The presence of a new singlet scalar particle a can open up new decay channels for the Higgs boson, through cascades of the form h --> 2a --> X, possibly making discovery through standard model channels impossible. If a is CP odd, its decays are particularly sensitive to new physics. Quantum effects from heavy fields can naturally make h --> 4 g the dominant decay which is difficult to observe at hadron colliders, and is allowed by CERN LEP for m(h) > 82 GeV. However, there are usually associated decays, either h --> 2g2gamma or h --> 4gamma, which are more promising. The decay h-->4gamma is a clean channel that can discover both a and h. At the CERN LHC with 300 fb(-1) of luminosity, a branching ratio of order 10(-4) is sufficient for discovery for a large range of Higgs boson masses. With total luminosity of approximately 8 fb(-1), discovery at the Fermilab Tevatron requires more than 5 x 10(-3) in branching ratio.
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http://dx.doi.org/10.1103/PhysRevLett.98.111802 | DOI Listing |
Phys Rev Lett
December 2024
School of Physics, Peking University, Beijing 100871, China.
In recent years, energy correlators have emerged as a powerful tool to explore the field theoretic structure of strong interactions at particle colliders. In this Letter we initiate a novel study of the nonperturbative power corrections to the projected N-point energy correlators in the limit where the angle between the detectors is small. Using the light-ray operator product expansion as a guiding principle, we derive the power corrections in terms of two nonperturbative quantities describing the fragmentation of quarks and gluons.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
The Institute of Mathematical Sciences, Taramani, 600113 Chennai, India.
Eur Phys J C Part Fields
December 2024
TRIUMF, Vancouver, BC V6T 2A3 Canada.
The Large Hadron Collider's high luminosity era presents major computational challenges in the analysis of collision events. Large amounts of Monte Carlo (MC) simulation will be required to constrain the statistical uncertainties of the simulated datasets below these of the experimental data. Modelling of high-energy particles propagating through the calorimeter section of the detector is the most computationally intensive MC simulation task.
View Article and Find Full Text PDFEur Phys J Spec Top
September 2024
Institute for Particle Physics Phenomenology, Department of Physics, Durham University, South Road, Durham, DH1 3LE UK.
Deep learning algorithms will play a key role in the upcoming runs of the Large Hadron Collider (LHC), helping bolster various fronts ranging from fast and accurate detector simulations to physics analysis probing possible deviations from the Standard Model. The game-changing feature of these new algorithms is the ability to extract relevant information from high-dimensional input spaces, often regarded as "replacing the expert" in designing physics-intuitive variables. While this may seem true at first glance, it is far from reality.
View Article and Find Full Text PDFEur Phys J C Part Fields
November 2024
School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ UK.
While searching at the Large Hadron Collider (LHC) for the production and decay of the CP-odd scalar ( ) in the 2-Higgs-Doublet Model (2HDM) with Natural Flavour Conservation (NFC) via the channels (through one-loop triangle diagrams) and (with GeV or GeV, with off-shell), respectively, a factorisation of the two processes is normally performed, with the state being on-shell. While this approach is gauge-invariant, it is not capturing the presence of either of the following two channels: (through one-loop triangle diagrams) or (through one-loop box diagrams). As the resolution of the mass cannot be infinitely precise, we affirm that all such contributions should be computed simultaneously, whichever the ( ) decay(splitting) products, thereby including all possible interferences amongst themselves.
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