Neutrons  

In General > s.a. experiments in quantum mechanics.
* History: 1932, Discovered by Chadwick; 1934, Chadwick and Goldhaber determined the mass accurately enough to determine that a n was not an ep bound state (as Rutherford had predicted); 2002, Evidence for neutrinoless double- decay reported, and quantum states in gravitational field.
* Mass: mn = 1.6749 × 10–27 kg.
* Electric dipole moment: In the standard model, the strong interaction should violate T-reversal symmetry, and thus CP symmetry; But such a symmetry violation would result in a neutron electric dipole moment 10 orders of magnitude larger than the current bound; In 1977, Roberto Peccei and Helen Quinn discovered a simple dynamical mechanism to enforce strong CP symmetry which, as Steven Weinberg and Frank Wilczek independently realized, implies the existence of the axion; 2006, currently the best experimental upper bound is 2.9 10–26 e·cm (90% c.l.); Soon experiments will do better.
@ History: De Gregorio HSPBS(05)phy [early 1930's], phy/06.
@ Electric dipole moment: Fortson et al PT(03)jun; Baker et al PRL(06) [upper bound].
@ n-p mass difference: Feynman & Speisman PR(54); Dashen & Frautschi PR(64) [proved wrong, see Kim phy/04].
@ Other topics: van den Brand & Huberts PW(96) [charge distribution]; Altschul qp/99 [gravity and acceleration].

Neutron Interferometry > s.a. equivalence principle; gravitomagnetism; phase.
* And gravity: Gravity-induced phases have already been detected, and they show that gravity at the quantum level is not a purely geometric effect, since the mass of the employed particles appears explicitly in the interference expression.
@ General references: Greenberger RMP(83) [and quantum mechanics, rev]; Rauch HPA(88); Unnerstall PLA(90) [comment]; Rauch & Vigier PLA(90); Rauch FP(93); Benatti & Floreanini PLB(99)qp [semigroups and dissipative evolution]; Felber et al FP(99) [in space and time]; Rauch & Werner 00 [r PT(02)jun].
@ Geometric and quantum phases: Werner CQG(94); Littrell et al PRA(97); Allman et al PRA(97); Bhandari qp/01/PRL; Rauch et al Nat(02) [confinement-induced].
@ And gravity: Wolf FP(90) [and quantum gravity]; Werner CQG(94); Camacho PLA(99)qp, PLA(99)qp; Varjú & Ryder AJP(00) [general relativistic treatment]; Nandi & Zhang PRD(02)gq [and equivalence principle]; Camacho & Macías PLB(05) [and torsion].
@ Related topics: Gähler & Zeilinger AJP(91) [wave phenomena, interference and diffraction].

Other Phenomenology > s.a. CPT tests; neutron stars.
@ Quantum states in gravitational field: Nesvizhevsky et al NIM(00), Nat(02); Schwarzschild PT(02)mar; Olevik et al qp/02; Westphal gq/02 [theory]; Nesvizhevsky PRD(03), comment Hansson et al PRD(03)qp, reply PRD(03); > s.a. tests of newtonian gravity.
@ Scattering: news pw(06)dec [and paper dating].
@ Decay: Klapdor-Kleingrothaus hp/02-in, et al FP(02) [neutrinoless double-]; Klapdor-Kleingrothaus FP(03) [first evidence].


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