astrophysical quark matter renxin xu ( 徐仁新 ) school of physics, peking university...

Astrophysical Quark Matter

Renxin Xu ( 徐仁新 )School of Physics, Peking University

“Astrophysical QM” http://vega.bac.pku.edu.cn/rxxu R. X. Xu

2005 年 10 月 12 日，扬州大学

Not only is the Universe stranger than we

imagine, it is stranger than we can imagine.

—— Arthur Eddington

Astrophysical laboratory: to find QGP?

Cosmic QCD phase separation: consequence?

Compact pulsar-like stars: quark stars?

Cosmic rays: quark nuggets?


SUMMARYSUMMARY Introduction: Introduction: quarkquark && quark matterquark matter

QM in the early UniverseQM in the early Universe

QM in pulsar-like compact starsQM in pulsar-like compact stars

QM as cosmic raysQM as cosmic rays

ConclusionsConclusions


Quark? A historical note …

M. Gell-Mann (1969)

Quarks?

1950s~1960s: A success in the classification of hadrons discovered in cosmic rays and in accelerators M. Gell-Mann (1964): Quarks? ---- in mathematical description, rather than in reality. Zweig, Chinese group (1960s): in reality? 1973: SU(3) non-Abelian gauge theory asymptotic freedom Experimental evidence for the last flavor of quark (top quark) in 1990s

Introduction: Quark matterIntroduction: Quark matterThe standard model of particle physics

Interaction via gauge bosons

QCDQCD


Experimental evidence for asymptotic freedom

Introduction: Quark matterIntroduction: Quark matter


M. R. Pennington (University of Durham) in: QCD and Hadronic Physics (Held in PKU, Beijing, June 20, 2005)

The Nobel prize in Physics (2004)

David J. Gross (L) of the University of California at Santa Barbara and his wife (R)

Frank Wilczek of the Massachusetts Institute of Technology.

H. David Politzer of the California Institute of Technology, Pasadena, California.

What is Quark Matter?

Expected in QCD

To be a direct consequence of aympt. freedom

T

A simple QCD phase diagram


(Hadron gas)

(QGP)


Can we find quark matter?Can we find quark matter?

Terrestrial experimentsRelativistic heavy ion colliders

Astrophysical observationsT-dominated QM: early UniverseD-dominated QM: compact stars



Solid Quark Matter?Introduction: Quark matterIntroduction: Quark matter

B

T0 QCD phase?Phase diagram for CO2

Solid?Liquid?

Gas?Hadron

QGP


T deconfinement

chiral sym. restor.

Two kinds of Quark Matter.

Solid QM?

T-dom.

D-dom.


Xu 2005

“Pulsars and Quark Stars” http://vega.bac.pku.edu.cn/rxxu R. X. Xu“Astrophysical QM” http://vega.bac.pku.edu.cn/rxxu R. X. Xu

Edward Witten (1984):1, cosmic QCD phase; 2, strange stars; 3, cosmic rays.



Bodmer-Witten’s conjecture

mu ~ 5

md ~ 10

ms ~150

=1.5N

F ~ 400

Farhi & Jaffe (1984) Greiner et al 1998





S. Banerjee, et al.hep-ph/0307366

Schwarzastro-ph/0303574Quark-hadron phase

transitiont ~ 10-5 s, Tc ~ 300 MeVFirst order reheating



Motivations to study quark-hadron transitionto know “What happened at the transition?”to set initial physical conditions for BBN

•inhomogeneous distribution abundancesto generate relics of cosmic QCD transition

•strange quark nuggets? (MACHOs?)•gravitational waves from colliding bubbles?•magnetic fields with ~ 100 kpc correlations?•QCD balls as a new CDM candidate?•black holes formation during the transition?

L. Landau (1962)S. Chandrasekhar (1983)

Maybe there are stars with

nuclear density after collapse?

Degenerate pressure is not omnipotent in standing against the gravitational collapse

A historical note of pulsars

“Neutron” star


Walter Baade and Fritz Zwickyproposed in 1934 that supernovaecould produce cosmic rays andneutron stars …

A historical note of pulsars

Pulsars (discovered in

1967) could be neutron

stars?

A. Hewish (1974)


Pulsars in conventional scenarioPulsars in conventional scenario


Radio pulsars: cosmological lighthouse ...Pulse sequences from a radio pulsar

Pulsar is pulsing …

Neutron Stars

or

Quark stars?

Pulsars in conventional scenarioPulsars in conventional scenario



Pulsars in conventional scenarioPulsars in conventional scenarioDistribution of radio pulsars in the Galaxy

Radio pulsars

Accretion-powered X-ray pulsarsX-ray bursts

AXP/SGRDim thermal “Neutron” stars

Compact center objects

Members of the family of pulsar-like stars …

What’s really the nature of pulsars?


The structure of normal Neutron stars

Heiselberg 2002

Atmosphere

Outer crust

Inner crust

Neutron matter

Core ？



Pulsars: quark stars?Ivanenko & Hurdgelaidze (1969)

Itoh (1970)

Bodmer (1971)

Asymptotic freedom

Witten (1984)

1986: Haensel et al.; Alcock et al.



http://chandra.harvard.edu/photo/2002/0211/0211_illustration.pdf

Neutron Stars

v.s.

Quark Stars



Two requirements for forming quark starQuark de-confinement can occur

•An estimate of c ： (4R3/3)-1 ~ 1.5 N

Strange matter in bulk is absolutely stable __(Bodmer-Witten’s conjecture)

•Note: Strangelet in RHIC could be unstable!

Unfortunately, one can not know if these two are satisfied from the first principles (QCD). But the requirements seem ok …



Structure of strange star: bare or crusted

Electric field:

E ~ 1017V/cm



How to form a quark star?



What if to form a quark star, rather than a neutron stars, in a CC-process?

This idea is attractive since more energy and radiation (, ) are released …

It is still a challenge for astrophysicists to reproduce a successful core-collapse supernova!

Note: quark stars formed in this way should be bare!



A summary of our work only …


Evidence for quark stars?Evidence for quark stars?


To solve the binding energy problem (1999)Observations: drifting subpulses of PSRs

To expect non-atomic spectra (2002)Observations: thermal & non-thermal

To explain discrepancy between … (2004)Observations: free prec. & glitch of PSRs

To understand others …Observations: superE SGR, -profile (AG)



NASA News release (2002/4/10): RX J1856 a strange star?

Chandra



Submillisecond radio pulsar: FAST?

Low-mass & small-radius pulsar-like stars: X-ray interference telescopes MAXIM?

Gravitational wave observations: LIGO?

Dust emission from ms-pulsars: Spitzer?

How to identify clearly a quark star?



Five hundred meter Aperture Spherical Telescope



The higher the particle energy attained, the smaller __the scale of physics which can be probed.Cosmic rays vs. Particle physics

1937 (Anderson & Neddermeyer): 1947 (Powell): 1947(Rochester & Butler): strange part. 0, K, ...

Cosmic rays vs. AstrophysicsGenerally, astrophysics studies “cosmic rays”Astrophysics offers extreme environments


UHECRs:>~1019eV

The highest!

Within the Galaxy



GZK cutoff: estimations

Ep ~ 1019 eV, ~ Ep/1GeV ~ 1010

ECB ~ 3 K ~ 10-4 eV

Proton rest frameE’CB ~ ECB ~ MeV

Greisen PRL (1966); Zatsepin & Kuzmin JETP (1966)



The GZK cutoff'p p s

196 10 eVthE

with threshold

Other particles

Photon, Iron



No clear GZK cutoff observed Stecker 2003



ML03

UHECRs: quark nuggets (strangelets)?

What is Strangelet?=>A lump of strange matter

Advantages if UHECRs are strangelets:

Larger mass Beyond GZK cutoff

Higher electricity Easier to accelerate

Be not point-like No collapse to BHs(Xu & Wu 2003)



What is the astrophysical origin of strangelets?during the early Universe?

during the formation of quark stars!Acceleration in induced electric field ~ 1017/P10eV

Formation by stellar processes

1, Evaporation during SNEs

2, Collision of (low-mass) strange QSsGRBs



T deconfinement

chiral sym. restor.

How do strangelets evolve in the atmosphere?Solid strangelets

Fluid strangelets

Evaporating hadrons: n, p, ...



How can we detect strangelets?

Atmospheric Cerenkov radiation?

Atmospheric fluorescence radiation?

ESA: in YBJ?

Neutron detection in YBJ?

…?



Cosmic raydetectionin YBJ

ConclusionsConclusionsAstrophysical quark matter are reviewed. In addition to test GR, pulsars are also useful to test and to improve the fundamental strong interaction.

Possible evidence for quark stars are proposed.

The physics relevant to the elementary chromatic interaction could be improved if pulsar-like stars are quark stars.

A solid state of quark matter is suggested.


Thank you ！


1 ，规模上的差距“ 西方世界鞭先着”：在发达国家高等教育中已经非常普遍，并且教学水平和质量也相当高。

2 ，物理类对“天体物理”教育重视不够将实施大型天文科学工程： FAST 、 HXMT 、 SST

3 ，教材。胡中为、萧耐园、朱慈 ( 土盛 ) ，《天文学教程

（上下）》，高等教育出版社（ 2003 ）。李宗伟、肖兴华，《天体物理学》，高等教育

出版社（ 2000 ）……

我国天体物理教学中的问题

《天体物理导论》（约 30万字）北京大学出版社

（ 2005年底左右出版）

徐仁新

1 ，适用对象物理类本科生、研究生，对天体物理学感兴趣或从事天体物理研究的学者。

2 ，编写该教材的目的架起“天文学”与“物理学”两领域的桥梁，以便于现代天体物理研究在国内的开展。

3 ，先前的教学实践分别以讲义形式在清华（“天体物理”课）和北大（“天体物理导论”课）高年级本科生多次讲授。周学时 3 ，一学期。

教材定位以“普物”风格介绍发生在宇观层次的若干物理过程。将天体看作探索自然界基本物理规律的“极端实验室”。

“普物”风格 := 在定性和半定量的层次上认识、理解各类自然现象。

区别于“理论物理”课程数量级上一致，而“小数点后若干位”留给理论物理…

1 ，概况行星、恒星、星系；观测设备与学科展望

2 ，准备知识辐射——认识宇宙的重要窗口；磁化等离子体—— 99% 以上宇宙物质的状态。

3 ，恒星层次主序恒星——绝大多数肉眼所见的点点繁星；超新星——恒星晚期的爆发过程；吸积——致密天体的有效产能方式；白矮星——恒星演化残骸之一；脉冲星、中子星与夸克星——恒星演化残骸之二；黑洞——广义相对论预言的天体。

教材内容

1 ，概况 2 ，准备知识 3 ，恒星层次

４，星系与宇宙层次宇宙射线爆发源——紧次于“大爆炸”的现象；星系——组成宇宙的基本单元；宇宙——可观测的一切。

教材内容

教材内容：附录附录一、 Landau “：论恒星的理论”附录二、粒子物理标准模型简介附录三、粒子天体物理简介附录四、地外文明与系外行星系统附录五、数、单位制与常数

谢谢！

astrophysical quark matter renxin xu ( 徐仁新 ) school of physics, peking university...

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