Greg P Heath

The production of D ±- and D 0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb−1. The measurements cover the kinematic range 5<Q 2<1000 GeV2, 0.02<y<0.7, 1.5<p T <15 GeV and |η D |<1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, $F_{2}^{c\bar{c}}$ , to the proton structure function, F 2.

The dissociation of virtual photons, $γ^{\star} p \to X p$, in events with a large rapidity gap between $X$ and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities $Q^2&gt;2$ GeV$^2$ and $γ^{\star} p$ centre-of-mass energies $402$ GeV, where $M_X$ is the mass of the hadronic final state, $X$. Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of $t$, the squared four-momentum transfer at the proton vertex and $Φ$, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of $Q^2$ and $\xpom$, the fraction of the proton's momentum carried by the diffractive exchange, as well as $β$, the Bjorken variable defined with respect to the diffractive exchange.

This paper presents the first analysis of diffractive photon dissociation events in deep inelastic positron-proton scattering at HERA in which the proton in the final state is detected and its momentum measured. The events are selected by requiring a scattered proton in the ZEUS leading proton spectrometer (LPS) with χ L > 0.97, where xL is the fraction of the incoming proton beam momentum carried by the scattered proton. The use of the LPS significantly reduces the contamination from events with diffractive dissociation of the proton into low mass states and allows a direct measurement of t, the square of the four-momentum exchanged at the proton vertex. The dependence of the cross section ont is measured in the interval 0.073 < |t| < 0.4 GeV2 and is found to be described by an exponential shape with the slope parameterb = 7.2 ± 1.1(stat.) −0.9 +0.7 (syst.) GeV−2. The diffractive structure function FD (4) is presented as 0.9 a function of χ H ≃ 1 − χ L and β, the momentum fraction of the struck quark with respect to χ H , and averaged over thet interval 0.073 < |t′ < 0.4 GeV2 and the photon virtuality range 5 <Q 2 < 20 GeV2. In the kinematic range 4 × 104 < χ p < 0.03 and 0.015 < β < 0.5, the χ p dependence ofF D(4) is fitted with a form (1/χ p )α , yieldinga − 1.00 ± 0.09 (stat.) −0.05 +0.11 (syst.). Upon integration overL, the structure functionF 2 D(3) is determined in a kinematic range extending to higher χ p and lower β compared to our previous analysis; the results are discussed within the framework of Regge theory.

Cross sections for ${e}^{+}p$ neutral current deep inelastic scattering have been measured at a center-of-mass energy of $\sqrt{s}=318\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ with the ZEUS detector at HERA using an integrated luminosity of $63.2\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$. The double-differential cross section, ${d}^{2}\ensuremath{\sigma}/dxd{Q}^{2}$, is presented for $200\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}&lt;{Q}^{2}&lt;30\text{ }000\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}$ and for $0.005&lt;x&lt;0.65$. The single-differential cross sections $d\ensuremath{\sigma}/d{Q}^{2}$, $d\ensuremath{\sigma}/dx$ and $d\ensuremath{\sigma}/dy$ are presented for ${Q}^{2}&gt;200\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}$. The effect of $Z$-boson-exchange is seen in $d\ensuremath{\sigma}/dx$ measured for ${Q}^{2}&gt;10\text{ }000\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}$. The data presented here were combined with ZEUS ${e}^{+}p$ neutral current data taken at $\sqrt{s}=300\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ and the structure function ${F}_{2}^{\mathrm{e}\mathrm{m}}$ was extracted. All results agree well with the predictions of the Standard Model.

Measurements of the neutral current cross sections for deep inelastic scattering in e^- p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections dsigma/dQ^2, dsigma/dx and dsigma/dy and the double-differential cross sections in Q^2 and x are measured in the kinematic region y < 0.9 and Q^2 > 185 GeV^2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9 pb^-1 taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions xF_3 and xF_3^{\gamma Z} are determined by combining the e^- p results presented in this paper with previously measured e^+ p neutral current data. The asymmetry parameter A^- is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model.

Measurements of the cross sections for charged current deep inelastic scattering in e − p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb−1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections d σ/dQ 2, d σ/dx and d σ/dy are presented for Q 2>200 GeV2. The double-differential cross-section d 2 σ/dxdQ 2 is presented in the kinematic range 280<Q 2<30 000 GeV2 and 0.015<x<0.65. The measured cross sections are compared with the predictions of the Standard Model.

Measurements of the proton structure function $F_2$ for $0.6 < Q^2 < 17 {GeV}^2$ and $1.2 \times 10^{-5} < x <1.9 \times 10^{-3}$ from ZEUS 1995 shifted vertex data are presented. From ZEUS $F_2$ data the slopes $dF_2/d\ln Q^2$ at fixed $x$ and $d\ln F_2/d\ln(1/x)$ for $x < 0.01$ at fixed $Q^2$ are derived. For the latter E665 data are also used. The transition region in $Q^2$ is explored using the simplest non-perturbative models and NLO QCD. The data at very low $Q^2$ $\leq 0.65 {GeV}^2$ are described successfully by a combination of generalised vector meson dominance and Regge theory. From a NLO QCD fit to ZEUS data the gluon density in the proton is extracted in the range $3\times 10^{-5} < x < 0.7$. Data from NMC and BCDMS constrain the fit at large $x$. Assuming the NLO QCD description to be valid down to $Q^2\sim 1 {GeV}^2$, it is found that the $q\bar{q}$ sea distribution is still rising at small $x$ and the lowest $Q^2$ values whereas the gluon distribution is strongly suppressed.

A search for narrow-width resonances that decay into electron+jet or neutrino+jet has been performed with the ZEUS detector at HERA operating at center-of-mass energies of 300 and 318 GeV. An integrated e+p luminosity of 114.8 pb-1 and e-p luminosity of 16.7 pb-1 were used. No evidence for any resonance was found. Limits were derived on the Yukawa coupling as a function of the mass of a hypothetical resonance that has arbitrary decay branching ratios into electron+quark or neutrino+quark. These limits also apply to squarks predicted by R-parity-violating supersymmetry. Limits for the production of leptoquarks described by the Buchmuller-Ruckl-Wyler model were also derived for masses up to 400 GeV. For Yukawa coupling of 0.1, leptoquark masses up to 290 GeV are excluded.

The production of forward jets has been measured in deep inelastic ep collisions at HERA.The results are presented in terms of single differential cross sections as a function of the Bjorken scaling variable (x Bj ) and as triple differential cross sections d 3 σ/dx Bj dQ 2 dp 2 t,jet , where Q 2 is the four momentum transfer squared and p 2 t,jet is the squared transverse momentum of the forward jet.Also cross sections for events with a di-jet system in addition to the forward jet are measured as a function of the rapidity separation between the forward jet and the two additional jets.The measurements are compared with next-to-leading order QCD calculations and with the predictions of various QCD-based models.

The production of dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 61 pb-1. The dijet cross section has been measured for virtualities of the exchanged virtual photon, 5 < Q2 < 100 GeV2, and γ*p centre-of-mass energies, 100 < W < 250 GeV. The jets, identified using the inclusive kT algorithm in the γ*p frame, were required to have a transverse energy E* T,jet > 4 GeV and the jet with the highest transverse energy was required to have E* T,jet > 5 GeV. All jets were required to be in the pseudorapidity range -3.5<η* jet<0. The differential cross sections are compared to leading-order predictions and next-to-leading-order QCD calculations based on recent diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data.

The production of energetic neutrons in $ep$ collisions has been studied with the ZEUS detector at HERA. The neutron energy and $p_T^2$ distributions were measured with a forward neutron calorimeter and tracker in a $40 \pb^{-1}$ sample of inclusive deep inelastic scattering (DIS) data and a $6 \pb^{-1}$ sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper $p_T^2$ distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data.

A measurement of inclusive charged particle distributions in deep inelasticep scattering forγ*p centre-of-mass energies 75<W<175 GeV and momentum transfer squared 10<Q 2<160 GeV2 from the ZEUS detector at HERA is presented. The differential charged particle rates in theγ*p centre-of-mass system as a function of the scaled longitudinal momentum,x F, and of the transverse momentum,p* t and 〈p* t 2〉, as a function ofx F, W andQ 2 are given. Separate distributions are shown for events with (LRG) and without (NRG) a rapidity gap with respect to the proton direction. The data are compared with results from experiments at lower beam energies, with the naive quark parton model and with parton models including perturbative QCD corrections. The comparison shows the importance of the higher order QCD processes. Significant differences of the inclusive charged particle rates between NRG and LRG events at the sameW are observed. The value of 〈p* t 2〉 for LRG events with a hadronic massM x, which excludes the forward produced baryonic system, is similar to the 〈p* t 2〉 value observed in fixed target experiments atW≈M x.

Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 38.7 pb−1. The jets have been identified using the kT cluster algorithm in the longitudinally invariant inclusive mode in the laboratory frame; they have been selected with jet transverse energy, ETjet above 6 GeV and jet pseudorapidity, ηjet, between −1 and 3. Measurements of cross sections as functions of ETjet, Björken x and the photon virtuality, Q2, are presented. Three phase-space regions have been selected in order to study parton dynamics from the most global to the most restrictive region of forward-going (close to the proton-beam direction) jets at low x, where the effects of BFKL evolution might be present. The measurements have been compared to the predictions of leading-logarithm parton-shower Monte Carlo models and fixed-order perturbative QCD calculations. In the forward region, O(αs1) QCD calculations underestimate the data up to an order of magnitude at low x. An improved description of the data in this region is obtained by including O(αs2) QCD corrections, which account for the lowest-order tˆ-channel gluon-exchange diagrams, highlighting the importance of such terms in the parton dynamics at low x.

Charged particle production has been measured in Deep Inelastic Scattering (DIS) events using the ZEUS detector over a large range ofQ 2 from 10 to 1280 GeV2. The evolution withQ of the charged multiplicity and scaled momentum has been investigated in the current fragmentation region of the Breit frame. The data are used to study QCD coherence effects in DIS and are compared with correspondinge + e − data in order to test the universality of quark fragmentation.

Photoproduction at HERA is studied in $ep$ collisions, with the ZEUS detector, for $\gamma p$ centre-of-mass energies ranging from 130-270 GeV. A sample of events with two high-$p_T$ jets ($p_T > 6$ GeV, $\eta <1.6$) and a third cluster in the approximate direction of the electron beam is isolated using a clustering algorithm. These events are mostly due to resolved photoproduction. The third cluster is identified as the photon remnant. Its properties, such as the transverse and longitudinal energy flows around the axis of the cluster, are consistent with those commonly attributed to jets, and in particular with those found for the two jets in these events. The mean value of the photon remnant $p_T$ with respect to the beam axis is measured to be $2.1 \pm 0.2$ GeV, which demonstrates substantial mean transverse momenta for the photon remnant.

The production of the neutral strange hadrons K0 S, Λ and Λ̄ has been measured in ep collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, Λ (Λ̄) asymmetry and polarization have been measured in three kinematic regions: Q2 > 25 GeV2; 5 < Q2 < 25 GeV2; and in photoproduction (Q2≃0). In photoproduction the presence of two hadronic jets, each with at least 5 GeV transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at e+e- colliders, except for an enhancement of baryon relative to meson production in photoproduction.

A search for stop production in R-parity-violating supersymmetry has been performed in $e^{+}p$ interactions with the ZEUS detector at HERA, using an integrated luminosity of 65 pb$^{-1}$. At HERA, the R-parity-violating coupling $\lambda'$ allows resonant squark production, $e^+d\to\tilde{q}$. Since the lowest-mass squark state in most supersymmetry models is the light stop, $\tilde{t}$, this search concentrated on production of $\tilde{t}$, followed either by a direct R-parity-violating decay, or by the gauge decay to $b\tilde{\chi}^+_{1}$. No evidence for stop production was found and limits were set on $\lambda'_{131}$ as a function of the stop mass in the framework of the Minimal Supersymmetric Standard Model. The results have also been interpreted in terms of constraints on the parameters of the minimal Supergravity model.

Diffractive photoproduction of D*±(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb-1. The D* mesons were reconstructed in the kinematic range: transverse momentum pT(D*) > 1.9 GeV and pseudorapidity |η(D*)|<1.6, using the decay D*+→D0π+ s followed by D0→K-π+(+c.c.). Diffractive events were identified by a large gap in pseudorapidity between the produced hadronic state and the outgoing proton. Cross sections are reported for photon–proton centre-of-mass energies in the range 130 < W < 300 GeV and for photon virtualities Q2 < 1 GeV2, in two ranges of the Pomeron fractional momentum xIP<0.035 and xIP<0.01. The relative contribution of diffractive events to the inclusive D*±(2010) photoproduction cross section is about 6%. The data are in agreement with perturbative QCD calculations based on various parameterisations of diffractive parton distribution functions. The results are consistent with diffractive QCD factorisation.

This paper presents energy distributions of the hadronic system produced in neutral-current electron-proton deep-inelastic scattering at a centre of mass energy of 296 GeV. Comparison of the results with QCD Monte Carlo models shows that QCD radiation has a strong influence on the characteristics of the final state. The data are reasonably reproduced by the Lund model based on a matrix element calculation in first order ofα s , followed by appropriate parton showers, as well as by the colour dipole model. The HERWIG parton shower model also gives a reasonable representation of the data. Neither the first order matrix elements alone nor the Lund parton shower model, without the matrix element calculation, reproduce the data.

The cross sections for charged and neutral current deep inelastic scattering in e^+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an integrated luminosity of 23.8 pb^-1 at sqrt(s) = 318 GeV, are given for both e^+p charged current and neutral current deep inelastic scattering for both positive and negative values of the longitudinal polarisation of the positron beam. Single differential cross sections are presented for the kinematic region Q^2 > 200 GeV^2 . The measured cross sections are compared to the predictions of the Standard Model. A fit to the data yields sigma^CC (P_e = -1) = 7.4 +/- 3.9 (stat.) +/- 1.2 (syst.) pb, which is consistent within two standard deviations with the absence of right-handed charged currents in the Standard Model.

Subjet distributions were measured in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb-1. Jets were identified using the kT cluster algorithm in the laboratory frame. Subjets were defined as jet-like substructures identified by a reapplication of the cluster algorithm at a smaller value of the resolution parameter ycut. Measurements of subjet distributions for jets with exactly two subjets for ycut=0.05 are presented as functions of observables sensitive to the pattern of parton radiation and to the colour coherence between the initial and final states. Perturbative QCD predictions give an adequate description of the data.

This paper reports a search for excited electrons at the HERA electron-proton collider. In a sample corresponding to an integrated luminosity of 26 nb−, no evidence was found for any resonant state decaying into e−γ, νW− or e−Z0. Limits on the coupling strength of an excited electron have been determined for masses between 45 and 225 GeV. This study also reports the observation of the wide-angle eγ Compton scattering process.

Received 5 September 2006DOI:https://doi.org/10.1103/PhysRevD.74.059906©2006 American Physical Society

Differential dijet cross sections have been measured with the ZEUS detector for photoproduction events in which the hadronic final state containing the jets is separated with respect to the outgoing proton direction by a large rapidity gap. The cross section has been measured as a function of the fraction of the photon (ϰγ OBS) and pomeron (β OBS) momentum participating in the production of the dijet system. The observed ϰγ OBS dependence shows evidence for the presence of a resolved- as well as a direct-photon component. The measured cross section da/dβ OBS increases as β OBS increases indicating that there is a sizeable contribution to dijet production from those events in which a large fraction of the pomeron momentum participates in the hard scattering. These cross sections and the ZEUS measurements of the diffractive structure function can be described by calculations based on parton densities in the pomeron which evolve according to the QCD evolution equations and include a substantial hard momentum component of gluons in the pomeron.

The CMS Global Calorimeter Trigger system performs a wide-variety of calorimeter data processing functions required by the CMS Level-1 trigger.It is responsible for finding and classifying jets and tau-jets, calculating total and missing transverse energy, total transverse energy identified within jets, sorting e/γ candidates, and calculating several quantities based on forward calorimetry for minimumbias triggers.The system is based on high-speed serial optical links and large FPGAs.The system has provided CMS with calorimeter triggers during commissioning and cosmic runs throughout 2008.The performance of the system in validation tests and cosmic runs is presented here.

The ZEUS experiment has a three-level trigger system to select electron-proton interaction events from a large anticipated background of proton beam-gas. The first level decision is formed using pipelined hardware processors clocked at the 96 ns beam crossing frequency. A vital component of this decision is discrimination against upstream events using tracking detector information. The processors use three-dimensional space points measured in the central tracking detector to find pointing tracks over most of the θ range, and include forward tracking detector information to improve the resolution and angular coverage in the proton forward direction. The processor design status and performance simulation results are presented.

A search has been made for lepton-flavor-violating interactions of the type e+→plX, where l denotes a μ or τ with high transverse momentum, at a center-of-mass energy √s of 300 GeV with an integrated luminosity of 47.7 pb−1 using the ZEUS detector at HERA. No evidence was found for lepton-flavor violation and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below √s, limits are set on λeq1 √βlq, where λeq1 is the coupling of the LQ to an electron and a first-generation quark q1 and βlq is the branching ratio of the LQ to l and a quark. For LQ masses exceeding √s, limits are set on the four-fermion contact-interaction term λeqα λlqβ/M2LQ for leptoquarks that couple to an electron and a quark qα and also to l and a quark qβ. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in R-parity-violating supersymmetric models. In some cases involving heavy quarks and especially for l=τ, the ZEUS limits are the most stringent published to date.Received 8 January 2002DOI:https://doi.org/10.1103/PhysRevD.65.092004©2002 American Physical Society

A new method is employed to measure the neutral current cross section up to Bjorken-x values of one with the ZEUS detector at HERA using an integrated luminosity of 65.1 pb-1 for e+p collisions and 16.7 pb-1 for e-p collisions at sqrt{s}=318 GeV and 38.6 pb-1 for e+p collisions at sqrt{s}=300 GeV. Cross sections have been extracted for Q2 >= 648 GeV2 and are compared to predictions using different parton density functions. For the highest x bins, the data have a tendency to lie above the expectations using recent parton density function parametrizations.

This case study is one of the first ever reported examples of infection in a patient with anti-IFN-3 autoimmunity and demonstrates how overwhelming infection can sometimes present with visual symptoms. We report the case of a previously fit middle-aged patient presenting with painless loss of vision and loss of appetite. Examination showed choroidal abscess and a pan-uveitis, leading to admission for vitreous biopsy. Klebsiella pneumoniae was isolated both in the vitreous and in blood cultures. Subsequent investigation discovered a liver abscess which was treated with percutaneous drainage. Despite the administration of intravitreal antibiotics from the time of presentation, intravenous antibiotics and vitrectomy on the same day, the patient proceeded to need enucleation 19 days later, and now has only light perception in the remaining eye. The strong association between K. pneumoniae endophthalmitis and underlying liver abscess leads to a significant mortality rate. Early diagnosis is essential, with prompt aggressive treatment with antibiotics, but sadly the visual prognosis remains poor. In cases of suspected choroidal abscess, initiation of sepsis screen and immediate empirical treatment is vital to improve this prognosis. This patient had no significant past medical history, no known immunocompromise, was not diabetic and had no recent significant foreign travel. However, further immunological analysis demonstrated the presence of anti-IFN-3 antibodies, a hitherto under-reported potential cause of increased susceptibility to infection, and so cases of sepsis in previously healthy individuals should be considered for further immunology assessment.

The ZEUS Central Tracking Detector utilizes a time difference measurement to provide a fast determination of the z-coordinate of each hit. The z-by-timing measurement is achieved by using a Time-to-Amplitude Converter which has an intrinsic timing resolution of 36 ps, has pipelined readout, and has a multihit capability of 48 ns. In order to maintain the required sub-nanosecond timing accuracy, the technique incorporates an automated self-calibration system. The readout of the z-by-timing data utilizes a fully customized timing control system which runs synchronously with the HERA beam-crossing clock, and a data acquisition system implemented on a network of Transputers. Three dimensional space-points provided by the z-by-timing system are used as input to all three levels of the ZEUS trigger and for offline track reconstruction. The average z-resolution is determined to be 4.4 cm for multi-track events from positron-proton collisions in the ZEUS detector.

This chapter focuses on the role of physical activity in preventing cardiovascular disease (CVD), how much of it is needed, and the public health approaches to increasing physical activity at a population level. The wide-ranging and conclusive scientific benefits of physical activity have been established to prevent CVDs, maintain overall health, and improve quality of life. Physical activity needs to be promoted in all spheres of life by providing an environment in daily living that makes physical activity safe, enjoyable, and the preferred choice. Active transport is the preferred method of transport for CVD prevention, with additional environmental benefits. Creating an enabling environment and policy interventions by incentivizing and facilitating public transport can significantly address the burgeoning epidemic of CVD in low- and middle-income countries (LMICs).

In the 17th century Sir Isaac Newton wrote ``These are therefore the Agents in Nature able to make the Particles of Bodies ftick together by very ftrong Attractions, And it is the Bufinefs of Experimatal Philofophy to find them out''. In the $21st century the Large Hadron Collider (LHC) continues that ``business''. Bunches of protons will be accelerated to an energy of 7TeV/c per proton around a 27km circumference ring buried underneath French/Swiss countryside near Geneva. At a number of points around the ring counter-rotating bunches of protons will be passed through each other. Some of the protons will interact violently and the new particles generated will fly outwards into detectors surrounding the interaction region. Typically these detectors have millions of channels and data flows out of the ``front-end'' at about 400EBytes/year. Data can only be stored at about 1PByte/year, a factor of 4x10^5 less. Fortunately most interactions involve physical processes that are already understood and a multi-level trigger system is used to select data from interesting or unexpected events. This paper describes the Global Calorimeter Trigger (GCT), part of the trigger system for the Compact Muon Solenoid (CMS) detector at the LHC.