Mass Mh Research Articles

Capability of future linear colliders to discover heavy neutral CP-even and CP-odd Higgs bosons within type-I 2HDM

In this study, assuming the type-I 2HDM at standard model-like scenario, observability of heavy neutral CP-even and CP-odd Higgs bosons H and A at a linear collider operating at TeV is investigated through the signal process chain where the Z boson experiences a leptonic ( or ) decay and the H Higgs boson is assumed to decay into a di-photon. This signal process is motivated especially by the clean signature which leptonic and photonic events can provide at colliders, and also by the enhancement due to the charged Higgs-mediated contribution to H di-photon decay at large values. The simulation is based on four benchmark points according to which the Higgs mass mH (mA) varies within the range 150–300 (200–400) GeV. Energy smearing of jets and photons is performed, and momentum smearing is also applied to leptons. Results indicate that, for all of the assumed benchmark points, the Higgs bosons H and A are observable with measurable masses, and with signals exceeding 5σ at integrated luminosities 99 and , respectively. Such luminosities are easily accessible to future linear colliders.

Next-to-leading order QCD and electroweak corrections to Higgs-strahlung processes at the LHC**Supported by the National Natural Science Foundation of China (11465018)

In this paper we calculate the total and fiducial cross sections as well as differential distributions for the Higgs-strahlung or VH process pp → VH → lνl/l− l+ + H, (V = W or Z, l = e, μ) including QCD and electro-weak corrections up to next-to-leading order before and after reweighting photon PDFs of NNPDF2.3qed, NNPDF3.0qed, MRST2004qed, CT14QEDinc, and LUXqed at the LHC with 13 TeV and Higgs boson mass MH = 125 GeV. The predictions from the various photon PDFs before and after reweighting against each other are in good agreement. The photon PDF uncertainties of the photon-induced cross sections decrease significantly with the reweighting PDFs.

CEMPlifying reionization

The massive stars that ionized the Universe have short lifetimes and can only be studied near the time of formation, but any low-mass stars that formed contemporaneously might be observable in the local Universe today. We study the abundance pattern and spatial distribution of these ‘siblings of reionizers’ (SoRs) in the eagle cosmological hydrodynamical simulation. SoRs tend to be enriched to supersolar levels in α-elements compared to iron, and we investigate the resemblance between SoRs and the observed stars that are enhanced in carbon. In eagle galaxies resembling the Milky Way, ∼40 per cent of carbon-enhanced metal poor (CEMP) stars are SoRs. Conversely, ∼10 per cent of all SoRs are CEMP stars. This fraction increases to ≳ 50 per cent for SoRs of metallicity [Fe/H] < −4, and at such low metallicities, most of the CEMP stars are of CEMP-no subtype that are lacking neutron capture elements. Although these numbers may well depend on the details of the physical models implemented in eagle, the trends we describe are robust as they result from the strong feedback from star formation in early galaxies, itself a key ingredient of most current models of galaxy formation. We further find that most SoRs today reside in haloes with mass Mh |$\gtrapprox$| 1012 M⊙, and 50 per cent of them are in the halo of their central galaxy (distance >10 kpc), mainly because they were accreted onto their current host rather than formed in situ. To a good approximation, the SoRs are CEMP-no stars that reside in the stellar haloes of massive galaxies, with nearly half of them contributing to the intracluster light in groups and clusters.

Morbidity of Pediatric Obstructive Sleep Apnea in Children: Myth, Reality, or Hidden Iceberg?

We study the interaction of scalar glueball with quark–antiquark and four-quark spinless meson fields within the framework of a generalized linear sigma model in which the trace anomaly of QCD is exactly realized. To determine the pure scalar glueball mass (mh), we consider the decoupling limit in which the scalar glueball decouples from the meson fields. We find the exact relationship mh=2h0 where h0 is the vacuum expectation value of the scalar glueball field independent of the properties of the framework used.

HQE parameters from unquenched lattice data on pseudoscalar and vector heavy-light meson masses

We present a new lattice determination of some of the parameters appearing both in the Operator Product Expansion (OPE) analysis of the inclusive semileptonic B-meson decays and in the Heavy Quark Expansion (HQE) of the pseudoscalar (PS) and vector (V) heavy-light meson masses. We perform a lattice QCD (LQCD) computation of PS and V heavy-light meson masses for heavy-quark masses mh in the range from [see formula in PDF] to ≃ [see formula in PDF]. We employed the Nf = 2 + 1 + 1 gauge configurations of the European Twisted Mass Collaboration (ETMC) at three values of the lattice spacing a ≃ (0.062,0.082,0.089) fm with pion masses in the range Mπ ≃ (210 - 450) MeV. The heavy-quark mass is simulated directly on the lattice up to ≃ [see formula in PDF]. The interpolation to the physical [see formula in PDF] is performed using the ETMC ratio method and adopting the kinetic mass scheme. We obtain [see formula in PDF] (1 GeV) = 4.61(20) GeV (m̅b(m̅b) = 4.26(18) GeV in the MS scheme). The lattice data are analyzed in terms of the HQE and the matrix elements of dimension-4 and dimension-5 operators are extracted with good precision, namely: [see formula in PDF] and [see formula in PDF]. The data also allow for an estimate of the dimension-6 operator matrix elements.

Empirical analysis of particle masses from PDG-2016

Scalar field is responsible for particle mass generation within the Standard Model. We show here the specific role of scalar and vector field masses among masses of other particles. It is described as a common ”tuning effect” in particle masses with the parameters δ = 16me, me/3 derived directly from CODATA relation between masses of nucleons and the electron me. Masses of both leptons could be expressed as QED correction (α/2π) of boson masses MH, MZ.

Search for an invisibly decaying Higgs boson or dark matter candidates produced in association with a Z boson in pp collisions at [formula omitted] with the ATLAS detector

A search for an invisibly decaying Higgs boson or dark matter candidates produced in association with a leptonically decaying Z boson in proton–proton collisions at s=13 TeV is presented. This search uses 36.1 fb−1 of data collected by the ATLAS experiment at the Large Hadron Collider. No significant deviation from the expectation of the Standard Model backgrounds is observed. Assuming the Standard Model ZH production cross-section, an observed (expected) upper limit of 67% (39%) at the 95% confidence level is set on the branching ratio of invisible decays of the Higgs boson with mass mH=125 GeV. The corresponding limits on the production cross-section of the ZH process with the invisible Higgs boson decays are also presented. Furthermore, exclusion limits on the dark matter candidate and mediator masses are reported in the framework of simplified dark matter models.

GOLDRUSH. II. Clustering of galaxies at z ∼ 4–6 revealed with the half-million dropouts over the 100 deg2 area corresponding to 1 Gpc3

Abstract We present clustering properties from 579492 Lyman-break galaxies (LBGs) at z ∼ 4–6 over the 100 deg2 sky (corresponding to a 1.4 Gpc3 volume) identified in early data of the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. We derive angular correlation functions (ACFs) for the HSC LBGs with unprecedentedly high statistical accuracies at z ∼ 4–6, and compare them with the halo occupation distribution (HOD) models. We clearly identify significant ACF excesses in 10″ &amp;lt; θ &amp;lt; 90″, the transition scale between one- and two-halo terms, suggestive of the existence of the non-linear halo bias effect. Combining the HOD models and previous clustering measurements of faint LBGs at z ∼ 4–7, we investigate the dark matter halo mass (Mh) of the z ∼ 4–7 LBGs and its correlation with various physical properties including the star formation rate (SFR), the stellar-to-halo mass ratio (SHMR), and the dark matter accretion rate ($\skew4\dot{M}_{\,\rm h}$) over a wide mass range of Mh/M⊙ = 4 × 1010–4 × 1012. We find that the SHMR increases from z ∼ 4 to 7 by a factor of ∼4 at Mh ≃ 1 × 1011 M⊙ , while the SHMR shows no strong evolution in the similar redshift range at Mh ≃ 1 × 1012 M⊙ . Interestingly, we identify a tight relation of SFR$/\skew4\dot{M}_{\,\rm h}$–Mh showing no significant evolution beyond 0.15 dex in this wide mass range over z ∼ 4–7. This weak evolution suggests that the SFR$/\skew4\dot{M}_{\,\rm h}$–Mh relation is a fundamental relation in high-redshift galaxy formation whose star formation activities are regulated by the dark matter mass assembly. Assuming this fundamental relation, we calculate the cosmic star formation rate densities (SFRDs) over z = 0–10 (a.k.a. the Madau–Lilly plot). The cosmic SFRD evolution based on the fundamental relation agrees with the one obtained by observations, suggesting that the cosmic SFRD increase from z ∼ 10 to 4 − 2 (decrease from z ∼ 4–2 to 0) is mainly driven by the increase of the halo abundance (the decrease of the accretion rate).

Mass dependence of Higgs production at large transverse momentum

The transverse momentum distribution of the Higgs at large PT is complicated by its dependence on three important energy scales: PT, the top quark mass mt, and the Higgs mass mH. A strategy for simplifying the calculation of the cross section at large PT is to calculate only the leading terms in its expansion in mt2/PT2 and/or mH2/PT2. The expansion of the cross section in inverse powers of PT is complicated by logarithms of PT and by mass singularities. In this paper, we consider the top-quark loop contribution to the subprocess qoverline{q}to H+g at leading order in αs. We show that the leading power of 1/PT2 can be expressed in the form of a factorization formula that separates the large scale PT from the scale of the masses. All the dependence on mt and mH can be factorized into a distribution amplitude for toverline{t} in the Higgs, a distribution amplitude for toverline{t} in a real gluon, and an endpoint contribution. The factorization formula can be used to simplify calculations of the PT distribution at large PT to next-to-leading order in αs. The results are readily applied to the qg process via a straightforward analytical continuation.

Search for heavy neutral CP-even Higgs within lepton-specific 2HDM at a future linear collider

In this paper, the production process e−e+→AH is analyzed in the context of the lepton-specific (or type ▪) 2HDM and the question of observability of a neutral CP-even Higgs boson H at a linear collider operating at s=1 TeV is addressed. The CP-odd Higgs is assumed to experience a gauge-Higgs decay as A→ZH with hadronic decay of Z boson as the signature of signal events. The production chain is thus e+e−→AH→ZHH→jjℓℓℓℓ where ℓ is a τ or μ. Four benchmark points with different mass hypotheses are assumed for the analysis. The Higgs mass mH is assumed to vary within the range 150–300 GeV in increments of 50 GeV. The anti-kt algorithm is used to perform the jet reconstruction. Results indicate that the neutral CP-even Higgs H is observable through this production mechanism using the di-muon invariant mass distribution with possibility of mass measurement. The corresponding signal significances exceed 5σ at integrated luminosity of 3000 fb−1.

The FMOS-COSMOS Survey of Star-forming Galaxies at Z ∼ 1.6. V: Properties of Dark Matter Halos Containing Hα Emitting Galaxies

Abstract We study the properties of dark matter halos that contain star-forming galaxies at 1.43 ≤ z ≤ 1.74, using the FMOS-COSMOS survey. The sample consists of 516 objects with a detection of the Hα emission line, which represent the star forming population at this epoch, having a stellar mass range of 109.57 ≤ M */M ⊙ ≲ 1011.4 and a star-formation rate range of 15 ≲ SFR/(M ⊙ yr−1) ≲ 600. We measure the projected two-point correlation function while carefully taking into account observational biases, and find a significant clustering amplitude at scales of 0.04–10 h −1 cMpc, with a correlation length and a bias . We interpret our clustering measurement using a halo occupation distribution model. The sample galaxies appear to reside in halos with mass on average, which will likely become present-day halos of mass M h (z = 0) ∼ 2 × 1013 h −1 M ⊙, equivalent to the typical halo mass scale of galaxy groups. We then confirm the decline of the stellar-to-halo mass ratio at M h &lt; 1012 M ⊙, finding M */M h ≈ 5 × 10−3 at M h = 7. 5 × 1011 M ⊙, which is lower by a factor of 2–4 than those measured at higher masses (M h ∼ 1012–13 M ⊙). Finally, we use our results to illustrate the future capabilities of Subaru’s Prime-Focus Spectrograph, a next-generation instrument that will provide strong constraints on the galaxy-formation scenario by obtaining precise measurements of galaxy clustering at z &gt; 1.

The light composite Higgs boson in strong extended technicolor

This paper extends an earlier one describing the Higgs boson H as a light composite scalar in a strong extended technicolor model of electroweak symmetry breaking. The Higgs mass MH is made much smaller than ΛETC by tuning the ETC coupling very close to the critical value for electroweak symmetry breaking. The technicolor interaction, neglected in the earlier paper, is considered here. Its weakness relative to extended technicolor is essential to understanding the lightness of H compared to the low-lying spin-one technihadrons. Technicolor cannot be completely ignored, but implementing technigluon exchange together with strong extended technicolor appears difficult. We propose a solution that turns out to leave the results of the earlier paper essentially unchanged. An argument is then presented that masses of the spin-one technifermion bound states, ρH and aH, are much larger than MH and, plausibly, controlled by technicolor. Assuming MρH and MaH are in the TeV-energy region, we identify ρH and aH with the diboson excesses observed near 2 TeV by ATLAS and CMS in LHC Run 1 data, and we discuss their phenomenology for Runs 2 and 3.

Search for a light-charged Higgs in a two-Higgs-doublet type II seesaw model at the LHC

A charged Higgs in the type II two-Higgs-doublet model (THDM) has been bounded to be above a few hundred GeV by the radiative B decays. A Higgs triplet extension of the THDM not only provides an origin of neutrino masses and a completely new doubly-charged Higgs decay pattern, but it also achieves a light-charged Higgs with a mass of O(100) GeV through the new scalar couplings in the scalar potential. It was found that these light-charged Higgs decays depend on its mass mH±, tan⁡β, and mixing effect sin⁡θ±: at tan⁡β=1, if mH±>mW+mZ, b¯bW±, W±Z, and τν are the main decay modes; however, if mH±<mW+mZ, the main decay modes are then b¯bW and τν, and at tan⁡β=30, the τν mode dominates the other decays. When mt>mH±+mb, we found that the ATLAS and CMS recent upper bounds on the product of BR(t→H+b)BR(H+→τ+ν) can be directly applied and will give a strict constraint on the correlation of mH± and sin⁡θ±. If the upper bound of BR(t→H+b)BR(H+→τ+ν) is satisfied (escaped) for mt>(<)mH±+mb, it was found that the significance of discovering the charged Higgs through H±→W±Z is much lower than that through H±→b¯bW±. With a luminosity of 100 fb−1 at s=13 TeV and including the experimental bounds, the significance of the H±→b¯bW± signal can reach around 6.2(2.4)σ for mH±<(>)mW+mZ.

Cross section and Higgs mass measurement with Higgsstrahlung at the CEPC **Supported by the Joint Funds of the NSFC (U1232105) and CAS Hundred Talent Program (Y3515540U1)

The Circular Electron Positron Collider (CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It will operate at a center-of-mass energy of 240–250 GeV. The CEPC will accumulate an integrated luminosity of 5 ab−1 over ten years of operation, producing one million Higgs bosons via the Higgsstrahlung and vector boson fusion processes. This sample allows a percent or even sub-percent level determination of the Higgs boson couplings. With GEANT4-based full simulation and a dedicated fast simulation tool, we have evaluated the statistical precisions of the Higgstrahlung cross section σZH and the Higgs mass mH measurement at the CEPC in the Z → μ+μ− channel. The statistical precision of σZH (mH) measurement could reach 0.97% (6.9 MeV) in the model-independent analysis which uses only the information from Z boson decays. For the standard model Higgs boson, the mH precision could be improved to 5.4 MeV by including the information from Higgs decays. The impact of the TPC size on these measurements is investigated. In addition, we studied the prospect of measuring the Higgs boson decaying into invisible final states at the CEPC. With the Standard Model ZH production rate, the upper limit of could reach 1.2% at 95% confidence level.

Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana

Oxygen consumption (VO2), heart rate (fH), heart mass (Mh) and body mass (Mb) were measured during embryonic incubation and in hatchlings of green iguana (Iguana iguana). Mean fH and VO2 were unvarying in early stage embryos. VO2 increased exponentially during the later stages of embryonic development, doubling by the end of incubation, while fH was constant, resulting in a 2.7-fold increase in oxygen pulse. Compared to late stage embryos, the mean inactive level of VO2 in hatchlings was 1.7 fold higher, while fH was reduced by half resulting in a further 3.6 fold increase in oxygen pulse. There was an overall negative correlation between mean fH and VO2 when data from hatchlings was included. Thus, predicting metabolic rate as VO2 from measurements of fH is not possible in embryonic reptiles. Convective transport of oxygen to supply metabolism during embryonic incubation was more reliably indicated as an index of cardiac output (COi) derived from the product of fH and Mh. However, a thorough analysis of factors determining rates of oxygen supply during development and eclosion in reptiles will require cannulation of blood vessels that proved impossible in the present study, to determine oxygen carrying capacity by the blood and arteriovenous oxygen content difference (A-V diff), plus patterns of blood flow.

THE RESOLVE SURVEY ATOMIC GAS CENSUS AND ENVIRONMENTAL INFLUENCES ON GALAXY GAS RESERVOIRS

ABSTRACT We present the H i mass inventory for the REsolved Spectroscopy Of a Local VolumE (RESOLVE) survey, a volume-limited, multi-wavelength census of &gt;1500 z = 0 galaxies spanning diverse environments and complete in baryonic mass down to dwarfs of ∼109 . This first 21 cm data release provides robust detections or strong upper limits (1.4M H i &lt; 5%–10% of stellar mass M *) for ∼94% of RESOLVE. We examine global atomic gas-to-stellar mass ratios (G/S) in relation to galaxy environment using several metrics: group dark matter halo mass M h, central/satellite designation, relative mass density of the cosmic web, and distance to the nearest massive group. We find that at fixed M *, satellites have decreasing G/S with increasing M h starting clearly at M h ∼ 1012 , suggesting the presence of starvation and/or stripping mechanisms associated with halo gas heating in intermediate-mass groups. The analogous relationship for centrals is uncertain because halo abundance matching builds in relationships between central G/S, stellar mass, and halo mass, which depend on the integrated group property used as a proxy for halo mass (stellar or baryonic mass). On larger scales G/S trends are less sensitive to the abundance matching method. At fixed M h ≤ 1012 , the fraction of gas-poor centrals increases with large-scale structure density. In overdense regions, we identify a rare population of gas-poor centrals in low-mass (M h &lt; 1011.4 ) halos primarily located within ∼1.5× the virial radius of more massive (M h &gt; 1012 ) halos, suggesting that gas stripping and/or starvation may be induced by interactions with larger halos or the surrounding cosmic web. We find that the detailed relationship between G/S and environment varies when we examine different subvolumes of RESOLVE independently, which we suggest may be a signature of assembly bias.

Charged Higgs Analysis in CMS

An overview is given of the possible searches of the Charged Higgs Boson during run 2 of the LHC data taking period. The Charged Higgs boson emerges in several (minimal) Standard Model (SM) extensions such as the 2 Doublet Higgs Model, which predicts 5 physical Higgs bosons, consistent with the SM Higgs boson. Based on the main production and decay modes, the possible intermediate and final state particles are predicted for a Charged Higgs mass higher than the top quark mass (mH± > mt). In particular, the dominant H±→τν to tau nu and H±→tb channels are discussed in more detail together with their associated background.

Nonperturbative enhancement of superloop at strong coupling

We address the near-collinear expansion of NMHV six-particle scattering amplitudes at strong value of the 't Hooft coupling in planar maximally supersymmetric Yang–Mills theory. We complement recent studies of this observable within the context of the Pentagon Operator Product Expansion, via the dual superWilson loop description, by studying effects of multiple scalar exchanges that accompany (or not) massive flux-tube excitations. Due to the fact that holes have a very small, nonperturbatively generated mass mh which is exponentially suppressed in the 't Hooft coupling, their exchanges must be resummed in the ultraviolet limit, τ≪1/mh. This procedure yields a contribution to the expectation value of the superloop which enters on equal footing with the classical area — a phenomenon which was earlier observed for MHV amplitudes. In all components, the near-massless scalar exchanges factorize from the ones of massive particles, at leading order in strong coupling.

Dipole moments of charged leptons in the THDM-III with textures

We study the magnetic and weak magnetic dipole moments (WEDMs) of charged leptons in the framework of the two Higgs doublet model type III (THDM-III) with four zero textures. We first analyze the possibility that the discrepancy between the experimental measurements and the theoretical prediction of the muon anomalous magnetic dipole moment () in the standard model can be explained in the context of the model and then find values for the parameters of the THDM-III: neutral and charged Higgs boson masses (mH, ), mixing angles (), CP-violating angles and an additional parameter arising from the mass matrix (), for which a correspondence between theory and experiment is possible. We use and current low energy processes mixing, , , , , , , , and the rare higgs decay in order to determine the allowed parameter space of THDM-III and from these we give a prediction for the magnetic and WEDM of charged leptons, in particular of the τ lepton. The obtained magnetic dipole moment of the τ lepton is of the order of (10−8–10−7) and the weak magnetic is of the order (10−10–10−7).

Formation of emission line dots and extremely metal-deficient dwarfs from almost dark galaxies

Abstract Recent observations have discovered a number of extremely gas-rich very faint dwarf galaxies possibly embedded in low-mass dark matter haloes. We investigate star formation histories of these gas-rich dwarf (‘almost dark’) galaxies both for isolated and interacting/merging cases. We find that although star formation rates (SFRs) are very low (&amp;lt;10−5 M⊙ yr−1) in the simulated dwarfs in isolation for the total halo masses (Mh) of 108-109 M⊙, they can be dramatically increased to be ∼10−4 M⊙ yr−1 when they interact or merge with other dwarfs. These interacting faint dwarfs with central compact H ii regions can be identified as isolated emission line dots (‘ELdots’) owing to their very low surface brightness envelopes of old stars. The remnant of these interacting and merging dwarfs can finally develop central compact stellar systems with very low metallicities (Z/Z⊙ &amp;lt; 0.1), which can be identified as extremely metal-deficient (‘XMD’) dwarfs. These results imply that although there would exist many faint dwarfs that can be hardly detected in the current optical observations, they can be detected as isolated ELdots or XMD dwarfs, when they interact with other galaxies and their host environments. We predict that nucleated ultrafaint dwarfs formed from the darkest dwarf merging can be identified as low-mass globular clusters owing to the very low surface brightness stellar envelopes.