title: Q2 Dependence of quadrupole strength in the gamma*p --> Delta(+)(1232) --> p pi(0) transition.
abstract: Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.
authors.affiliation: University of Virginia, Department of Physics, Charlottesville, Virginia 22903, USA.
authors.forename: K
authors.initials: K
authors.lastname: Joo
authors.forename: L C
authors.initials: LC
authors.lastname: Smith
authors.forename: V D
authors.initials: VD
authors.lastname: Burkert
authors.forename: R
authors.initials: R
authors.lastname: Minehart
authors.forename: I G
authors.initials: IG
authors.lastname: Aznauryan
authors.forename: L
authors.initials: L
authors.lastname: Elouadrhiri
authors.forename: S
authors.initials: S
authors.lastname: Stepanyan
authors.forename: G S
authors.initials: GS
authors.lastname: Adams
authors.forename: M J
authors.initials: MJ
authors.lastname: Amaryan
authors.forename: E
authors.initials: E
authors.lastname: Anciant
authors.forename: M
authors.initials: M
authors.lastname: Anghinolfi
authors.forename: D S
authors.initials: DS
authors.lastname: Armstrong
authors.forename: B
authors.initials: B
authors.lastname: Asavapibhop
authors.forename: G
authors.initials: G
authors.lastname: Audit
authors.forename: T
authors.initials: T
authors.lastname: Auger
authors.forename: H
authors.initials: H
authors.lastname: Avakian
authors.forename: S
authors.initials: S
authors.lastname: Barrow
authors.forename: H
authors.initials: H
authors.lastname: Bagdasaryan
authors.forename: M
authors.initials: M
authors.lastname: Battaglieri
authors.forename: K
authors.initials: K
authors.lastname: Beard
authors.forename: M
authors.initials: M
authors.lastname: Bektasoglu
authors.forename: W
authors.initials: W
authors.lastname: Bertozzi
authors.forename: N
authors.initials: N
authors.lastname: Bianchi
authors.forename: A S
authors.initials: AS
authors.lastname: Biselli
authors.forename: S
authors.initials: S
authors.lastname: Boiarinov
authors.forename: B E
authors.initials: BE
authors.lastname: Bonner
authors.forename: W K
authors.initials: WK
authors.lastname: Brooks
authors.forename: J R
authors.initials: JR
authors.lastname: Calarco
authors.forename: G P
authors.initials: GP
authors.lastname: Capitani
authors.forename: D S
authors.initials: DS
authors.lastname: Carman
authors.forename: B
authors.initials: B
authors.lastname: Carnahan
authors.forename: P L
authors.initials: PL
authors.lastname: Cole
authors.forename: A
authors.initials: A
authors.lastname: Coleman
authors.forename: D
authors.initials: D
authors.lastname: Cords
authors.forename: P
authors.initials: P
authors.lastname: Corvisiero
authors.forename: D
authors.initials: D
authors.lastname: Crabb
authors.forename: H
authors.initials: H
authors.lastname: Crannell
authors.forename: J
authors.initials: J
authors.lastname: Cummings
authors.forename: E
authors.initials: E
authors.lastname: De Sanctis
authors.forename: R
authors.initials: R
authors.lastname: De Vita
authors.forename: P V
authors.initials: PV
authors.lastname: Degtyarenko
authors.forename: R A
authors.initials: RA
authors.lastname: Demirchyan
authors.forename: H
authors.initials: H
authors.lastname: Denizli
authors.forename: L C
authors.initials: LC
authors.lastname: Dennis
authors.forename: A
authors.initials: A
authors.lastname: Deppman
authors.forename: K V
authors.initials: KV
authors.lastname: Dharmawardane
authors.forename: K S
authors.initials: KS
authors.lastname: Dhuga
authors.forename: C
authors.initials: C
authors.lastname: Djalali
authors.forename: G E
authors.initials: GE
authors.lastname: Dodge
authors.forename: D
authors.initials: D
authors.lastname: Doughty
authors.forename: P
authors.initials: P
authors.lastname: Dragovitsch
authors.forename: M
authors.initials: M
authors.lastname: Dugger
authors.forename: S
authors.initials: S
authors.lastname: Dytman
authors.forename: M
authors.initials: M
authors.lastname: Eckhause
authors.forename: Y V
authors.initials: YV
authors.lastname: Efremenko
authors.forename: H
authors.initials: H
authors.lastname: Egiyan
authors.forename: K S
authors.initials: KS
authors.lastname: Egiyan
authors.forename: L
authors.initials: L
authors.lastname: Farhi
authors.forename: R J
authors.initials: RJ
authors.lastname: Feuerbach
authors.forename: J
authors.initials: J
authors.lastname: Ficenec
authors.forename: K
authors.initials: K
authors.lastname: Fissum
authors.forename: T A
authors.initials: TA
authors.lastname: Forest
authors.forename: H
authors.initials: H
authors.lastname: Funsten
authors.forename: M
authors.initials: M
authors.lastname: Gai
authors.forename: V B
authors.initials: VB
authors.lastname: Gavrilov
authors.forename: S
authors.initials: S
authors.lastname: Gilad
authors.forename: G P
authors.initials: GP
authors.lastname: Gilfoyle
authors.forename: K L
authors.initials: KL
authors.lastname: Giovanetti
authors.forename: P
authors.initials: P
authors.lastname: Girard
authors.forename: K A
authors.initials: KA
authors.lastname: Griffioen
authors.forename: M
authors.initials: M
authors.lastname: Guidal
authors.forename: M
authors.initials: M
authors.lastname: Guillo
authors.forename: V
authors.initials: V
authors.lastname: Gyurjyan
authors.forename: D
authors.initials: D
authors.lastname: Hancock
authors.forename: J
authors.initials: J
authors.lastname: Hardie
authors.forename: D
authors.initials: D
authors.lastname: Heddle
authors.forename: J
authors.initials: J
authors.lastname: Heisenberg
authors.forename: F W
authors.initials: FW
authors.lastname: Hersman
authors.forename: K
authors.initials: K
authors.lastname: Hicks
authors.forename: R S
authors.initials: RS
authors.lastname: Hicks
authors.forename: M
authors.initials: M
authors.lastname: Holtrop
authors.forename: C E
authors.initials: CE
authors.lastname: Hyde-Wright
authors.forename: M M
authors.initials: MM
authors.lastname: Ito
authors.forename: D
authors.initials: D
authors.lastname: Jenkins
authors.forename: J H
authors.initials: JH
authors.lastname: Kelley
authors.forename: M
authors.initials: M
authors.lastname: Khandaker
authors.forename: K Y
authors.initials: KY
authors.lastname: Kim
authors.forename: W
authors.initials: W
authors.lastname: Kim
authors.forename: A
authors.initials: A
authors.lastname: Klein
authors.forename: F J
authors.initials: FJ
authors.lastname: Klein
authors.forename: M
authors.initials: M
authors.lastname: Klusman
authors.forename: M
authors.initials: M
authors.lastname: Kossov
authors.forename: Y
authors.initials: Y
authors.lastname: Kuang
authors.forename: S E
authors.initials: SE
authors.lastname: Kuhn
authors.forename: J M
authors.initials: JM
authors.lastname: Laget
authors.forename: D
authors.initials: D
authors.lastname: Lawrence
authors.forename: A
authors.initials: A
authors.lastname: Longhi
authors.forename: K
authors.initials: K
authors.lastname: Loukachine
authors.forename: M
authors.initials: M
authors.lastname: Lucas
authors.forename: R W
authors.initials: RW
authors.lastname: Major
authors.forename: J J
authors.initials: JJ
authors.lastname: Manak
authors.forename: C
authors.initials: C
authors.lastname: Marchand
authors.forename: S K
authors.initials: SK
authors.lastname: Matthews
authors.forename: S
authors.initials: S
authors.lastname: McAleer
authors.forename: J W C
authors.initials: JW
authors.lastname: McNabb
authors.forename: B A
authors.initials: BA
authors.lastname: Mecking
authors.forename: M D
authors.initials: MD
authors.lastname: Mestayer
authors.forename: C A
authors.initials: CA
authors.lastname: Meyer
authors.forename: M
authors.initials: M
authors.lastname: Mirazita
authors.forename: R
authors.initials: R
authors.lastname: Miskimen
authors.forename: V
authors.initials: V
authors.lastname: Muccifora
authors.forename: J
authors.initials: J
authors.lastname: Mueller
authors.forename: G S
authors.initials: GS
authors.lastname: Mutchler
authors.forename: J
authors.initials: J
authors.lastname: Napolitano
authors.forename: G
authors.initials: G
authors.lastname: Niculescu
authors.forename: B
authors.initials: B
authors.lastname: Niczyporuk
authors.forename: R A
authors.initials: RA
authors.lastname: Niyazov
authors.forename: M S
authors.initials: MS
authors.lastname: Ohandjanyan
authors.forename: A
authors.initials: A
authors.lastname: Opper
authors.forename: Y
authors.initials: Y
authors.lastname: Patois
authors.forename: G A
authors.initials: GA
authors.lastname: Peterson
authors.forename: S
authors.initials: S
authors.lastname: Philips
authors.forename: N
authors.initials: N
authors.lastname: Pivnyuk
authors.forename: D
authors.initials: D
authors.lastname: Pocanic
authors.forename: O
authors.initials: O
authors.lastname: Pogorelko
authors.forename: E
authors.initials: E
authors.lastname: Polli
authors.forename: B M
authors.initials: BM
authors.lastname: Preedom
authors.forename: J W
authors.initials: JW
authors.lastname: Price
authors.forename: L M
authors.initials: LM
authors.lastname: Qin
authors.forename: B A
authors.initials: BA
authors.lastname: Raue
authors.forename: A R
authors.initials: AR
authors.lastname: Reolon
authors.forename: G
authors.initials: G
authors.lastname: Riccardi
authors.forename: G
authors.initials: G
authors.lastname: Ricco
authors.forename: M
authors.initials: M
authors.lastname: Ripani
authors.forename: B G
authors.initials: BG
authors.lastname: Ritchie
authors.forename: F
authors.initials: F
authors.lastname: Ronchetti
authors.forename: P
authors.initials: P
authors.lastname: Rossi
authors.forename: D
authors.initials: D
authors.lastname: Rowntree
authors.forename: P D
authors.initials: PD
authors.lastname: Rubin
authors.forename: C W
authors.initials: CW
authors.lastname: Salgado
authors.forename: M
authors.initials: M
authors.lastname: Sanzone
authors.forename: V
authors.initials: V
authors.lastname: Sapunenko
authors.forename: M
authors.initials: M
authors.lastname: Sargsyan
authors.forename: R A
authors.initials: RA
authors.lastname: Schumacher
authors.forename: Y G
authors.initials: YG
authors.lastname: Sharabian
authors.forename: J
authors.initials: J
authors.lastname: Shaw
authors.forename: S M
authors.initials: SM
authors.lastname: Shuvalov
authors.forename: A
authors.initials: A
authors.lastname: Skabelin
authors.forename: E S
authors.initials: ES
authors.lastname: Smith
authors.forename: T
authors.initials: T
authors.lastname: Smith
authors.forename: D I
authors.initials: DI
authors.lastname: Sober
authors.forename: M
authors.initials: M
authors.lastname: Spraker
authors.forename: P
authors.initials: P
authors.lastname: Stoler
authors.forename: M
authors.initials: M
authors.lastname: Taiuti
authors.forename: S
authors.initials: S
authors.lastname: Taylor
authors.forename: D
authors.initials: D
authors.lastname: Tedeschi
authors.forename: R
authors.initials: R
authors.lastname: Thompson
authors.forename: L
authors.initials: L
authors.lastname: Todor
authors.forename: T Y
authors.initials: TY
authors.lastname: Tung
authors.forename: M F
authors.initials: MF
authors.lastname: Vineyard
authors.forename: A
authors.initials: A
authors.lastname: Vlassov
authors.forename: H
authors.initials: H
authors.lastname: Weller
authors.forename: L B
authors.initials: LB
authors.lastname: Weinstein
authors.forename: R
authors.initials: R
authors.lastname: Welsh
authors.forename: D P
authors.initials: DP
authors.lastname: Weygand
authors.forename: S
authors.initials: S
authors.lastname: Whisnant
authors.forename: M
authors.initials: M
authors.lastname: Witkowski
authors.forename: E
authors.initials: E
authors.lastname: Wolin
authors.forename: A
authors.initials: A
authors.lastname: Yegneswaran
authors.forename: J
authors.initials: J
authors.lastname: Yun
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: J
authors.initials: J
authors.lastname: Zhao