A
bstract
Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the ...measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 10
35
cm
−2
s
−1
, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.
We propose a new experiment to measure the running of the electromagnetic coupling constant in the space-like region by scattering high-energy muons on atomic electrons of a low-
Z
target through the ...elastic process
μ
e
→
μ
e
. The differential cross section of this process, measured as a function of the squared momentum transfer
t
=
q
2
<
0
, provides direct sensitivity to the leading-order hadronic contribution to the muon anomaly
a
μ
HLO
. By using a muon beam of 150 GeV, with an average rate of
∼
1.3
×
10
7
muon/s, currently available at the CERN North Area, a statistical uncertainty of
∼
0.3% can be achieved on
a
μ
HLO
after two years of data taking. The direct measurement of
a
μ
HLO
via
μ
e
scattering will provide an independent determination, competitive with the time-like dispersive approach, and consolidate the theoretical prediction for the muon
g
-2 in the Standard Model. It will allow therefore a firmer interpretation of the measurements of the future muon
g
-2 experiments at Fermilab and J-PARC.
We study the physics of the ideal relativistic rotating gas at thermodynamical equilibrium and provide analytical expressions of the momentum spectra and polarization vector for the case of massive ...particles with spin 1/2 and 1. We show that the finite angular momentum
J
entails an anisotropy in momentum spectra, with particles emitted orthogonally to
J
having, on average, a larger momentum than along its direction. Unlike in the non-relativistic case, the proper polarization vector turns out not to be aligned with the total angular momentum with a non-trivial momentum dependence.
We compare different procedures for combining fixed-order tree-level matrix-element generators with parton showers. We use the case of W-production at the Tevatron and the LHC to compare different ...implementations of the so-called CKKW and MLM schemes using different matrix-element generators and different parton cascades. We find that although similar results are obtained in all cases, there are important differences.
The MUonE experiment aims at providing a novel determination of the leading hadronic contribution to the muon anomalous magnetic moment through the study of elastic muon-electron scattering. Since ...the initial-state electrons are bound in a low-Z atomic target, the interaction between the incoming muons and the nuclei is expected to be the main source of experimental background. In this article, we study the production of a real lepton pair from the muon-nucleus scattering, discussing its numerical impact in the MUonE kinematic configuration. The process is described as a scattering of a muon in an external Coulomb field with the addition of a form factor to describe the nuclear charge distribution. The calculation is implemented in the fully differential Monte Carlo event generator Mesmer, without introducing any approximation on the angular variables.
Indirect searches have the potential to probe scales beyond the realm of direct searches. In this paper, we consider the implications of two parity violating experiments: weak charge of proton QWp ...and the Caesium atom QWCs on the solutions to lepton flavor nonuniversality violations in the decay of B mesons. Working in a generic implementation of a minimal Z′ model, we assume the primary contribution being due to the electron to facilitate comparison with the low q2 parity violating experiments. We demonstrate that the conclusion is characterized by different limiting behavior depending on the chirality of the lepton current. The correlation developed in this study demonstrates the effectiveness in studying the synergy between different experiments leading to a deeper understanding of the interpretation of the existing data. It is shown that a possible future improvement in the parity violating experiments can have far reaching implications in the context of direct searches. We also comment on the prospect of addition of the muon to the fits and the role it plays in ameliorating the constraints on models of Z′. This offers a complimentary understanding of the pattern of the coupling of the new physics to the leptons, strongly suggesting either a muon only or a combination of solutions to the anomalies.
New look at scalar mesons MAIANI, L; PICCININI, F; POLOSA, A. D ...
Physical review letters,
11/2004, Letnik:
93, Številka:
21
Journal Article
Recenzirano
Odprti dostop
Light scalar mesons are found to fit rather well a diquark-antidiquark description. The resulting nonet obeys mass formulas which respect, to a good extent, the Okubo-Zweig-Iizuka (OZI) rule. OZI ...allowed strong decays are reasonably reproduced by a single amplitude describing the switch of a qq pair, which transforms the state into two colorless pseudoscalar mesons. Predicted heavy states with one or more quarks replaced by charm or beauty are briefly described; they should give rise to narrow states with exotic quantum numbers.
Purpose
Previous studies demonstrated decreased quality of life (QoL) in differentiated thyroid cancer (DTC) survivors and suggested QoL variability related to time from thyroidectomy and ...levothyroxine dosage. The aims of this study were to evaluate QoL in thyroidectomized subjects in different levothyroxine states and to evaluate the association between TSH and thyroid hormones and QoL.
Methods
Prospective 5-year study enrolling 208 patients thyroidectomized for DTC, studied in one to four times according to levothyroxine dosage: withdrawal (WITHD), complete (C-SUPP) and mild TSH-suppression (M-SUPP), replacement (REPL). Each patient was allowed to participate into the study more than one time. A total of 300 evaluations were collected, consisting of detailed thyroid hormone profile and QoL assessment through the ThyPRO questionnaire.
Results
Comparing the four groups, significant differences were found for anxiety, impaired social and daily life and item 12 (overall impact of thyroid disease) domains (
p
< 0.05). Interestingly, C-SUPP subjects reported the best scores in almost all ThyPRO scales. Significant correlations were found between QoL and pituitary–thyroid axis function, as well as between QoL and gender, being females more affected. At multiple regression analyses fT3 demonstrated to be the best explanatory factor for overall impact of thyroid disease on the patient’s life, followed by gender.
Conclusions
TSH-suppressive doses of levothyroxine are more effective in improving QoL in DTC patients after thyroidectomy. These results confirm the urgent need of further studies aimed to define the best treatment of hypothyroidism, effective on well-being and harmless for patients.
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