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BMy. CepHH 3. OH3HKA. ACTPOHOMHfl. 2022. №2
LFV in Meson and Baryon Decays—Theory Overview
Diego Guadagnoli E-mail: diego.guadagnoli@lapth. cnrs.fr
LAPTh, CNRS et Université Savoie Mont-Blanc, F-74941 Annecy, France Received April 1, 2022
A summary and outlook of the theory motivations and status of searches for lepton flavour violation (LFV) in meson and baryon (semi-)leptonic decays is provided. The contribution is structured as follows: (i) A short overview of b ^ s as well as b ^ c data; (ii) General arguments for pursuing LFV in b-hadron decays; (iii) Additional arguments for possible LFV signatures in other meson decays, in particular of kaons. Emphasis is on a presentation accessible to a wider public, describing the underlying motivation and physics arguments with a minimum of equations.
Keywords: BSM physics, lepton flavor violation, baryon decays.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 112-115.
SUSY Dark Matter Direct Detection Prospects Based on (g — 2)p
Manimala Chakraborti1'", Sven Heinemeyer2'6, Ipsita Saha3'c E-mail: amani.chakraborti@gmail.com, bSven.Heinemeyer@cern.ch, cipsita.saha@ipmu.jp
1Astrocent, Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences, ul. Rektorska 4, 00-614 Warsaw, Poland 2IFT (UAM/CSIC), Cantoblanco, 28049, Madrid, Spain 3Kavli IPMU (WPI), UTIAS, University of Tokyo, Kashiwa, Chiba 277-8583, Japan
Received January 15, 2022
An electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) with masses of a few hundred GeV can account for variety of experimental data, assuming the lightest neutralino to be the lightest supersymmetric (SUSY) particle: the non-observation at the LHC, searches owing to their small production cross sections, the results for the (upper limit of the) Dark Matter (DM) relic abundance and the DM Direct Detection (DD) limits. Such a light EW sector can in particular explain the reinforced 4.2 a discrepancy between the experimental result for (g — 2)M, and its Standard Model (SM) prediction. Using the improved limits on (g — 2)M, we review the predictions for the future prospects of the DD experiments. This analysis is performed for several different realizations of DM in the MSSM: bino, bino/wino, wino and higgsino DM. We find that higgsino, wino and one type of bino scenario can be covered by future DD experiments. Mixed bino/wino and another type of bino DM can reach DD cross sections below the neutrino floor. In these cases future collider experiments must cover the remaining parameter space.
Keywords: BSM physics, SUSY Dark Matter, muon g — 2.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 116-119.
The Any Light Particle Search Experiment at DESY
Katharina-Sophie Isleif E-mail: katharina-sophie. isleif@desy.de
Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
(ALPS Collaboration) Received January 14, 2022
The Any Light Particle Search (ALPS II) is a light shining through a wall (LSW) experiment searching for axion-like elementary particles in the sub-eV mass range, which are motivated by astrophysics and cosmology and fulfill the requirements for being dark matter. ALPS II aims to measure an axion-to-photon coupling of 2 x 10-11 GeV-1, which is several orders of magnitude better than that of previous LSW experiments and will thus investigate a new parameter range. The increased performance is achieved by enhancing the magnetic field interaction length to 2 x 106 m and by amplifying the signal in an optical cavity on each side of a light-tight barrier. The expected signal is in the order of 1 photon per day, which will be measured by photon detectors with very low dark count rates of 0(10-6 Hz). This article gives a technical overview on the experiment design, previous and ongoing investigations and the current status with focus on the single photon detection.
Keywords: axion-like particles, single photon detector, transition edge sensor, high-finesse optical cavities, high-power laser, high magnetic field.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 120-125.
