Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138948
Mathur and Mehta won the third prize in the 2023 Gravity Research Foundation Essay Competition for proving the universality of black hole (BH) thermodynamics. Specifically, they demonstrated that any Extremely Compact Object (ECO) must have the same BH thermodynamic properties regardless of whether or not the ECO possesses an event horizon. The result is remarkable, but it was obtained under the approximation according to which the BH emission spectrum has an exactly thermal character. In fact, strong arguments based on energy conservation and BH back reaction imply that the spectrum of the Hawking radiation cannot be exactly thermal. In this work the result of Mathur and Mehta will be extended to the case where the radiation spectrum is not exactly thermal using the concept of BH dynamical state.
{"title":"Universality of the thermodynamics of a quantum-mechanically radiating black hole departing from thermality","authors":"","doi":"10.1016/j.physletb.2024.138948","DOIUrl":"10.1016/j.physletb.2024.138948","url":null,"abstract":"<div><p>Mathur and Mehta won the third prize in the 2023 Gravity Research Foundation Essay Competition for proving the universality of black hole (BH) thermodynamics. Specifically, they demonstrated that any Extremely Compact Object (ECO) must have the same BH thermodynamic properties regardless of whether or not the ECO possesses an event horizon. The result is remarkable, but it was obtained under the approximation according to which the BH emission spectrum has an exactly thermal character. In fact, strong arguments based on energy conservation and BH back reaction imply that the spectrum of the Hawking radiation cannot be exactly thermal. In this work the result of Mathur and Mehta will be extended to the case where the radiation spectrum is not exactly thermal using the concept of <em>BH dynamical state</em>.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005069/pdfft?md5=ad2f7c60f0a3129ff68047158e44508c&pid=1-s2.0-S0370269324005069-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138949
The exotic decay modes of the already discovered 125-GeV scalar into a pair of light pseudoscalars are a good probe of those new physics scenarios where such pseudoscalars exist. Searches in the mass region where the pseudoscalar (A) is lighter than 62.5 GeV have yielded null findings so far. No search has yet examined GeV where the cross section is suppressed by the off-shell pseudoscalar. We point out a possible enhancement of the sensitivity of probing hAA coupling in the context of a Type-X two Higgs doublet model. We focus on , and select events with two same-sign τ-jets along with a pair of same-sign leptons. This enables much more effective background elimination than in the erstwhile proposed channels. Taking two values of the ττA coupling into account, we obtain limits on the hAA coupling that can be probed at 2σ and 3σ significance, for ranging up to 85 GeV. For GeV, too, we find the probe through our suggested channel exhibits considerable improvement upon the usual -based searches conducted at the LHC. Within this region, achieving the reach of coupling at 3000 fb−1 luminosity using our strategy would require approximately ∼ 3.6 fb−1 luminosity using conventional -based searches.
{"title":"Improving probes of hAA coupling in the Type-X two Higgs doublet model scenario: The crucial role of τ-jet charge identification","authors":"","doi":"10.1016/j.physletb.2024.138949","DOIUrl":"10.1016/j.physletb.2024.138949","url":null,"abstract":"<div><p>The exotic decay modes of the already discovered 125-GeV scalar into a pair of light pseudoscalars are a good probe of those new physics scenarios where such pseudoscalars exist. Searches in the mass region where the pseudoscalar (<em>A</em>) is lighter than 62.5 GeV have yielded null findings so far. No search has yet examined <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>A</mi></mrow></msub><mo>></mo><mn>62.5</mn></math></span> GeV where the cross section is suppressed by the off-shell pseudoscalar. We point out a possible enhancement of the sensitivity of probing <em>hAA</em> coupling in the context of a Type-X two Higgs doublet model. We focus on <span><math><mi>h</mi><mo>→</mo><mi>A</mi><msup><mrow><mi>A</mi></mrow><mrow><mo>(</mo><mo>⁎</mo><mo>)</mo></mrow></msup><mo>→</mo><mn>4</mn><mi>τ</mi></math></span>, and select events with two same-sign <em>τ</em>-jets along with a pair of same-sign leptons. This enables much more effective background elimination than in the erstwhile proposed channels. Taking two values of the <em>ττA</em> coupling into account, we obtain limits on the <em>hAA</em> coupling that can be probed at 2<em>σ</em> and 3<em>σ</em> significance, for <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>A</mi></mrow></msub></math></span> ranging up to 85 GeV. For <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>A</mi></mrow></msub><mo><</mo><mn>62.5</mn></math></span> GeV, too, we find the probe through our suggested channel exhibits considerable improvement upon the usual <span><math><mn>2</mn><mi>μ</mi><mn>2</mn><mi>τ</mi></math></span>-based searches conducted at the LHC. Within this region, achieving the reach of <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mi>h</mi><mi>A</mi><mi>A</mi></mrow></msub></math></span> coupling at 3000 fb<sup>−1</sup> luminosity using our strategy would require approximately ∼<!--> <!-->3.6<span><math><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>5</mn></mrow></msup></math></span> fb<sup>−1</sup> luminosity using conventional <span><math><mn>2</mn><mi>μ</mi><mn>2</mn><mi>τ</mi></math></span>-based searches.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005070/pdfft?md5=0934d4f1c6fb7de89fcfdfc1f928d20d&pid=1-s2.0-S0370269324005070-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138946
One of the leading ideas for the beginning of the Universe is the Hartle-Hawking ‘No-Boundary Proposal.’ Since the Cobordism Conjecture claims that any spacetime allows for a dynamical boundary, we suggest that one may equally well consider a ‘Boundary Proposal’. Specifically, the corresponding euclidean instanton is a sphere with two holes around north and south pole cut out. Analogously to the Hartle-Hawking proposal, the sphere is then cut in two at the equator and half of it is dropped. The equator is glued to an expanding Lorentzian de Sitter space, implementing a beginning of the Universe with a spacelike spherical boundary at its earliest moment. This process is in principle on equal footing with the one based on the no-boundary instanton. In fact, if the Linde-Vilenkin sign choice is used, this ‘Boundary’ creation process may even dominate. An intriguing implication arises if tensionless end-of-the-world branes, as familiar from type-IIA or M-theory, are available: Analogously to the Boundary Proposal, one may then be able to create a compact, flat torus universe from nothing, without any exponential suppression or enhancement factors.
{"title":"The boundary proposal","authors":"","doi":"10.1016/j.physletb.2024.138946","DOIUrl":"10.1016/j.physletb.2024.138946","url":null,"abstract":"<div><p>One of the leading ideas for the beginning of the Universe is the Hartle-Hawking ‘No-Boundary Proposal.’ Since the Cobordism Conjecture claims that any spacetime allows for a dynamical boundary, we suggest that one may equally well consider a ‘Boundary Proposal’. Specifically, the corresponding euclidean instanton is a sphere with two holes around north and south pole cut out. Analogously to the Hartle-Hawking proposal, the sphere is then cut in two at the equator and half of it is dropped. The equator is glued to an expanding Lorentzian de Sitter space, implementing a beginning of the Universe with a spacelike spherical boundary at its earliest moment. This process is in principle on equal footing with the one based on the no-boundary instanton. In fact, if the Linde-Vilenkin sign choice is used, this ‘Boundary’ creation process may even dominate. An intriguing implication arises if tensionless end-of-the-world branes, as familiar from type-IIA or M-theory, are available: Analogously to the Boundary Proposal, one may then be able to create a compact, flat torus universe from nothing, without any exponential suppression or enhancement factors.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005045/pdfft?md5=268d3c07bcc141e58a4239dfc29f30b2&pid=1-s2.0-S0370269324005045-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138952
Understanding how momentum anisotropies arise in small collision systems is important for a quantitative understanding of collectivity in terms of QCD dynamics in small and large collision systems. In this letter we present results for small collision systems from the newly developed parton cascade Alpaca, which faithfully encodes the AMY effective kinetic theory. Alpaca reproduces quantitatively previously known results from a calculation in the single-hit approximation for small values of the coupling. We discuss in detail how such a comparison is to be carried out. Particularly at larger coupling a generic difference between the two approaches becomes apparent, namely that in parton cascades particles interact over a finite distance while in direct integrations of the Boltzmann equation the interactions are local. This leads to quantitative differences in the extracted values for the elliptic flow coefficient. These discrepancies appear in situations where the mean free path is not large compared to the interaction time and the applicability of kinetic theory is thus questionable.
{"title":"Small systems and the single-hit approximation in the AMY parton cascade Alpaca","authors":"","doi":"10.1016/j.physletb.2024.138952","DOIUrl":"10.1016/j.physletb.2024.138952","url":null,"abstract":"<div><p>Understanding how momentum anisotropies arise in small collision systems is important for a quantitative understanding of collectivity in terms of QCD dynamics in small and large collision systems. In this letter we present results for small collision systems from the newly developed parton cascade <span>Alpaca</span>, which faithfully encodes the AMY effective kinetic theory. <span>Alpaca</span> reproduces quantitatively previously known results from a calculation in the single-hit approximation for small values of the coupling. We discuss in detail how such a comparison is to be carried out. Particularly at larger coupling a generic difference between the two approaches becomes apparent, namely that in parton cascades particles interact over a finite distance while in direct integrations of the Boltzmann equation the interactions are local. This leads to quantitative differences in the extracted values for the elliptic flow coefficient. These discrepancies appear in situations where the mean free path is not large compared to the interaction time and the applicability of kinetic theory is thus questionable.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005100/pdfft?md5=a9a687c780309eaa002c8759c1908b7c&pid=1-s2.0-S0370269324005100-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138940
The nearly aligned Higgs Effective Field Theory (naHEFT) is based on the general assumption: all deviations in the Higgs boson couplings are originated from quantum one-loop effects of new particles that are integrated out. If the new particles integrated out have the same non-decoupling property, physics of the electroweak symmetry breaking can be then described by several parameters in the naHEFT, so that there is a correlation among the Higgs boson couplings such as hγγ, hWW and hhh couplings. In this paper, we analyze the strongly first-order electroweak phase transition (EWPT) with the condition of sphaleron decoupling and the completion condition of the phase transition, and investigate the relation among the deviations in the Higgs boson couplings and the dynamics of the EWPTs. We also take into account the gravitational wave spectrum as well as the primordial black hole predicted at the EWPT. We show that if the new particles integrated out include charged scalar states future precision measurements of the hγγ coupling can give a useful prediction on the hhh coupling to realize the strongly first-order EWPT. We can explore the nature of EWPT and the new physics behind it by the combination of precision measurements of various Higgs boson couplings at future collider experiments, gravitational wave observations at future space-based interferometers and searches for primordial black holes.
{"title":"Exploring loop-induced first-order electroweak phase transition in the Higgs effective field theory","authors":"","doi":"10.1016/j.physletb.2024.138940","DOIUrl":"10.1016/j.physletb.2024.138940","url":null,"abstract":"<div><p>The nearly aligned Higgs Effective Field Theory (naHEFT) is based on the general assumption: all deviations in the Higgs boson couplings are originated from quantum one-loop effects of new particles that are integrated out. If the new particles integrated out have the same non-decoupling property, physics of the electroweak symmetry breaking can be then described by several parameters in the naHEFT, so that there is a correlation among the Higgs boson couplings such as <em>hγγ</em>, <em>hWW</em> and <em>hhh</em> couplings. In this paper, we analyze the strongly first-order electroweak phase transition (EWPT) with the condition of sphaleron decoupling and the completion condition of the phase transition, and investigate the relation among the deviations in the Higgs boson couplings and the dynamics of the EWPTs. We also take into account the gravitational wave spectrum as well as the primordial black hole predicted at the EWPT. We show that if the new particles integrated out include charged scalar states future precision measurements of the <em>hγγ</em> coupling can give a useful prediction on the <em>hhh</em> coupling to realize the strongly first-order EWPT. We can explore the nature of EWPT and the new physics behind it by the combination of precision measurements of various Higgs boson couplings at future collider experiments, gravitational wave observations at future space-based interferometers and searches for primordial black holes.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324004982/pdfft?md5=bb7c1aaef542e9ea8744824e114c3a3b&pid=1-s2.0-S0370269324004982-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138945
Recently, in [1], it was demonstrated that various regular black hole metrics can be derived within a theory featuring an infinite number of higher curvature corrections to General Relativity. Moreover, truncating this infinite series at the first few orders already yields a reliable approximation of the observable characteristics of such black holes [2]. Here, we further establish the existence of another regular black hole solution, particularly the D-dimensional extension of the Dymnikova black hole, within the equations of motion incorporating an infinite tower of higher-curvature corrections. This solution is essentially nonperturbative in the coupling parameter, rendering the action, if it exists, incapable of being approximated by a finite number of powers of the curvature. In addition, we compute the dominant quasinormal frequencies of such black holes using both the Bernstein polynomial method and the 13th order WKB method with Padé approximants, obtaining a high degree of agreement between them.
最近[1]的研究证明,在广义相对论中具有无限多个高曲率修正的理论中,可以推导出各种规则的黑洞度量。此外,在前几阶截断这个无穷级数已经可以得到这类黑洞可观测特征的可靠近似值[2]。在这里,我们进一步确定了另一种规则黑洞解的存在,特别是 Dymnikova 黑洞的 D 维扩展,其运动方程中包含了高曲率修正的无限塔。这种方案在耦合参数上本质上是非扰动的,因此即使存在作用,也无法用曲率的有限次幂来近似。此外,我们还使用伯恩斯坦多项式方法和带有帕代近似值的 13 阶 WKB 方法计算了这种黑洞的主导准正态频率,两者之间获得了高度一致。
{"title":"Dymnikova black hole from an infinite tower of higher-curvature corrections","authors":"","doi":"10.1016/j.physletb.2024.138945","DOIUrl":"10.1016/j.physletb.2024.138945","url":null,"abstract":"<div><p>Recently, in <span><span>[1]</span></span>, it was demonstrated that various regular black hole metrics can be derived within a theory featuring an infinite number of higher curvature corrections to General Relativity. Moreover, truncating this infinite series at the first few orders already yields a reliable approximation of the observable characteristics of such black holes <span><span>[2]</span></span>. Here, we further establish the existence of another regular black hole solution, particularly the <em>D</em>-dimensional extension of the Dymnikova black hole, within the equations of motion incorporating an infinite tower of higher-curvature corrections. This solution is essentially nonperturbative in the coupling parameter, rendering the action, if it exists, incapable of being approximated by a finite number of powers of the curvature. In addition, we compute the dominant quasinormal frequencies of such black holes using both the Bernstein polynomial method and the 13th order WKB method with Padé approximants, obtaining a high degree of agreement between them.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005033/pdfft?md5=5d078de3bcd44a24c79ac927965c4084&pid=1-s2.0-S0370269324005033-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138938
A search is presented for the pair production of higgsinos in gauge-mediated supersymmetry models, where the lightest neutralinos decay into a light gravitino in association with either a Higgs h or a Z boson. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb−1 of proton–proton collisions at a centre-of-mass energy of . It targets final states in which a Higgs boson decays into a photon pair, while the other Higgs or Z boson decays into a pair, with missing transverse momentum associated with the two gravitinos. Search regions dependent on the amount of missing transverse momentum are defined by the requirements that the diphoton mass should be consistent with the mass of the Higgs boson, and the mass with the mass of the Higgs or Z boson. The main backgrounds are estimated with data-driven methods using the sidebands of the diphoton mass distribution. No excesses beyond Standard Model expectations are observed and higgsinos with masses up to are excluded, assuming a branching fraction of 100% for . This analysis excludes higgsinos with masses of for branching fractions to as low as 36%, thus providing complementarity to previous ATLAS searches in final states with multiple leptons or multiple b-jets, targeting different decays of the electroweak bosons.
{"title":"Search for pair-produced higgsinos decaying via Higgs or Z bosons to final states containing a pair of photons and a pair of b-jets with the ATLAS detector","authors":"","doi":"10.1016/j.physletb.2024.138938","DOIUrl":"10.1016/j.physletb.2024.138938","url":null,"abstract":"<div><p>A search is presented for the pair production of higgsinos <span><math><mover><mrow><mi>χ</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> in gauge-mediated supersymmetry models, where the lightest neutralinos <span><math><msubsup><mrow><mover><mrow><mi>χ</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mn>1</mn></mrow><mrow><mn>0</mn></mrow></msubsup></math></span> decay into a light gravitino <span><math><mover><mrow><mi>G</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> in association with either a Higgs <em>h</em> or a <em>Z</em> boson. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb<sup>−1</sup> of proton–proton collisions at a centre-of-mass energy of <span><math><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mspace></mspace><mrow><mi>TeV</mi></mrow></math></span>. It targets final states in which a Higgs boson decays into a photon pair, while the other Higgs or <em>Z</em> boson decays into a <span><math><mi>b</mi><mover><mrow><mi>b</mi></mrow><mrow><mo>¯</mo></mrow></mover></math></span> pair, with missing transverse momentum associated with the two gravitinos. Search regions dependent on the amount of missing transverse momentum are defined by the requirements that the diphoton mass should be consistent with the mass of the Higgs boson, and the <span><math><mi>b</mi><mover><mrow><mi>b</mi></mrow><mrow><mo>¯</mo></mrow></mover></math></span> mass with the mass of the Higgs or <em>Z</em> boson. The main backgrounds are estimated with data-driven methods using the sidebands of the diphoton mass distribution. No excesses beyond Standard Model expectations are observed and higgsinos with masses up to <span><math><mn>320</mn><mspace></mspace><mrow><mi>GeV</mi></mrow></math></span> are excluded, assuming a branching fraction of 100% for <span><math><msubsup><mrow><mover><mrow><mi>χ</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mn>1</mn></mrow><mrow><mn>0</mn></mrow></msubsup><mo>→</mo><mi>h</mi><mover><mrow><mi>G</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span>. This analysis excludes higgsinos with masses of <span><math><mn>130</mn><mspace></mspace><mrow><mi>GeV</mi></mrow></math></span> for branching fractions to <span><math><mi>h</mi><mover><mrow><mi>G</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> as low as 36%, thus providing complementarity to previous ATLAS searches in final states with multiple leptons or multiple <em>b</em>-jets, targeting different decays of the electroweak bosons.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324004969/pdfft?md5=8e26fd74c80752b9eea646caf252edf1&pid=1-s2.0-S0370269324004969-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138951
High-energy photons of gamma-ray bursts (GRBs) might be emitted at different intrinsic times with energy dependence at the source. In this letter, we expand the model from previous works on testing the Lorentz Invariance Violation (LV) with the observed GRB data from the Fermi Gamma-ray Space Telescope. We reanalyze the previous data with the full Bayesian parameter estimation method and get consistent results by assuming that the time delays are due to an LV term and a constant intrinsic time delay term. Subsequently, we neglect the LV effect and only consider the intrinsic time delay effect. We assume a common intrinsic time delay term along with a source energy correlated time delay of high-energy photons. We find that the energy-dependent emission times can also explain the observed GRB data of high-energy photon events. Finally, we integrate these two physical mechanisms into a unified model to distinguish and evaluate their respective contributions using the observed GRB data.
伽马射线暴(GRBs)的高能光子可能会在不同的本征时间发射出来,并与源头的能量有关。在这封信中,我们利用费米伽马射线太空望远镜观测到的伽马射线暴数据,扩展了之前测试洛伦兹不变量(LV)的模型。我们用全贝叶斯参数估计方法重新分析了以前的数据,并通过假设时间延迟是由 LV 项和一个恒定的内在时间延迟项引起的,得到了一致的结果。随后,我们忽略了 LV 效应,只考虑了固有时延效应。我们假设高能光子有一个共同的本征时延项和源能量相关时延。我们发现,与能量相关的发射时间也可以解释观测到的高能光子事件的 GRB 数据。最后,我们将这两种物理机制整合到一个统一的模型中,利用观测到的 GRB 数据来区分和评估它们各自的贡献。
{"title":"Energy-dependent intrinsic time delay of gamma-ray bursts on testing Lorentz invariance violation","authors":"","doi":"10.1016/j.physletb.2024.138951","DOIUrl":"10.1016/j.physletb.2024.138951","url":null,"abstract":"<div><p>High-energy photons of gamma-ray bursts (GRBs) might be emitted at different intrinsic times with energy dependence at the source. In this letter, we expand the model from previous works on testing the Lorentz Invariance Violation (LV) with the observed GRB data from the Fermi Gamma-ray Space Telescope. We reanalyze the previous data with the full Bayesian parameter estimation method and get consistent results by assuming that the time delays are due to an LV term and a constant intrinsic time delay term. Subsequently, we neglect the LV effect and only consider the intrinsic time delay effect. We assume a common intrinsic time delay term along with a source energy correlated time delay of high-energy photons. We find that the energy-dependent emission times can also explain the observed GRB data of high-energy photon events. Finally, we integrate these two physical mechanisms into a unified model to distinguish and evaluate their respective contributions using the observed GRB data.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005094/pdfft?md5=2188e164ac1f4308da58d74ec4b83e3a&pid=1-s2.0-S0370269324005094-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138942
The relationship between QCD and the string model offers a valuable perspective for exploring the interaction potential between quarks. In this study, we investigate the restoration of chiral symmetry in connection with the Unruh effect experienced by accelerating observers. Utilizing the Schwinger model, we analyze the critical point at which the string or chromoelectric flux tube between quark-antiquarks breaks with increasing separation between quarks. In this study, the critical distance for quark-antiquark chromoelectric flux tube or string breaking is determined to be fm. The acceleration and Unruh temperature corresponding to this critical point signify the transition of the system's chiral symmetry from a broken to a restored state. Our estimates for the critical acceleration ( cm/s2) and Unruh temperature ( GeV) align with previous studies. This analysis illuminates the interplay between chiral symmetry restoration, the Unruh effect, and the breaking of the string or chromoelectric flux tube within the context of quark interactions.
{"title":"Locating quark-antiquark string breaking in QCD through chiral symmetry restoration and Hawking-Unruh effect","authors":"","doi":"10.1016/j.physletb.2024.138942","DOIUrl":"10.1016/j.physletb.2024.138942","url":null,"abstract":"<div><p>The relationship between QCD and the string model offers a valuable perspective for exploring the interaction potential between quarks. In this study, we investigate the restoration of chiral symmetry in connection with the Unruh effect experienced by accelerating observers. Utilizing the Schwinger model, we analyze the critical point at which the string or chromoelectric flux tube between quark-antiquarks breaks with increasing separation between quarks. In this study, the critical distance for quark-antiquark chromoelectric flux tube or string breaking is determined to be <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>1.294</mn><mo>±</mo><mn>0.040</mn></math></span> fm. The acceleration and Unruh temperature corresponding to this critical point signify the transition of the system's chiral symmetry from a broken to a restored state. Our estimates for the critical acceleration (<span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>1.14</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>34</mn></mrow></msup></math></span> cm/s<sup>2</sup>) and Unruh temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0.038</mn></math></span> GeV) align with previous studies. This analysis illuminates the interplay between chiral symmetry restoration, the Unruh effect, and the breaking of the string or chromoelectric flux tube within the context of quark interactions.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005008/pdfft?md5=eb90d812bc50fdb8b84282723fb114c7&pid=1-s2.0-S0370269324005008-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.physletb.2024.138944
In the context of gravity, cosmological inflation takes a different turn. gravity is a modified theory of gravity, where the Lagrangian is a function of the non-metricity scalar Q. gravity theory is part of an extensive class of modified gravity theories designed to explain the accelerated expansion of the universe without the requirement for dark energy. In this paper, we study the modified gravity in which the scalar field is non-minimally coupled with the matter (it has a new interaction term with the inflaton scalar field (ϕ) and non-metricity scalar (Q)). In pursuit, an inflationary model is extended and investigated by determining the slow-roll parameters and obtaining the model's linear perturbations after calculating the field equation. By comparing the model parameters with the CMB observational data, the model is adapted to observational data through the constraint of the parameters. After some numerical calculations, we show our model is consistent with observational data and free of the phantom if and .
{"title":"Inflation scenario in a non-minimal f(Q) gravity model","authors":"","doi":"10.1016/j.physletb.2024.138944","DOIUrl":"10.1016/j.physletb.2024.138944","url":null,"abstract":"<div><p>In the context of <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity, cosmological inflation takes a different turn. <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity is a modified theory of gravity, where the Lagrangian is a function of the non-metricity scalar <em>Q</em>. <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity theory is part of an extensive class of modified gravity theories designed to explain the accelerated expansion of the universe without the requirement for dark energy. In this paper, we study the modified gravity <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> in which the scalar field is non-minimally coupled with the matter (it has a new interaction term <span><math><mi>α</mi><mi>Q</mi><mo>(</mo><mn>1</mn><mo>+</mo><msup><mrow><mi>ϕ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> with the inflaton scalar field (<em>ϕ</em>) and non-metricity scalar (<em>Q</em>)). In pursuit, an inflationary model is extended and investigated by determining the slow-roll parameters and obtaining the model's linear perturbations after calculating the field equation. By comparing the model parameters with the CMB observational data, the model is adapted to observational data through the constraint of the parameters. After some numerical calculations, we show our model is consistent with observational data and free of the phantom if <span><math><mn>1</mn><mo><</mo><mi>α</mi><mo><</mo><mn>1.5</mn></math></span> and <span><math><mn>1.42</mn><mo><</mo><msub><mrow><mi>γ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo><</mo><mn>1.75</mn></math></span>.</p></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0370269324005021/pdfft?md5=06bd5fb09c20d422986f3d0b14c68697&pid=1-s2.0-S0370269324005021-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}