Holographic description of Hadrons from String Theory

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Holographic descriptionofHadronsfromString
Theory
(Review)

• Shigeki Sugimoto (IPMU)

(based on works with T.Sakai, H.Hata, S.Yamato,
K. Hashimoto, T.Imoto, )
/17
Rencontres de Moriond, March 25, 2011 _at_ La
Thuile, Italy
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Claim
String theory can be a theory of hadrons
The string scale here is around 1 GeV.
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Im NOT saying QCD is wrong.
dual !
String theory (in a certain curved background)
QCD
Holographic QCD
Gauge/String duality
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What is Gauge/String duality?
Maldacena 1997,etc.
dual!
String theory in a curved background
Gauge theory
4 dim
10 dim
Holographic dual
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Why it works?
D-brane
open strings
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How can we realize QCD in string theory?
Sakai-S.S. 2004
(14) dim D-brane
(18) dim D-brane
S1
4 dim
D8
D8
D4
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Holographic QCD
D4-brane on
(low energy)
QCD with massless quarks
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(low energy)
QCD with massless quarks
Open closed string theory in this
background
dual
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Do we have hadrons?
Particles in this system
Closed strings
Open strings on D8
D8-brane
D4 wrapped on
D4-brane
Nc strings are attached
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Surprise
A lot of properties of hadrons can be
extracted using this new description!
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Caution
We have only estimated the leading terms in the
and expansions.
is around 1 GeV.
Quark masses are neglected.
We should not expect too much.
But, dont be too pessimistic!
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Meson effective theory is written as a 5 dim
YM-CS theory in a curved background.
CS5-form

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A lot of old models are reproduced without making
any phenomenological assumptions!
Skyrme model Skyrme
1961 Vector meson dominance Sakurai
1960, Gell-Mann-Zachriasen 1961 Gell-Mann Sharp
Wagner model Gell-Mann Sharpe-Wagner
1962 Hidden local symmetry
Bando-Kugo-Uehara-Yamawaki-Yanagida 1985
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Other mesons, including higher spin mesons, are
obtained as excited string states.
Imoto-Sakai-S.S. 2010
higher spin meson
rotating open string
1st excited states
2nd excited states
3rd excited states
(See arXiv1005.0655 for more details)
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Baryon spectrum
Hata-Yamato-Sakai-S.S. 2007
D-brane
soliton in the 5dim theory

We can analyze the spectrum, magnetic
moments, charge radii by quantizing this soliton
cf) Skyrme model
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Properties of nucleons
Hashimoto-Sakai-S.S. 2008
See also, Hong-Rho-Yee-Yi 2007,
Hata-Murata-Yamato 2008, Kim-Zahed 2008
nucleon ele-mag form factor
dipole ( experiment)
our result
GeV2
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Conclusion
String theory can be a theory of hadrons
dual !
String theory (in a certain curved background)
QCD
Holographic QCD