In this paper, we studied the impact of the off-diagonal SNSI parameters in the future long-baseline neutrino oscillation experiments DUNE and P2SO. In our analysis, we found that the sensitivities of these experiments altered in a very non-trivial way due to the presence of these parameters. Depending on the values of these parameters, they can either completely mimic the standard scenario or can wash out their CP sensitivity. For large values of parameters $$\eta _{e\mu }$$ and $$\eta _{e\tau }$$ , we obtained larger mass ordering and octant sensitivities as compared to the standard three flavour scenario. For the parameter $$\eta _{\mu \tau }$$ , the mass ordering sensitivity and the precision of $$\Delta m^2_{31}$$ deteriorated compared to the standard scenario. Our results also showed that the sensitivities were significantly influenced by the phases of the off-diagonal parameters.

India

Sambit Pusty

Rudra Majhi

Dinesh Singha

Croatia

Monojit Ghosh

Rukmani Mohanta

Impact of scalar NSI with off-diagonal parameters at DUNE and P2SO

<p>Motivated by recent anomalies in observables associated with flavor-changing neutral current transitions, specifically <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>−</mo></msup></math> processes, we present a comprehensive analysis of lepton flavor-violating (LFV) decay modes mediated by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math> transitions with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mo>ℓ</mo><mn>1</mn></msub><mo>≠</mo><msub><mo>ℓ</mo><mn>2</mn></msub></math>. While such LFV processes are forbidden within the standard model, they naturally arise in several of its extensions, including models featuring additional vectorlike fermions and extra <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> bosons. Employing the most general effective Hamiltonian for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math> transitions, we derive the angular distributions of the relevant decay modes. Adopting a model-independent framework, we systematically study the LFV decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>*</mo></msup><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>s</mi></msub><mo stretchy="false">→</mo><mi>ϕ</mi><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msubsup><mi>K</mi><mn>2</mn><mo>*</mo></msubsup><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math>. Although LFV mesonic decays have been widely explored, the corresponding baryonic decays remain comparatively underinvestigated. We provide bounds on the branching ratio (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi></math>), forward-backward asymmetry (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">A</mi><mrow><mi>F</mi><mi>B</mi></mrow></msub></math>), and longitudinal lepton polarization fraction (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">F</mi><mi>L</mi></msub></math>). Furthermore, considering the projected sensitivities of the LHCb upgrade and Belle II experiments, we estimate upper limits for these observables, offering promising avenues for probing new physics in these LFV channels.</p>

Aishwarya Bhatta

Dhiren Panda

Unraveling new physics effects in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msub><mo>ℓ</mo><mn>1</mn></msub><msub><mo>ℓ</mo><mn>2</mn></msub></math> transitions with a model-independent perspective

In this work, we explore the possibility of probing the mass ordering sensitivity as a function of supernova distance in the context of the ongoing neutrino experiment NO <italic>&#957;</italic>A. We provide a detailed study of the active-active and active-sterile mixing frameworks, illustrating how supernova neutrinos can be used to realize the existence of sterile neutrinos. Interestingly, we infer that observation of the NC channel alone can differentiate between the presence and absence of sterile neutrinos. Our results indicate that the primary channel of NO <italic>&#957;</italic>A can distinguish normal mass ordering from inverted mass ordering at 5 <italic>&#963;</italic> confidence level for a supernova explosion occurring at a distance of 5 kpc. Additionally, we examine the impact of systematic uncertainties on mass ordering sensitivity, showing that higher levels of systematics lead to a reduction in sensitivity. Similarly, the inclusion of energy smearing significantly diminishes ordering sensitivity.

Papia Panda

Probing neutrino mass ordering with supernova neutrinos at NO <italic>&#957;</italic>A including the effect of sterile neutrinos

The Deep Underground Neutrino Experiment (DUNE) is a proposed long-baseline neutrino oscillation experiment that will project an on-axis wide-band neutrino beam over a distance of 1300 km to determine the unknowns in the neutrino sector. Given the baseline of 1300 km and the intense beam facility, DUNE is a promising experiment to study the sub-leading effects such as environmental decoherence, matter induced non-standard interactions (NSIs), neutrino decay, etc. In this study, we investigate how NSI and environmental decoherence affect the neutrino oscillation probabilities simultaneously. Considering the modified probabilities we obtain the updated mass hierarchy (MH) and CP violation (CPV) sensitivities of DUNE. Furthermore, we demonstrate the sensitivity of DUNE to distinguish between the effects of NSI and environmental decoherence.

Chinmay Bera

K. Deepthi

The effect of non-standard interactions and environmental decoherence at DUNE

In this study, we explore two intriguing new physics scenarios: the theory of Large Extra Dimensions (LED) and the theory of neutrino decay. We analyze the impact of LED on neutrino oscillations in the contexts of Protvino to Super-ORCA (P2SO), DUNE, and T2HK, with a particular emphasis on P2SO. In contrast, the effects of neutrino decay are examined exclusively in the context of P2SO. For the LED scenario, we find that combining data from P2SO, DUNE, and T2HK can yield tighter constraints than current bounds, but only if all oscillation parameters are measured with high precision. In the case of neutrino decay, P2SO can achieve slightly better bounds compared to ESSnuSB and MOMENT, although its bounds remain weaker than those provided by DUNE and T2HK. Regarding sensitivities to unresolved oscillation parameters, the existence of LED has a minimal impact on the determination of CP violation, mass ordering and octant. However, neutrino decay can significantly influence the sensitivities related to CP violation and octant in a non-trivial manner.

Priya Mishra

Samiran Roy

Study of Large Extra Dimension and neutrino decay at P2SO experiment

In this work, we investigate the effect of curved spacetime on neutrino oscillation. In a curved spacetime, the effect of curvature on fermionic fields is represented by spin connection. The spin connection consists of a non-universal “contorsion” part which is expressed in terms of vector and axial current density of fermions. The contraction of contorsion part with the tetrad fields, which connects the internal flat space metric and the spacetime metric, is called torsion. In a scenario where neutrino travels through background of fermionic matter at ordinary densities in a curved spacetime, the Hamiltonian of neutrino oscillation gets modified by the torsional coupling constants $$\lambda _{21}^{\prime }$$ and $$\lambda _{31}^{\prime }$$ . The aim of this work is to study the effect of $$\lambda _{21}^{\prime }$$ and $$\lambda _{31}^{\prime }$$ in DUNE and P2SO. In our study we, (i) discuss the effect of torsional coupling constants on the neutrino oscillation probabilities, (ii) estimate the capability of P2SO and DUNE to put bounds on these parameters and (iii) show how the physics sensitivities get modified in presence of torsion.

Effect of torsion in long-baseline neutrino oscillation experiments

We perform an analysis of the consequences of various new physics operators on the lepton flavor violating (LFV) decay modes mediated through <math><mi>b</mi><mo>→</mo><mi>s</mi><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>1</mn></mrow></msub><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math> transitions. We scrutinize the imprints of the (pseudo)scalar and axial (vector) operators on the exclusive LFV decay channels <math><msub><mrow><mi>B</mi></mrow><mrow><mo>(</mo><mi>s</mi><mo>)</mo></mrow></msub><mo>→</mo><mo>(</mo><mi>ϕ</mi><mo>,</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>,</mo><msubsup><mrow><mi>K</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>⁎</mo></mrow></msubsup><mo>)</mo><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>1</mn></mrow></msub><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math> and <math><msub><mrow><mi>Λ</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>→</mo><mi>Λ</mi><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>1</mn></mrow></msub><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math>, where <math><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math> represent μ or τ. The new physics parameters are constrained by using the upper limits of the branching fractions of the <math><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>→</mo><mi>τ</mi><mi>μ</mi></math> and <math><mi>B</mi><mo>→</mo><mi>K</mi><mi>τ</mi><mi>μ</mi></math> processes, assuming the new physics couplings to be real. We then explore the key observables such as the branching fractions, the forward-backward asymmetries, and the longitudinal polarization fractions of the <math><mi>B</mi><mo>→</mo><mo>(</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>,</mo><mi>ϕ</mi><mo>,</mo><msubsup><mrow><mi>K</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>⁎</mo></mrow></msubsup><mo>)</mo><msup><mrow><mi>τ</mi></mrow><mrow><mo>±</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>∓</mo></mrow></msup></math> decays. In addition, we also investigate the impact of the new physics couplings on the baryonic <math><msub><mrow><mi>Λ</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>→</mo><mi>Λ</mi><msup><mrow><mi>τ</mi></mrow><mrow><mo>±</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>∓</mo></mrow></msup></math> decay channels mediated by the <math><mi>b</mi><mo>→</mo><mi>s</mi></math> quark level transition. With the experimental prospects at LHCb upgrade and Belle II, we also predict the upper limits of the above-discussed observables, which could intrigue the new physics search in these channels.

Manas Kumar Mohapatra

Exploring the lepton flavor violating decay modes → in SMEFT approach

In this paper, we investigate the sensitivities of the upcoming long-baseline neutrino experiments P2SO and T2HKK to the long-range force (LRF). In the context of these two experiments, our objective is to study (i) their capabilities to put bounds on the LRF parameters as well as on constraining the mass and coupling strength of the new gauge boson, which gives rise to LRF due to matter density in Sun and (ii) the effect of LRF in the measurement of standard oscillation parameters. In our study, we find that among the different neutrino experiments, the best bounds on the LRF parameters including mass of the new gauge boson and its coupling strength will come from the P2SO experiment. Our study also shows that LRF has non-trivial effect on the determination of the standard neutrino oscillation parameters except the precision of   <math> <mtext>∆</mtext> <msubsup> <mi>m</mi> <mn>31</mn> <mn>2</mn> </msubsup> </math>  $$ \Delta {m}_{31}^2 $$ . For this parameter, the precision remains unaltered in the presence of LRF for both these experiments.

Study of long range force in P2SO and T2HKK

At present, there are several measurements of B decays that exhibit discrepancies with the predictions of the Standard Model, and suggest the presence of new physics in <math><mi>b</mi><mo>→</mo><mi>s</mi></math> and <math><mi>b</mi><mo>→</mo><mi>c</mi><mo>(</mo><mi>u</mi><mo>)</mo></math> quark level transitions. Motivated by the prospects of the ongoing high-luminosity B factories, we study the exclusive <math><mi>B</mi><mo>→</mo><msub><mrow><mi>a</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>(</mo><mn>1260</mn><mo>)</mo><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mi>ℓ</mi></mrow></msub></math> process within the Standard Model Effective Field Theory (SMEFT) formalism, to understand the sensitivity of various new physics operators. The new physics parameters are constrained by using the experimental branching fractions of the (semi)leptonic <math><mi>B</mi><mo>→</mo><mi>ℓ</mi><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></math> and <math><mi>B</mi><mo>→</mo><mo>(</mo><mi>π</mi><mo>,</mo><mi>ρ</mi><mo>,</mo><mi>ω</mi><mo>)</mo><mi>ℓ</mi><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></math> processes (where <math><mi>ℓ</mi><mo>=</mo><mi>e</mi><mo>,</mo><mi>μ</mi><mo>,</mo><mi>τ</mi></math>) which undergo <math><mi>b</mi><mo>→</mo><mi>u</mi><mi>ℓ</mi><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></math> quark level transitions. We then perform a comprehensive angular analysis of the exclusive <math><mi>B</mi><mo>→</mo><msub><mrow><mi>a</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>(</mo><mn>1260</mn><mo>)</mo><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mi>ℓ</mi></mrow></msub></math> process in the Standard Model and in the presence of various new physics operators. We also provide the predictions and comment on various observables, such as branching ratio, forward-backward asymmetry, and the test of lepton flavor non universality of the <math><mi>B</mi><mo>→</mo><msub><mrow><mi>a</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>(</mo><mn>1260</mn><mo>)</mo><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mrow><mi>ℓ</mi></mrow></msub></math> channel.

Imprints of new physics operators in the semileptonic process in SMEFT approach

In this paper we have studied the phenomenon of nonstandard interaction mediated by a scalar field (SNSI) in the context of P2SO experiment and compared its sensitivity with DUNE. In particular, we have studied the capability of these two experiments to put bounds on the diagonal SNSI parameters, i.e., <math><mrow><msub><mrow><mi>η</mi></mrow><mrow><mi>e</mi><mi>e</mi></mrow></msub></mrow></math>, <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math>, and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math> and studied the impact of these parameters on the determination of neutrino mass ordering, octant of <math><msub><mi>θ</mi><mn>23</mn></msub></math> and <math><mi>C</mi><mi>P</mi></math> violation (CPV). In our analysis we find that, the parameter <math><mi>Δ</mi><msubsup><mi>m</mi><mn>31</mn><mn>2</mn></msubsup></math> has a nontrivial role if one wants estimate the bounds on <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math> and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math> assuming SNSI does not exist in nature. Our results show that sensitivity of P2SO and DUNE to constraint <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math> and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math> are similar whereas the sensitivity of DUNE is slightly better for <math><msub><mi>η</mi><mrow><mi>e</mi><mi>e</mi></mrow></msub></math>. We find that the mass ordering and CPV sensitivities are mostly affected by <math><msub><mi>η</mi><mrow><mi>e</mi><mi>e</mi></mrow></msub></math> compared to <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math> and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math> if one assumes SNSI exists in nature. On the other hand, octant sensitivity is mostly affected by <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math> and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math>. These sensitivities can be either higher or lower than the standard three flavor scenario depending on the relative sign of the SNSI parameters. Regarding the precision of atmospheric mixing parameters, we find that the precision of <math><msub><mi>θ</mi><mn>23</mn></msub></math> deteriorates significantly in the presence of <math><msub><mi>η</mi><mrow><mi>μ</mi><mi>μ</mi></mrow></msub></math> and <math><msub><mi>η</mi><mrow><mi>τ</mi><mi>τ</mi></mrow></msub></math>.