Excited neutrino search potential of the FCC-based electron-hadron colliders

The production potential of the excited neutrinos at the FCC-based electron-hadron colliders, namely the ERL60$\otimes$FCC with $\sqrt{s}=3.46$ TeV, the ILC$\otimes$FCC with $\sqrt{s}=10$ TeV, and the PWFA-LC$\otimes$FCC with $\sqrt{s}=31.6$ TeV, has been analyzed. The branching ratios of the excited neutrinos have been calculated for the different decay channels and shown that the dominant channel is $\nu^{\star}\rightarrow eW^{+}$. We have calculated the production cross sections with the process of $ep\rightarrow\nu^{\star}q\rightarrow eW^{+}q$ and the decay widths of the excited neutrinos with the process of $\nu^{\star}\rightarrow eW^{+}$. The signals and corresponding backgrounds are studied in detail to obtain accessible mass limits. It is shown that the discovery limits obtained on the mass of the excited neutrino are $2452$ GeV for $L_{int}=100$ $fb^{-1}$, $5635$ GeV for $L_{int}=10$ $fb^{-1}$ ($6460$ GeV for $L_{int}=100$ $fb^{-1}$), and $10200$ GeV for $L_{int}=1$ $fb^{-1}$ ($13960$ GeV for $L_{int}=10$ $fb^{-1}$), for the center-of-mass energies of $3.46$, $10$, and $31.6$ TeV, respectively.Comment: 16 pages, 9 figures, 5 table

On the representation of multi-ideals by tensor norms

A tensor norm $\beta= (\beta_{n})_{n=1}^{\infty}$ is smooth if the natural correspondence $(E_{1} \otimes\cdots\otimes E_{n} \otimes\mathbb{K},\beta_{n+1}) \longleftrightarrow (E_{1} \otimes\cdots\otimes E_{n} ,\beta_{n})$ is always an isometric isomorphism. In this paper we study the representation of multi-ideals and of ideals of multilinear forms by smooth tensor norms

Excited muon searches at the FCC based muon-hadron colliders

We study the excited muon production at the FCC based muon-hadron colliders. We give the excited muon decay widths and production cross section. We deal with the $\mu p\rightarrow\mu^{\star}q\rightarrow\mu\gamma q$ process and we plot the transverse momentum, rapidity and invariant mass distributions of final state particles to get the discovery cuts. By using discovery cuts, we get the mass limits for excited muons. It is shown that the discovery limits on the mass of $\mu^{\star}$ are 2.2 TeV, 5.9 TeV and 7.5 TeV for $\mu63$-FCC, $\mu750$-FCC and $\mu1500$-FCC, respectively.Comment: 13 pages, 10 figures, 3 tables, version of published in Adv. High Energy Physic

X-ray outbursts of AXPs and SGRs

We show that the X‐ray enhancement light curves of transient AXP∕SGRs can be reproduced by the active fallback disk model. We solve the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma‐ray burst. Our preliminary results indicate that a critical temperature around 1500 K leads to a thermal‐viscous instability in the fallback disks of all AXP∕SGRs. The effect of the instability on the light curves are different for transient and persistent sources due to different pre‐burst disk conditions in these systems

SEARCH FOR GRAVITATIONALLY REDSHIFTED 2.2 MEV LINE FROM 4U 1820-30

We have analyzed 1.7 Ms of the INTEGRAL data of the Low Mass X-Ray Binary (LMXB) 4U 1820-30 and searched for the redshifted 2.2 MeV neutron capture gamma-ray line. This source is unique in that it is thought to be accreting pure Helium and might be a powerful 2.2 MeV line source. If detected, this line would strongly constrain the neutron star equation of state, motivating this search. The line is expected to be redshifted to 1.30-1.72 MeV so we scanned the 1-2 MeV region. Although we failed to detect the redshifted 2.2 MeV line, mainly due to the intense background noise to which INTEGRAL is exposed, we placed upper limits on the source’s flux for different line widths. We plan to do analysis on the rest of the data (over 8 Ms) in the future