8 DEC 2025
11:00 - 12:00

Abstract:

The associated production of top-quark pairs with a W boson (tt̄W) is a rare Standard Model process that serves as a crucial probe for electroweak interactions, top-quark couplings, and potential new physics contributions, while also posing challenges for Monte Carlo modeling due to its complexity. In this analysis, the ATLAS Collaboration presents the first detailed differential cross sections measurement of tt̄W using the full Run-2 dataset (140 fb⁻¹ at √s = 13 TeV). The measurement targets leptonic final states with two same-sign or three isolated leptons (electrons or muons), employing advanced machine-learning techniques for heavy-flavor tagging and background rejection. The inclusive cross section is extracted via a binned maximum-likelihood fit, yielding: σ(tt̄W) = 880 ± 80 fb — about 1.8σ above the state-of-the-art NLO QCD prediction of 745 ± 82 fb, highlighting possible tensions in scale choices or higher-order effects. Differential distributions in lepton multiplicities, jet kinematics, and angular variables are unfolded to particle level and compared, revealing generally good agreement in normalized shapes. Additionally, the relative charge asymmetry: A_C(rel) = 0.33 ± 0.05 is measured, aligning well with theory (0.322 ± 0.008). The presentation will discuss analysis challenges.

Based on:
https://doi.org/10.1007/JHEP05(2024)131


Meeting Place:
Seminar Room, School of Particles and Accelerators, IPM

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

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

9 DEC 2025
14:00 - 15:00

Date and time

Tuesday, December 9, 2025 (18 Azar), 2:00 pm (Tehran time)




Link

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


Abstract
The cosmic gravitational focusing (CGF) of relic provides an independent measurement of the cosmic relics such as cosmic neutrinos and light dark matter (DM). This effect eventually produces a dipole density distribution that can affect the galaxy formation and thus can be reconstructed with galaxy surveys such as DESI. For cosmic neutrinos, the CGF have a mass forth power dependence which can help determine neutrino mass ordering. Also, for light DM, the mass dependence scales as second power. The CGF is most sensitive in the region 0.1-100 eV, where it offers a sensitivity two orders of magnitude stronger than the existing constraints from the Lyman-$\alpha$ and $\Delta N_{\rm eff}$.




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

10 DEC 2025
14:00 - 15:00

It is commonly believed that quantum information scrambling is a hallmark of evolution under a chaotic Hamiltonian. In this talk, I will explore the possibility that scrambling can also occur during integrable dynamics. Using four standard diagnostics of quantum information scrambling, I will demonstrate that scrambling can indeed arise in integrable systems provided that the time evolution generator carries a sufficient amount of randomness. I will argue that a chaotic structure within a sector of the Hilbert space is already enough to enable scrambling of quantum information, even when the underlying Hamiltonian remains integrable.





Venue: Room D, 3rd Floor, Farmanieh Building, IPM
Link: https://vmeeting2.ipm.ir/b/nan-gkn-wmh-exh

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

10 DEC 2025
14:00 - 15:00

In this talk, I will present an overview of the journey of matter throughout cosmic evolution, the formation of planets, and the emergence of life on Earth. I will then introduce the methods used to detect exoplanets and habitable worlds, along with nearly 40 planets discovered by our group. Finally, I will discuss the statistics of habitable exoplanets in the Milky Way galaxy and recent observations related to the search for signs of life beyond Earth.

17 DEC 2025
12:30 - 13:30

Inflation is the leading paradigm for the dynamics of the early Universe and for the generation of large scale structures in the cosmos. In this talk, we review early universe cosmology and inflationary model buildings and their connections to osmological observations. We also briefly review our recent works on quantum loop corrections in the primordial power spectrum.



Indico Link: https://indico.hep.ipm.ir/e/H.Firouzjahi


Meeting Place: Seminar Room, School of Particles and Accelerators, IPM


Link to Join Virtually: https://www.skyroom.online/ch/ipm-particles/special-seminar


Link: https://indico.hep.ipm.ir/e/H.Firouzjahi

24 DEC 2025
18:00 - 19:30

Quantum many-body problems are notoriously difficult, with complexity growing exponentially with system size. Perturbative methods often fail in strongly interacting systems or in the presence of flat bands or van Hove singularities. Inspired by the concept of local integrals of motion, we present a non-perturbative approach that systematically reduces many-body properties to exact solutions of more tractable few-body problems. By mapping wavefunctions to Slater-determinant-like states defined by occupation numbers, we show that observables can be expressed as polynomials in these numbers, with coefficients determined by solving n-body problems (n <= p). For nearly integrable systems, the expansion truncates, allowing few-body solutions to yield nearly exact results for finite-density many-body systems. We validate the method on the 2D interacting models.

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

7 FEB 2026
08:00 - 18:00

Venue: Farmanieh Building, IPM
Link: https://qpm.ipm.ac.ir/conferences/NSQIS/

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

8 FEB 2026
08:00 - 18:00

Venue: Farmanieh Building, IPM
Link: https://qpm.ipm.ac.ir/conferences/NSQIS/

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