JHEP

The production of ϒ(nS) mesons (n = 1, 2, 3) in pPb and Pbp collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV is measured by the LHCb experiment, using a data sample corresponding to an integrated luminosity of 31.8 nb$^{−1}$. The ϒ(nS) mesons are reconstructed through their decays into two opposite-sign muons. The measurements comprise the differential production cross-sections of the ϒ(1S) and ϒ(2S) states, their forward-to-backward ratios and nuclear modification factors. The measurements are performed as a function of the transverse momentum p$_{T}$ and rapidity in the nucleon-nucleon centre-of-mass frame y$^{*}$ of the ϒ(nS) states, in the kinematic range p$_{T}$ < 25 GeV/c and 1.5 < y$^{*}$ < 4.0 (−5.0 < y$^{*}$ < −2.5) for pPb (Pbp) collisions. In addition, production cross-sections for ϒ(3S) are measured integrated over phase space and the production ratios between all three ϒ(nS) states are determined. Suppression for bottomonium in proton-lead collisions is observed, which is particularly visible in the ratios. The results are compared to theoretical models.

JHEP

Measurements of Higgs boson properties in the H → γγ decay channel are reported. The analysis is based on data collected by the CMS experiment in proton-proton collisions at $\sqrt{s}=13$ TeV during the 2016 LHC running period, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. Allowing the Higgs mass to float, the measurement yields a signal strength relative to the standard model prediction of 1.18$_{− 0.14}^{+ 0.17}$  = 1.18$_{− 0.11}^{+ 0.12}$ (stat)$_{− 0.07}^{+ 0.09}$ (syst)$_{− 0.06}^{+ 0.07}$ (theo), which is largely insensitive to the exact Higgs mass around 125 GeV. Signal strengths associated with the different Higgs boson production mechanisms, couplings to bosons and fermions, and effective couplings to photons and gluons are also measured.

JHEP

A search for heavy resonances, decaying into the standard model vector bosons and the standard model Higgs boson, is presented. The final states considered contain a b quark-antiquark pair from the decay of the Higgs boson, along with electrons and muons and missing transverse momentum, due to undetected neutrinos, from the decay of the vector bosons. The mass spectra are used to search for a localized excess consistent with a resonant particle. The data sample corresponds to an integrated luminosity of 35.9 fb$^{−1}$ collected in 2016 by the CMS experiment at the CERN LHC from proton-proton collisions at a center-of-mass energy of 13 TeV. The data are found to be consistent with background expectations. Exclusion limits are set in the context of spin-0 two Higgs doublet models, some of which include the presence of dark matter. In the spin-1 heavy vector triplet framework, mass-degenerate W′ and Z′ resonances with dominant couplings to the standard model gauge bosons are excluded below a mass of 2.9 TeV at 95% confidence level.

PoS

The Mu2e Experiment at Fermilab will search for coherent, neutrinoless conversion of negative muons into electrons in the field of an aluminum nucleus. The dynamics of this process is well modelled by a two-body decay, resulting in a mono-energetic electron with an energy slightly below the muon rest mass (∼104.967 MeV). If no events are observed in three years of run- ning, Mu2e will set an upper limit on the ratio between the conversion rate and the capture rate Rμe ≤ 6 × 10−17 (@ 90% C.L.). This will improve the current limit of a factor of 104 over previous experiments The experiment complements and extends the current search for μ → eγ decay at MEG as well as the direct searches for new physics at the LHC. Indeed, such a charged lepton flavor-violating reaction probes new physics at a scale inaccessible with direct searches at either present or planned high energy colliders.We briefly present the physics motivation for Mu2e, the current status of the experiment and the design of the muon beamline and the detector, devoting particular attention to the R&D phase, simulation and test carried out to prove the validity of the electromagnetic calorimeter configuration.

JHEP

A search for resonances in the mass range 12–70 GeV produced in association with a b quark jet and a second jet, and decaying to a muon pair, is reported. The analysis is based on data from proton-proton collisions at center-of-mass energies of 8 and 13 TeV, collected with the CMS detector at the LHC and corresponding to integrated luminosities of 19.7 and 35.9 fb$^{−1}$, respectively. The search is carried out in two mutually exclusive event categories. Events in the first category are required to have a b quark jet in the central region (|η| ≤ 2.4) and at least one jet in the forward region (|η| > 2.4). Events in the second category are required to have two jets in the central region, at least one of which is identified as a b quark jet, no jets in the forward region, and low missing transverse momentum. An excess of events above the background near a dimuon mass of 28 GeV is observed in the 8 TeV data, corresponding to local significances of 4.2 and 2.9 standard deviations for the first and second event categories, respectively. A similar analysis conducted with the 13 TeV data results in a mild excess over the background in the first event category corresponding to a local significance of 2.0 standard deviations, while the second category results in a 1.4 standard deviation deficit. The fiducial cross section measurements and 95% confidence level upper limits on those for a resonance consistent with the 8 TeV excess are provided at both collision energies.

J.Contemp.Phys.

Owing to the growing interest in the low-energy nuclear physics, it becomes relevant to enhance the potential of the experimental facilities at Yerevan Physics Institute (YerPhI). The complex unit based on the linear electron accelerator LUE-75 (ARUS synchrotron injector) for applied and fundamental experiments with electron beams, the intensity and energy of which can vary in a wide range of 10$^{–18}$–10$^{–5}$ А and 10–50 MeV, has been created. In recent years, the regimes developed at LUE-75 were applied to obtain the controllable electron beams of extremely low intensity used for calibration of detectors.

Phys.Part.Nucl.Lett.

Experimental results on pion decays obtained with the PIBETA spectrometer at the Paul Scherrer Institute (PSI) are reviewed. For pion beta decay π$^{+}$ → π$^{0}$е$^{+}$ν (πβ), a precision measurement of relative probability yields Г(πβ) = [1.036 ± 0.004(stat) ± 0.004(syst) ± 0.003(π$^{+}$→е$^{+}$ν)] × 10$^{–8}$, which implies V$_{ud}$ = 0.9728(30) for the corresponding element of the Cabibbo–Kobayashi–Maskawa mixing matrix. Using a sample of 65 × 10$^{3}$ events, relative probability of the π$^{+}$→е$^{+}$νγ radiative pion decay (RPD) in the kinematic region of E$_{γ}$ > 10 MeV and θ$_{eγ}$ > 40° is measured as B$^{exp}$ = 73.86(54) × 10$^{–8}$. A statistical analysis of measured E$_{e+}$ and E$_{γ}$ distributions for this decay yield the values F$_{V}$ = 0.0258(17) and F$_{A}$ = 0.0117(17) for the pion weak formfactors. Assuming that F$_{V}$ linearly depends on the е$^{+}$ν invariant mass q$^{2}$ as F$_{V}$(q$^{2}$) = F$_{V}$(0)(1 + aq$^{2}$), the slope parameter is extracted as а = 0.10(6). The pion polarizability and neutral-pion lifetime are estimated as α$_{E}$ = 2.78(10) × 10$^{–4}$ fm$^{3}$ and τ(π$^{0}$) = (8.5 ± 1.1) × 10$^{–17}$ s, respectively. The data for decays π$^{+}$→ е$^{+}$ ν and ${\mu ^ + } \to {e^ + }v\bar v\gamma$ have been collected and are being processed. The follow-up PEN experiment aims at reducing the uncertainty on the π$^{+}$ → е$^{+}$ ν relative probability by almost an order of magnitude (to 5 × 10$^{–4}$).

JHEP

A search for the electroweak production of supersymmetric particles in proton-proton collisions at a center-of-mass energy of 13 TeV is presented in final states with a τ lepton pair. Both hadronic and leptonic decay modes are considered for the τ leptons. Scenarios involving the direct pair production of τ sleptons, or their indirect production via the decays of charginos and neutralinos, are investigated. The data correspond to an integrated luminosity of 35.9 fb$^{−1}$ collected with the CMS detector in 2016. The observed number of events is consistent with the standard model background expectation. The results are interpreted as upper limits on the cross section for τ slepton pair production in different scenarios. The strongest limits are observed in the scenario of a purely left-handed low mass τ slepton decaying to a nearly massless neutralino. Exclusion limits are also set in the context of simplified models of chargino-neutralino and chargino pair production with decays to τ leptons, and range up to 710 and 630 GeV, respectively.

JHEP

A search for a Higgs boson decaying into a pair of electrons or muons and a photon is described. Higgs boson decays to a Z boson and a photon (H → Zγ → ℓℓγ, ℓ = e or μ), or to two photons, one of which has an internal conversion into a muon pair (H → γ$^{*}$γ → μμγ) were considered. The analysis is performed using a data set recorded by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. No significant excess above the background prediction has been found. Limits are set on the cross section for a standard model Higgs boson decaying to opposite-sign electron or muon pairs and a photon. The observed limits on cross section times the corresponding branching fractions vary between 1.4 and 4.0 (6.1 and 11.4) times the standard model cross section for H → γ$^{*}$γ → μμγ (H → Zγ → ℓℓγ) in the 120–130 GeV mass range of the ℓℓγ system. The H → γ$^{*}$γ → μμγ and H → Zγ →ℓℓγ analyses are combined for m$_{H}$ =125GeV, obtaining an observed (expected) 95% confidence level upper limit of 3.9 (2.0) times the standard model cross section.

Eur. Phys. J. C

The production of a ${\text {Z}}$ boson, decaying to two charged leptons, in association with jets in proton-proton collisions at a centre-of-mass energy of 13 $\,\text {TeV}$ is measured. Data recorded with the CMS detector at the LHC are used that correspond to an integrated luminosity of 2.19 $\,\text {fb}^\text {-1}$ . The cross section is measured as a function of the jet multiplicity and its dependence on the transverse momentum of the ${\text {Z}}$ boson, the jet kinematic variables (transverse momentum and rapidity), the scalar sum of the jet momenta, which quantifies the hadronic activity, and the balance in transverse momentum between the reconstructed jet recoil and the ${\text {Z}}$ boson. The measurements are compared with predictions from four different calculations. The first two merge matrix elements with different parton multiplicities in the final state and parton showering, one of which includes one-loop corrections. The third is a fixed-order calculation with next-to-next-to-leading order accuracy for the process with a ${\text {Z}}$ boson and one parton in the final state. The fourth combines the fully differential next-to-next-to-leading order calculation of the process with no parton in the final state with next-to-next-to-leading logarithm resummation and parton showering.

Phys.Rev.Lett.

A combination of the searches for pair-produced vectorlike partners of the top and bottom quarks in various decay channels (T→Zt/Wb/Ht, B→Zb/Wt/Hb) is performed using 36.1  fb-1 of pp collision data at s=13  TeV with the ATLAS detector at the Large Hadron Collider. The observed data are found to be in good agreement with the standard model background prediction in all individual searches. Therefore, combined 95% confidence-level upper limits are set on the production cross section for a range of vectorlike quark scenarios, significantly improving upon the reach of the individual searches. Model-independent limits are set assuming the vectorlike quarks decay to standard model particles. A singlet T is excluded for masses below 1.31 TeV and a singlet B is excluded for masses below 1.22 TeV. Assuming a weak isospin (T,B) doublet and |VTb|≪|VtB|, T and B masses below 1.37 TeV are excluded.

Phys.Rev.D

A search for a time-varying ν¯e signal was performed with 621 days of data acquired by the Daya Bay Reactor Neutrino Experiment over 704 calendar days. The time spectrum of the measured ν¯e flux normalized to its prediction was analyzed with a Lomb-Scargle periodogram, which yielded no significant signal for periods ranging from 2 hours to nearly 2 years. The normalized time spectrum was also fit for a sidereal modulation under the Standard Model Extension (SME) framework to search for Lorentz and CPT violation (LV-CPTV). Limits were obtained for all six flavor pairs e¯μ¯,e¯τ¯, μ¯τ¯, e¯e¯,μ¯μ¯ and τ¯τ¯ by fitting them one at a time, constituting the first experimental constraints on the latter three. Daya Bay’s high statistics and unique layout of multiple directions from three pairs of reactors to three experimental halls allowed the simultaneous constraint of individual SME LV-CPTV coefficients without assuming others contribute negligibly, a first for a neutrino experiment.

Phys.Rev.Lett.

This Letter presents a measurement of γγ→μ+μ- production in Pb+Pb collisions recorded by the ATLAS detector at the Large Hadron Collider at sNN=5.02  TeV with an integrated luminosity of 0.49  nb-1. The azimuthal angle and transverse momentum correlations between the muons are measured as a function of collision centrality. The muon pairs are produced from γγ through the interaction of the large electromagnetic fields of the nuclei. The contribution from background sources of muon pairs is removed using a template fit method. In peripheral collisions, the muons exhibit a strong back-to-back correlation consistent with previous measurements of muon pair production in ultraperipheral collisions. The angular correlations are observed to broaden significantly in central collisions. The modifications are qualitatively consistent with rescattering of the muons while passing through the hot matter produced in the collision.

Phys. Rev. D

A search for electroweak production of supersymmetric particles is performed in two-lepton and three-lepton final states using recursive jigsaw reconstruction, a technique that assigns reconstructed objects to the most probable hemispheres of the decay trees, allowing one to construct tailored kinematic variables to separate the signal and background. The search uses data collected in 2015 and 2016 by the ATLAS experiment in s=13  TeV proton-proton collisions at the CERN Large Hadron Collider corresponding to an integrated luminosity of 36.1  fb-1. Chargino-neutralino pair production, with decays via W/Z bosons, is studied in final states involving leptons and jets and missing transverse momentum for scenarios with large and intermediate mass splittings between the parent particle and lightest supersymmetric particle, as well as for the scenario where this mass splitting is close to the mass of the Z boson. The latter case is challenging since the vector bosons are produced with kinematic properties that are similar to those in Standard Model processes. Results are found to be compatible with the Standard Model expectations in the signal regions targeting large and intermediate mass splittings, and chargino-neutralino masses up to 600 GeV are excluded at 95% confidence level for a massless lightest supersymmetric particle. Excesses of data above the expected background are found in the signal regions targeting low mass splittings, and the largest local excess amounts to 3.0 standard deviations.

JHEP

A search for charged Higgs boson decaying to a charm and a bottom quark ( ${\mathrm{H}}^{+}\to \mathrm{c}\overline{\mathrm{b}}$ ) is performed using 19.7 fb$^{−1}$ of pp collision data at $\sqrt{s}=8$ TeV. The production mechanism investigated in this search is $\mathrm{t}\overline{\mathrm{t}}$ pair production in which one top quark decays to a charged Higgs boson and a bottom quark and the other decays to a charged lepton, a neutrino, and a bottom quark. Charged Higgs boson decays to $\mathrm{c}\overline{\mathrm{b}}$ are searched for, resulting in a final state containing at least four jets, a charged lepton (muon or electron), and missing transverse momentum. A kinematic fit is performed to identify the pair of jets least likely to be the bottom quarks originating from direct top quark decays and the invariant mass of this pair is used as the final observable in the search. No evidence for the presence of a charged Higgs boson is observed and upper limits at 95% confidence level of 0.8–0.5% are set on the branching fraction ℬ(t → H$^{+}$b), assuming ℬ(H$^{+}$ → $\mathrm{c}\overline{\mathrm{b}}$ ) = 1.0 and ℬ(t → H$^{+}$b) + ℬ(t → Wb) = 1.0, for the charged Higgs boson mass range 90–150 GeV.

JHEP

Measurements of the differential jet cross section are presented as a function of the jet mass in dijet events, in bins of jet transverse momentum, with and without a jet grooming algorithm. The data have been recorded by the CMS Collaboration in proton-proton collisions at the LHC at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 2.3 fb$^{−1}$. The absolute cross sections show slightly different jet transverse momentum spectra in data and Monte Carlo event generators for the settings used. Removing this transverse momentum dependence, the normalized cross section for ungroomed jets is consistent with the prediction from Monte Carlo event generators for masses below 30% of the transverse momentum. The normalized cross section for groomed jets is measured with higher precision than the ungroomed cross section. Semi-analytical calculations of the jet mass beyond leading logarithmic accuracy are compared to data, as well as predictions at leading order and next-to-leading order, which include parton showering and hadronization. Overall, in the normalized cross section, the theoretical predictions agree with the measured cross sections within the uncertainties for masses from 10 to 30% of the jet transverse momentum.

Eur. Phys. J. C

Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also combined all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\phi$ is obtained by means of a five-parameter fitting function that besides a $\phi$ -independent term includes four modulations predicted by theory: $\sin \phi$ , $\sin 2 \phi$ , $\sin 3\phi$ and $\cos \phi$ . The amplitudes of the five terms have been extracted, first, for the hadrons in the whole available kinematic region. In further fits, performed for hadrons from a restricted kinematic region, the $\phi$ -dependence is determined as a function of one of three variables (Bjorken-x, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the others. Except the $\phi$ -independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties.

Phys.Rev.D

The DarkSide-50 direct-detection dark matter experiment is a dual-phase argon time projection chamber operating at Laboratori Nazionali del Gran Sasso. This paper reports on the blind analysis of a (16 660±270)  kg d exposure using a target of low-radioactivity argon extracted from underground sources. We find no events in the dark matter selection box and set a 90% C.L. upper limit on the dark matter–nucleon spin-independent cross section of 1.14×10-44  cm2 (3.78×10-44  cm2, 3.43×10-43  cm2) for a WIMP mass of 100  GeV/c2 (1  TeV/c2, 10  TeV/c2).

Phys.Rev.D

Results are reported from a search for long-lived particles in proton-proton collisions at s=13  TeV delivered by the CERN LHC and collected by the CMS experiment. The data sample, which was recorded during 2015 and 2016, corresponds to an integrated luminosity of 38.5  fb-1. This search uses benchmark signal models in which long-lived particles are pair-produced and each decays into two or more quarks, leading to a signal with multiple jets and two displaced vertices composed of many tracks. No events with two well-separated high-track-multiplicity vertices are observed. Upper limits are placed on models of R-parity violating supersymmetry in which the long-lived particles are neutralinos or gluinos decaying solely into multijet final states or top squarks decaying solely into dijet final states. For neutralino, gluino, or top squark masses between 800 and 2600 GeV and mean proper decay lengths between 1 and 40 mm, the analysis excludes cross sections above 0.3 fb at 95% confidence level. Gluino and top squark masses are excluded below 2200 and 1400 GeV, respectively, for mean proper decay lengths between 0.6 and 80 mm. A method is provided for extending the results to other models with pair-produced long-lived particles.

Phys. Rev. D

Direct searches for lepton flavor violation in decays of the Z boson with the ATLAS detector at the LHC are presented. Decays of the Z boson into an electron or muon and a hadronically decaying τ lepton are considered. The searches are based on a data sample of proton-proton collisions collected by the ATLAS detector in 2015 and 2016, corresponding to an integrated luminosity of 36.1  fb-1 at a center-of-mass energy of s=13  TeV. No statistically significant excess of events above the expected background is observed, and upper limits on the branching ratios of lepton-flavor-violating decays are set at the 95% confidence level: B(Z→eτ)<5.8×10-5 and B(Z→μτ)<2.4×10-5. This is the first limit on B(Z→eτ) with ATLAS data. The upper limit on B(Z→μτ) is combined with a previous ATLAS result based on 20.3  fb-1 of proton-proton collision data at a center-of-mass energy of s=8  TeV and the combined upper limit at 95% confidence level is B(Z→μτ)<1.3×10-5.

Phys.Rev.D

By analyzing an e+e- data sample corresponding to an integrated luminosity of 2.93  fb-1 taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure the branching fractions of the Cabibbo-favored hadronic decays D0→K-π+η′, D0→KS0π0η′, and D+→KS0π+η′, which are determined to be (6.43±0.15stat±0.31syst)×10-3, (2.52±0.22stat±0.15syst)×10-3, and (1.90±0.17stat±0.13syst)×10-3, respectively. The precision of the branching fraction of D0→K-π+η′ is significantly improved, and the processes D0→KS0π0η′ and D+→KS0π+η′ are observed for the first time.

Eur. Phys. J. C

Measurements of ${\mathrm {B}} ^{*}_{\mathrm {s}2}(5840)^0$ and ${\mathrm {B}} _{{\mathrm {s}}1}(5830)^0$ mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of , collected with the CMS detector at the LHC at a centre-of-mass energy of $8\,\text {TeV}$ . The analysis studies P-wave ${\mathrm {B}} ^0_{\mathrm {s}}$ meson decays into ${\mathrm {B}} ^{(*)+} \mathrm {K} ^-$ and ${\mathrm {B}} ^{(*)0} \mathrm {K} ^0_{\mathrm {S}}$ , where the ${\mathrm {B}} ^+$ and ${\mathrm {B}} ^0$ mesons are identified using the decays ${\mathrm {B}} ^+ \rightarrow {\mathrm {J}}/\psi \mathrm {K} ^+$ and ${\mathrm {B}} ^0 \rightarrow {\mathrm {J}}/\psi \mathrm {K} ^{*}(892)^0$ . The masses of the P-wave ${\mathrm {B}} ^0_{\mathrm {s}}$ meson states are measured and the natural width of the ${\mathrm {B}} ^{*}_{\mathrm {s}2}(5840)^0$ state is determined. The first measurement of the mass difference between the charged and neutral ${\mathrm {B}} ^{*}$ mesons is also presented. The ${\mathrm {B}} ^{*}_{\mathrm {s}2}(5840)^0$ decay to ${\mathrm {B}} ^0 \mathrm {K} ^0_{\mathrm {S}}$ is observed, together with a measurement of its branching fraction relative to the ${\mathrm {B}} ^{*}_{\mathrm {s}2}(5840)^0 \rightarrow {\mathrm {B}} ^+ \mathrm {K} ^-$ decay.

PoS

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decay in $^{76}$Ge and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modules of natural and $^{76}$Ge-enriched germanium detectors totalling $44.1\ \mathrm{kg}$, operating at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Commissioning of the experiment began in June 2015, followed by data production with the full detector array in August 2016. The ultra-low background and record energy resolution achieved by the MAJORANA DEMONSTRATOR enable a sensitive neutrinoless double-beta decay search, as well as additional searches for physics beyond the Standard Model. I will discuss the design elements that enable these searches, along with the latest results, focusing on the neutrinoless double-beta decay search. I will also discuss the current status and the future plans of the MAJORANA DEMONSTRATOR, as well as the plans for a future tonne-scale $^{76}$Ge experiment.

JHEP

A search for charged Higgs bosons heavier than the top quark and decaying via H$^{±}$ → tb is presented. The data analysed corresponds to 36.1 fb$^{−1}$ of pp collisions at $\sqrt{s}=13$ TeV and was recorded with the ATLAS detector at the LHC in 2015 and 2016. The production of a charged Higgs boson in association with a top quark and a bottom quark, pp → tbH$^{±}$, is explored in the mass range from m$_{H}$± = 200 to 2000 GeV using multi-jet final states with one or two electrons or muons. Events are categorised according to the multiplicity of jets and how likely these are to have originated from hadronisation of a bottom quark. Multivariate techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching ratio of a charged Higgs boson as a function of its mass, which range from 2.9 pb at m$_{H}$± = 200 GeV to 0.070 pb at m$_{H}$± = 2000 GeV. The results are interpreted in two benchmark scenarios of the Minimal Supersymmetric Standard Model.

Phys.Rev.D

A search is performed for a heavy particle decaying into different-flavor, dilepton pairs (eμ, eτ or μτ), using 36.1  fb-1 of proton-proton collision data at s=13  TeV collected in 2015–2016 by the ATLAS detector at the Large Hadron Collider. No excesses over the Standard Model predictions are observed. Bayesian lower limits at the 95% credibility level are placed on the mass of a Z′ boson, the mass of a supersymmetric τ-sneutrino, and on the threshold mass for quantum black-hole production. For the Z′ and sneutrino models, upper cross-section limits are converted to upper limits on couplings, which are compared with similar limits from low-energy experiments and which are more stringent for the eτ and μτ modes.