Scalaron the mighty: producing dark matter and baryon asymmetry at reheating

In R^2-inflation scalaron slow roll is responsible for the inflationary stage, while its oscillations reheat the Universe. We find that the same scalaron decays induced by gravity can also provide the dark matter production and leptogenesis. With R^2-term and three Majorana fermions added to the Standard Model, we arrive at the phenomenologically complete theory capable of simultaneously explaining neutrino oscillations, inflation, reheating, dark matter and baryon asymmetry of the Universe. Besides the seesaw mechanism in neutrino sector, we use only gravity, which solves all the problems by exploiting scalaron.Comment: 13 pages; v2: minor corrections; v3: 14 pages, journal versio

Free scalar dark matter candidates in R^2-inflation: the light, the heavy and the superheavy

Gravity takes care of both inflation and subsequent reheating in Starobinsky's R^2-model. The latter is due to inflaton gravitation decays dominated by scalar particle production. It is tempting to suggest that dark matter particles are also produced in this process. Since free scalars being too hot cannot serve as viable dark matter (Phys.Lett.B700:157-162,2011), we further study the issue considering two options: scalars with non-minimal coupling to gravity and superheavy scalars generated at inflationary stage. We found that the first option allows for viable warm or cold dark matter if scalar mass exceeds 0.8 MeV. The second option implies supercold dark matter with particle mass 10^16 GeV, which production is saturated at the end of inflation when inflaton-dependent scalar mass rapidly changes and violates adiabaticity. Similar result holds for superheavy fermion dark matter.Comment: 15 pages, 3 figures; journal versio

Термическая гелий-кислородная смесь в лечебном алгоритме больных с COVID-19

Background. The paper discusses the use of a thermal helium-oxygen mixture (t-Не/О2 ), a novel technology, in treating patients with the 2019-nCoV acute respiratory disease (COVID-19) who develop life-threatening respiratory failure. Aim to evaluate the safety and efficacy of t-Не/О2 inhalation combined with standard therapy in the treatment of acute respiratory failure in patients with COVID-19. Materials and Methods. This was a single-center, randomized, prospective study of 70 patients with COVID-19. All patients were divided into two groups: in Group 1 (n = 38) patients received t-He/О2 in addition to the standard COVID-19 treatment; and in Group 2 (n = 32) patients were given the standard treatment in accordance with the Clinical Treatment Guidelines for patients with COVID-19, developed by the Ministry of Health of the Russian Federation. The male/female ratio was 18/20 in Group 1 and 18/14 in Group 2. The mean age of the patients in the study was 53.5 years (43; 62): 56 years (42; 64) in Group 1 and 52 years (43; 66) in Group 2. All patients had computed tomography (CT) signs of lung injury: ground-glass opacities and areas of consolidation. SARS-CoV-2 RNA was detected in 30 Group 1 patients and 28 Group 2 patients. The patients were matched by sex, age, body mass index (BMI), area of pulmonary involvement, and laboratory findings. All patients provided voluntary informed consent to participate in the study and signed a consent form. Results. Inhalation of thermal helium-oxygen mixture combined with standard therapy did not cause any procedure-related side effects in any of the patients. The following changes were observed in all patients: pO2 /FiO2 , SpO2 , and lymphocyte counts increased, C-reactive protein (CRP) levels decreased, and D-dimer and ferritin levels returned to normal. In Group 1 statistically significant changes in the above-mentioned parameters were seen within three days, while in Group 2 the same changes were observed between Days 7 and 10 of treatment. In Group 1 patients cleared SARS-CoV-2 within 4872 hours after initiation of inhalation, which was confirmed by polymerase chain reaction (PCR), and in Group 2 virus elimination was achieved within 72168 hours. Conclusion. The addition of inhalation of a thermal gas mixture of helium and oxygen (t-He/О2 ) to the standard therapy for patients with SARS-CoV-2 infection, CT signs of pneumonia (grades СT2 or CT3), and acute respiratory failure improves gas exchange, contributes to a more rapid virus elimination, and indirectly reduces inflammation.Обоснование. В представленной работе речь пойдет о новой технологии применения термического гелия и кислорода (t-Не/О2 ) в лечении больных с вирусным заболеванием СOVID-19 на этапе развития жизнеугрожающего синдрома дыхательной недостаточности. Цель изучить безопасность и эффективность ингаляционной терапии t-Не/О2 в лечении острой дыхательной недостаточности пациентов с СOVID-19 на фоне стандартной терапии. Материалы и методы. В одноцентровое рандомизированное проспективное исследование было включено 70 пациентов с COVID-19. Пациенты были разделены на две группы: в первой (n = 38) в стандартный протокол лечения COVID-19 была включена терапия t-Не/О2 ; во второй (n = 32) проводилась стандартная терапия в соответствии с клиническими рекомендациями Минздрава России для больных с COVID. В первой группе соотношение мужчины/женщины 18/20, а во второй 18/14. Средний возраст пациентов в исследовании составлял 53,5 года (43 года мужчины; 62 года женщины), в первой группе 56 лет (42 и 64 года соответственно), во второй 52 года (43 и 66 лет). У всех пациентов имелись КТ-признаки поражения легких по типу матового стекла, участки консолидации. Тест РНК коронавируса SARS-CoV-2 положительный в первой группе у 30 пациентов, во второй у 28. Пациенты сопоставимы по полу, возрасту, индексу массы тела (ИМТ), площади поражения легочной паренхимы, лабораторным данным. Всеми пациентами было подписано информированное добровольное согласие на участие в исследовании. Результаты. Вследствие применения термической гелий-кислородной смеси на фоне стандартной терапии ни у одного пациента объективных побочных эффектов, связанных с процедурой, не выявлено. У всех пациентов обнаружены следующие изменения: повышение pО2 /FiO2, SpO2 и уровня лимфоцитов, снижение концентрации С-реактивного белка, восстановление уровней Д-димера, ферритина. Эти признаки статистически значимо изменились в первой группе в течение 3 сут, тогда как во второй группе на 710-е сут терапии. Элиминация вируса SARS-CoV-2 в первой группе происходила в течение 4872 ч от момента начала ингаляции, что подтверждалось методом ПЦР, а во второй в течение 72168 ч. Заключение. Включение ингаляций термической газовой смеси гелия с кислородом (t-Не/О2 ) в стандартную терапию пациентов, переносящих инфекционное заболевание, вызванное SARS-CоV-2, c КТ-признаками пневмонии (КТ2, КТ3), с острой дыхательной недостаточностью улучшает газообмен, способствует ускорению элиминации вируса и опосредованно повышает противовоспалительный эффект

High Precision Mass Measurements in Ψ\Psi and Υ\Upsilon Families Revisited

High precision mass measurements in $\Psi$ and $\Upsilon$ families performed in 1980-1984 at the VEPP-4 collider with OLYA and MD-1 detectors are revisited. The corrections for the new value of the electron mass are presented. The effect of the updated radiative corrections has been calculated for the $J/\Psi(1S)$ and $\Psi(2S)$ mass measurements.Comment: 5 pages, 1 table, submitted to Phys. Lett.

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

Search for scalar top quark pair production in natural gauge mediated supersymmetry models with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

The results of a search for pair production of the lighter scalar partners of top quarks in 2.05 fb-1 of pp collisions at sqrt(s) =7 TeV using the ATLAS experiment at the LHC are reported. Scalar top quarks are searched for in events with two same flavour opposite-sign leptons (electrons or muons) with invariant mass consistent with the Z boson mass, large missing transverse momentum and jets in the final state. At least one of the jets is identified as originating from a b-quark. No excess over Standard Model expectations is found. The results are interpreted in the framework of R-parity conserving, gauge mediated Supersymmetry breaking `natural' scenarios, where the neutralino is the next-to-lightest supersymmetric particle. Scalar top quark masses up to 310 GeV are excluded for the lightest neutralino mass between 115 GeV and 230 GeV at 95% confidence level, reaching an exclusion of the scalar top quark mass of 330 GeV for the lightest neutralino mass of 190 GeV. Scalar top quark masses below 240 GeV are excluded for all values of the lightest neutralino mass above the Z boson mass.Comment: 7 pages plus author list (20 pages total), 4 figures, 1 table, matches published PLB versio