Calendar

Mar
3
Gio
Measurement of the W boson mass at LHCb @ on-line
Mar 3 @ 11:00 am – 12:00 pm

Seminario di Fenomenologia INFN/DIFI – Mika Vesterinen (Warwick University)

Global fits to precision electroweak data are sensitive to physics beyond the Standard Model but this sensitivity is currently limited by the precision with which the W mass has been directly measured. The most precise measurements of the W mass have been at hadron collider experiments using the kinematic distributions in leptonic W decays. I present the first measurement of the W mass with the LHCb experiment, which is a single-arm small-angle spectrometer experiment at the LHC. I will start with an introduction to the standard model and the precision electroweak observables before describing the challenges in measuring the W mass and the solutions used in LHCb’s measurement. This measurement is based on a subset of the existing LHCb data and I will present an outlook for a more precise measurement with the full dataset, and future combinations with the other LHC experiments.

Per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Mar
10
Gio
Astrometric techniques for the calibration of the ASTRI Cherenkov telescope @ on-line e Aula 601
Mar 10 @ 11:00 am – 12:00 pm

Seminario pheno/astro INFN/DIFI – Dr. Simone Iovenitti (INAF)

ASTRI is an Italian project for the study of Very High-Energy astrophysical phenomena up to 300 TeV and beyond. After the success of the first prototype instrument located in Italy, ASTRI-Horn, the project is entering the realization phase of the MiniArray: 9 identical Cherenkov telescopes working in stereoscopic mode to be installed in Tenerife, Canary Islands. The ASTRI telescopes present a dual-mirror Schwarzschild-Couder optical configuration (never adopted before in gamma-ray astronomy) and a Cherenkov camera based on fast SiPM sensors, able to image the nanosecond atmospheric flashes produced by energetic cosmic photons. Unfortunately, such devices are almost blind to the steady flux of stars in the field of view and consequently the calibration of their pointing represents a technological challenge, also because the compactness of the structure prevents from installing auxiliary monitoring camera sharing the same optical system of the telescope. However, exploiting the so-called Variance method (a statistical algorithm implemented in the ASTRI electronics) the star signal can be successfully recovered by ASTRI (down to ~ 7 mag), offering the potentiality to image the night sky background and meet the demanding pointing requirement (few arc-sec) despite the coarse pixel size of the camera (11 arc-min). To this end, dedicated astrometry techniques have been developed on purpose. Their validation with data from ASTRI-Horn revealed the presence of unexpected systematic errors, demonstrating the importance of such analysis. At present, similar routines for the astrometric calibration of the pointing are being developed to be implemented in the MiniArray, enhancing the accuracy of the whole system.
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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Mar
14
Lun
Increasing the precision of the QCD coupling around the tau mass scale @ Aula 601 e online
Mar 14 @ 2:00 pm – 3:00 pm

Seminario di Fenomenologia – Dr. Diogo Boito (Universidade de Sao Paulo/University of Vienna)

The theoretical precision of many crucial observables in the
Standard Model is nowadays limited by our knowledge of QCD parameters.
Determining the strong coupling and quark masses with smaller uncertainties is
therefore a fundamental task in order to match the reduced errors
that are expected from present and future experiments.
Extracting the QCD parameters is not a straightforward task, since
they are not physical observables: theory input is as important as experimental data. I will
discuss recent developments in the precise determination of the strong coupling
around the tau mass scale, which represents one of the most stringent
tests of asymptotic freedom. I will discuss a viable solution to a
long-standing problem related to the renormalization group improvement
of the perturbative series, the interplay between perturbative and
non-perturbative contributions, and the role of recent experimental
data.
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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Mar
17
Gio
Assessments strategies that promote engaged learning in STEM @ on-line
Mar 17 @ 3:00 pm – 4:00 pm

Seminario di didattica – Claudia De Grandi (Utah University)

Claudia de Grandi ha studiato a Milano, e si è formata durante il suo PhD e post-doc, all’università di Boston e poi a Yale, come fisica teorica della materia condensata. Dal 2018, de Grandi è Assistant Professor (Lecturer) of Educational Practice all’Università dello Utah, US. Da diversi anni i suoi interessi principali di ricerca riguardano soprattutto la didattica della fisica. Il seminario è rivolto a tutti i docenti dei nostri corsi di laurea, e sarà una importante occasione di formazione: spero partecipiate numerosi!

Abstract:
Educational research shows correlation between students’ learning gains and formative assessment. Active learning techniques in STEM have been proven to produce better learning outcomes. I will argue for the need to shift from a traditional instructor-centered approach to an interactive student-centered course structure which offers continuous opportunities for formative feedback. I will provide concrete examples of assessment approaches in STEM that build collaboration among students and instructors, increase student self-efficacy, and hence help students achieve content mastery.
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Zoom link:
https://utah.zoom.us/j/94051338743
Passcode: 17marzo

Mar
24
Gio
The critical $O(N)$ CFT @ on-line e Aula 601
Mar 24 @ 11:00 am – 12:00 pm

Seminario teorico INFN/DIFI – Johan Henriksson (Università di Pisa)

Fifty years ago Wilson and Fisher published their renowned paper on the epsilon-expansion of the critical $O(N)$ model. Nowadays we may think of the critical $O(N)$ model as a two-parameter family of conformal field theories, labeled by $N$ and spacetime dimension $d$. Advances in both diagrammatic technology and CFT methods have led to a constant supply of new results for the $O(N)$ CFT, both perturbatively and non-perturbatively. In this talk, I will give an introduction to the $O(N)$ CFT from the perspective of conformal field theory, with a focus on the often-implicit assumption of spectrum continuity, which is the conjectural assumption that all conformal data, such as critical exponents and operator scaling dimensions, depend continuously on the parameters $N$ and $d$.

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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Apr
7
Gio
Quantum Information and AdS/CFT @ on-line
Apr 7 @ 11:00 am – 12:00 pm

Seminario teorico INFN/DIFI – René Meyer (Julius-Mazimilian Universitat Würzburg)

In recent years, the study of quantum information measures has been fruitful in the understanding of quantum many body systems as well as black holes. The connection to gravity is given by the AdS/CFT correspondence, which maps strongly correlated quantum systems to weakly coupled gravity in one additional dimension, and vice-versa. In this talk I will give a pedagogical introduction to the AdS/CFT correspondence, its usefulness in studying strongly interacting quantum matter, as well as its relation to quantum information theory, and here in particular to quantum computational complexity. Finally, I will present several recent research results of our research group in this direction, and conclude with possible future directions.

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Per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Apr
11
Lun
Properties of heavy mesons in a hot medium within a thermal effective theory @ Aula 602 e online
Apr 11 @ 11:00 am – 12:00 pm

Seminario di fenomenologia INFN/DIFI – Dr. Gloria Montaña (Barcelona University)

The quark-⁠gluon plasma (QGP) is expected to be produced with heavy-⁠ion collisions at RHIC and LHC at very high temperatures and vanishing baryon densities. Charmed mesons are a promising probe of this hot state of strongly interacting matter, as charm quarks are produced in the early stages of the collision and experience the whole evolution of the system. In order to describe the experimental data, a proper theoretical understanding of the propagation of charmed mesons in a hot medium is mandatory. While lattice QCD is becoming an increasingly important tool in this regime, we employ a complementary theoretical methodology that allows us to approach the QGP transition from the
hadronic phase. In particular, we have recently studied the thermal modification of open-⁠charm mesons in a hot mesonic medium by applying an effective field theory based on chiral and heavy-⁠quark spin-⁠flavour symmetries [1,2]. In this approach, the in-⁠ medium unitarized amplitudes of the scattering of the heavy mesons off the light mesons and the self-⁠energies of the heavy mesons are calculated
self-⁠consistently. I will summarize our findings regarding the in-⁠medium properties (masses and decay widths) of the ground-⁠state heavy mesons, as well as those of the excited mesonic states that are
dynamically generated in our heavy-⁠light molecular model, such as the D_0^*(2300) and the D_{s0}^*(2317). Besides, I will report on our results for the open-⁠charm Euclidean correlators and their comparison with those obtained with lattice QCD [3]. Finally, I will discuss the effect on the heavy-⁠flavour transport coefficients, like the drag and transport coefficients, of the scattering of the heavy mesons with the hot medium [4].

[1] G. Montana, A. Ramos, L. Tolos and J. M. Torres-⁠Rincon, Phys.
Lett. B 806 (2020), 135464.
[2] G. Montana, A. Ramos, L. Tolos and J. M. Torres-⁠Rincon, Phys.
Rev. D 102 (2020) 9, 096020.
[3] G. Montana, O. Kaczmarek, L. Tolos and A. Ramos, Eur. Phys. J. A
56 (2020) 11, 294
[4] J. M. Torres-⁠Rincon, G. Montana, A. Ramos and L. Tolos,
Phys.Rev.C 105 (2022) 2, 025203
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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Apr
21
Gio
Theory of pinned viscoelastic hydrodynamics @ on-line e Aula 601
Apr 21 @ 11:00 am – 12:00 pm

Seminario di Fisica Teorica INFN/DIFI – Dr Akash Jain (Amsterdam U.)

Symmetries are a powerful organizational tool in physics that can be used to construct effective theories for physical systems without a detailed understanding of their microscopic constituents. The symmetries under consideration need not be fundamental. Even the knowledge about approximate effective symmetries of the system under consideration can go a long way in constructing an effective description. In this talk, we will construct an effective theory for pinned viscoelastic crystals by exploiting approximate translational symmetry. We will analyze the constraints from the second law of thermodynamics and use these to derive the damping-attenuation relation in pinned crystals. In the process, we will also unravel various new transport coefficients that show up in the stress and energy constitutive relations of these systems and probe their physical significance. The talk will be based on https://arxiv.org/abs/2112.1437
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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Apr
28
Gio
Quark-Gluon Plasma at the LHC: studying the extreme state of QCD with heavy-ion collisions @ on-line
Apr 28 @ 11:00 am – 12:00 pm

Colloquium INFN/DIFI – Andrea Dainese (INFN Padova)

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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Mag
5
Gio
Collinear functions for QCD resummations @ A601 e online
Mag 5 @ 11:00 am – 12:00 pm

Seminario di Fisica Teorica – Prasanna Dhani (INFN Genova)
Singular factors originating from the QCD factorisation of scattering amplitudes in soft and collinear limits play a prominent role in both organising and computing high-order perturbative contributions to hard-scattering cross sections. In this talk, I will report on recent work done in collaboration with Stefano Catani. We start from the factorisation structure of scattering amplitudes in the collinear limit, and we introduce collinear functions that have a process-independent structure. These collinear functions, which are defined at the fully-differential level, can then be integrated over the appropriate observable-dependent phase space to compute logarithmically-enhanced contributions to the corresponding observable. For transverse-momentum dependent observables, we show how the collinear functions can be defined without introducing what is known as rapidity divergences in the literature. We present the results of explicit computations of the collinear functions up to next-to-next-to-leading order.
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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271