CC BY
2
18
BMy. CepHH 3. OH3HKA. ACTPOHOMHfl. 2022. №2
Search for Heavy Neutral Lepton Production in NA62
Kereibay Dias (for the NA62 Collaboration) E-mail: dkereiba@cern.ch
Joint Institute Nuclear Research, Dubna, Russian Federation Received January 15, 2022
A search for heavy neutral lepton (N) production in K+ ^ ^+N and K+ ^ e+N decays is carried out by the NA62 experiment using the data collected in 2016-2018. The K + ^ results are expressed as upper limits of 0(10-8) of the neutrino mixing parameter |Um4|2 for N masses in the range 200-384 MeV/c2 and lifetime exceeding 50 ns. From the K+ ^ e+N analysis, upper limits for neutrino mixing matrix element |Ue4|2 are established near the level of 10-9 over most of the accessible heavy neutral lepton mass range 144-462 MeV/c2, with the same assumption about the heavy lepton lifetime.
Keywords: Standart Model, sterile neutrinos, heavy neutral leptons.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 220-222.
Search for Additional Higgs Boson with CMS Detector at LHC
Gouranga Kole (on behalf of CMS Collaboration) E-mail: gouranga.kole@cern.ch
University of Cyprus. Nicosia, Cyprus Received January 15, 2022
In this report we summarized an overview of the additional Higgs boson searches, based on the data collected by the CMS experiment in proton-proton collision by the CERN LHC. The results includes the Run-2 data taking period corresponding to an integrated luminosity of 137 fb-1 at the center-of-mass energy of 13 TeV. A Model-independent upper limit at 95% confidence level on various branching fraction and/or process production cross-section times branching fraction are reported.
Keywords: additional Higgs boson, charged Higgs boson.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 223-225.
How to Detect the Lightest Glueball
B.P. Kosyakov", E.Yu. Popov, M.A. Vronskii E-mail: akosyakov. boris@gmail. com
Russian Federal Nuclear Center-VNIIEF, Sarov, 607188 Russia Received January 15, 2022
We suggest a procedure for detecting the lightest glueball in a head-on collision of photons whose center-of-mass energy in the range 1.3 — 2 GeV. A phenomenological basis for this suggestion is recent evidence for scattering of light by light in LHC experiments. With this evidence, the cross section of the lightest glueball creation in 77 collisions is estimated to be ~ 60 nb. The predominant mode of the lightest glueball decay, predicted from the gauge/gravity duality, is the decay into p0p0. Since the p0 decays into n+n-, a drastic increase of the n+n-n+n- yield is expected as the center-of-mass energy approaches the mass of the lightest glueball. It is this fact which will be the unique signature of the lightest glueball detection.
Keywords: glueballs, collider physics, hadron physics.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 226-227.
Electroweak Measurements at CMS
Alexander Lanyov (on behalf of the CMS Collaboration) E-mail: Alexander.Lanyov@cern.ch
Joint Institute for Nuclear Research. Dubna, 141980 Russia Received January 15, 2022
This report presents the recent results by the CMS Collaboration on the electroweak sector of the Standard model, including single boson and Drell-Yan production, as well as multiboson processes. Detailed studies included measurements of differential cross sections and many other observables, such as asymmetries, ratios for lepton flavor universality, anomalous gauge couplings, etc.
Keywords: electroweak interactions, Z bosons, Drell-Yan process, multiboson interactions, LHC.
English version: Moscow University Physics Bulletin. 2022. 77, No. 2. Pp. 228-231.
