在CMS梁管中,MoEDAL搜索通过施温格效应产生的磁单极
B Acharya1, J Alexandre1, S C Behera2
1Theoretical Particle Physics & Cosmology Group, Physics Department, King's College, London, United Kingdom.
Physical review letters
|August 30, 2024
概括
研究人员在LHC的重离子碰撞中寻找磁单极 (MMs). 没有发现MMs,但该研究为这些假设粒子设定了新的世界领先的质量极限.
科学领域:
- 粒子物理学 粒子物理学
- 高能物理 高能物理
- 核物理 核物理 核物理
背景情况:
- 一些大统一理论预测磁单极 (MMs) 的存在.
- 在高能粒子碰撞中寻找MMs是基本物理学的一个关键目标.
研究的目的:
- 为了寻找在超外围与 (Pb-Pb) 碰撞中产生的磁单极 (MMs).
- 为了确定具有高磁荷的MMs的质量限制.
主要方法:
- 利用了在LHC运行1期间收集的2.76 TeV质量中心能量Pb-Pb碰撞的数据.
- 采用MoEDAL实验的SQUID磁力计扫描CMS光束管道,寻找被困的MMs.
- 通过施温格效应,利用碰撞过程中产生的超高磁场来潜在地产生MM.
主要成果:
- 没有观察到任何暗示磁单极的信号.
- 建立了第一个可靠的,世界领先的高磁荷MM的质量极限.
- 设置在2到45迪拉克单位的范围内为MMs设置迄今为止最强的极限,不包括高达80GeV的质量,保证值为95%.
结论:
- 搜索没有提供磁断的证据.
- 这项研究为磁单极的可能质量提供了显著的限制.
- 这项研究推动了寻找超越标准模型的新物理学的研究.
相关概念视频
Atomic Nuclei: Nuclear Magnetic Moment
1.1K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.1K
Diamagnetism
2.4K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.4K
Magnetic Damping
437
Eddy currents can produce significant drag on motion, called magnetic damping. For instance, when a metallic pendulum bob swings between the poles of a strong magnet, significant drag acts on the bob as it enters and leaves the field, quickly damping the motion.
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
437
Atomic Nuclei: Magnetic Resonance
639
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
639
Magnetic Moment of an Electron
1.2K
Electrons revolving around a nucleus are analogous to a circular current carrying loop. This current produces a magnetic dipole moment proportional to the electron's orbital angular momentum. Since the orbital angular momentum is quantized in terms of the reduced Planck's constant, the dipole moment is quantized in the Bohr Magneton. The value of the Bohr magneton is 9.27 x 10-24 Am2. Electrons also have an intrinsic spin angular momentum, and the associated spin magnetic moment is...
1.2K
Atomic Nuclei: Nuclear Relaxation Processes
632
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
632


