18 Questions 22 Answers 0 Followers
Questions related from Basabendu Barman
In context with electroweak precision tests, Peskin-Takeuchi or oblique or S,T,U parameters are quite familiar. I am looking for some references where these things are nicely explained (I have...
06 June 2018 4,226 0 View
As we know, the observed mass of a particle is the sum of the bare mass and the quantum corrections. Physically, how can I understand bare mass? Is it the mass at the tree level?
06 June 2017 2,411 1 View
Majorana fermions do not have vector interaction and hence there is no spin-independent direct search cross section for majorana like WIMPs. Can anyone please show me the proof ?
04 April 2017 5,608 3 View
In the book 'Particle Dark Matter: Observations, Models and Searches' by Gianfranco Bertone I came across the following statement: '...the sea quarks and gluons do not contribute to the vector...
04 April 2017 3,378 11 View
How can I obtain the DM DM -> SM SM annihilation cross section if the DM effective operator is given? It would be really helpful if someone can show me the detail derivation.
03 March 2017 3,314 4 View
For a Vector Boson DM, I have the following spin-independent direct detection (scattering) cross-section with nucleus (please see the attahced file), where n_n and n_p are the number of nucleons...
03 March 2017 4,126 4 View
In collider physics I have frequently come across H_T cut over jet momenta. How do we define this quantity and what is the physical reason for applying this apart from missing energy cut?
02 February 2017 8,736 3 View
In two Higgs doublet model (2HDM), how the W and Z bosons get mass? I am specifically looking for Type II 2HDM case.
01 January 2017 1,116 8 View
I have a Feynman graph in t-channel with vector (X)-scalar(\phi)-scalar(\phi) vertex. Can someone please help me to find out what is the vertex factor for such a process and how can I calculate...
01 January 2017 7,660 4 View
We know that ${\gamma_{mu},\gamma_{nu}}$= 2 $g_{\mu\nu}$, where $g_{\mu\nu}$ is the flat metric . That shows spinors are someway related to the metric of space. Can anyone please explain how?
09 September 2016 9,889 3 View
in context with group theory I came across the term 'invariant subalgebra' which says: some generators of group G which goes either into itself or zero under commutation with any element of the...
07 July 2016 5,546 7 View
In case of time-independent perturbation theory in Quantum mechanics, we find that, the first order correction to the energy is the expectation value of the perturbation in the unperturbed...
07 July 2016 8,900 5 View
Regarding observability of signal over background, experimentalists quote a quantity something like S/sqrt(B) where S is the number of "signal events" and B is the number of "background events"....
06 June 2016 4,389 1 View
I have come across the term "normalized hypercharge" in context with group theory in particle physics. I want to know what is the meaning of "normalization" of hypercharge and how to compute this.
06 June 2016 5,832 7 View
This might be a very naive question but I really don't have a proper answer. Why Bosons have integer spins while Fermions have half-integer spins?
06 June 2016 7,625 0 View
In high energy physics we frequently encounter terms like 'on-shell production' and 'off-shell production', I need to know what exactly do they mean
05 May 2016 6,060 3 View
In context with quark models we frequently come across CKM(Cabibbo–Kobayashi–Maskawa matrix) matrix. I need a clear idea on how CKM matrix helps.
01 January 2016 5,022 4 View
Standard texts say that whenever the rate of annihilation goes below the rate of expansion "decoupling" takes place and when the abundance of the decoupled entity does not change with time we say...
10 October 2015 9,292 5 View
