QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy
Abstract For a discrete symmetry that is anomalous under QCD, the domain walls produced in the early universe from its spontaneous breaking can naturally annihilate due to QCD instanton effects. The gravitational waves generated from wall annihilation have their amplitude and frequency determined by...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2023-12-01
|
| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP12(2023)194 |
| _version_ | 1797233834350084096 |
|---|---|
| author | Yang Bai Ting-Kuo Chen Mrunal Korwar |
| author_facet | Yang Bai Ting-Kuo Chen Mrunal Korwar |
| author_sort | Yang Bai |
| collection | DOAJ |
| description | Abstract For a discrete symmetry that is anomalous under QCD, the domain walls produced in the early universe from its spontaneous breaking can naturally annihilate due to QCD instanton effects. The gravitational waves generated from wall annihilation have their amplitude and frequency determined by both the discrete symmetry breaking scale and the QCD scale. The evidence of stochastic gravitational waves at nanohertz observed by pulsar timing array experiments suggests that the discrete-symmetry-breaking scale is around 100 TeV, assuming the domain-wall explanation. The annihilation temperature is about 100 MeV, which could naturally be below the QCD phase transition temperature. We point out that the QCD phase transition within some domains with an effective large QCD θ angle could be a first-order one. To derive the phase diagram in θ and temperature, we adopt a phenomenological linear sigma model with three quark flavors. The domain-wall explanation for the NANOGrav, EPTA, PPTA and CPTA results hints at a first-order QCD phase transition, which predicts additional gravitational waves at higher frequencies. If the initial formation of domain walls is also a first-order process, this class of domain-wall models predicts an interesting gravitational wave spectroscopy with frequencies spanning more than ten orders of magnitude, from nanohertz to 100 Hz. |
| first_indexed | 2024-03-08T16:24:58Z |
| format | Article |
| id | doaj.art-82a91fc10de542fc80946b3d220dbd2f |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-04-24T16:22:28Z |
| publishDate | 2023-12-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-82a91fc10de542fc80946b3d220dbd2f2024-03-31T11:07:50ZengSpringerOpenJournal of High Energy Physics1029-84792023-12-0120231213410.1007/JHEP12(2023)194QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopyYang Bai0Ting-Kuo Chen1Mrunal Korwar2Department of Physics, University of Wisconsin-MadisonDepartment of Physics, University of Wisconsin-MadisonDepartment of Physics, University of Wisconsin-MadisonAbstract For a discrete symmetry that is anomalous under QCD, the domain walls produced in the early universe from its spontaneous breaking can naturally annihilate due to QCD instanton effects. The gravitational waves generated from wall annihilation have their amplitude and frequency determined by both the discrete symmetry breaking scale and the QCD scale. The evidence of stochastic gravitational waves at nanohertz observed by pulsar timing array experiments suggests that the discrete-symmetry-breaking scale is around 100 TeV, assuming the domain-wall explanation. The annihilation temperature is about 100 MeV, which could naturally be below the QCD phase transition temperature. We point out that the QCD phase transition within some domains with an effective large QCD θ angle could be a first-order one. To derive the phase diagram in θ and temperature, we adopt a phenomenological linear sigma model with three quark flavors. The domain-wall explanation for the NANOGrav, EPTA, PPTA and CPTA results hints at a first-order QCD phase transition, which predicts additional gravitational waves at higher frequencies. If the initial formation of domain walls is also a first-order process, this class of domain-wall models predicts an interesting gravitational wave spectroscopy with frequencies spanning more than ten orders of magnitude, from nanohertz to 100 Hz.https://doi.org/10.1007/JHEP12(2023)194Cosmology of Theories BSMEarly Universe Particle PhysicsPhase Transitions in the Early Universe |
| spellingShingle | Yang Bai Ting-Kuo Chen Mrunal Korwar QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy Journal of High Energy Physics Cosmology of Theories BSM Early Universe Particle Physics Phase Transitions in the Early Universe |
| title | QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy |
| title_full | QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy |
| title_fullStr | QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy |
| title_full_unstemmed | QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy |
| title_short | QCD-collapsed domain walls: QCD phase transition and gravitational wave spectroscopy |
| title_sort | qcd collapsed domain walls qcd phase transition and gravitational wave spectroscopy |
| topic | Cosmology of Theories BSM Early Universe Particle Physics Phase Transitions in the Early Universe |
| url | https://doi.org/10.1007/JHEP12(2023)194 |
| work_keys_str_mv | AT yangbai qcdcollapseddomainwallsqcdphasetransitionandgravitationalwavespectroscopy AT tingkuochen qcdcollapseddomainwallsqcdphasetransitionandgravitationalwavespectroscopy AT mrunalkorwar qcdcollapseddomainwallsqcdphasetransitionandgravitationalwavespectroscopy |