We propose a fixed-target experiment to search for Axion-like particles (ALPs) coupling to photons, which utilizes electron and positron beams available at KEK Linac. The sensitivity to ALP is evaluated for two shielding setups in conjunction with ot
her beam dump experiments, fixed-target experiments, and $e^+e^-$ collider experiments. This study shows that the two setups can explore the gap between the search region excluded by the beam dump experiments and the $e^+e^-$ collider experiments.
We examine the feasibility of the Bell test (i.e., detecting a violation of the Bell inequality) with the ATLAS detector in Large Hadron Collider (LHC) at CERN through the flavor entanglement between the B mesons. After addressing the possible issues
that arise associated with the experiment and how they may be treated based on an analogy with conventional Bell tests, we show in our simulation study that under realistic conditions (expected from the LHC Run 3 operation) the Bell test is feasible under mild assumptions. The definitive factor for this promising result lies primarily in the fact that the ATLAS detector is capable of measuring the decay times of the B mesons independently, which was not available in the previous experiment with the Belle detector at KEK. This result suggests the possibility of the Bell test in much higher energy domains and may open up a new arena for experimental studies of quantum foundations.
The technique of weak value amplification, proposed by Aharonov et al. in 1988, has been applied for various fields of physics for the purpose of precision measurement, which is made possible by exploiting the freedom of `postselection specifying act
ively the final state in the physical process. Here we report for the first time the feasibility of utilizing the technique of weak value amplification in high energy particle physics, especially in measuring the CP-violating parameters in B meson decays, where the effective lifetime of the decay mode is expected to be prolonged statistically due to the postselection. Our analysis shows that, when adopted in the Belle II experiment at the SuperKEKB collider, the effective lifetime may be prolonged up to 2.6 times, and that the measurement precision of the CP-violating parameters will also be improved by its effect.
The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long shutdown, the detector was extracted from the experiment and brought to surface, to equip it with new service quart
er panels, to repair the modules and to ease installation of the Insertable B-Layer (IBL). The IBL is a fourth layer of pixel detectors, and has been installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using light weight staves and CO2 based cooling system have been adopted. An overview of the refurbishing of the Pixel Detector and the IBL project as well as the experience in its construction will be presented, focusing on adopted technologies, module and stave production, qualification of assembly procedure, integration of staves around the beam pipe and commissioning of the detector.
Measurement of the Higgs coupling to W-bosons is an important test of our understanding of the electroweak symmetry breaking mechanism. We study the sensitivity of the International Linear Collider (ILC) to the presence of anomalous HW+W- couplings u
sing ZH -> nu nu WW* -> nu nu 4j events. Using an effective Lagrangian approach, we calculate the differential decay rates of the Higgs boson including the effects of new dimension-5 operators. We present a Monte Carlo simulation of events at the ILC, using a full detector simulation based on geant4 and a real event reconstruction chain. Expected constraints on the anomalous couplings are given.
The Littlest Higgs Model with T-parity is one of the attractive candidates of physics beyond the Standard Model. One of the important predictions of the model is the existence of new heavy gauge bosons, where they acquire mass terms through the break
ing of global symmetry necessarily imposed on the model. The determination of the masses are, hence, quite important to test the model. In this paper, the measurement accuracy of the heavy gauge bosons at the international linear collider (ILC) is reported.
The measurement of the Higgs coupling to W bosons is an important program at the international linear collider (ILC) to search for the anomaly in the coupling to the gauge bosons. We study the sensitivity of ILC to the Higgs anomalous coupling to W b
osons by using ZH->vvWW* events. In this article, we report the status of the study.
The Littlest Higgs Model with T-parity is one of the attractive candidates of physics beyond the Standard Model. One of the important predictions of the model is the existence of new heavy gauge bosons, where they acquire mass terms through the break
ing of global symmetry necessarily imposed on the model. The determination of the masses are, hence, quite important to test the model. In this paper, the measurement accuracy of the heavy gauge bosons at ILC is eported.
Measurement of the cross-section of ee->ZHH offers the information of the trilinear Higgs self-coupling, which is important to confirm the mechanism of the electro-weak symmetry breaking. Since there is huge background in the signal region, backgroun
d rejection is key point to identify ZHH events. In this paper, we study the possibility to observe the $ZHH$ events at ILC by using ZHH->vvHH/qqHH events.
Measurement of the cross-section of e+e- -> ZHH offers the information of the trilinear Higgs self-coupling, which is important to confirm the mechanism of the electro-weak symmetry breaking. Since there is huge background in the signal region, backg
round rejection is key point to identify ZHH events. In this paper, we study the possibility to observe the ZHH events at ILC by using ZHH -> nu nu HH, resulting 4 jets.
