سخنران: رامین کرد والش‌آبادی - پژوهشگاه دانش های بنیادی، پژوهشکده ذرات و شتابگر

8 مرداد 1404
11:00 تا 12:00

PDFxTMDLib : یک کتابخانه ++C با کارایی بالا برای توابع توزیع پارتونی همراستا و وابسته به تکانه عرضی


Link: https://www.skyroom.online/ch/ipm-particles/weekly-seminar

سخنران: فروز میرمسعودی

8 مرداد 1404
14:00 تا 15:00

چکیده:

We have considered the spin-1/2 XXZ chain model which is exactly solvable with the Bethe anzats method. It is shown adding a single defect away from edges is sufficient to see a chaos signature in the model. In this work, we have studied the time behavior of the Loschmidt-echo (LE) by considering domain-wall and Neel states as two product initial states and also a Bell state as an entangled initial state. We have used the numerical full diagonalization method to have full spectrum of the model. It is shown that very short times behavior of the LE is independent from defect and initial state, and the decay is quadratic. Moreover, results show that in the chaotic regime and for intermediate times, the exponential decay behavior of the LE shows some changes by removing defect from the chain in the domain-wall and Bell states, while no changes is seen in the Neel state. To get some intuition of these changes, we have addressed the relation between the dynamics of the LE and the local density of states features.
Based on : https://iopscience.iop.org/article/10.1088/1402-4896/ab0582


لینک حضور آنلاین در سمینار


https://vmeeting2.ipm.ir/b/nan-gkn-wmh-exh

Link: http://qpm.ipm.ac.ir/

سخنران: F. Arias-Aragon, National Institute for Nuclear Physics (INFN), Frascati National Laboratory

7 مرداد 1404
14:00 تا 15:00

Date and time

Tuesday, July 29th, 2025 (7 Mordad), 2:00 pm (Tehran zone)




Link

https://www.skyroom.online/ch/schoolofphysics/highenergyseminar


Abstract
The ATOMKI collaboration measured excesses in electron-positron production from nuclear transitions of beryllium, helium and carbon nuclei. All these excesses are compatible with the emission of a new boson with mass around 17 MeV, denoted X17. An independent search for this particle, harnessing a particle physics experiment, was performed at the Positron Annihilation into Dark Matter Experiment (PADME), where a positron beam collided against a diamond target expecting to produce resonantly the X17 particle. Given the presumably narrow width of this particle, a precise theoretical computation of the signal shape was required to account for electron motion within the target. After including the theoretical modelling of this effect in their analysis, the PADME collaboration has reported an excess in electron-positron events centered around 17 MeV. This excess was later independently shown to largely reduce the uncertainty on the expected X17 mass when combined with nuclear observables. As a byproduct of these studies, electron motion in large Z materials has been shown to enhance centre-of-mass energy in fixed-target experiments and allow for a new energy scan mechanism relevant for the measurement of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment.

Link: https://www.skyroom.online/ch/schoolofphysics/highenergyseminar

سخنران: دکتر منیره احمدپور - دانشگاه تهران

6 مرداد 1404
11:00 تا 12:00

کاوش در پدیده محبوس سازی QCD با استفاده از درهم تنیدگی اسپینی



Link: https://www.skyroom.online/ch/ipm-particles/journal-club

سخنران: A. Maleki, Sharif University of Technology

31 تیر 1404
11:00 تا 12:00

Date and time

Tuesday, July 22nd, 2025 (31 Tir), 11:00 AM (Tehran zone)




Link

https://www.skyroom.online/ch/schoolofphysics/highenergyseminar


Abstract


This talk addresses the intersection of physics at the smallest and largest scales, where quantum mechanics meets cosmology. We highlight the relevance of this interplay to foundational problems in both cosmology and high energy physics. Our discussion spans the potential quantum features manifesting at galactic or cosmological scales, as well as the role of quantum interferometry in enabling ultra-sensitive measurements in high-energy experiments. These experimental advances not only push the boundaries of precision measurement (such as the detection of gravitational waves), but also open promising avenues for probing quantum aspects of gravity, one of the most profound unresolved questions in theoretical physics.

Link: https://www.skyroom.online/ch/schoolofphysics/highenergyseminar

سخنران: دکتر بهراد تقوی - پژوهشکده ذرات و شتابگرها

30 تیر 1404
11:00 تا 12:00

نابهنجاری (همدیس) چیست؟



Link: https://www.skyroom.online/ch/ipm-particles/journal-club

سخنران: روح الله جعفری

25 تیر 1404
14:00 تا 15:00

چکیده:

We study the impact of noise on the dynamics of entanglement in the transverse-field Ising chain, with the field quenched linearly across one or both of the quantum critical points of the model. Taking concurrence as a measure of entanglement, we find that a quench generates entanglement between nearest- and next-nearest-neighbor spins, with noise reducing the amount of entanglement. Focusing on the next nearest-neighbor concurrence, known to exhibit Kibble-Zurek scaling with the square root of the quench rate in the noiseless case, we find a different result when noise is present: The concurrence now scales logarithmically with the quench rate, with a noise-dependent amplitude. This is also different from the anti-Kibble-Zurek scaling of defect density with quench rate when noise is present, suggesting that noisy entanglement generation is largely independent from the rate of defect formation. Intriguingly, the critical time scale beyond which no entanglement is produced by a noisy quench scales as a power law with the strength of noise, with the same exponent as that which governs the optimal quench time for which defect formation is at a minimum in a standard quantum annealing scheme.


لینک حضور آنلاین در سمینار


https://vmeeting2.ipm.ir/b/nan-gkn-wmh-exh

Link: http://qpm.ipm.ac.ir/

سخنران: دکتر سمیه محمودی - پژوهشگاه دانش های بنیادی، پژوهشکده ذرات و شتابگرها

25 تیر 1404
11:00 تا 12:00

دوشکستی کیهانی: ابزاری برای کاوش در ماهیت مادهً تاریک

Link: https://www.skyroom.online/ch/ipm-particles/weekly-seminar

سخنران: V. Kamali, McGill University

24 تیر 1404
14:00 تا 15:00

Date and time

Tuesday, July 15th, 2025 (24 Tir), 2:00 pm (Tehran zone)




Link

https://www.skyroom.online/ch/schoolofphysics/highenergyseminar


Abstract

In this talk, I will explain a model of warm inflation driven by axion-like particles interacting with $U(1)$ gauge fields, with implications for the early universe's thermal evolution. By extending traditional warm inflation models, we introduce a dissipation mechanism through the thermal fluctuations of electromagnetic fields, leading to a non-trivial backreaction on the inflaton's dynamics. Our results are consistent with CMB observations, even for a natural sub-Plankian Axion decay constant $f
Link: https://www.skyroom.online/ch/schoolofphysics/highenergyseminar

سخنران: دکتر فرید تقی نواز - پژوهشکده ذرات و شتابگرها

23 تیر 1404
11:00 تا 12:00

امکان تفسیرهیدرودینامیکی برای نواحی نزدیک به نقاط ثابت غیردمایی



Link: https://www.skyroom.online/ch/ipm-particles/journal-club

سخنران: A. De Rujula, IFT, UAM/CSIC, Madrid & Theory Division of CERN

4 تیر 1404
18:00 تا 19:30

Date and time,


6-7:30pm, Wednesday 25 June 2025 (4 Tir 1404)


Venue: Online

Link:https://www.skyroom.online/ch/schoolofphysics/colloquium

Abstract:
Gamma Ray Bursts (GRBs) and Cosmic Rays (CRs) are easily understandable. Solid observations of quasars and micro-quasars show how these objets emit “Cannonballs” (CBs), though the underlying mechanisms are not theoretically well understood. The assumption that core-collapse supernovae emit CBs plus some trivial relativistic kinematics provide a successful understanding of GRBs and CRs. The self-defined “official experts” on these fields resist the evidence, in an explicitly inquisitorial way.



Link: https://www.skyroom.online/ch/schoolofphysics/colloquium

سخنران: ابوتراب یغمایی؛ دانشگاه شهید بهشتی

26 خرداد 1404
16:00 تا 18:00

رویکرد درونی به تعبیر نظریه های فیزیکی و ملاحظاتی دربارۀ آن

Link: https://philosophy.ipm.ac.ir/

سخنران: المیرا قاسمی

25 خرداد 1404
16:00 تا 17:30



Link: https://ipm.ac.ir/images/news/PH2500118.jpg