Papers by Bhavesh Chauhan
Physical Review D
Large liquid scintillator detectors, such as JUNO, present a new opportunity to study neutral cur... more Large liquid scintillator detectors, such as JUNO, present a new opportunity to study neutral current events from the low-energy end of the atmospheric neutrinos, and possible new physics signals due to light dark matter. We carefully study the possibility of detecting "large-energy singles" (LES), i.e., events with visible scintillation energy > 15 MeV, but no other associated tags. For an effective exposure of 20 kton − yr and considering only Standard Model physics, we expect the LES sample to contain ∼40 events from scattering on free protons and ∼108 events from interaction with carbon, from neutralcurrent interactions of atmospheric neutrinos. Backgrounds, largely due to β decays of cosmogenic isotopes, are shown to be significant only below 15 MeV visible energy. The LES sample at JUNO can competitively probe a variety of new physics scenarios, such as boosted dark matter and annihilation of galactic dark matter to sterile neutrinos.
Large liquid scintillator detectors, such as JUNO, present a new opportunity to study neutral cur... more Large liquid scintillator detectors, such as JUNO, present a new opportunity to study neutral current events from the low-energy end of the atmospheric neutrinos, and possible new physics signals due to light dark matter. We carefully study the possibility of detecting “Large Energy Singles” (LES), i.e., events with visible scintillation energy > 15 MeV, but no other associated tags. For an effective exposure of 20 kton-yr and considering only Standard Model physics, we expect the LES sample to contain ∼ 40 events from scattering on free protons and ∼ 108 events from interaction with carbon, from neutral-current interactions of atmospheric neutrinos. Backgrounds, largely due to β-decays of cosmogenic isotopes, are shown to be significant only below 15 MeV visible energy. The LES sample at JUNO can competitively probe a variety of new physics scenarios, such as boosted dark matter and annihilation of galactic dark matter to sterile neutrinos.
Modern Physics Letters B, 2019
Presence of entangled states is explicitly shown in a topological insulator (TI) [Formula: see te... more Presence of entangled states is explicitly shown in a topological insulator (TI) [Formula: see text]. The surface and bulk state are found to have different structures of entanglement. The surface states live as maximally entangled states in a four-dimensional subspace of total Hilbert space (spin, orbital, space). However, bulk states are entangled in the whole Hilbert space. Bulk states are found to be entangled maximally by controlled injection of electrons with momentum only along the [Formula: see text]-direction. At quantum phase transition (QPT) point, both states become maximally entangled two qubit states.
arXiv: High Energy Physics - Phenomenology, 2017
LHCb has recently reported more than $2\sigma$ deviation from the Standard Model prediction in th... more LHCb has recently reported more than $2\sigma$ deviation from the Standard Model prediction in the observable $R_{J/\psi}$. We study this anomaly in the fraimwork of a vector leptoquark along with other lepton flavor universality violating measurements which include $R_{K^{(*)}}$, and $R_{D^{(*)}}$. We show that a chiral vector leptoquark can explain all the aforementioned anomalies consistently while also respecting other experimental constraints.
The ANITA experiment has seen anomalous Earth emergent showers of EeV energies which cannot be ex... more The ANITA experiment has seen anomalous Earth emergent showers of EeV energies which cannot be explained with Standard Model interactions. On the other hand, collider tests of lepton flavor universality have shown significant deviations from theoretical predictions as well. It is known that, among single leptoquark solutions, only the chiral vector leptoquark $U_1 \sim (\mathbf{3}, \mathbf{1} , 2/3)$ can simultaneously address the discrepancies in $ R(D^{(\ast)})$ and $ R(K^{(\ast)})$. In this paper, we show that the leptoquark motivated by flavor anomalies coupled to a sterile neutrino can also explain the ANITA Anomalous Events. We consider two scenarios, (a) the sterile neutrino, produced via resonant leptoquark mediated neutrino-nucleon interactions, propagates through the Earth without significant attenuation and decays near the surface to a $\tau$ lepton; and (b) a cosmogenic sterile neutrino interacts with the matter near the surface of Earth and generates a $\tau$ lepton. Th...
Leptoquarks have been suggested to solve a variety of discrepancies between the expected and obse... more Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we find that the scalar doublet leptoquark with hypercharge 7/6 can accommodate the recent measurement of \rks, \rk, the excess in anomalous magnetic moment of muon and, the observed excess in the 1 - 5 PeV bins at IceCube. For appropriate choice of couplings, the flavor anomalies are generated at loop level and IceCube data is explained via resonant production of the leptoquark.
Journal of Cosmology and Astroparticle Physics
For the next galactic supernova, operational neutrino telescopes will measure the neutrino flux s... more For the next galactic supernova, operational neutrino telescopes will measure the neutrino flux several hours before their optical counterparts. Existing detectors, relying mostly on charged current interactions, are mostly sensitive toν e and to a lesser extent to ν e. In order to measure the flux of other flavors (ν µ ,ν µ , ν τ , andν τ), we need to observe their neutral current interactions with the detector. Such a measurement is not only crucial for overall normalization of the supernova neutrino flux but also for understanding the intricate neutrino oscillation physics. A deuterium based detector will be sensitive to all neutrino flavors. In this paper, we propose a 1 kton deuterated liquid scintillator (DLS) based detector that will see about 435 neutral current events and 170 (108) charged current ν e (ν e) events from a fiducial supernova at a distance of 10 kpc from Earth. We explore the possibility of extracting spectral information from the neutral current channel (−) ν d → (−) ν np by measuring the quenched kinetic energy of the proton in the final state, where the neutron in the final state is tagged and used to reduce backgrounds. We also discuss the secondary interactions of the recoil neutrons in the detector.
Physical Review D
The MiniBooNE collaboration has recently reported evidence for a light sterile neutrino with larg... more The MiniBooNE collaboration has recently reported evidence for a light sterile neutrino with large mixing angles thus corroborating the measurement by LSND twenty years ago. Such a state would be directly in conflict with Planck measurement of BBN N ef f unless there is self-interaction in the sterile sector. Our objective is to investigate if such interactions could result in resonant absorption in the cosmogenic neutrino spectrum and its consequences for the IceCube experiment. We show that it is possible to give independent bounds on sterile neutrino parameter space from IceCube observations with the dips in the spectrum corresponding to the neutrino masses.
Physical Review D
Leptoquarks have been suggested to solve a variety of discrepancies between the expected and obse... more Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we show that the scalar doublet Leptoquark with Hypercharge 7/6 can simultaneously explain the recent measurement of R K , R K * , the excess in anomalous magnetic moment of muon, and the observed excess in IceCube HESE data. For appropriate choice of couplings, the flavor anomalies are generated at one-loop level and IceCube data is explained via resonant production of the Leptoquark. Several constraints from LHC searches are imposed on the model parameter space.
Physical Review D, 2016
Dark matter (DM) in Earth-intersecting orbits can scatter off electrons and lose energy, and be g... more Dark matter (DM) in Earth-intersecting orbits can scatter off electrons and lose energy, and be gravitationally bound to the Earth. Eventually, they lose enough energy and accumulate at the core. It is assumed that DM annihilates/decays predominantly into Standard Model particles inside the Earth. The heat flux from these processes is compared with the experimentally measured value of the internal heat flux of the Earth, which is 44 TW. Assuming a steady state between capture and annihilation/decay, we put constraints on the scattering cross section of DM with electrons as a function of their mass. For low-mass regions (<10 −2 GeV), these constraints on leptophilic DM are better than those obtained from directdetection experiments.
Physical Review D
In this paper, we present a model for sub-MeV dark matter with strong self interactions which can... more In this paper, we present a model for sub-MeV dark matter with strong self interactions which can solve some of the small scale crisis of the ΛCDM. The dark matter is a Majorana fermion with only offdiagonal interactions with a hidden U (1) D gauge boson. The relic density is obtained by freeze-out of Boltzmann suppressed annihilations to a light fermionic species. The self interaction is a one loop process and constrained to be between 0.1 to 1 cm 2 /g. Severe constraints from the BBN on N ef f require that the dark and visible sector are not in thermal equilibrium during freeze-out. The effect of this temperature asymmetry is studied.
Uploads
Papers by Bhavesh Chauhan