We explore the collider relevance of a charge-radius coupling among light mesons in composite Higgs models. In particular, we focus of a coupling of the photon to the composite Higgs and a composite ...singlet, arising from isospin violation in the underlying theory. This coupling offers a deep probe of the composite nature of the Higgs mechanism, being sensitive to the electromagnetic and weak isospin structure of its constituents. The main collider effect consists in the production of the Higgs boson in association with a light composite pseudo-scalar. We present an exploratory cut-and-count analysis at hadron colliders, like the LHC, showing that an efficient background suppression can be achieved. More sophisticated techniques, however, are necessary to select a sufficient number of signal events, due to the small production rates. This justifies further investigation of this channel, which is highly complementary to other searches for compositeness in the Higgs sector.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The CMS and ATLAS experiments at the LHC have announced the discovery of a Higgs boson with mass at approximately 125 GeV/c2 in the search for the Standard Model Higgs boson via, notably, the 2/y and ...ZZ to four leptons final states. Considering the recent results of the Higgs boson searches from the LHC, we study the lightest scalar Higgs boson hi in the Next-to-Minimal Supersymmetric Standard Model by restricting the next-to- lightest scalar Higgs boson h2 to be the observed to the 125 GeV/c2 state. We perform a scan over the relevant NMSSM parameter space that is favoured by low fine-tuning considerations. Moreover, we also take the experimental constraints from direct searches, B-physics observables, relic density, and anomalous magnetic moment of the muon measurements, as well as the theoretical considerations, into account in our specific scan. We find that the signal rate in the two-photon final state for the NMSSM Higgs boson hi with the mass range from about 80 GeV/e2 to about 122 CeV/c2 can be enhanced by a factor of up to 3.5 when the Higgs boson h2 is required to be compatible with the excess from latest LHC results. This motivates the extension of the search at the LHC for the Higgs boson hi in the diphoton final state down to masses of 80 GeV/c2, particularly with the upcoming proton-proton collision data to be taken at center-of-mass energies of 13-14 TeV.
We explore the collider relevance of a charge-radius coupling among light mesons in composite Higgs models. In particular, we focus of a coupling of the photon to the composite Higgs and a composite ...singlet, arising from isospin violation in the underlying theory. This coupling offers a deep probe of the composite nature of the Higgs mechanism, being sensitive to the electromagnetic and weak isospin structure of its constituents. The main collider effect consists in the production of the Higgs boson in association with a light composite pseudo-scalar. We present an exploratory cut-and-count analysis at hadron colliders, like the LHC, showing that an efficient background suppression can be achieved. More sophisticated techniques, however, are necessary to select a sufficient number of signal events, due to the small production rates. This justifies further investigation of this channel, which is highly complementary to other searches for compositeness in the Higgs sector.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Many researches from both theoretical and experimental perspectives have been performed to search for a new Higgs Boson that is lighter than the 125
Higgs boson, which was discovered at the ...LHC in 2012. In this study, we explore the possibility of constraining a lighter neutral custodial fiveplet scalar
in the Georgi-Machacek (GM) model using the latest results of the search for a lighter Higgs boson decaying into two photons from LHC data. The custodial-singlet mass eigenstate
h
or
H
is considered to be the LHC observed 125
Higgs boson. A new set of constrained parameters that is favoured by low-mass
is proposed to generate events efficiently. The production of
from a scan based on the constrained parameters is compared to the latest results of the search for a lighter Higgs boson decaying into two photons by the CMS Collaboration after applying theoretical constraints from the GM model and constraints from all existing relevant experimental measurements, including the recent results of the Higgs boson searches by the LHC. Numerical analyses of the surviving GM parameter space are performed. The tendencies and correlations of the GM input parameters from phenomenological studies are summarized. In addition, the discovery potential of the other interesting decay channels of this low-mass neutral custodial fiveplet scalar are discussed.
Calibration results of CMS electromagnetic calorimeter photodetectors Balandras, A.; Depasse, P.; Donini, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2003, Letnik:
504, Številka:
1-3
Journal Article
Recenzirano
The Compact Muon Solenoid is one of two generic detectors currently being constructed for the Large Hadron Collider at CERN foreseen to begin data taking in 2007. The electromagnetic calorimeter ...consists of a barrel and endcaps made of PbWO4 scintillating crystals. In the barrel, the scintillation signal is read out by Hamamatsu avalanche photodiodes, connected in parallel in a structure called a “capsule”, one for each of the 61200 channels. We present the calibration results and performance statistics obtained for more than 5000 production capsules.
We first build a minimal model of vectorlike quarks where the dominant Higgs boson production process at LHC-the gluon fusion-can be significantly suppressed, being motivated by the recent stringent ...constraints from the search for direct Higgs production over a wide Higgs mass range. Within this model, compatible with the present experimental constraints on direct Higgs searches, we demonstrate that the Higgs (h) production via a heavy vectorlike top-partner (t sub(2)) decay, pp arrow right t sub(2)t sub(2), t sub(2) arrow right th, allows to discover a Higgs boson at the LHC and measure its mass, through the decay channels h arrow right gamma gamma or h arrow right ZZ. We also comment on the recent hint in LHC data from a possible ~ 125 GeV Higgs scalar, in the presence of heavy vectorlike top quarks.
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