Physics Letters B最新文献

{"title":"Single-proton removal reaction in the IQMD+GEMINI model benchmarked by elemental fragmentation cross sections of 29−33Si on carbon at ∼230 MeV/nucleon","authors":"Guang-Shuai Li ,&nbsp;Bao-Hua Sun ,&nbsp;Jun Su ,&nbsp;Isao Tanihata ,&nbsp;Satoru Terashima ,&nbsp;Jian-Wei Zhao ,&nbsp;Er-Xi Xiao ,&nbsp;Ji-Chao Zhang ,&nbsp;Liu-Chun He ,&nbsp;Ge Guo ,&nbsp;Wei-Ping Lin ,&nbsp;Wen-Jian Lin ,&nbsp;Chuan-Ye Liu ,&nbsp;Chen-Gui Lu ,&nbsp;Bo Mei ,&nbsp;Dan-Yang Pang ,&nbsp;Ye-Lei Sun ,&nbsp;Zhi-Yu Sun ,&nbsp;Meng Wang ,&nbsp;Feng Wang ,&nbsp;Xue-Heng Zhang","doi":"10.1016/j.physletb.2024.139143","DOIUrl":"10.1016/j.physletb.2024.139143","url":null,"abstract":"<div><div>We report on the first measurement of the elemental fragmentation cross sections (EFCSs) of <span><math><mmultiscripts><mrow><mi>Si</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>29</mn><mo>−</mo><mn>33</mn></mrow></mmultiscripts></math></span> on a carbon target at ∼230 MeV/nucleon. The experimental data covering charge changes of Δ<em>Z</em> = 1-4 are reproduced well by the isospin-dependent quantum molecular dynamics (IQMD) coupled with the evaporation GEMINI (IQMD+GEMINI) model. We further explore the mechanisms underlying the single-proton removal reaction in this model framework. We conclude that the cross sections from direct proton knockout exhibit an overall weak dependence on the mass number of Si projectiles. The proton evaporation induced after the projectile excitation significantly affects the cross sections for neutron-deficient Si isotopes, while neutron evaporation plays a crucial role in the reactions of neutron-rich Si isotopes. It is presented that the relative magnitude of one-proton and one-neutron separation energies is an essential factor that influences evaporation processes. Therefore, proton evaporation should be incorporated into the reaction model in addition to the direct proton knockout in analyses of Gade-Tostevin systematic for single-proton removal reactions.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139143"},"PeriodicalIF":4.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691125","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}

{"title":"Finite beaming effect on QED cascades","authors":"Suo Tang","doi":"10.1016/j.physletb.2024.139136","DOIUrl":"10.1016/j.physletb.2024.139136","url":null,"abstract":"<div><div>The quantum electrodynamic (QED) theory predicts the photon emission and pair creation involved in QED cascades occur mainly in a forward cone with finite angular spread <span><math><mi>Δ</mi><mi>θ</mi><mo>∼</mo><mn>1</mn><mo>/</mo><msub><mrow><mi>γ</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> along the momenta of incoming particles. This finite beaming effect has been assumed to be negligible because of the particles' ultra-relativistic Lorentz factor <span><math><msub><mrow><mi>γ</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>≫</mo><mn>1</mn></math></span> in laser-driven QED cascades. We develop an energy- and angularly resolved particle-tracking code, resolving both the energy spectra and the momentum profile of the outgoing particles in each QED event, which improves substantially the agreement between the simulation and exact QED results. We investigate QED cascades driven by two counter-propagating circularly polarized laser pulses, and show that the narrow beaming could be accumulated to effectively suppress the long-term growth of cascades, even though it can hardly affect the early formation of cascades. For QED cascades longer than 10 laser cycles, the finite beaming effect could decrease the final pair yield, especially at ultrahigh intensities <span><math><mi>ξ</mi><mo>&gt;</mo><mn>600</mn></math></span>, by more than 10%.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139136"},"PeriodicalIF":4.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691139","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}

{"title":"Theoretical underpinnings of CP-violation at the high-energy frontier","authors":"Shaouly Bar-Shalom ,&nbsp;Amarjit Soni ,&nbsp;Jose Wudka","doi":"10.1016/j.physletb.2024.139135","DOIUrl":"10.1016/j.physletb.2024.139135","url":null,"abstract":"<div><div>We present a general analysis for the discovery potential of CP-violation (CPV) searches in scattering processes at TeV-scale colliders in an effective field theory framework, using the SMEFT basis for higher dimensional operators. In particular, we systematically examine the CP-violating sector of the SMEFT framework in some well motivated limiting cases, based on flavour symmetries of the underlying heavy theory. We show that, under naturality arguments of the underlying new physics (NP) and in the absence of (or suppressed) flavour-changing interactions, there is only a single operator, <span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>t</mi><mi>ϕ</mi></mrow></msub><mo>=</mo><msup><mrow><mi>ϕ</mi></mrow><mrow><mi>†</mi></mrow></msup><mi>ϕ</mi><mrow><mo>(</mo><msub><mrow><mover><mrow><mi>q</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mn>3</mn></mrow></msub><mi>t</mi><mo>)</mo></mrow><mover><mrow><mi>ϕ</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> which alters the top-Yukawa coupling, that can generate a non-vanishing CP-violating effect from tree-level SM×NP interference terms. We find, however, that CPV from <span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>t</mi><mi>ϕ</mi></mrow></msub><mo>=</mo><msup><mrow><mi>ϕ</mi></mrow><mrow><mi>†</mi></mrow></msup><mi>ϕ</mi><mrow><mo>(</mo><msub><mrow><mover><mrow><mi>q</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mn>3</mn></mrow></msub><mi>t</mi><mo>)</mo></mrow><mover><mrow><mi>ϕ</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> is expected to be at best of <span><math><mi>O</mi><mo>(</mo><mn>1</mn><mtext>%</mtext><mo>)</mo></math></span> and, therefore, very challenging if at all measurable at the LHC or other future high-energy colliders. We then conclude that a potentially measurable CP-violating effect of <span><math><mi>O</mi><mo>(</mo><mn>10</mn><mtext>%</mtext><mo>)</mo></math></span> can arise in high-energy scattering processes <em>only</em> if flavour-changing interactions are present in the underlying NP; in this case a sizable CPV can be generated at the tree-level by pure NP×NP effects and not from SM×NP interference. We provide several examples of CPV at the LHC and at a future <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> collider to support these statements.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"860 ","pages":"Article 139135"},"PeriodicalIF":4.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691138","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}

{"title":"On Krichever tau-function and Verlinde formula","authors":"A. Marshakov","doi":"10.1016/j.physletb.2024.139126","DOIUrl":"10.1016/j.physletb.2024.139126","url":null,"abstract":"<div><div>We remind the definition and main properties of the Krichever quasiclassical tau-function, and turn to the application of these formulas for recent studies of two-dimensional quantum gravity. We show, that in the case of minimal gravity it turns to be directly related with the Verlinde formula for minimal models, giving in particular case its one more direct proof. Generalizations for continuous “complex Liouville” theory are also briefly discussed.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139126"},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691140","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}

{"title":"The μ − τ reflection symmetry breaking in a B − L model with T7 × Z8 × Z2 symmetry","authors":"V.V. Vien","doi":"10.1016/j.physletb.2024.139132","DOIUrl":"10.1016/j.physletb.2024.139132","url":null,"abstract":"<div><div>We suggest a neutrino mass matrix texture satisfying the <span><math><mi>μ</mi><mo>−</mo><mi>τ</mi></math></span> reflection symmetry in a <span><math><mi>B</mi><mo>−</mo><mi>L</mi></math></span> model with <span><math><msub><mrow><mi>T</mi></mrow><mrow><mn>7</mn></mrow></msub></math></span> symmetry by introducing additional singlet scalars and invoking the Type-I seesaw mechanism in which the hierarchical patterns of charged lepton and neutrino masses and of lepton mixing are addressed. The Dirac and Majorana mass matrices hint for a realistic lepton mixing pattern in which the <span><math><mi>μ</mi><mo>−</mo><mi>τ</mi></math></span> symmetry is broken by the contribution from the charged lepton sector. Explicit relations between the Yukawa-like couplings and the observed neutrino oscillation parameters are established. The Yukawa-like couplings in the charged-lepton sector are expressed in terms of three charged lepton masses whereas the Yukawa-like couplings in the neutrino sector are expressed in terms of three observed neutrino mixing angles, two neutrino mass-squared splittings and the lightest neutrino mass, whose magnitudes are in the same order. The considered model is satisfied for both normal and inverted neutrino mass hierarchies and for both lower and higher octants in the light of the recent experimental data.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139132"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655249","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}

{"title":"Spin-orbit entanglement in the Color Glass Condensate","authors":"Shohini Bhattacharya ,&nbsp;Renaud Boussarie ,&nbsp;Yoshitaka Hatta","doi":"10.1016/j.physletb.2024.139134","DOIUrl":"10.1016/j.physletb.2024.139134","url":null,"abstract":"<div><div>We compute the spin-orbit correlations of quarks and gluons at small-<em>x</em> and show that the helicity and the orbital angular momentum of individual partons are strongly anti-aligned even in unpolarized or spinless hadrons and nuclei. Combined with the fact that gluons in the Color Glass Condensate are linearly polarized, our finding indicates that the helicity and the orbital angular momentum of single gluons are maximally entangled in a quantum mechanical sense.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139134"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655205","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}

{"title":"Measurement of upward-going milli-charged particles at the Pierre Auger Observatory","authors":"Ye Xu,&nbsp;Jieqin Lan,&nbsp;Weiwei Gao","doi":"10.1016/j.physletb.2024.139127","DOIUrl":"10.1016/j.physletb.2024.139127","url":null,"abstract":"<div><div>It is assumed that superheavy dark matter particles with O(EeV) mass may decay to relativistic milli-charged particles (MCPs). The upward-going MCPs passing through the Earth can be measured by the fluorescence detectors (FD) of the Pierre Auger observatory (Auger). The massless hidden photon model is taken for MCPs to interact with nuclei, so that the numbers and fluxes of expected MCPs may be evaluated at the FD of Auger. Based on the assumption that no events are observed at the FD of Auger in 14 years, the corresponding upper limits on MCP fluxes are calculated at 90% C. L. These results indicate that MCPs can be directly detected in the secondaries' energy range O(1 EeV)-O(10 EeV) at the FD of Auger, when <span><math><mn>3</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>13</mn></mrow></msup><mo>≲</mo><msup><mrow><mi>ϵ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>≲</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span>. And a new region of 0.7 GeV &lt; <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>M</mi><mi>C</mi><mi>P</mi></mrow></msub></math></span> &lt; 10 GeV and <span><math><mn>1.2</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></math></span> &lt; <em>ϵ</em> &lt; <span><math><mn>4.5</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span> is ruled out in the <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>M</mi><mi>C</mi><mi>P</mi></mrow></msub></math></span>-<em>ϵ</em> plane with 14 years of Auger data.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139127"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655251","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}

{"title":"Replica wormhole and AMPS firewall","authors":"Amir A. Khodahami,&nbsp;Azizollah Azizi","doi":"10.1016/j.physletb.2024.139130","DOIUrl":"10.1016/j.physletb.2024.139130","url":null,"abstract":"<div><div>We investigate the potential for generating an AMPS firewall from the replica wormhole topology, which describes the post-Page time spacetime in the evaporation process of a black hole. Our analysis reveals that this topology gives rise to a Dirac delta force experienced by infalling particles at the event horizon, consistent with the AMPS firewall hypothesis. This force, proportional to the particle's total energy squared, is a direct consequence of the inherent Dirac delta in the Ricci scalar of the replica wormhole. We provide a regularization scheme for this force, which is crucial for obtaining physically meaningful results. Notably, our approach suggests that considering the replica wormhole resolves both the information paradox and the AMPS argument regarding the monogamy of entanglement simultaneously, yielding a more coherent framework.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139130"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655202","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}

{"title":"Parametrically amplified super-radiance towards hot big bang universe","authors":"Motohiko Yoshimura ,&nbsp;Kunio Kaneta ,&nbsp;Kin-ya Oda","doi":"10.1016/j.physletb.2024.139133","DOIUrl":"10.1016/j.physletb.2024.139133","url":null,"abstract":"<div><div>We propose a mechanism of preheating stage after inflation, using a new idea of parametrically amplified super-radiance. Highly coherent state, characterized by macro-coherence of scalar field coupled to produced massless particle in pairs, is created by parametric resonance effects associated with field oscillation around its potential minimum, within a Hubble volume. The state is described effectively by the simple Dicke-type of super-radiance model, and super-radiant pulse is emitted within a Hubble time, justifying neglect of cosmic expansion. Produced particles are shown to interact to change their energy and momentum distribution to realize thermal hot big bang universe. A long standing problem of heating after inflation may thus be solved. A new dark matter candidate produced at the emergence of thermalized universe is suggested as well.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139133"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655211","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}

{"title":"Exploring wobbling motion in triaxial even-even nuclei","authors":"Y.M. Wang,&nbsp;Q.B. Chen","doi":"10.1016/j.physletb.2024.139131","DOIUrl":"10.1016/j.physletb.2024.139131","url":null,"abstract":"<div><div>The potential presence of wobbling motions in even-even nuclei ¹¹²Ru, ¹¹⁴Pd, ¹⁵⁰Nd, and ¹⁸⁸Os are explored by the five-dimensional collective Hamiltonian based on the relativistic density functional theory (5DCH-RDFT). The theoretical results successfully reproduce experimental energy spectra and electromagnetic transition probabilities. Analyses of the potential energy surfaces and probability density distributions in the <span><math><mo>(</mo><mi>β</mi><mo>,</mo><mi>γ</mi><mo>)</mo></math></span> deformation plane as well as the quadrupole asymmetry parameter <span><math><mo>〈</mo><mi>cos</mi><mo>⁡</mo><mn>3</mn><mi>δ</mi><mo>〉</mo></math></span> reveal that ¹⁵⁰Nd shows near-axial symmetry in contrast to the triaxial deformation in ¹¹²Ru, ¹¹⁴Pd, and ¹⁸⁸Os. Additionally, spin coherent state (SCS) map is introduced for the first time to the 5DCH framework to visualize the geometry of angular momentum. It is revealed that the wobbling mode, characterized by oscillations of total angular momentum <strong><em>J</em></strong> about the medium axis, is present in ¹¹²Ru but absent in ¹⁵⁰Nd.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"859 ","pages":"Article 139131"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655247","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}