16 research outputs found
Left-right model with TeV fermionic dark matter and unification
The ingredients for a model with a TeV right-handed scale, gauge coupling
unification, and suitable dark matter candidates lie at the heart of left-right
symmetry with broken D-parity. After detailing the contents of such a model,
with SU(2)R self-conjugate fermions at the right-handed scale aiding in
unification of couplings, we explore its dark matter implications and collider
signatures.Comment: Published version. 11 Pages, 4 figures. More details provided for
unification of gauge couplings and for proton decay lifetime estimate.
References adde
Complementary bound on mass from Higgs to diphoton decay
Using the left-right symmetric model as an illustrative example, we suggest a
simple and straightforward way of constraining the mass directly from the
decay of the Higgs boson to two photons. The proposed method is generic and
applicable to a diverse range of models with a -boson that couples to the
SM-like Higgs boson. Our analysis exemplifies how the precision measurement of
the Higgs to diphoton signal strength can have a pivotal role in probing the
scale of new physics.Comment: 8 pages, 2 figure
A twisted tale of the transverse-mass tail
We propose a tantalizing possibility that misinterpretation of the
reconstructed missing momentum may have yielded the observed discrepancies
among measurements of the -mass in different collider experiments. We
introduce a proof-of-principle scenario characterized by a new physics
particle, which can be produced associated with the -boson in hadron
collisions and contributes to the net missing momentum observed in a detector.
We show that these exotic events pass the selection criteria imposed by various
collaborations at reasonably high rates. Consequently, in the presence of even
a handful of these events, a fit based on the ansatz that the missing momentum
is primarily due to neutrinos (as it happens in the Standard Model), yields a
-boson mass that differs from its true value. Moreover, the best fit mass
depends on the nature of the collider and the center-of-mass energy of
collisions. We construct a barebones model that demonstrates this possibility
quantitatively while satisfying current constraints. Interestingly, we find
that the nature of the new physics particle and its interactions appear as a
variation of the physics of Axion-like particles after a field redefinition.Comment: 24 pages, 7 figures, a new appendix added, version published in JHE
Notes on a Z′
We reexamine anomaly free U(1) extensions of the standard model in the light of LHC Drell-Yan data, constraints from unitarity, and neutrino-electron scattering to put model-independent bounds in the parameter space populated by MZ′, the Z- Z′ mixing angle (αz ), and the extra U(1) effective gauge coupling (gx′ ). We propose a formalism where any model dependence is absorbed into these three parameters
CEPC Technical Design Report -- Accelerator
International audienceThe Circular Electron Positron Collider (CEPC) is a large scientific project initiated and hosted by China, fostered through extensive collaboration with international partners. The complex comprises four accelerators: a 30 GeV Linac, a 1.1 GeV Damping Ring, a Booster capable of achieving energies up to 180 GeV, and a Collider operating at varying energy modes (Z, W, H, and ttbar). The Linac and Damping Ring are situated on the surface, while the Booster and Collider are housed in a 100 km circumference underground tunnel, strategically accommodating future expansion with provisions for a Super Proton Proton Collider (SPPC). The CEPC primarily serves as a Higgs factory. In its baseline design with synchrotron radiation (SR) power of 30 MW per beam, it can achieve a luminosity of 5e34 /cm^2/s^1, resulting in an integrated luminosity of 13 /ab for two interaction points over a decade, producing 2.6 million Higgs bosons. Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons, facilitating precise measurements of Higgs coupling at sub-percent levels, exceeding the precision expected from the HL-LHC by an order of magnitude. This Technical Design Report (TDR) follows the Preliminary Conceptual Design Report (Pre-CDR, 2015) and the Conceptual Design Report (CDR, 2018), comprehensively detailing the machine's layout and performance, physical design and analysis, technical systems design, R&D and prototyping efforts, and associated civil engineering aspects. Additionally, it includes a cost estimate and a preliminary construction timeline, establishing a framework for forthcoming engineering design phase and site selection procedures. Construction is anticipated to begin around 2027-2028, pending government approval, with an estimated duration of 8 years. The commencement of experiments could potentially initiate in the mid-2030s
CEPC Technical Design Report -- Accelerator
International audienceThe Circular Electron Positron Collider (CEPC) is a large scientific project initiated and hosted by China, fostered through extensive collaboration with international partners. The complex comprises four accelerators: a 30 GeV Linac, a 1.1 GeV Damping Ring, a Booster capable of achieving energies up to 180 GeV, and a Collider operating at varying energy modes (Z, W, H, and ttbar). The Linac and Damping Ring are situated on the surface, while the Booster and Collider are housed in a 100 km circumference underground tunnel, strategically accommodating future expansion with provisions for a Super Proton Proton Collider (SPPC). The CEPC primarily serves as a Higgs factory. In its baseline design with synchrotron radiation (SR) power of 30 MW per beam, it can achieve a luminosity of 5e34 /cm^2/s^1, resulting in an integrated luminosity of 13 /ab for two interaction points over a decade, producing 2.6 million Higgs bosons. Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons, facilitating precise measurements of Higgs coupling at sub-percent levels, exceeding the precision expected from the HL-LHC by an order of magnitude. This Technical Design Report (TDR) follows the Preliminary Conceptual Design Report (Pre-CDR, 2015) and the Conceptual Design Report (CDR, 2018), comprehensively detailing the machine's layout and performance, physical design and analysis, technical systems design, R&D and prototyping efforts, and associated civil engineering aspects. Additionally, it includes a cost estimate and a preliminary construction timeline, establishing a framework for forthcoming engineering design phase and site selection procedures. Construction is anticipated to begin around 2027-2028, pending government approval, with an estimated duration of 8 years. The commencement of experiments could potentially initiate in the mid-2030s