The recent result of the Higgs search at the LHC experiment has lead to more attention to the supersymmetric standard models with heavy sfermions.Among them, the models with the almost pure wino being the lightest supersymmetric particle (LSP) have been widely discussed due to their success in providing a consistent dark matter candidate. The notable phenomenological feature of the wino LSP is the degeneracy with its charged SU(2) L partner (the charged wino) in mass. The tiny mass splitting makes the charged wino longlived, which allows us to detect the wino production at the LHC experiment by searching for the disappearing charged tracks inside the detectors. Since the reach of the experiment is sensitive to the mass splitting, it is mandatory to estimate it very precisely. We therefore perform a full calculation of the mass splitting at two-loop level, and find that the splitting is reduced by a few MeV compared to the one-loop calculation. This reduction leads to about a 10-30 % longer lifetime of the charged wino, with which the current constraint on the wino mass by the ATLAS experiment is improved by about 10 %.
Sub-GeV Dark Matter particles upscattered by cosmic rays gain enough kinetic energy to pass the thresholds of large volume detectors on Earth. We then use public Super-Kamiokande and MiniBooNE data to derive a novel limit on the scattering cross section of Dark Matter with electrons that extends down to sub-keV masses, closing a previously allowed wide region of parameter space. We finally discuss search strategies and prospects at existing and planned neutrino facilities.PACS numbers: 95.35.+d (Dark matter), 95.55.Vj (Neutrino, muon, pion, and other elementary particle detectors; cosmic ray detectors)
The purpose of this study was to determine the origin and subsequent spread of feline calicivirus (FCV), feline herpesvirus (FHV), and feline enteric coronavirus (FECV) in cats relinquished to shelters. FCV was isolated from the oral fauces of 11% of healthy cats upon entry, and isolation rates were highest for kittens (33%). FHV shedding was very low (4%) at the time of entry and occurred mainly in juveniles. FECV shedding was also common among newly relinquished cats (33%), especially older kittens and juveniles (90%). The subsequent spread of all three viruses was rapid and efficient in the shelter environment. Fifteen percent of cats were shedding FCV, 52% FHV, and 60% FECV after 1 week. More detailed studies were done with FECV shedding, which could be accurately quantitated. The amounts of FECV shed by infected cats ranged from 10(2)to 10(16)particles/swab of feces. FECV shedding was several logs higher in young kittens with primary infection than adult cats with primary infections. The mean levels of FECV shedding among adults were the same for primary and chronic infections. Although shelters were not the primary source of these viruses for many relinquished cats, factors intrinsic to the shelter environment were critical in amplifying shedding and spread to susceptible individuals. Extrinsic factors were especially important for the spread of FHV and FECV. FHV shedding rates increased from 4% to 50% in 1 week's time. The speed and magnitude of the increase in FHV shedding suggested that there was reactivation of latent infections as well as acquisition of new infections. FECV shedding increased 10 to 1,000,000 fold in 1 week among cats that were already infected at entry, and more than one-half of initially negative cats were shedding FECV a week later. Feline calicivirus infection was the least likely to spread in the shelter. The infection rate only increased from 11 to 15% in 1 week.
We investigate the production of axion quanta during the early universe evolution of an axion-like field rolling down a wiggly potential. We compute the growth of quantum fluctuations and their back-reaction on the homogeneous zeromode. We evaluate the transfer of kinetic energy from the zero mode to the quantum fluctuations and the conditions to decelerate the axion zero-mode as a function of the Hubble rate, the slope of the potential, the size of the barriers and the initial field velocity. We discuss how these effects impact the relaxion mechanism. arXiv:1911.08472v1 [hep-ph] 19 Nov 2019 1 As this work was being completed, Ref. appeared, which considers the production of axion quantum fluctuations during oscillations about the minimum of the potential, as in . This effect is important only if the initial position of the axion field is tuned very close to the top of the barrier of the axion potential, at the level of ∼ 10 −7 . Such peculiar initial position was recently motivated by some inflation dynamics in  and by anthropic arguments in .
Cosmic-ray anti-deuterium and anti-helium have long been suggested as probes of dark matter, as their secondary astrophysical production was thought extremely scarce. But how does one actually predict the secondary flux? Anti-nuclei are dominantly produced in pp collisions, where laboratory cross section data is lacking. We make a new attempt at tackling this problem by appealing to a scaling law of nuclear coalescence with the physical volume of the hadronic emission region. The same volume is probed by Hanbury Brown-Twiss (HBT) two-particle correlations. We demonstrate the consistency of the scaling law with systems ranging from central and off-axis AA collisions to pA collisions, spanning 3 orders of magnitude in coalescence yield. Extending the volume scaling to the pp system, HBT data allows us to make a new estimate of coalescence, that we test against preliminary ALICE pp data. For anti-helium the resulting cross section is 1-2 orders of magnitude higher than most earlier estimates. The astrophysical secondary flux of anti-helium could be within reach of a five-year exposure of AMS02.challenge, instead, is in computing the production cross sections. Invoking the HBT-coalescence relation, we derive new estimates for thed and 3 He yield in pp collisions, forming the basis of our results in Fig.
Abstract:We discuss the Type-X (lepton-specific) two Higgs doublet model as a solution of the anomaly of the muon g − 2. We consider various experimental constraints on the parameter space such as direct searches for extra Higgs bosons at the LEP II and the LHC Run-I, electroweak precision observables, the decay of B s → µ + µ − , and the leptonic decay of the tau lepton. We find that the measurement of the tau decay provides the most important constraint, which excludes the parameter region that can explain the muon g − 2 anomaly at the 1σ level. We then discuss the phenomenology of extra Higgs bosons and the standard model-like Higgs boson (h) to probe the scenario favored by the g − 2 data at the collider experiments. We find that the 4τ , 3τ and 4τ + W/Z signatures are expected as the main signal of the extra Higgs bosons at the LHC. In addition, we clarify that the value of the hτ τ coupling is predicted to be the standard model value times about −1.6 to −1.0, and the branching fraction of the h → γγ mode deviates from the standard model prediction by −30% to −15%. Furthermore, we find that the exotic decay mode, h decaying into the Z boson and a light CP-odd scalar boson, is allowed, and its branching fraction can be a few percent. These deviations in the property of h will be tested by the precision measurements at future collider experiments.
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