra) mass is the one appearing in the fundamental Lagrangian, and the long-distance (constituent) mass is the relevant one for hadron mass calculations.
@ General references: Gell-Mann PL(64); & Zweig; Mermin PT(93)dec [pronunciation]; Albrow CP(95) [top]; Campagnari & Franklin RMP(97), Liss & Tipton SA(97)sep [top]; Particle Data Group PLB(04).
@ Masses: Chandra Raju & Chintalapati IJTP(05) [ito standard model parameters]; > s.a. mass.

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