# Chiral Phase Transition Temperature in ( $2+1$ )-Flavor QCD

## Abstract

The chiral phase transition temperature T$$0\atop{c}$$ is a fundamental quantity of QCD. To determine this quantity we have performed simulations of (2 + 1)-flavor QCD using the Highly Improved Staggered Quarks (HISQ/tree) action on $$N_{\tau}$$ = 6,8 and 12 lattices with aspect ratios $$N_σ$$ =$$N_{\tau}$$ ranging from 4 to 8. In our simulations the strange quark mass is fixed to its physical value $$m^{phy}_{s}$$, and the values of two degenerate light quark masses $$m_l$$ are varied from $$m^{phy}_{s}$$ /20 to $$m^{phy}_{s}$$ /160 which correspond to a Goldstone pion mass $$m_{\pi}$$ ranging from 160 MeV to 55 MeV in the continuum limit. By investigating the light quark mass dependence and the volume dependence of various chiral observables, e.g. chiral susceptibilities and Binder cumulants, no evidence for a first order phase transition in our current quark mass window is found. Two estimators T_{60} and $$T_δ$$ are proposed to extract the chiral phase transition temperature T$$0\atop{c}$$ in the chiral and continuum limit and our current estimate for T$$0\atop{c}$$ is 132 $$^{+3}_{-6}$$ MeV.

- Authors:

- Publication Date:

- Research Org.:
- Brookhaven National Lab. (BNL), Upton, NY (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP); German Research Foundation (DFG); National Natural Science Foundation of China (NSFC); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)

- Contributing Org.:
- HotQCD collaboration

- OSTI Identifier:
- 1550581

- Alternate Identifier(s):
- OSTI ID: 1560007

- Report Number(s):
- BNL-212050-2019-JAAM

Journal ID: ISSN 0031-9007; PRLTAO; 062002

- Grant/Contract Number:
- SC0012704; 315477589- TRR 211; 05P15PBCAA; 05P18PBCA1; 11775096; 1535012

- Resource Type:
- Published Article

- Journal Name:
- Physical Review Letters

- Additional Journal Information:
- Journal Name: Physical Review Letters Journal Volume: 123 Journal Issue: 6; Journal ID: ISSN 0031-9007

- Publisher:
- American Physical Society

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

### Citation Formats

```
Ding, H. -T., Hegde, P., Kaczmarek, O., Karsch, F., Lahiri, Anirban, Li, S. -T., Mukherjee, Swagato, Ohno, H., Petreczky, P., Schmidt, C., Steinbrecher, P., and HotQCD Collaboration. Chiral Phase Transition Temperature in ( 2 + 1 )-Flavor QCD. United States: N. p., 2019.
Web. doi:10.1103/PhysRevLett.123.062002.
```

```
Ding, H. -T., Hegde, P., Kaczmarek, O., Karsch, F., Lahiri, Anirban, Li, S. -T., Mukherjee, Swagato, Ohno, H., Petreczky, P., Schmidt, C., Steinbrecher, P., & HotQCD Collaboration. Chiral Phase Transition Temperature in ( 2 + 1 )-Flavor QCD. United States. https://doi.org/10.1103/PhysRevLett.123.062002
```

```
Ding, H. -T., Hegde, P., Kaczmarek, O., Karsch, F., Lahiri, Anirban, Li, S. -T., Mukherjee, Swagato, Ohno, H., Petreczky, P., Schmidt, C., Steinbrecher, P., and HotQCD Collaboration. Thu .
"Chiral Phase Transition Temperature in ( 2 + 1 )-Flavor QCD". United States. https://doi.org/10.1103/PhysRevLett.123.062002.
```

```
@article{osti_1550581,
```

title = {Chiral Phase Transition Temperature in ( 2 + 1 )-Flavor QCD},

author = {Ding, H. -T. and Hegde, P. and Kaczmarek, O. and Karsch, F. and Lahiri, Anirban and Li, S. -T. and Mukherjee, Swagato and Ohno, H. and Petreczky, P. and Schmidt, C. and Steinbrecher, P. and HotQCD Collaboration},

abstractNote = {The chiral phase transition temperature T$0\atop{c}$ is a fundamental quantity of QCD. To determine this quantity we have performed simulations of (2 + 1)-flavor QCD using the Highly Improved Staggered Quarks (HISQ/tree) action on $N_{\tau}$ = 6,8 and 12 lattices with aspect ratios $N_σ$ =$N_{\tau}$ ranging from 4 to 8. In our simulations the strange quark mass is fixed to its physical value $m^{phy}_{s}$, and the values of two degenerate light quark masses $m_l$ are varied from $m^{phy}_{s}$ /20 to $m^{phy}_{s}$ /160 which correspond to a Goldstone pion mass $m_{\pi}$ ranging from 160 MeV to 55 MeV in the continuum limit. By investigating the light quark mass dependence and the volume dependence of various chiral observables, e.g. chiral susceptibilities and Binder cumulants, no evidence for a first order phase transition in our current quark mass window is found. Two estimators T60 and $T_δ$ are proposed to extract the chiral phase transition temperature T$0\atop{c}$ in the chiral and continuum limit and our current estimate for T$0\atop{c}$ is 132 $^{+3}_{-6}$ MeV.},

doi = {10.1103/PhysRevLett.123.062002},

journal = {Physical Review Letters},

number = 6,

volume = 123,

place = {United States},

year = {2019},

month = {8}

}

https://doi.org/10.1103/PhysRevLett.123.062002

*Citation information provided by*

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Web of Science

#### Figures / Tables:

*m*,

_{u,d}*m*) at zero baryon number density for $m^{tri}_{s}$ < $m^{phy}_{s}$ (left) and $m^{tri}_{s}$ > $m^{phy}_{s}$ (right).

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Figures / Tables found in this record:

*Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.*