Multimuon Production Research Articles

Discovery potential of FASER\u03bd with contained vertex and through-going events

FASERν is a newly proposed detector whose main mission is to detect the neutrino flux from the collision of the proton beams at the ATLAS Interaction Point (IP) during the run III of the LHC in 2022–2024. We show that this detector can also test certain beyond standard model scenarios, especially the ones in which the neutrino interaction with matter fields can produce new unstable particles decaying back into charged leptons. Models of this kind are motivated by the MiniBooNE anomaly. We show that, if the new physics involves multi-muon production by neutrinos scattering off matter fields, including the neutrino flux interactions in the rock before the detector in the analysis (i.e., accounting for the through-going muon pairs) can significantly increase the effective detector mass and its sensitivity to new physics. We propose a concrete model that can give rise to such a multi-muon signal.

Search for sphalerons: IceCube vs. LHC

We discuss the observability of neutrino-induced sphaleron transitions in the IceCube detector, encouraged by a recent paper by Tye and Wong (TW), which argued on the basis of a Bloch wave function in the periodic sphaleron potential that such transitions should be enhanced compared to most previous calculations. We calculate the dependence on neutrino energy of the sphaleron transition rate, comparing it to that for conventional neutrino interactions, and we discuss the observability of tau and multi-muon production in sphaleron-induced transitions. We use IceCube 4-year data to constrain the sphaleron rate, finding that it is comparable to the upper limit inferred previously from a recast of an ATLAS search for microscopic black holes at the LHC with ∼ 3/fb of collisions at 13 TeV. The IceCube constraint is stronger for a sphaleron barrier height E Sph ≳ 9 TeV, and would be comparable with the prospective LHC sensitivity with 300/fb of data at 14 TeV if E Sph ∼ 11 TeV.

Early SUSY discovery at LHC via sparticle cascade decays to same-sign and multimuon states

In the very early stages of LHC running, uncertainties in detector performance will lead to large ambiguities in jet, electron and photon energy measurements, along with inferred missing transverse energy ETmiss. However, muon detection should be quite straightforward, with the added benefit that muons can be reliably detected down to transverse energies of order 5 GeV. Supersymmetry discovery through multimuon channels has been extensively explored in the literature, but always relying on hard ETmiss cuts. Here, we quantify signal and background rates for same-sign (SS) dimuon and multimuon production at the LHC without any ETmiss cuts. The LHC, operating at s=10 TeV, should be able to discover a signal over expected background consistent with gluino pair production for mg˜≲450 (550) GeV in the SS dimuon plus ⩾4 jets state with just 0.1 (0.2) fb−1 of integrated luminosity.

Multi-lepton production at high transverse momentum in ep collisions at HERA

Multi-electron and multi-muon production have been measured at high transverse momentum in electron-proton collisions at HERA. Good overall agreement is found with the Standard Model predictions, dominated by photon-photon interactions. Events are observed with a di-electron mass above 100 GeV, a domain where the Standard Model prediction is low.

Multimuon production by muons

We evaluate and compare the predictions of the principal mechanisms that are expected to produce multimuon signals $\ensuremath{\mu}N\ensuremath{\rightarrow}(n\ensuremath{\mu})X$, namely (i) $\ensuremath{\mu}\overline{\ensuremath{\mu}}$ pair formation by bremsstrahlung and by photon-photon interaction, (ii) $c\overline{c}$ and $b\overline{b}$ heavy-quark production by photon-gluon fusion, and (iii) muon production by hadronic final-state interactions. We concentrate attention mainly on trimuons, but include some discussion of opposite-sign and same-sign dimuons, wrong-sign single muons, and diffractive $\ensuremath{\psi}$ production.

Weak interactions of thebquark

In weak-interaction models with two charged $W$ bosons of comparable mass, there exists a novel possibility for the weak interactions of the $b$ quark, in which the ${(\overline{u}b)}_{R}$ current occurs with maximal strength. It is noted that multimuon production in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at above ${Q}^{2}\ensuremath{\gtrsim}{(12 \mathrm{GeV})}^{2}$ will distinguish this scheme from the conventional one. We also present a Higgs system that leads naturally to this type of coupling, in a class of gauge models.

Gauge theory of weak and electromagnetic interactions with an SU(3)×U(1) symmetry

A gauge-theory model of weak and electromagnetic interactions is proposed. The symmetry group is SU(3)\ifmmode\times\else\texttimes\fi{}U(1) and the fermions are all placed in triplets (or antitriplets) and singlets. The theory is vectorlike and hence anomaly-free. Discrete symmetries are imposed to avoid unwanted mixings and to appropriately restrict the Higgs potential. The details of fermion and boson mass generation are given. The couplings and masses of the two massive neutral flavor-preserving gauge bosons are determined by fitting the neutral-current data; agreement is excellent. We also analyze the predictions for multimuon production in neutrino scattering as a function of lepton and hadron masses. Finally we examine the limits on such processes as ${K}_{L}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, $\ensuremath{\mu}\ensuremath{\rightarrow}e\ensuremath{\gamma}$, etc.

Multimuon production in deep-inelasticμ-nucleus scattering

Multimuon production in deep-inelastic $\ensuremath{\mu}$-nucleus scattering is estimated using the quarkparton model and the assumption that the secondary muons come from the production of a charmed-particle-antiparticle pair out of the $c\overline{c}$ pair in the sea of the nucleon and the subsequent semileptonic decay of these charmed particles. The calculated $x$, $y$, and ${Q}^{2}$ distributions are in agreement with the preliminary data reported by Chen of the Cornell-Michigan State-UCB-UCSD group.

Multimuon Production in Deep-Inelastic Muon Scattering

The characteristics of a model calculation of multimuon production in deep-inelastic muon scattering is presented. In the model the muons are assumed to originate from the production and subsequent weak decay of a pair of hadrons that carry new quantum numbers and have a mass of approx.1.8 GeV. The results of the calculation are to be compared with the forthcoming experimental data, and could shed light on the properties of the new hadrons. (AIP)