The nature of compressed baryonic matter

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

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

( )

Pulsar searching and timing with FAST“PKU Astrophysics Colloquium 2012”

Oct. 21, 2012; Biejing

Introduction: what’s compressed BM?

EoS of compressed BM: specu. & obs.

To understand EoS by large telescope

Conclusions

Summary

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

1

Introduction: what’s compressed BM?

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

color number 1 1 3 3electricity 0 -1 +2/3 -1/3

1st generation e e u(2-8MeV) d(5-15MeV)2nd generation c(~1GeV) s(~200MeV)3rd generation t(~100GeV) b(~4GeV)

Leptons Quarks（mass）

Higgs Boson

13 Totally: 62

48

Strong electro-magn. Weak gravityGauge Boson gluon photon W, Z graviton

Spin 1 1 1 2number 8 1 3 1

• What is baryon: the standard model of particle physics

Baryon (a quark) = 1/3

The particle has been the subject of a 45-year hunt to explain how matter attains its mass.

5!

Introduction: what’s compressed BM?

~100 cm ~10-8 cm ~10-13 cm

...

. {uud} {udd}

A brief history about compressed baryonic matter …• G. Gamow (~1930): incompressible liquid drop for atomic nuclei• L. Landau (1932, before n): what if drops are concentrated by

gravity?• Landau’s idea of “gigantic nucleus” develops to normal NS model...• What if the quark degree of freedom (and w & s int.) is not

negligible? our answer: {u, d, s}, > 6 (rather than 3) grouped in a cluster in CBM.Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

A rubbermade of NM/SM

All of theworld's population

Introduction: what’s compressed BM?

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

Introduction: what’s compressed BM?

EoS of compressed BM: specu. & obs.

To understand EoS by large telescope

Conclusions

Summary

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

EoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

• EoS of compressed BM: the mainstream …Alford (2004)

coupling between quarks?… DSE approach of NQCD

A quark clustering phase?

? Clustering ← BEC ← BCS

Xu 2009, JPG, 36, 064010

EoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

~ (1, 10) kmconventional neutron star quark-cluster star

• Gravity-bound (weak binding) vs. Self-bound (strong)• Atmosphere vs. {q-clusters, electron sea}

• Differences between NS & quark-cluster star?

(Heiselberg, 2000) (Xu, 2011)

EoS of compressed BM: specu. & obs.

Metal ball V.S. Quark-cluster star

ions/nuclei

E-M interaction strong/color one

quark clusters

• A quark-cluster star looks like a big metal ballEoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

• A realistic quark cluster: H-dibaryon?H-particles in lattice QCD:Beane et al. [NPLQCD Collaboration], Phys. Rev. Lett. 106, 162001 (2011)Inoue et al. [HAL QCD Collaboration], Phys. Rev. Lett. 106, 162002 (2011)

What if quarks are clustered as H-diabaryons in QS?Lai, Gao & Xu (arXiv:1107.0834)

Interaction between H’s is mediated by - mesons:

In-medium stiffening effect: Brown-Rho scaling modified.

EoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

• A realistic quark cluster: H-star?

M-R, M-c

Mmax-V0

EoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

• A corresponding-state approach to …EoS of compressed BM: specu. & obs.

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

Wilczek (2007)

• Dimensionless parameters:

• Corresponding state law EoS

• The results (Guo, Lai & Xu; arXiv1209.3688):

Introduction: what’s compressed BM?

EoS of compressed BM: specu. & obs.

To understand EoS by large telescope

Conclusions

Summary

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

To understand EoS by large telescope

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

1, Timing (ToA): spin-behavior + space-time fluctuations + post-Newtonian orbital effects + binary parameter + ISM + planetary ephemeris + time standards/navigation?

2, Pulse profile: radiative process (magnetospheric activity) + ISM

• Key observables of radio pulsars

Large radio FAST telescopes are certainly necessary to measure precisely these two.

• To measure the mass of radio pulsars• To measure the inertial of momentum of NS• To find sub-ms radio pulsars• …

To understand EoS by large telescope

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

• To know compressed BM by large telescope

(Sala et al. ApJ, arXiv:1204.3627)

Lai & Xu (2009, Nq = 18, U0 = 100 MeV)

(Lai & Xu 2009 MNRAS, 398, L31)

Demorest et al. (2010)

PSR J1614

To understand EoS by large telescope

Introduction: what’s compressed BM?

EoS of compressed BM: specu. & obs.

To understand EoS by large telescope

Conclusions

Summary

Compressed baryonic matter http://vega.bac.pku.edu.cn/rxxu R. X. Xu

Conclusions• Pulsars are not only extreme labs of gravity, but also of the fundamental strong interaction.

• As manifestation of compressed baryonic matter, pulsars are sending us message being essential for us to know non-perturbative QCD.

• We are suggesting: realistic compressed baryonic matter at a few nuclear densities is composed by quark-cluster matter.Thanks!