The European Physical Journal C最新文献

Large fluctuations in NSPT computations: a lesson from O(N) non-linear sigma models

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-03-01 DOI: 10.1140/epjc/s10052-025-13887-7

Paolo Baglioni, Francesco Di Renzo

{"title":"Large fluctuations in NSPT computations: a lesson from O(N) non-linear sigma models","authors":"Paolo Baglioni, Francesco Di Renzo","doi":"10.1140/epjc/s10052-025-13887-7","DOIUrl":"10.1140/epjc/s10052-025-13887-7","url":null,"abstract":"<div>In the last three decades, numerical stochastic perturbation theory (NSPT) has proven to be an excellent tool for calculating perturbative expansions in theories such as Lattice QCD, for which standard, diagrammatic perturbation theory is known to be cumbersome. Despite the significant success of this stochastic method and the improvements made in recent years, NSPT apparently cannot be successfully implemented in low-dimensional models due to the emergence of huge statistical fluctuations: as the perturbative order gets higher, the signal to noise ratio is simply not good enough. This does not come as a surprise, but on very general grounds, one would expect that the larger the number of degrees of freedom, the less severe the fluctuations will be. By simulating 2D O(N) non-linear sigma models for different values of N, we show that indeed the fluctuations are tamed in the large N limit, meeting our expectations: for a large number of internal degrees of freedom (i.e. for large enough N), NSPT perturbative computation can be pushed to large perturbative orders n. By re-expressing our perturbative expansions as power series in the gN (’t Hooft) coupling, we show some evidence that at any given order n there is a tendency to gaussianity for the stochastic process distributions at large N. By summing our series, we can verify leading order results for the energy and its (field theoretic) variance in the large N limit. We finally establish general relationships between the various perturbative orders in the expansion of the (field theoretic) variance of a given observable and combinations of variances and covariances of given orders NSPT stochastic processes. Having established all this, we conclude discussing interesting applications of NSPT computations in the context of theories similar to O(N) (i.e. (CP(N-1)) models).</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13887-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527662","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}

引用次数: 0

Exploring (phi )CDM model dynamics 探索 CDM 模型的动态性

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-28 DOI: 10.1140/epjc/s10052-025-13920-9

Pierros Ntelis, Jackson Levi Said

{"title":"Exploring (phi )CDM model dynamics","authors":"Pierros Ntelis, Jackson Levi Said","doi":"10.1140/epjc/s10052-025-13920-9","DOIUrl":"10.1140/epjc/s10052-025-13920-9","url":null,"abstract":"<div>In this paper, we introduce the (phi )CDM model, and we compare to the concordance model. We provide their epoch evolution, we perform a dynamical analysis to each model, and a comparative analysis between the two models. We revitalise these two models, since we study them in systems with higher number of variables. Furthermore, the (phi )CDM model is more complete than the one that we found in the literature, since we take into account all the so far discovered epochs, radiation, matter, and dark energy epochs. In contrast in the literature there is no study including the radiation epoch for this model. We find that both models can describe the generally accepted scenario of cosmic evolution, and current observations. Both models, describe qualitative and quantitative current observations about the epoch behaviour of the species of the universe. We find the (phi )CDM model has the following exotic transition from a dominant radiation energy density ratio epoch and a low dominant matter energy density ratio and high dominant radiation energy density ratio epoch, towards a dominant scalar potential energy density ratio epoch, in the matter-potential-scalar plane.</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13920-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513261","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}

引用次数: 0

Slow-roll approximations in Einstein–Gauss–Bonnet gravity formulated in terms of e-folding numbers

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-28 DOI: 10.1140/epjc/s10052-025-13895-7

E. O. Pozdeeva

引用次数: 0

Non-commutativity in modified loop cosmology

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-28 DOI: 10.1140/epjc/s10052-025-13760-7

Abolhassan Mohammadi

{"title":"Non-commutativity in modified loop cosmology","authors":"Abolhassan Mohammadi","doi":"10.1140/epjc/s10052-025-13760-7","DOIUrl":"10.1140/epjc/s10052-025-13760-7","url":null,"abstract":"<div>In this study, we explore the pre-inflationary dynamics of the universe using a non-commutative extension of the mLQC-I framework. By incorporating a scalar field potential, we show that key features of Loop Quantum Cosmology (LQC), such as the quantum bounce and the super-inflationary phase, are preserved. Numerical solutions to the modified Hamiltonian equations, with initial conditions set at the quantum bounce, reveal that the universe’s early expansion rate is sensitive to the shape of the potential. For a chaotic potential, the inclusion of non-commutativity results in a faster expansion rate, whereas for the Starobinsky potential, the expansion rate decreases with increasing non-commutative parameter (theta ). Additionally, higher values of (theta ) lead to an increased time derivative of the Hubble parameter, causing a shorter yet more expansive super-inflationary phase. Over time, Hubble parameters for different values of (theta ) converge. For the Starobinsky potential, the Hubble parameter consistently decreases with larger (theta ), resulting in a prolonged super-inflationary stage. The study also addresses the validation of the Hamiltonian constraint during the evolutionary time.</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13760-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513262","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}

引用次数: 0

Unveiling the composition of the single-charm molecular pentaquarks: insights from radiative decay and magnetic moment

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-27 DOI: 10.1140/epjc/s10052-025-13891-x

Fu-Lai Wang, Si-Qiang Luo, Xiang Liu

{"title":"Unveiling the composition of the single-charm molecular pentaquarks: insights from radiative decay and magnetic moment","authors":"Fu-Lai Wang, Si-Qiang Luo, Xiang Liu","doi":"10.1140/epjc/s10052-025-13891-x","DOIUrl":"10.1140/epjc/s10052-025-13891-x","url":null,"abstract":"<div>In order to unravel the composition of the isoscalar DN, (D^*N,) (D_1N,) and (D_2^*N) molecular pentaquarks, we carry out a systematic investigation of their M1 and E1 radiative decays and magnetic moment properties. Using the constituent quark model and taking into account the S–D wave mixing effect and the coupled channel effect, our analysis yields numerical results indicating that the M1 and E1 radiative decays and the magnetic moment properties of these molecular pentaquarks provide some insights into their inner structures. These results can provide crucial clues for distinguishing their spin-parity quantum numbers and configurations in experimental studies. In addition, we highlight the importance of the electromagnetic properties as key observables for elucidating the inner structures of the observed (Lambda _c^{+} (2940)) and (Lambda _c^{+} (2910).) We hope that these findings can inspire our experimental colleagues to further explore the family of the single-charm molecular pentaquarks and to investigate the inner structures of the (Lambda _c^{+} (2940)) and (Lambda _c^{+} (2910)) in future studies.</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13891-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513310","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}

引用次数: 0

Quasinormal modes of a d-dimensional regular black hole featuring an integrable singularity

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-27 DOI: 10.1140/epjc/s10052-025-13926-3

Zhongzhinan Dong, Dan Zhang, Guoyang Fu, Jian-Pin Wu

引用次数: 0

Measurements of the quantum yield of silicon using Geiger-mode avalanching photodetectors

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-25 DOI: 10.1140/epjc/s10052-025-13883-x

Harry Lewis, Mahsa Mahtab, Fabrice Retière, Austin De St. Croix, Kurtis Raymond, Maia Henriksson-Ward, Nicholas Morrison, Aileen Zhang, Andrea Capra, Ryan Underwood

{"title":"Measurements of the quantum yield of silicon using Geiger-mode avalanching photodetectors","authors":"Harry Lewis, Mahsa Mahtab, Fabrice Retière, Austin De St. Croix, Kurtis Raymond, Maia Henriksson-Ward, Nicholas Morrison, Aileen Zhang, Andrea Capra, Ryan Underwood","doi":"10.1140/epjc/s10052-025-13883-x","DOIUrl":"10.1140/epjc/s10052-025-13883-x","url":null,"abstract":"<div>Accurate characterization of quantum yield is crucial to the reconstruction of energy depositions in silicon at the eV scale. This work presents a new method for experimentally calculating quantum yield using vacuum UV-sensitive silicon photomultipliers (SiPMs), which can be used to determine the probabilities that a UV photon absorbed in a silicon crystal will produce one, two, or three electron–hole pairs. Results are presented which fully constrain the distribution at photon energies up to 7.75 eV. This method works by exploiting the saturation of photon detection efficiency which occurs when these devices are biased sufficiently high above their avalanche breakdown voltage. The measured quantum yield values are lower than those that have been previously reported by experimental data and modelling – this is expected to impact the sensitivity of experiments searching for light dark matter through direct detection in semiconductors, and should also be taken into account when characterizing the performance of UV photodetectors with high quantum efficiency. Measurements have been taken using a Hamamatsu VUV4 and an FBK VUV-HD3 device, showing good agreements between devices, and at a range of temperatures from 163–233 K. The validity of the method is assessed using supplementary measurements of absolute photon detection efficiency, and an additional novel method of measuring average quantum yield using DC current–voltage measurements of SiPMs is presented and used for corroboration.</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13883-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489419","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}

引用次数: 0

Measurement of K fluorescence analysis in ancient bone using X-ray transition edge sensor and semiconductor detectors

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-25 DOI: 10.1140/epjc/s10052-025-13845-3

Zhi-Wei Li, Si-Ming Guo, Shuo Zhang, Jin-Jie Wu, Zhen Wang, Nan Li, Zhong-Tao Wang

{"title":"Measurement of K fluorescence analysis in ancient bone using X-ray transition edge sensor and semiconductor detectors","authors":"Zhi-Wei Li, Si-Ming Guo, Shuo Zhang, Jin-Jie Wu, Zhen Wang, Nan Li, Zhong-Tao Wang","doi":"10.1140/epjc/s10052-025-13845-3","DOIUrl":"10.1140/epjc/s10052-025-13845-3","url":null,"abstract":"<div>Transition edge sensor (TES) have high energy resolution, which can extremely improve in various scientific experiments the energy spectrum analysis capability and have a wide range of applications in almost all fields covering the whole wave band of electromagnetic waves. The same Chinese ancient human bone sample was measured by fluorescence analysis using SDD, Si-PIN detector and TES detector. Typical representative results among the measurements of the three detectors were selected for comparative analyses. The experimental results showed that the TES detector has obvious advantages compared with the semiconductor detector, with a resolution of 21.2eV@3.69 keV, compared to 115.8 eV @ 3.69 keV and 143.9 eV @ 3.69 for SDD and Si-PIN detectors, respectively. TES detector even found some spectral lines that cannot be measured by semiconductor detectors, such as the 0.916 keV L line of Cu, L line of 2.86 keV Rh and so on. The experimental results demonstrate the TES detector’s outstanding performance in elemental spectral line detection. Compared to observations with semiconductor detectors, using X-ray TES enables clear resolution of spectral lines corresponding to elements present in the sample.</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13845-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489418","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}

引用次数: 0

On scale-separated supersymmetric (hbox {AdS}_2) flux vacua

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-25 DOI: 10.1140/epjc/s10052-025-13915-6

Niccolò Cribiori, Fotis Farakos, Nikolaos Liatsos

引用次数: 0

New axion contribution to the two-photon decays of neutral pions

IF 4.2 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-02-24 DOI: 10.1140/epjc/s10052-025-13906-7

Zhen-Yan Lu, Yang Huang, Ji-Gui Cheng, Qi Lu, Shu-Peng Wang

引用次数: 0