Tag: Physics briefing
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Search for double Higgs production with multiple leptons
Using events containing multiple leptons, the CMS Collaboration looked for production of a pair of Higgs bosons, but could not find any evidence. However there is some extra events in data with high mass values for the Higgs boson pair when compared with total expectation of Higgs boson pair signal and background. Only with more…
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Search for rare production of vector boson pairs
Vector boson (W, Z) scattering process is a purely weak process which have been studied here to investigate interesting characteristics of the standard model and to test new physics scenarios that have a sizable indirect impact on the measurable quantities. This analysis looks for production of two opposite sign W bosons accompanied by a pair…
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In a detector far, far away: searching for elusive long-lived travellers by tracing pairs of muons
A search for long-lived particles decaying into two muons has been performed by the CMS collaboration. Many scenarios of beyond standard model physics envisage such a possibility, whereby the exotic particles, travel before decaying, a considerable distance which can range from few microns to several kilometres depending on detailed properties. The striking experimental signature of…
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A possible new decay mode of the Higgs boson
CMS looked for a relatively rare decay mode of the Higgs boson, viz., to a Z boson and a photon (H → Z𝛾 ). The Z was identified via its decays to electron and muon pairs (e+e- or 𝝁+ 𝝁-). The spectrum for the combined mass of the three particles (e+, e- and 𝛾 and…
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Two Ends of a Seesaw
Experiments have established that the neutrinos do have non-zero mass but extremely tiny, though in standard model they are treated as mass-less. This can be explained using theoretical ideas of Majorana and Weinberg. The testable prediction at the LHC is the production of 2 same-sign muons unaccompanied by neutrinos. Data collected by the CMS experiment…
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Detecting the creation of top quarks out of light
Ask someone what experiments at the CERN-LHC do, they will tell you: ‘You accelerate two protons to very high energy, smash them together and look in great detail at all particles created from the disintegration of the protons.’
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CMS Collaboration measures the mass of the top quark with unparalleled accuracy
The CMS collaboration has substantially improved the precision with which the top quark mass is measured. The latest result, a measurement of the top quark mass of 171.77 ± 0.38 GeV, was presented at CERN last week and estimates the value of the top quark mass with a precision of about 0.22%. The gain comes…
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Using light to make cousins of the electron
In heavy ion collisions, for ultra-peripheral processes, simultaneous emission of photons by oppositely moving 2 lead ions can occasionally produce a pair of tau leptons. The CMS Collaboration has observed such a phenomena, for the first time in the LHC data. The results were presented in the recently concluded Moriond and Quark Matter conferences.
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Deep learning technique identifies complex decays of tau leptons
State-of-the art machine learning techniques have been used by scientists of the CMS collaboration to identify efficiently the hadronic decays of the tau leptons vis-a-vis jets (sprays of particles boosted in a given direction). This will help the CMS experiment in a big way to discriminate quickly, in real time of the LHC collision, the…
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Leptons Popping out of Thin Air
Physicists at the CMS experiment have been searching for new particles in exciting new places. In a recently published paper, they explore the possibility that the Large Hadron Collider (LHC) could be producing never-before-seen particles that travel into the CMS detector before transforming into known particles. And because no one knows for sure what undiscovered…