6 FEB 2025
14:00 - 16:00



Zoom room information:
https://us06web.zoom.us/j/81916335336?pwd=5zQT4lutMiBoY5Xp1pkFGtbqiaGozg.1
Meeting ID: 819 1633 5336
Passcode: 559618
Venue: Niavaran, Lecture Hall 1

5 FEB 2025
11:00 - 12:00

Abstract:

In this paper, we explore the interactions between light axion-like particles (ALPs) and top quarks, gluons, and W-bosons. Utilizing high-energy probes at the LHC, we probe these couplings in the context of single top quark production associated with a W-boson and an ALP. We analyze the latest LHC Run II data on tt spin correlation measurements to establish constraints on these couplings. Additionally, we compare these constraints with those derived from loop-induced couplings and indirect searches involving B-meson decays. Furthermore, we derive two-dimensional limits on the ALP couplings with top quarks and gluons.

Based on:
arXiv:2408.11588

Indico Link:
https://indico.hep.ipm.ir/e/y.hosseini2

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

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

5 FEB 2025
15:30 - 17:00

Kahler manifolds appear naturally in both Algebraic and Differential Geometry: projective complex varieties from Algebraic Geometry, and smooth manifolds with Riemannian metrics with holonomy U(n). Understanding when a manifold may admit a Kahler structure and how far it is from that is a key problem in geometry. Classically, tools from global analysis (harmonic forms and Hodge theory) provide striking topological properties of Kahler manifolds, linking topology and analysis. We shall review this circle of ideas, and recent results on the construction of manifolds admitting complex structures (and even both complex and symplectic structures simultaneously) but not admitting Kahler structures.

Venue: Online via Zoom:
Meeting ID: 894 4268 0102
Passcode: 362880
Venue: , (Online)

4 FEB 2025
11:00 - 12:30

Abstract:



Understanding the nature of Dark Matter remains one of the most pressing questions in the intersection of Particle Physics and Cosmology. It is well understood that dark matter may emerge through diverse paradigms and span a broad range of energy scales, each with distinct models and scenarios. Focusing specifically on the “DM as particles” paradigm, neutrino experiments offer unique opportunities to probe for evidence of new physics. This becomes even more important given the limitations of simpler models, such as the Weakly Interacting Massive Particle (WIMP), which has faced strong constraints from direct search experiments. These constraints necessitate exploring more complex models, including those involving multi-component dark matter, new approaches such as searching for boosted particles, and the development of novel measurement techniques. These efforts could provide us with an encouraging outlook in the near future. In this talk, I will discuss how combining data from experiments enables the testing of more complex models such as Low-Mass Multi-Component Dark Matter scenarios, and extends sensitivity beyond traditional approaches.

4 FEB 2025
14:00 - 15:00

Date and time

Tuesday, February 4th, 2025 (Bahman 16th, 1403), 2:00 pm (Tehran zone)




Link

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


Abstract
Next-generation neutrino experiments, such as JUNO, Hyper-K, and DUNE, offer new, unique probes into neutrino and beyond the standard model physics. In this talk, I will discuss how each detector's target material (or size) will lead to distinct signatures and how they could be used in new physics and precision studies. For JUNO, we will utilize low-energy neutrino signals in Carbon to discover the atmospheric tau-neutrino flux. For DUNE, nuclear transitions in Argon allow for new and exciting measurements of solar neutrinos à la SNO. Finally, for Hyper-K, its size, and sensitivity to low-energy neutrinos will allow it to measure neutrinos coming from dark matter annihilating within Jupiter's core, reaching sensitivities similar to current direct detection experiments.

3 FEB 2025
11:00 - 12:00

Abstract:

The proton, one of the components of atomic nuclei, is composed of fundamental particles called quarks and gluons. Gluons are the carriers of the force that binds quarks together, and free quarks are never found in isolation—that is, they are confined within the composite particles in which they reside. The origin of quark confinement is one of the most important questions in modern particle and nuclear physics because confinement is at the core of what makes the proton a stable particle and thus provides stability to the Universe. The internal quark structure of the proton is revealed by deeply virtual Compton scattering, a process in which electrons are scattered off quarks inside the protons, which subsequently emit high-energy photons, which are detected in coincidence with the scattered electrons and recoil protons. Here we report a measurement of the pressure distribution experienced by the quarks in the proton. We find a strong repulsive pressure near the centre of the proton (up to 0.6 femtometers) and a binding pressure at greater distances. The average peak pressure near the centre is about 1035 pascals, which exceeds the pressure estimated for the most densely packed known objects in the Universe, neutron stars. This work opens up a new area of research on the fundamental gravitational properties of protons, neutrons and nuclei, which can provide access to their physical radii, the internal shear forces acting on the quarks and their pressure distributions.

Based on:
https://doi.org/10.1038/s41586-018-0060-z

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

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

29 JAN 2025
15:30 - 17:00

Actions of algebraic groups appear in many problems of Algebraic Geometry, encoding certain symmetries. Often one is interested in factoring out these symmetries and producing a new geometric object, a so-called quotient that parametrises the orbits of the action. In this framework, Geometric Invariant Theory (GIT) developed by David Mumford in 1965 deals with the problem of the existence of quotients, with an algebro-geometric structure, of an algebraic variety by the action of a reductive group. This method is extremely useful which also has important and surprising connections with symplectic geometry. In this lecture we shall give a gentle introduction to GIT construction, mainly focusing on the affine case. The algebraic side of this story is about finding the subalgebra of invariants (for an algebra with a group action) which dates back to Hilbert?s 14th problem.




Online via Zoom:


Meeting ID: 908 611 6889


Passcode: 362880
Venue: Niavaran, Lecture Hall 1

29 JAN 2025
17:30 - 18:30

I will talk about two methods used to derive non-vanishing results for a family of L-functions; the one-level density and the moments of L-functions. I will mention what these methods are and how they are used to get non-vanishing.

Zoom link: https://kocun.zoom.us/j/99715471656
Meeting ID: 997 1547 1656
passcode: 848084
Venue: , (Zoom Lecture)

27 JAN 2025
15:30 - 16:30

This lecture is an exposition of the work of Dr. Ardavaan-Raad on superluminal radiation and its expected impact in applied physics, engineering and futuristic technological developments. This lecture is dedicated to the memory of Houshang Ardavaan-Raad.

Zoom link:
https://www.zoom.us/join
Meeting ID: 851 5140 7291
Passcode: 362880
Venue: Niavaran, Lecture Hall 1

27 JAN 2025
13:00 - 14:00

Abstract:

In non-central ultra-relativistic heavy-ion collisions, the angular momentum can reach magnitudes of ${\cal O}(10^4 −10^5)\hbar$, resulting in significant vorticity within the quark-gluon plasma (QGP). One intriguing consequence of this rotation is its impact on the chiral symmetry restoration and deconfinement phase transitions, a topic that has attracted considerable attention in recent years. In this talk, I will review some recent advances in using holographic techniques to explore these rotational effects. Beginning with a basic holographic model, I will discuss its limitations and show how employing more refined models resolves these issues, achieving consistency with lattice QCD results. The findings highlight the necessity of incorporating rotational effects on both gluodynamics and chiral dynamics simultaneously to obtain accurate predictions.

Based on:
https://arXiv:2405.06386v1, arXiv:2010.14478v2

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

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